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Diseases fungi Black & White Stock Photos
RMRDE61W–. The fungi which cause plant disease . Plant diseases; Fungi. zu THE FUXGI WHICH CAUSE PLANT DISEASE The basidiospores are capable of infecting onlj- the appropriate alternate host and that when the parts are still j^oung and tender. An abnormal development of germ tubes instead of the usual promycelium has been reported in some instances. According to Lloj'd & Ridgwaj^ ^°' several crops of basidiospores are pro- duced in one season. The various species usually make good subjects with which to studj^ infection. The teliospore masses placed in water soon become covered with basidiospores.
RMPG44WH–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 228 MYCOLOGY species are not given space in this book. It should be stated, however, that Murrill classifies his genera and species differently from the authors that have preceded him where many of the new genera were classified under the geneia. Polyporus and Boletus (Fig. 90). The arrangement of Murrill seems to be a more satisfactory presentation of these groups than those systems which have gone before and is founded on more natural characters. The nomenclature which this author ado
RMRDE1MR–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 488 SPECIAL PLANT PATHOLOGY ?C^^ division, and by a sort of gemmation. The myxamoeba are provided with several nuclei. The formation of spores soon begins by the suc- cessive simultaneous divisions of the myxamoeba, so that each nucleus and surrounding mass of cytoplasm is differentiated, as a spore by the formation of a spore wall about them. The diseased ceUs are crammed full of such spores, which escape only when the root disintegrates. The liberated spores will germi- nate in water
RMPG455D–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. SAC FUNGI IN PARTICULAR 135 much can be said that the wall consists of a carbohydrate, probably some isomer of cellulose. Lining the inner surface of the cell wall is a layer of protoplasm which may be called the ectoplasm, which probably serves as an osmotic membrane. The cytoplasm fills the rest of the cell with the exception of spaces occupied by the vacuoles of glycogen, nuclear vacuoles, oil globules, the nucleus and nuclear granules. The glycogen is gradually used up as it probabl
RMRDE2FF–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 188 MYCOLOGY American mycologists, pycnia (pycnium), in which spermatia, or pycniospores, are formed. Pycnia indicate the nature of the life cycle and furnish positive characters for identification. Arthur has shown that if pycnia and urediniospores are found arising from the same mycelium, ascidia do not occur in the cycle; and if pycnia and telio- spores are found there are neither uredinia nor a3cia in the life cycles. These pycnospores are accompanied or succeeded by aeciospores (ae
RMPG4E6J–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. CHARACTERISTICS OF THE TRUE FUNGI 43 gradations which preclude an absolute pronouncement as to whether a plant is a saprophyte, or a parasite.' Botanists generally concede that the true fungi have been derived from filamentous algal ancestors and the groups of algae from which the principal forms of fungi have. Fig. 12.—Russula nigricans parasitized by Nyclalis aslerophora. (After Brefeld.) been derived are fairly well known. For example, it is beUeved that such fungi as belong to the o
RMRE1HYB–. A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. Plate IV,. C.B.P.6U. Weet,WewTixaji&Co lith.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Plowright, Charles Bagge, 1849-1910. London, Paul, Trench & Co.
RMPG468M–. The fungi which cause plant disease . Plant diseases; Fungi. 286 THE FUNGI WHICH CAUSE PLANT DISEASE attacking first the parenchyma cells and medullary rays. The young stromata appear under the bark bearing when young small unicellular conidia. The stromata later turn hard and black and. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Stevens, Frank Lincoln, 1871-1934. New York : Macmillan
RMRDE2F6–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 190 MYCOLOGY upright and divided transversely into four cells, each of which cuts off abasidiospore. These basidiospores are blown to the leaves, twigs, or fruits of the barberry where a mycelium is formed. Later pycnia (spermogonia) appear on the upper side of its leaf. These are accom- panied by round, fringed depressions, the cluster cups or aecia, which appear in the spring on the lower side of the leaves. The aeciospores are arranged in chains. These spring spores, asciospores, are
RMPG4529–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 190 MYCOLOGY upright and divided transversely into four cells, each of which cuts off abasidiospore. These basidiospores are blown to the leaves, twigs, or fruits of the barberry where a mycelium is formed. Later pycnia (spermogonia) appear on the upper side of its leaf. These are accom- panied by round, fringed depressions, the cluster cups or aecia, which appear in the spring on the lower side of the leaves. The aeciospores are arranged in chains. These spring spores, asciospores, are
RMRDE6BJ–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 169 1-celled. The conidiophores, which serve better to characterize the genus, are swollen at the end, and bear numerous sterigmata (Fig. 120) on which the spores are borne basipetally in chains. Sclerotia are sometimes formed. The members of the genus are all saprophytes but some of them. A Fig. 120. — Asper- gillus, conidio- phore. After King.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance o
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 333 phologically inseparable as are also their secia when grown upon their common host. An excellent example of such biologic specialization is offered in the common pine Peridermium. iEcia may be produced upon the pine by sowing of Coleosporium teliospores from Senecio, Campanula, Pulsatilla, etc., but the seciospores which develop on the pine are capable of in- fecting only those species of hosts from which the teho- spores were taken. Similarly Eriksson "* has de- termined that though rus Stock Photo](https://c8.alamy.com/comp/PG4633/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-333-phologically-inseparable-as-are-also-their-secia-when-grown-upon-their-common-host-an-excellent-example-of-such-biologic-specialization-is-offered-in-the-common-pine-peridermium-iecia-may-be-produced-upon-the-pine-by-sowing-of-coleosporium-teliospores-from-senecio-campanula-pulsatilla-etc-but-the-seciospores-which-develop-on-the-pine-are-capable-of-in-fecting-only-those-species-of-hosts-from-which-the-teho-spores-were-taken-similarly-eriksson-quot-has-de-termined-that-though-rus-PG4633.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 333 phologically inseparable as are also their secia when grown upon their common host. An excellent example of such biologic specialization is offered in the common pine Peridermium. iEcia may be produced upon the pine by sowing of Coleosporium teliospores from Senecio, Campanula, Pulsatilla, etc., but the seciospores which develop on the pine are capable of in- fecting only those species of hosts from which the teho- spores were taken. Similarly Eriksson "* has de- termined that though rus Stock Photo")
RMPG4633–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 333 phologically inseparable as are also their secia when grown upon their common host. An excellent example of such biologic specialization is offered in the common pine Peridermium. iEcia may be produced upon the pine by sowing of Coleosporium teliospores from Senecio, Campanula, Pulsatilla, etc., but the seciospores which develop on the pine are capable of in- fecting only those species of hosts from which the teho- spores were taken. Similarly Eriksson "* has de- termined that though rus
RMRE1HXK–. A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. 12 .^-. W^ ^' V.) rjt:. '0. 'West,Kewma.n&£o Ijth,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Plowright, Charles Bagge, 1849-1910. London, Paul, Trench & Co.
RMPG4DK3–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 6S4 LAPORATORY EXERCISES ing microtome (Fig. 230); (3) by the rotary microtome, the material having been imbedded in paraffin. If desirable, the material to be cut on the sliding microtome. can be prepared by the celloidin method. Where the sections to be made are of woody material they can be cut directly on the sliding microtome, and the sections,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration an
RMRDEG68–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 46 MYCOLOGY branches are coarser in Penicillium and do not form the fine-pointed ends found in Mucor. The presence of transverse walls in the fungi is thought of sufficient importance to make a subclass known as the MYCOMYCETES to contain all of the true fungi EUMYCETES which have a mycelium which is multicellular in contradistinction to those which have unicellular mycelia and that form the subclass PHYCOMYCETES. From this spreading mycelium of transversely septated hyphas in Penicilli
RMPG45PN–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 519 In part=Mycosph£erella, Leptosphcpria. The genus is a very large one similar to Phoma and Phyllosticta except in its spore form and in the ostiole which is frequently very large. Septoria and Phleospora are distinguished only by the lesser development of the walls of the latter and many species which in early stages pass as Phleospora would in older stages be classed as Septoria. Septoria and Rhabdospora are distinguished only by the part of the host affected, stem or leaf, and many forms in
RMRDE1PX–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. GALLS 391 thorns. Branches of Vaccinium mtis-idcea are enlarged by Calyptospora Goeppertiana and those of Juniperus and Chamacyparis by rusts of the genus Gymnosporangium. Various species of the genus Exobasidium produce soft, edible galls. All such galls are mycocecidia (Fig. 84). Various algae, such as Cystoseira opuntioides, C. ericoides, and Ecto- carpus Valiantei, Uve parasitically and cause tissue excrescences, while the higher plants, especially of the family Loranthaceje, produc
RMPG45F1–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 651 infection. The ascigerous stage was said by Smith ^ to be a Neocosmospora and the many wilts caused by Fusarium have by various authors M'ho follow Smith been reported as Neocosmospora though without real evidence that they are such. See page 205. Recent studies of Hig- gins'*' and Butler^ ra- dicate that the Fusarium of the Neocosmospora is a saprophyte and that the Fusariums parasitic in the wilt diseases are as yet unknown in ascigerous form. The Fusarium parasitic on cotton is believed to
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 333 phologically inseparable as are also their secia when grown upon their common host. An excellent example of such biologic specialization is offered in the common pine Peridermium. iEcia may be produced upon the pine by sowing of Coleosporium teliospores from Senecio, Campanula, Pulsatilla, etc., but the seciospores which develop on the pine are capable of in- fecting only those species of hosts from which the teho- spores were taken. Similarly Eriksson "* has de- termined that though rus Stock Photo](https://c8.alamy.com/comp/RDE63K/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-333-phologically-inseparable-as-are-also-their-secia-when-grown-upon-their-common-host-an-excellent-example-of-such-biologic-specialization-is-offered-in-the-common-pine-peridermium-iecia-may-be-produced-upon-the-pine-by-sowing-of-coleosporium-teliospores-from-senecio-campanula-pulsatilla-etc-but-the-seciospores-which-develop-on-the-pine-are-capable-of-in-fecting-only-those-species-of-hosts-from-which-the-teho-spores-were-taken-similarly-eriksson-quot-has-de-termined-that-though-rus-RDE63K.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 333 phologically inseparable as are also their secia when grown upon their common host. An excellent example of such biologic specialization is offered in the common pine Peridermium. iEcia may be produced upon the pine by sowing of Coleosporium teliospores from Senecio, Campanula, Pulsatilla, etc., but the seciospores which develop on the pine are capable of in- fecting only those species of hosts from which the teho- spores were taken. Similarly Eriksson "* has de- termined that though rus Stock Photo")
RMRDE63K–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 333 phologically inseparable as are also their secia when grown upon their common host. An excellent example of such biologic specialization is offered in the common pine Peridermium. iEcia may be produced upon the pine by sowing of Coleosporium teliospores from Senecio, Campanula, Pulsatilla, etc., but the seciospores which develop on the pine are capable of in- fecting only those species of hosts from which the teho- spores were taken. Similarly Eriksson "* has de- termined that though rus
RMPG44RG–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. FUNGI IMPERKECTX (dEUTEROMYCETES) 261 groups of ASCOMYCETALES. Four families are included in this order, and these families include a considerable number of important genera of fungi, which specifically are the cause of important plant diseases. Phyllosticta is a genus, the species of which are confined to leaves, and they produce characteristic leaf spots on a great variety of plants. The specific name of the fungus is usually derived from that of the host plant attacked, as for exampl
RMRDDAWH–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 273 were usually entirely embedded, with the beaks only protruding and were often numerous and crowded. Cultural evidence that Edgerton's specimens were actually genetically connected with the cotton anthracnose are wanting. The fungus has been repeatedly studied in pure culture and numerous inoculations have thoroughly proved its pathogenicity, the disease usually showing within a few days after inoculation, though sometimes incubation is delayed much longer. Infection of stems is often at a wou
RMPG44EM–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 488 SPECIAL PLANT PATHOLOGY ?C^^ division, and by a sort of gemmation. The myxamoeba are provided with several nuclei. The formation of spores soon begins by the suc- cessive simultaneous divisions of the myxamoeba, so that each nucleus and surrounding mass of cytoplasm is differentiated, as a spore by the formation of a spore wall about them. The diseased ceUs are crammed full of such spores, which escape only when the root disintegrates. The liberated spores will germi- nate in water
RMRDE59B–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 519 In part=Mycosph£erella, Leptosphcpria. The genus is a very large one similar to Phoma and Phyllosticta except in its spore form and in the ostiole which is frequently very large. Septoria and Phleospora are distinguished only by the lesser development of the walls of the latter and many species which in early stages pass as Phleospora would in older stages be classed as Septoria. Septoria and Rhabdospora are distinguished only by the part of the host affected, stem or leaf, and many forms in
RMPG4DJ3–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 662 LABORATORY KXERCISES Fig. 236, when extended. Correct focus is determined by the observation of the image upon a paper surface in place of the usual ground glass.. Fig. 236.—Edinger's drawing apparatus with attachment for photo-micrography. The following tables have been prepared with the view of simplifying the use of the apparatus as much as possible, and the best results can only be obtained when. Please note that these images are extracted from scanned page images that may have
RMRDE1PB–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 394 GENERAL PLANT PATHOLOGY fibrovascular system of the cedar leaf (Fig. i6i). From, or near the base of the cedar apple, where the vascular elements are much con- torted, arise many branches, which extend radially almost to the cortex. Harshberger* has investigated the galls produced by two species of Gymnosporangium on the coastal white cedar, Chanuecyparis thyoides, and Stewart^ has published an account of the anatomy of Gymnosporangium galls and Peridermium gaUs. There may be an ove
RMPG44K9–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 368 GENERAL PLANT PATHOLOGY growth of the mesophyll cells and the space originally occupied by the former is finally filled with the cells of the mesophyll. Excess of water is one of the contributing causes in the formation of intumescences, as also treatment of plants with poisons, especially copper salts. Abnormal succulence, as an hypertrophy, is such where plants with normally thin leaves, develop thick ones in their place. Salt solutions, if used experimentally upon certain plants,
RMRE1J1D–. A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. 42 British Uredinecs and Ustilagine<2. like Puccinia spores, but have, in the European species, generally two germ-pores in each cell, and these are placed. Fig. 3.—Chrysomyxa rJwdodendri. Section of spore-bed showing the compound teleu- tospores (a), one of which is in the act of germination, having emitted a promycelium (^) from upper corner of its super
RMPG4GW4–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 117 The oogonium after fertilization gives rise to a more or less complicated system of ascogenous hyphae, very simple in the Erysiphaceae, very complex in some Discomycetes, which produces the asci. The sterile parts of the ascocarp, the paraphyses and enveloping structures, arise from parts below the oogonium and antheridium. The very young ascus usually receives two nuclei from the parent strand of the ascogenous hypha. These nuclei unite giving the. Please note that these images are extracted
RMRDE6N6–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 117 The oogonium after fertilization gives rise to a more or less complicated system of ascogenous hyphae, very simple in the Erysiphaceae, very complex in some Discomycetes, which produces the asci. The sterile parts of the ascocarp, the paraphyses and enveloping structures, arise from parts below the oogonium and antheridium. The very young ascus usually receives two nuclei from the parent strand of the ascogenous hypha. These nuclei unite giving the. Please note that these images are extracted
RMPG452H–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 188 MYCOLOGY American mycologists, pycnia (pycnium), in which spermatia, or pycniospores, are formed. Pycnia indicate the nature of the life cycle and furnish positive characters for identification. Arthur has shown that if pycnia and urediniospores are found arising from the same mycelium, ascidia do not occur in the cycle; and if pycnia and telio- spores are found there are neither uredinia nor a3cia in the life cycles. These pycnospores are accompanied or succeeded by aeciospores (ae
RMRDE22Y–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 276 GENERAL PLANT PATHOLOGY As an internal determining cause, the formation of enzymes under abnormal conditions must be reckoned as causal, as well, as nutritive disturbances which produce monstrosities and the like. Having classified the chief causes of disease, a more detailed descrip- tion of these factors should be put in a form available for student use. Much of the information is scattered, and part of it is buried in foreign botanic and pathologic journals, which can be consulte
RMPG4GJ7–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 169 1-celled. The conidiophores, which serve better to characterize the genus, are swollen at the end, and bear numerous sterigmata (Fig. 120) on which the spores are borne basipetally in chains. Sclerotia are sometimes formed. The members of the genus are all saprophytes but some of them. A Fig. 120. — Asper- gillus, conidio- phore. After King.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance o
RMRDEFPF–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. SAC FUNGI IN PARTICULAR 135 much can be said that the wall consists of a carbohydrate, probably some isomer of cellulose. Lining the inner surface of the cell wall is a layer of protoplasm which may be called the ectoplasm, which probably serves as an osmotic membrane. The cytoplasm fills the rest of the cell with the exception of spaces occupied by the vacuoles of glycogen, nuclear vacuoles, oil globules, the nucleus and nuclear granules. The glycogen is gradually used up as it probabl
RMPG4GEC–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 185 to similarity of habit and the frequent abnormal development of the appendages, so that the published references are not always reliable. Microsphsera L6viell6 (p. 175) Perithecia globose to subglobose; asci several, 2 to 8-spored-, appendages not interwoven with the mycelium, branched in a definite manner at the apex, usually dichotomously and often very ornately, rarely undivided or merely once dichotomous. According to Salmon there are thirteen species; Engler and Prantl' recognize thirty.
RMRDETC5–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 662 LABORATORY KXERCISES Fig. 236, when extended. Correct focus is determined by the observation of the image upon a paper surface in place of the usual ground glass.. Fig. 236.—Edinger's drawing apparatus with attachment for photo-micrography. The following tables have been prepared with the view of simplifying the use of the apparatus as much as possible, and the best results can only be obtained when. Please note that these images are extracted from scanned page images that may have
RMPG44PJ–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 276 GENERAL PLANT PATHOLOGY As an internal determining cause, the formation of enzymes under abnormal conditions must be reckoned as causal, as well, as nutritive disturbances which produce monstrosities and the like. Having classified the chief causes of disease, a more detailed descrip- tion of these factors should be put in a form available for student use. Much of the information is scattered, and part of it is buried in foreign botanic and pathologic journals, which can be consulte
RMRDEFRM–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. HIGHER FUNGI 127. Fig 40.—rHagraminatic representation of the development'of the ascogenous hyphal system and of the mature ascus. {AfUr ClausseH.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Harshberger, John W. (John William), 1869-1929. Philadelphia : P. Blakiston's Son & Co
RMPG457X–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. gS MYCOLOGY The important genera of the family are Mucor, Rhizoptis, Phycomy- ces, Absidia, Sporodinia, Thamnidium, Dicranophora, Pilaira and Ptlo- holiis. The genus Mucor, a key for the identification of the species will be given at the end of the book, was established in 1729. by Micheli. The genus may be divided into three groups of species. The first division includes those species with unbranched spcsrangiophores, such as Mucor mucedo. The second group comprises the moulds with clu
RMRDE277–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 228 MYCOLOGY species are not given space in this book. It should be stated, however, that Murrill classifies his genera and species differently from the authors that have preceded him where many of the new genera were classified under the geneia. Polyporus and Boletus (Fig. 90). The arrangement of Murrill seems to be a more satisfactory presentation of these groups than those systems which have gone before and is founded on more natural characters. The nomenclature which this author ado
RMPG46AH–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 273 were usually entirely embedded, with the beaks only protruding and were often numerous and crowded. Cultural evidence that Edgerton's specimens were actually genetically connected with the cotton anthracnose are wanting. The fungus has been repeatedly studied in pure culture and numerous inoculations have thoroughly proved its pathogenicity, the disease usually showing within a few days after inoculation, though sometimes incubation is delayed much longer. Infection of stems is often at a wou
RMRE1J13–. A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. 8o British Uredinecs and Usiilaginecs. abundantly. As the teleutospores are of pretty large size, their germination is easily observed. I have found them germinate much more freely in summer than in late autumn (Plate VII. Fig. 18). U. tragopogi (Pers.) {U. receptaculorum, Fries).—The germination was observed by Tulasne,* and by Von Wald- heim.t to consist in
RMPG460Y–. The fungi which cause plant disease . Plant diseases; Fungi. zu THE FUXGI WHICH CAUSE PLANT DISEASE The basidiospores are capable of infecting onlj- the appropriate alternate host and that when the parts are still j^oung and tender. An abnormal development of germ tubes instead of the usual promycelium has been reported in some instances. According to Lloj'd & Ridgwaj^ ^°' several crops of basidiospores are pro- duced in one season. The various species usually make good subjects with which to studj^ infection. The teliospore masses placed in water soon become covered with basidiospores.
RMRDEFY8–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. gS MYCOLOGY The important genera of the family are Mucor, Rhizoptis, Phycomy- ces, Absidia, Sporodinia, Thamnidium, Dicranophora, Pilaira and Ptlo- holiis. The genus Mucor, a key for the identification of the species will be given at the end of the book, was established in 1729. by Micheli. The genus may be divided into three groups of species. The first division includes those species with unbranched spcsrangiophores, such as Mucor mucedo. The second group comprises the moulds with clu
RMPG4GKX–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 149 earlier known as Gloeosporium ribis (Lib.) Mont. & Desm. Old leaves bearing the latter fimgus were wintered out-doors in filter paper and in the spring were found with this ascigerous stage. The ascospores were isolated, grown in pure culture and typical conidia were produced. The ascospores also infected the host leaves successfully producing there the typical Gloeosporium. The conidial stage is the only one ordinarily seen. The acervuli are subepidermal elevating the epidermis to form a
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 307 cept the awn and rachis is entirely transformed into smut. In water and in nutrient solutions the spores germinate by a single promycelium, 1 to 3-septate, and often branched, but without sporidia. That infection is floral in loose smut of both wheat and barley was first shown by Maddox ^' and the fact was corrob- orated by Wakagawa,'* Brefeld ^* and Hecke.'^' " The my- celium has been demonstrated in the embryo by Broili.^^' The spores falling between the glumes germinate, penetrate the Stock Photo](https://c8.alamy.com/comp/RDDANE/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-307-cept-the-awn-and-rachis-is-entirely-transformed-into-smut-in-water-and-in-nutrient-solutions-the-spores-germinate-by-a-single-promycelium-1-to-3-septate-and-often-branched-but-without-sporidia-that-infection-is-floral-in-loose-smut-of-both-wheat-and-barley-was-first-shown-by-maddox-and-the-fact-was-corrob-orated-by-wakagawa-brefeld-and-hecke-quot-the-my-celium-has-been-demonstrated-in-the-embryo-by-broili-the-spores-falling-between-the-glumes-germinate-penetrate-the-RDDANE.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 307 cept the awn and rachis is entirely transformed into smut. In water and in nutrient solutions the spores germinate by a single promycelium, 1 to 3-septate, and often branched, but without sporidia. That infection is floral in loose smut of both wheat and barley was first shown by Maddox ^' and the fact was corrob- orated by Wakagawa,'* Brefeld ^* and Hecke.'^' " The my- celium has been demonstrated in the embryo by Broili.^^' The spores falling between the glumes germinate, penetrate the Stock Photo")
RMRDDANE–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 307 cept the awn and rachis is entirely transformed into smut. In water and in nutrient solutions the spores germinate by a single promycelium, 1 to 3-septate, and often branched, but without sporidia. That infection is floral in loose smut of both wheat and barley was first shown by Maddox ^' and the fact was corrob- orated by Wakagawa,'* Brefeld ^* and Hecke.'^' " The my- celium has been demonstrated in the embryo by Broili.^^' The spores falling between the glumes germinate, penetrate the
RMPG4H38–. The fungi which cause plant disease . Plant diseases; Fungi. Fig. 45.—Cucumber seedlings. Pots 5, 6, and 8 inoculated with Pythium. Pot 7, Control. After Atkinson. species, bear conidia on branches which are of the same character as the myceHum itself. The conidia germinate either by a rupture of the wall or by the formation of a beak-like process through which the protoplasm is extruded, after which it becomes differentiated into zoospores. Gemmae, very like the conidia in ap- pearance, are also produced. The oogonia are quite like the conidia and gemmae in structure but develop oospores wi
RMRE1HXD–. A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. Plate TOL. 03 P.del. Vfest.lfewitum&Colitb.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Plowright, Charles Bagge, 1849-1910. London, Paul, Trench & Co.
![. The fungi which cause plant disease . Plant diseases; Fungi. 48 THE FUNGI WHICH CAUSE PLANT DISEASE inoculations were made to tomato. Smith demonstrated experi- mentally the efficiency of the potato beetle in transmitting the disease. The disease was described for tobacco by Stevens ^^ and Stevens and Sackett."^ Successful inoculations were reported upon tobacco by E. F. Smith in 1909 ^^^ though in his eariier trials tobacco and pepper gave negative results when inoculated with this bacillus. In addi- tion to the above hosts it is known to grow upon Datura, Solanum nigrum, Phj^salis and Stock Photo](https://c8.alamy.com/comp/PG4H6H/the-fungi-which-cause-plant-disease-plant-diseases-fungi-48-the-fungi-which-cause-plant-disease-inoculations-were-made-to-tomato-smith-demonstrated-experi-mentally-the-efficiency-of-the-potato-beetle-in-transmitting-the-disease-the-disease-was-described-for-tobacco-by-stevens-and-stevens-and-sackettquot-successful-inoculations-were-reported-upon-tobacco-by-e-f-smith-in-1909-though-in-his-eariier-trials-tobacco-and-pepper-gave-negative-results-when-inoculated-with-this-bacillus-in-addi-tion-to-the-above-hosts-it-is-known-to-grow-upon-datura-solanum-nigrum-phjsalis-and-PG4H6H.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. 48 THE FUNGI WHICH CAUSE PLANT DISEASE inoculations were made to tomato. Smith demonstrated experi- mentally the efficiency of the potato beetle in transmitting the disease. The disease was described for tobacco by Stevens ^^ and Stevens and Sackett."^ Successful inoculations were reported upon tobacco by E. F. Smith in 1909 ^^^ though in his eariier trials tobacco and pepper gave negative results when inoculated with this bacillus. In addi- tion to the above hosts it is known to grow upon Datura, Solanum nigrum, Phj^salis and Stock Photo")
RMPG4H6H–. The fungi which cause plant disease . Plant diseases; Fungi. 48 THE FUNGI WHICH CAUSE PLANT DISEASE inoculations were made to tomato. Smith demonstrated experi- mentally the efficiency of the potato beetle in transmitting the disease. The disease was described for tobacco by Stevens ^^ and Stevens and Sackett."^ Successful inoculations were reported upon tobacco by E. F. Smith in 1909 ^^^ though in his eariier trials tobacco and pepper gave negative results when inoculated with this bacillus. In addi- tion to the above hosts it is known to grow upon Datura, Solanum nigrum, Phj^salis and
RMRDEG30–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 66 MYCOLOGY Ijeen shed, thus permitting the opening out of the cap and the freei discharge of the remaining spores. The discliarged spores are convcyec by tlie wind (Fig. 20). The musliroom type is the usual Icind when the spores are discharged without deliquescence. The spores of Bulgaria, Gyromitra, Peziza and others of thi AscoMYCETAiKS are scattered by the wind, but those of Ascobolu immersus and Saccobohis arc dispersed by herbivores. The spores 0 Peziza repanda, according to Bulle
RMPG45WA–. The fungi which cause plant disease . Plant diseases; Fungi. 410 THE FUNGI WHICH CAUSE PLANT DISEASE S. purpureum Pers. Hymenophore expanded, leathery, arched, grayish-white; hy- menium smooth, purple. This species is constantly associated with an English and Cana- dian disease of drupaceous and pomaceous trees, manifest by a. Fig. 295.—Oak timber rotted by Stereum frustulosum. The lighter colored, irregular, small bodies are sporophores. After von Schrenk and Spaulding. silvering of the leaves, death of branches and finally of the tree. The causal agency of the fimgus has not been fully est
RMRDDAR5–. The fungi which cause plant disease . Plant diseases; Fungi. 286 THE FUNGI WHICH CAUSE PLANT DISEASE attacking first the parenchyma cells and medullary rays. The young stromata appear under the bark bearing when young small unicellular conidia. The stromata later turn hard and black and. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Stevens, Frank Lincoln, 1871-1934. New York : Macmillan
RMPG456H–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 114 MYCOLOGY authors, are placed in the family Peronosporace^e. Details of the important forms which cause plant diseases will be given in the third part of this book. These fungi will be referred to under each genus following the systematic generic key which is here given. Generic Key of the Family. Peronosporace.* Mycelium of these fungi parasitic or saprophytic in plant tissues; zoosporangia as distinct organs producing biciliate zoospores. Zoospores formed out of, protoplaem which e
RMRDETDX–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 6S4 LAPORATORY EXERCISES ing microtome (Fig. 230); (3) by the rotary microtome, the material having been imbedded in paraffin. If desirable, the material to be cut on the sliding microtome. can be prepared by the celloidin method. Where the sections to be made are of woody material they can be cut directly on the sliding microtome, and the sections,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration an
RMPG4GWT–. The fungi which cause plant disease . Plant diseases; Fungi. Fig. 75.—Sphsrotheca castagnei. Fertilization and de- velopment of the perithecium. Og= oogonium, an= antheridium, st= stalk-cell. 6 as the ascogonium derived from the oogonium. After Harper. short, innate; again they are long, loose or floccosc. They may emerge through stomata singly or in tufts or they may form sporo- genous cushions below the epidermis or again they may be borne inside of a hollow structure, the pycnidium, which covers them. Chlamydospores are also found. One or several distinct types of sporification may belong
RMRDE24A–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. FUNGI IMPERKECTX (dEUTEROMYCETES) 261 groups of ASCOMYCETALES. Four families are included in this order, and these families include a considerable number of important genera of fungi, which specifically are the cause of important plant diseases. Phyllosticta is a genus, the species of which are confined to leaves, and they produce characteristic leaf spots on a great variety of plants. The specific name of the fungus is usually derived from that of the host plant attacked, as for exampl
RMPG4HB2–. The fungi which cause plant disease . Plant diseases; Fungi. 24 THE FUNGI WHICH CAUSE PLANT DISEASE hypodermic injection produced only limited lesions but similar inoculations with a mixed culture of Ps. avenae and Bacillus avense produced typical disease. Manns, moreover, noticed that the virulence of the Pseudomonas decreased when kept in culture free from the Bacillus, also that in the disease as it occurs in nature these two organisms are associated. His conclusion is that the Pseudomonas is the active parasite and that the Bacillus is an important, perhaps a necessary symbiont.. 3 1 2 F
RMRDE4TE–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 651 infection. The ascigerous stage was said by Smith ^ to be a Neocosmospora and the many wilts caused by Fusarium have by various authors M'ho follow Smith been reported as Neocosmospora though without real evidence that they are such. See page 205. Recent studies of Hig- gins'*' and Butler^ ra- dicate that the Fusarium of the Neocosmospora is a saprophyte and that the Fusariums parasitic in the wilt diseases are as yet unknown in ascigerous form. The Fusarium parasitic on cotton is believed to
RMPG4E7J–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 24 MYCOLOGY Cell Division and Reproduction.—As with olher plant cells in general it may be said that growth is not conditioned on cell division. Growth is the enlargement of the cell, not merely a swollen condition, and this increase in size is within definite limits for each species, which can be determined by statistic study. As long as division is not preceded by nuclear division, the term fission is apphcable. Certain students of the group claim that there is a division of the nucle
![. A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. P] ate VII.. 12 .^-. W^ ^' V.) rjt:. '0. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Plowright, Charles Bagge, 1849-1910. London, Paul, Trench & Co. Stock Photo](https://c8.alamy.com/comp/RE1HXR/a-monograph-of-the-british-uredineae-and-ustilagineae-with-an-account-of-their-biology-including-the-methods-of-observing-the-germination-of-their-spores-and-of-their-experimental-culture-smut-fungi-rust-fungi-smut-diseases-fungi-p-ate-vii-12-w-v-rjt-0-please-note-that-these-images-are-extracted-from-scanned-page-images-that-may-have-been-digitally-enhanced-for-readability-coloration-and-appearance-of-these-illustrations-may-not-perfectly-resemble-the-original-work-plowright-charles-bagge-1849-1910-london-paul-trench-amp-co-RE1HXR.jpg ". A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. P] ate VII.. 12 .^-. W^ ^' V.) rjt:. '0. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Plowright, Charles Bagge, 1849-1910. London, Paul, Trench & Co. Stock Photo")
RMRE1HXR–. A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. P] ate VII.. 12 .^-. W^ ^' V.) rjt:. '0. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Plowright, Charles Bagge, 1849-1910. London, Paul, Trench & Co.
RMPG4DG3–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. APPENDIX VII 709 hence, it is probably widely distributed. Its stolon-producing character is very characteristic and diagnostic. Penicillium ilalicum (Fig. 247) and P. olivaceum occur on tropic fruits, including pineapples, lemons, oranges, etc. The fungus causes extensive putrefaction in such fleshy fruits as the pineapple. Penicillium brevicauie (Fig. 248) grows on decayed paper and it has been recom- mended by Gosio for the detection of arsenic, since when grown in media with traces
RMRE1J1X–. A monograph of the British Uredineae and Ustilagineae, with an account of their biology including the methods of observing the germination of their spores and of their experimental culture. Smut fungi; Rust fungi; Smut diseases; Fungi. 24 British Uredinece and Ustilaginecs. shining as a small yellow tubercle. The epidermis becomes ruptured by the pressure of the young growing secidium from below ; and, either before or soon afterwards, the pseudo- peridium itself gives way at its summit, exposing the ripe secidiospores. The ruptured peridium now becomes re- curved, and, as seen from above, t
RMPG467G–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 303 Son agglutinated Spore-balls (variable) composed of thick-walled spores 10. Tolyposporella. Spore-balls with peripheral spores and central sterile cells 11. Testicularia. Of these genera numbers three to eleven inclusive occur on un- important plants. Among them are: Polygonum, Rynchospora, Psilocary, Cyperus, Carex, Luzula, Juncus, Fimbrystylis, Cissis; various unimportant grasses, members of the Carduaceae, Faba- ceae, Nyctaginacese, Amarantaceae, Cyperacese, Dracenaceae, and Eriocaulacese.
RMRDETAM–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. Fig. 238.—Spray punips isolated and with bucket attachments.. Fig. 239.—Spray barrel with pump.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Harshberger, John W. (John William), 1869-1929. Philadelphia : P. Blakiston's Son & Co
RMPG4DRH–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. LABORATORY AND TEACHING METHODS 583 $. Note the optic combinations used and keep a record of them with the calcu- lated micrometer value. Repeat for each of the other combinations. To meas- ure an object by this method, read off the number of divisions of the eyepiece micrometer it occupies and express the result in microus by looking up the standard value for the optic combination used. Example.—Detetraine how many of the stage micrometer divisions correspond with the eyepiece micromet
RMRDE1TX–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 378 GENERAL PLANT PATHOLOGY and this is sometimes due to limitations of space relations. Sometimes the callus is most luxuriant, as in cuttings of Populus pyratnidalis (Figs. 150 and 151) and Lamium orvala (Fig. 152), which produces the largest callous rolls among herbaceous plants. All organs of the plant. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not
RMPG4615–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 363 The seciospores are borne in secia which rest in orange or yellow spots often strongly thickened. Pycnia abound. The aecium with its thick peridium is erumpent and projects to some distance above the host surface, this character giving rise to the separate form- genus, Roestelia. The peridial margin which may be lacerate or fimbriate is used in specific characteriza- tion. The spores are borne and function as in ordinary secia. They bear several germ pores. jEciospores germi- nate at once and
RMRDE2AK–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 208 MYCOLOGY Belonging to the genus Gymnoconia (Fig. 92) is the orange rust of raspberry and blackberry which is found throughout the United States and Canada. It is also widely distributed in Europe and Asia. The genus Phragmidium, which is confined entirely to plants of the rose family, is autcecious. Warts are formed on the teliospores by the contraction of an outer gelatinous layer which with a rigid middle lamina and the arrangement of the germ pores distinguishes Phrag-. Fig. 78.—
RMPG463N–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLAXT DISEASE 331 In all of the rusts so far investigated that have an aecium or primary uredinium there is in the aecio-mycehum or the primary uredinio-mycelimn a fusion of uninucleated cells, gametes. This cellular fusion is not, however, followed by a nuclear fusion until after long delay; but the two nuclei remain in the fusion cell and when this cell divides both nuclei divide mitotically and simul- taneously but still independently of each other (conjugate division). This process continues through the ae
RMRDE1XB–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 368 GENERAL PLANT PATHOLOGY growth of the mesophyll cells and the space originally occupied by the former is finally filled with the cells of the mesophyll. Excess of water is one of the contributing causes in the formation of intumescences, as also treatment of plants with poisons, especially copper salts. Abnormal succulence, as an hypertrophy, is such where plants with normally thin leaves, develop thick ones in their place. Salt solutions, if used experimentally upon certain plants,
RMPG4HCX–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 7 The decay of the host liberates the spores in the soil. Their germination may be readily studied upon a microscope slide where in from five to twentj'-four hours uninucleate zoospores are produced. The zoospores are differentiated into an inner. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Stevens, Frank Lincoln, 1871-193
RMRDEFJT–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. i6o MYCOLOGY or in the substratum, and are mostly spheric. A wall (peridium) is present inclosing the clustered eight-spored asci which arise from the interior basal part of the perithecium. The perithecium opens by an apical mouth or pore and is either isolated or imbedded in a stroma which takes manifold forms. The formation of conidiophores. and conidiospores varies in the different families and genera. Sometimes a distinct conidial layer is formed; at other times the conidiospores a
RMPG449A–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. DETAILED ACCOUNT OF SPECIFIC PLANT DISEASES 527 and frequently, become the prey of maggots which riddle them with holes and burrows. It is also eagerly gathered by mycophagists who know it to be an excellent article of food. The mycelium of the fungus may live in the dead wood of a tree after it has been killed for a number of years, so that the same tree may produce successive crops of edible fruit bodies. The destruction, which the mycelium works, is characteristic. The heartwood is r
RMRDE5RK–. The fungi which cause plant disease . Plant diseases; Fungi. 410 THE FUNGI WHICH CAUSE PLANT DISEASE S. purpureum Pers. Hymenophore expanded, leathery, arched, grayish-white; hy- menium smooth, purple. This species is constantly associated with an English and Cana- dian disease of drupaceous and pomaceous trees, manifest by a. Fig. 295.—Oak timber rotted by Stereum frustulosum. The lighter colored, irregular, small bodies are sporophores. After von Schrenk and Spaulding. silvering of the leaves, death of branches and finally of the tree. The causal agency of the fimgus has not been fully est
RMPG4569–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. HIGHER FUNGI 125 antheridium, which is cut o£E by a partition wall. The walls between the two orgjins are dissolved and the male nucleus passes through the opening formed wanders toward the egg nucleus with which it fuses. Immediately after fertilization, the oogonium begins steady growth, and some of the outer cells formed become the cover. Fig. 39.—Diagrammatic representation of the development of the ascogenous hyphal system. {After Claassen.) cells of the perithecium. But ascogenous
RMRDEFJ1–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. MILDEWS AND RELATED FUNGI 167 contents into a single large one, from which the ascogenous hyphae then arise. Family 5. Pezizace^.—The apothecia of this family are saucer- or cup-shaped, sessile or stalked, arising from a mycelium which is found in the substratum. The peridium and hypothecium consists of rounded cells and they are of fleshy, or leathery consistency.. The asci, which are usually eight-spored, are separated by distinct para- physes. The spores are usually hyaline. Lacknea
RMPG4H2E–. The fungi which cause plant disease . Plant diseases; Fungi. Fig. 50.—^Albugo. A, section through a sorus showing epidermis, conidia, conidiophores and mycelium; B, conidiophores and conidia; C, myce- lium and haustoria. After Bergen and Davis. in clusters; the spores are borne in basipetal succession and remain attached in rather long chains tmless disturbed. The mycelium is very fine, intercellular and penetrates the cells by globular haustoria. The rudimentary oogonium is multi- nucleate and filled with uniform proto- plasm. As the oogonium grows older the protoplasm within differentiates
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 77. Fig. 47.—^P. citriophora; de- velopment of swarmsporea from sporangia. After Smith and Smith. and the contents of the antheridium are carried over to the egg by a fertilizing tube. Members of the genus are aggressively parasitic only under most favorable environmental conditions of heat an(f moisture. Some sixteen species are known. P. de baryanum Hesse, is most com- mon''"'' as the cause of "Damping Off." Zoosporangia or "conidia" globose to eUiptic, usually papillat Stock Photo](https://c8.alamy.com/comp/RDE71F/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-77-fig-47p-citriophora-de-velopment-of-swarmsporea-from-sporangia-after-smith-and-smith-and-the-contents-of-the-antheridium-are-carried-over-to-the-egg-by-a-fertilizing-tube-members-of-the-genus-are-aggressively-parasitic-only-under-most-favorable-environmental-conditions-of-heat-anf-moisture-some-sixteen-species-are-known-p-de-baryanum-hesse-is-most-com-monquot-as-the-cause-of-quotdamping-offquot-zoosporangia-or-quotconidiaquot-globose-to-euiptic-usually-papillat-RDE71F.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 77. Fig. 47.—^P. citriophora; de- velopment of swarmsporea from sporangia. After Smith and Smith. and the contents of the antheridium are carried over to the egg by a fertilizing tube. Members of the genus are aggressively parasitic only under most favorable environmental conditions of heat an(f moisture. Some sixteen species are known. P. de baryanum Hesse, is most com- mon''"'' as the cause of "Damping Off." Zoosporangia or "conidia" globose to eUiptic, usually papillat Stock Photo")
RMRDE71F–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 77. Fig. 47.—^P. citriophora; de- velopment of swarmsporea from sporangia. After Smith and Smith. and the contents of the antheridium are carried over to the egg by a fertilizing tube. Members of the genus are aggressively parasitic only under most favorable environmental conditions of heat an(f moisture. Some sixteen species are known. P. de baryanum Hesse, is most com- mon''"'' as the cause of "Damping Off." Zoosporangia or "conidia" globose to eUiptic, usually papillat
RMPG447P–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 538 SPECIAL PLANT PATHOLOGY has been considered to be of such great importance, that strict quaran- tine regulations were established in order to keep it out of the country, but the result of a thorough exploration of the New England States during the summer of 1916 has shown its general distribution through- out them and even as far west as Minnesota. It appears to have been. Fig. 193.—White pine blister-rust, Cronarliutn ribicola. yl. Diseased tree with £ecial blisters broken open fro
RMRDDBWT–. The fungi which cause plant disease . Plant diseases; Fungi. 178 THE FUNGI WHICH CAUSE PLANT DISEASE species belonging to eighty-nine genera; one hundred forty-six more hosts, some doubtful, are reported. Among the economic host genera are Adonis, Alyssum, Anemone, Aquilegia, Brassica, Calendula, Catalpa, Clematis, Cucumis (?), Cucurbita (?), Dahlia, Daucus, Delphinium, Diervilla, Dipsacus, Fagopyrum, Lupinus, Lycopersicum, Medicago, Paeonia, Phaseolus, Pisum, Tragopogon, Trifolium, Verbena, Vicia, Scabiosa, Symphytum, Valeriana. This is the most variable species of this genus varying widely
RMPG44KW–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 35° GENERAL PLANT PATHOLOGY red cedar by Gymnosporangmm juniperi-virginianm. The crown galls, or possible vegetal cancers, are another illustration of such excres- cences, while malformations are represented by peach leaf curl and the witches' brooms on trees. 12. Exudations.—The formation of slimy substances, which flow from trees and plants, the diseased conditions known as bacteriosis, •rummosis' and resinosis, illustrate the character of the exudations from. Fig. 139.—Burl, or enlar
RMRDE2H4–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 14 MYCOLOGY rather uniformly through the spore plasm and are of unequal size. Vacuoles are formed in a still further condensation of the sporangial protoplasm and each of these apparent vacuoles is pierced by a capilli- tial thread which runs through its central axis. Droplets of water are formed along the capilUtial thread as a still further evidence of water extrusion. Cleavage planes now appear at the periphery of the mass of sporangial protoplasm and progress inwardly toward the cen
![. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 388 GENERAL PLANT PATHOLOGY within the tumor cells as the result of the meUbolism of the im- prisoned bacteria (Psetidomonas tumefaciens). Growth of the tumor comes about not by the direct application of stimuli, but indirectly by the removal of various inhibitions. Under normal conditions the physiologic brakes are on at all times, more or less, in both plants and animals, and only when they are entirely or largely removed in. ^l^*"M^^^i2 Fig. 155.—Cross-section of one lobe of tub Stock Photo](https://c8.alamy.com/comp/PG44HF/a-text-book-of-mycology-and-plant-pathology-plant-diseases-fungi-in-agriculture-plant-diseases-fungi-388-general-plant-pathology-within-the-tumor-cells-as-the-result-of-the-meubolism-of-the-im-prisoned-bacteria-psetidomonas-tumefaciens-growth-of-the-tumor-comes-about-not-by-the-direct-application-of-stimuli-but-indirectly-by-the-removal-of-various-inhibitions-under-normal-conditions-the-physiologic-brakes-are-on-at-all-times-more-or-less-in-both-plants-and-animals-and-only-when-they-are-entirely-or-largely-removed-in-lquotmi2-fig-155cross-section-of-one-lobe-of-tub-PG44HF.jpg ". A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 388 GENERAL PLANT PATHOLOGY within the tumor cells as the result of the meUbolism of the im- prisoned bacteria (Psetidomonas tumefaciens). Growth of the tumor comes about not by the direct application of stimuli, but indirectly by the removal of various inhibitions. Under normal conditions the physiologic brakes are on at all times, more or less, in both plants and animals, and only when they are entirely or largely removed in. ^l^*"M^^^i2 Fig. 155.—Cross-section of one lobe of tub Stock Photo")
RMPG44HF–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 388 GENERAL PLANT PATHOLOGY within the tumor cells as the result of the meUbolism of the im- prisoned bacteria (Psetidomonas tumefaciens). Growth of the tumor comes about not by the direct application of stimuli, but indirectly by the removal of various inhibitions. Under normal conditions the physiologic brakes are on at all times, more or less, in both plants and animals, and only when they are entirely or largely removed in. ^l^*"M^^^i2 Fig. 155.—Cross-section of one lobe of tub
RMRDE6HR–. The fungi which cause plant disease . Plant diseases; Fungi. 138 THE FUNGI WHICH CAUSE PLANT DISEASE walled and short livfed, the later ones thicker walled and more enduring. After some weeks these tufts cease forming and disappear. The mycelium within the fruit persists, turns olivaceous and forms large irregular sclerotioid masses which on the following spring may produce fresh conidia. These sclerotioid (mummified) fruits under suitable conditions. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and ap
RMPG44DF–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. DETAILED ACCOUNT OF SPECIFIC DISEASES OF PLANTS 495 branches, or at the base of the tree, are evidences that the trees are attacked by the chestnut blight fungus. The cankers on smooth bark are especially marked, and with a reddish-brown color in contrast with the healthy bark can be seen for a considerable distance (Fig. 171). As sunken, or swollen diseased areas of the bark, they occur on branches of all sizes and generally the cankers are ellipsoidal with the long ajds up and down th
RMRDEG94–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 24 MYCOLOGY Cell Division and Reproduction.—As with olher plant cells in general it may be said that growth is not conditioned on cell division. Growth is the enlargement of the cell, not merely a swollen condition, and this increase in size is within definite limits for each species, which can be determined by statistic study. As long as division is not preceded by nuclear division, the term fission is apphcable. Certain students of the group claim that there is a division of the nucle
RMPG45A5–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. GENERAL PHYSIOLOGY OF FUNGI 65 second and the spores of the common mushroom shortly after leaving the cap fall at the rate of i mm. per second approximately. The violent discharge of the spores prevents the adhesive spores from massing together and from sticking fast to the gUl surface. At first the spore is shot out horizontally, then under the influence of gravity, it describes a sharp curve and then falls vertically. The path described by the falling spore has been appropriately call
RMRDE23A–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. FUNGI IMPERFECTI (dEUTEROMYCETES) 267 fungus which causes leaf spot of beets, Cercospora beticola. The form genus Fusarium (Fig. 109), established by Link in 1809, is one which has come into prominence recently as associated with the production of serious plant diseases. At least eleven species are found on the sweet potato (Fig. 108), and these have been investigated by H. W. WoUenweber' and other mycologists. He finds that the genus has a number of vegetative and spore stages the vari
RMPG44T9–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. MUSHROOMS AND TOADSTOOLS 249 continued directly upward from the strand. Of these tissues, the medullary bundle spreads out at its upper end and forms a dense sheaf-like head by repeated branching and anastomosing. The cortical layer of tissue becomes the outer wall of the volva; the sheaf- like head gradually differentiates into all the other parts of the older egg. In such differentiation the central column first appears. The formation of the gelatinous layer of the volva now begins in
RMRDE1K9–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. DETAILED ACCOUNT OF SPECIFIC DISEASES OF PLANTS 495 branches, or at the base of the tree, are evidences that the trees are attacked by the chestnut blight fungus. The cankers on smooth bark are especially marked, and with a reddish-brown color in contrast with the healthy bark can be seen for a considerable distance (Fig. 171). As sunken, or swollen diseased areas of the bark, they occur on branches of all sizes and generally the cankers are ellipsoidal with the long ajds up and down th
![. The fungi which cause plant disease . Plant diseases; Fungi. 326 THE FUNGI WHICH CAUSE PLANT DISEASE In a few species "*'' ^^ there are what are known as amphispores or resting forms of urediniospores provided with thickened walls. They have colorless contents and pedicels more persistent than those of the usual urediniospore. III. Telia (teleuto-sori). Toward the latter part of the grow- ing seasons another kind of spore appears, often in the same sorus with the urediniospore and from the same mycehum. It is of various forms in different genera, one or more- celled, varies in shape, th Stock Photo](https://c8.alamy.com/comp/PG464D/the-fungi-which-cause-plant-disease-plant-diseases-fungi-326-the-fungi-which-cause-plant-disease-in-a-few-species-quot-there-are-what-are-known-as-amphispores-or-resting-forms-of-urediniospores-provided-with-thickened-walls-they-have-colorless-contents-and-pedicels-more-persistent-than-those-of-the-usual-urediniospore-iii-telia-teleuto-sori-toward-the-latter-part-of-the-grow-ing-seasons-another-kind-of-spore-appears-often-in-the-same-sorus-with-the-urediniospore-and-from-the-same-mycehum-it-is-of-various-forms-in-different-genera-one-or-more-celled-varies-in-shape-th-PG464D.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. 326 THE FUNGI WHICH CAUSE PLANT DISEASE In a few species "*'' ^^ there are what are known as amphispores or resting forms of urediniospores provided with thickened walls. They have colorless contents and pedicels more persistent than those of the usual urediniospore. III. Telia (teleuto-sori). Toward the latter part of the grow- ing seasons another kind of spore appears, often in the same sorus with the urediniospore and from the same mycehum. It is of various forms in different genera, one or more- celled, varies in shape, th Stock Photo")
RMPG464D–. The fungi which cause plant disease . Plant diseases; Fungi. 326 THE FUNGI WHICH CAUSE PLANT DISEASE In a few species "*'' ^^ there are what are known as amphispores or resting forms of urediniospores provided with thickened walls. They have colorless contents and pedicels more persistent than those of the usual urediniospore. III. Telia (teleuto-sori). Toward the latter part of the grow- ing seasons another kind of spore appears, often in the same sorus with the urediniospore and from the same mycehum. It is of various forms in different genera, one or more- celled, varies in shape, th
RMRDE71R–. The fungi which cause plant disease . Plant diseases; Fungi. Fig. 45.—Cucumber seedlings. Pots 5, 6, and 8 inoculated with Pythium. Pot 7, Control. After Atkinson. species, bear conidia on branches which are of the same character as the myceHum itself. The conidia germinate either by a rupture of the wall or by the formation of a beak-like process through which the protoplasm is extruded, after which it becomes differentiated into zoospores. Gemmae, very like the conidia in ap- pearance, are also produced. The oogonia are quite like the conidia and gemmae in structure but develop oospores wi
RMPG4DTC–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. DETAILED ACCOUNT OF SPECIFIC PLANT DISEASES 561 extent by chilly nights with alternating warm days. Cluster cups that originate from spores produced on the wheat plant, develop aecio- spores, which will infect only wheat plants. If it should happen that these aeciospores are blown to rye, oats, barley and rye, no infection takes place, so that the same specialization of spores form is noticeable here as with the uredospores. In America, the barberry shrubs are extremely rare and to acco
RMRDEG48–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. GENERAL PHYSIOLOGY OF FUNGI 65 second and the spores of the common mushroom shortly after leaving the cap fall at the rate of i mm. per second approximately. The violent discharge of the spores prevents the adhesive spores from massing together and from sticking fast to the gUl surface. At first the spore is shot out horizontally, then under the influence of gravity, it describes a sharp curve and then falls vertically. The path described by the falling spore has been appropriately call
RMPG454H–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. Fig. 51.—Stcrigmatocystis niger ^Aspergillus niger) showing conidiophores and coni- diospore formation with stages in germination of spores. (After Henri Coupin.) The genus Thidavia is represented by a common pathogenic species, T. basicola, whose life history and pathogenic character will be de-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly
RMRDE25A–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. MUSHROOMS AND TOADSTOOLS 249 continued directly upward from the strand. Of these tissues, the medullary bundle spreads out at its upper end and forms a dense sheaf-like head by repeated branching and anastomosing. The cortical layer of tissue becomes the outer wall of the volva; the sheaf- like head gradually differentiates into all the other parts of the older egg. In such differentiation the central column first appears. The formation of the gelatinous layer of the volva now begins in
![. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 39 This he demonstrated b}^ culture and cross inoculation in fruits to be identical with the pear blight organism, though inoculations in plum twigs did not give disease, presumably due to the high re- sistance of this plant. Similarly Paddock has shown this organism to attack the apricot.'"' Detmers has reported what she regarded as this bhght caused by this Bacillus on blackberries." Other hosts are hawthorn, shad bush, mountain ash. By inoculations with pure cultures of the apple bod Stock Photo](https://c8.alamy.com/comp/PG4H7P/the-fungi-which-cause-plant-disease-plant-diseases-fungi-the-fungi-which-cause-plant-disease-39-this-he-demonstrated-b-culture-and-cross-inoculation-in-fruits-to-be-identical-with-the-pear-blight-organism-though-inoculations-in-plum-twigs-did-not-give-disease-presumably-due-to-the-high-re-sistance-of-this-plant-similarly-paddock-has-shown-this-organism-to-attack-the-apricotquot-detmers-has-reported-what-she-regarded-as-this-bhght-caused-by-this-bacillus-on-blackberriesquot-other-hosts-are-hawthorn-shad-bush-mountain-ash-by-inoculations-with-pure-cultures-of-the-apple-bod-PG4H7P.jpg ". The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 39 This he demonstrated b}^ culture and cross inoculation in fruits to be identical with the pear blight organism, though inoculations in plum twigs did not give disease, presumably due to the high re- sistance of this plant. Similarly Paddock has shown this organism to attack the apricot.'"' Detmers has reported what she regarded as this bhght caused by this Bacillus on blackberries." Other hosts are hawthorn, shad bush, mountain ash. By inoculations with pure cultures of the apple bod Stock Photo")
RMPG4H7P–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 39 This he demonstrated b}^ culture and cross inoculation in fruits to be identical with the pear blight organism, though inoculations in plum twigs did not give disease, presumably due to the high re- sistance of this plant. Similarly Paddock has shown this organism to attack the apricot.'"' Detmers has reported what she regarded as this bhght caused by this Bacillus on blackberries." Other hosts are hawthorn, shad bush, mountain ash. By inoculations with pure cultures of the apple bod
RMRDET4K–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. 7i8 ADDITIONAL EXERCISES. Fig. 259.—Penicillium spinulosum. a, b, Conidial fructifications, consisting of single verticils of conidiiferous cells; c, conidiiferous cell with chain of conidiospores (smooth); d, f. ripe echinulate conidiospores; c, swollen end of conidiophore; g, h, sketches of conidial fructifications. {Afler Thorn.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of t
RMPG4DGG–. A text-book of mycology and plant pathology . Plant diseases; Fungi in agriculture; Plant diseases; Fungi. APPENDIX VII 70s long and septate. The conidiospores are bluish-green, globose-cylindric, 4 to sn in diameter. Roquefort cheese is a hard rennet cheese made from the milk of sheep. Some imitations are made from cow's milk. The most striking characteristic of this cheese is the mottled, or marbled appearance of the interior due to the develop- ment of this fungus, which is the principal ripening agent. The manufacture of Roquefort cheese has been carried on for at least two centuries in
RMRDE621–. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 363 The seciospores are borne in secia which rest in orange or yellow spots often strongly thickened. Pycnia abound. The aecium with its thick peridium is erumpent and projects to some distance above the host surface, this character giving rise to the separate form- genus, Roestelia. The peridial margin which may be lacerate or fimbriate is used in specific characteriza- tion. The spores are borne and function as in ordinary secia. They bear several germ pores. jEciospores germi- nate at once and
RMPG4H4Y–. The fungi which cause plant disease . Plant diseases; Fungi. 60 THE FUNGI WHICH CAUSE PLANT DISEASE protoplasm is therefore continuous througliout the whole plant body and may be regarded as constituting one cell though it may be of great extent and bear very numerous nuclei. Such multi- nucleate cells, coenocytes, may be regarded as cell complexes with the walls omitted. In one comparatively small order, the Chytridiales, there is often no filamentous mycelium and the vegetative body consists merely of a globular, irregularly spherical or amoeboid cell. Such forms are thought by some mycolo
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