RMMA7HGR–. Elementary botany . Fig. 427. Cell from carnation leaf, showing haustorium of rust mycelium grasping the nucleus of the host, h, haustori- um ; n, nucleus of host. Fig. 428. Intercellular mycelium with haustoria entering the cells. A, of Cystopus candidus (white rust); />, of Peronospora calotheca. (De Bary.) of other parasitic fungi the threads of the mycelium themselves penetrate the cells of the host, while in still others the mycelium courses only between the cells of the host (fungus of peach leaf-curl for example) and derives food materials from the protoplasm or cell-sap of the hos
RMANF28F–Downy mildew Peronospora viciae mycelium on field or broad bean Vicia fabae leaf
RFM8H7WR–Grape Peronospora or downy mildew. Fungus vineyards. It causing grape diseases. It attacks the leaves, young wood, flowers and fruit.
RMAGWKYT–Blue mould or downy mildew Peronospora tabacina infection on ornamental tobacco Nicotiana
RM2GEN5P0–Randersacker, Germany. 19th Aug, 2021. Beate Leopold, managing director of Weinbauring Franken, shows the infestation of fungal spores of the so-called downy mildew (peronospora) on leaves of a vine. The fungal disease is threatening the grapes in some vineyards in Franconia. After the many rains in spring and summer, the fungus is a widespread problem throughout Germany, but also in other European countries. Credit: Daniel Karmann/dpa/Alamy Live News
RMANF28D–Downy mildew Peronospora viciae mycelium and necrotic lesions on field or broad bean Vicia fabae leaf
RM2GDRNP3–Auggen, Germany. 12th Aug, 2021. Jürgen Gugelmeier, chairman of the board of the Winzerkeller Auggener Schäf wine cooperative, inspects leaves and grapes damaged by the so-called downy mildew (peronospora) in a particularly heavily infested vineyard. The owner of the vines (not in the picture) had made a mistake in plant protection. The vintners in the southwest expect a smaller harvest in 2021. According to the association, they are worried about the fungal infestation, among other things. Regionally, harvest losses of up to 40 percent are expected. Credit: Philipp von/dpa/Alamy Live News
RMA160W5–Downy mildew Peronospora viciae lesions on field bean leaves
RM2HGAJ5G–Beautifully delicate Aquilegia flowering in a natural garden setting in close-up. natural environmental flower portrait
RM2EH6M3J–Downy mildew (Peronospora manshurica) disease lesions on on the upper surface of a soyabean leaf, Thailand
RM2AJ4YGR–The Journal of microscopy and natural science . P&ronosporoy oulsvrv&OrzbTru. THE JOURNAL OF MICROSCOPY AND NATURAL SCIENCE: the journal ofThe Postal Microscopical Society. OCTOBER, 1884. ®n tbe peronoepor^. By George Norman, M.R.C.S.E. Plates 20, 21, 22, 23, 24. Second Part. AVING given a general account of the life-historyof the Peronosporoe, we can now proceed to examinesome of the more striking members of the genus,beginning with those least known, and reserving thepotato fungus to the last. P. Gangliformis, the Lettuce Peronospora. Threads of the mycelium stout, now and thentorulose; suck
RMPG4AKJ–. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. MISCELLANEOUS CRQPS. 157 The larvsB of this moth (already described) feed on the roots of lettuces. The Lettuce Mildew {Peronospora ganglioniformis, Fig. 61) produces pallid patches on lettuce leaves, and " in bad cases summer lettuces are quickly reduced to pu- trescent masses." The conidiophores of this fungus are. Fig. 51.—Lettuob Mildew {Peronospora ganglioniformis). A. A oonidiophore and conidia. B. Oospores (resting-spores). X 195 diam. (Zeiss's C. and 3 oc). fl
RF2GYAGX9–Falscher Mehltau
RMT1FKR0–Diseases and decays of Connecticut Diseases and decays of Connecticut tobacco diseasesdecaysof00ande Year: 1940 Figure 2. Some fungi that cause tobacco diseeises, all greatly magnified. A-E, the mildew fungus Peronospora tahacina. A, Sporophore with developing summer spores at tips. B, Mature summer spores. C, Germination of the summer spores. D, Cross- section of a winter spore. E, Haustorium inside a leaf cell and a segment of mycelium between the leaf cells. F, Spores of the fungus Aliernaria tenuis, causing brown-spot and freckle rot. G, Mycelium of the same fungus. H, Sporophore and hea
RMMCK6XK–. FiG. iO.—PlasmoiMi-a viticola. Conidiophores, much enlarged, (v. Tubeuf del.) tion in rain-drops discharge six to eight swarming cells from which germ-tubes grow into the epidermis of the host-plant ; thus the disease spreads rapidly during moist weather and a Peronospora viticola, 1890. Maguus, Wittviaclc's Gartenzeit, 1883. Scribuer, Reijort of U.S. Dept. of ArjricuUure for 1886, pp. 96-105; this contains an excellent account of this milde-n-. Articles on this subject dealing with remedial measures are frequently published in the U.S. Amer. Department reports and bulletins, in the bulletin
RFM8H80F–Grape Peronospora or downy mildew. Fungus vineyards. It causing grape diseases. It attacks the leaves, young wood, flowers and fruit.
RM2HGAJ5B–Beautifully delicate Aquilegia flowering in a natural garden setting in close-up. natural environmental flower portrait
RM2EH6M46–Downy mildew (Peronospora manshurica) disease lesions on on the upper surface of a soyabean leaf, Thailand
RM2G7W2HA–Beautifully delicate Aquilegia flowering in a natural garden setting in close-up. natural environmental flower portrait
RM2DEYBYN–Downy mildew (Pseudoperonospora cubensis) a water mould causing downy mildew lesions on the leaf of a cucumber plant, Greece
RM2AJ4YNK–The Journal of microscopy and natural science . P&ronosporoy oulsvrv&OrzbTru. THE JOURNAL OF MICROSCOPY AND NATURAL SCIENCE: the journal ofThe Postal Microscopical Society. OCTOBER, 1884. ®n tbe peronoepor^. By George Norman, M.R.C.S.E. Plates 20, 21, 22, 23, 24. Second Part. AVING given a general account of the life-historyof the Peronosporoe, we can now proceed to examinesome of the more striking members of the genus,beginning with those least known, and reserving thepotato fungus to the last. P. Gangliformis, the Lettuce Peronospora. Threads of the mycelium stout, now and thentorulose; suck
RMPG3RTH–. The essentials of botany. Botany. 140 BOTANY. fungus which protrude through the epidermis of the host. In the Mildews (species of Peronospora) these branches. Fig. 66.âShowing tips of two conidia-beaiing branches of Potato-mildew (Peronospora infestans). Highly magnified. find their way through the breathing-pores, and bear their spores singly upon lateral branchlets (Fig. 66); in the White Rusts (species of Cystopus) the conidia-bearing branches collect under the epidermis and rupture it. Here the coni- dia are borne in chains or bead-like rows (Fig. 67). 292. In some species the conidia ge
RMT0DA3X–Dr L Rabenhorst's Kryptogamen-Flora von Dr. L. Rabenhorst's Kryptogamen-Flora von Deutschland, Oesterreich und der Schweiz drlrabenhorstskr0104rabe Year: 1892 444 Gattung Peronospora durchgeführt, sie umfasst jetzt die Sectio lY Pleuroblastae der im Jahre 18(i3 von de Bary (1. c.) gegebenen Eintheilung der alten Gattung Peronospora. Vor de Bary's grundlegender Arbeit waren die weitverbreiteten Species dieser Gattung unter mancherlei anderen Namen von älteren Autoren beschrieben worden, besonders gehören einige Species der Gattung Botrytis hierher. Bonorden (AUgem. Mycologie p. 95) stellte
RMMCK6JM–. Fio. iO.—Plasmo2>a.ra viticota. Conidiophores, much enlarged, (v. Tubeuf del.) tion in rain-drops discharge six to eight swarming cells from which germ-tubes grow into the epidermis of the host-plant ; thus the disease spreads rapidly during moist weather and a Peronospora vtticola, 1890. Magniis, Witt7)iarJ:'s Gartenzeit, 1883. Scribner, Iie2Jort of U.S. Dtqit. of Agriculture for 1S86, pp. 96-105 ; this contains an excellent account of this mildew. Articles on this subject dealing with remedial measures are frequently published in the U.S. Amer. Department reports an.l bulletins, in the
RM2HANTM5–Beautifully delicate Aquilegia flowering in a natural garden setting in close-up. natural environmental flower portrait
RM2EM4FXP–Downy mildew (Pseudoperonospora cubensis) a water mould causing downy mildew lesions on the leaf of a squash plant, Thailand
RM2AJ6BP5–Fungous diseases of plants . m (zoo- sporangium). Oospore free from the wall of the oogoniuni. Plasmopara 2. Conidium becoming a swarm sporangium, conidiophore short, irregular in form and diameter, oospore filling oogonium, withclosely adherent walls Sclerospora 3. Conidium germinating by means of a germ tube. a. Conidium provided with a terminal papilla from which the germ tube proceeds. Fertile tips arising from adisk-like swelling Bremia b. Conidium without papilla. Fertile tips ordinarily branch- like Peronospora B. Conidiophore incomplete when first conidia produced. Fertile tips swellin
RMPG42WK–. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. PERONOSPORA. 133 oospore-coat (oospores of P. viciae have a coat with a regular net- work). It occurs on stems, leaves, and petioles of clovers, lucerne and other Papilionaceae, often with disastrous effect. P. sparsa, Berk. (Britain and U.S. America). This parasite on the rose was first observed in England. It injures indoor roses, causing a fall of the leaf, preceded by the appearance of lilac-coloured spots which
RMMCK9MC–. Fig. 4.—The crown of an alfalfa plant, showing the warts, or galls, produced by the crown-wart fungus. (Courtesy of Jones and Dresch- ler; from Cir. 326.) Downy Mildew.—In this disease of alfalfa, the upper leaves become partly yellow with the edges turned down. The lower sides of the leaves develop a delicate, fuzzy, violet-colored fungus growth, Peronospora trifoliorum. The disease is common in winter and spring but not very destructive. It disappears with dry weather. Dwarf.—Affected plants usually show a few normal stalks and nu- merous short, fine stems with small leaves coming from the
RM2G7W2H9–Beautifully delicate Aquilegia flowering in a natural garden setting in close-up. natural environmental flower portrait
RMAPFBP4–Downy mildew Pseudoperonospora cubensis lesions on a cucumber leaf Greece
RM2AN3YM9–Handbuch der Pflanzenkrankheiten . Fig. 19. Durch Plasmopara viticola er-krankte Traube (Lederbeeren). (( gesunde, / schwach, c stark befallene unddaher eingetrocknete Beeren, / kranke Stellenam Traubenstiel. Nat. Gr. (Nach Millardet.) 1) Note siüla Peronospora della Vite in Rivista di Fatol. Veg. II, 1893, S. 109. 3. Peronosporineae. 155 artig zusammengezogenen, intercellularen Mycel lieranwäclist. Die Zoo-sporen besitzen zwei Wimpern. Die Früchte des Pilzes entstehen aus den nesterweis zwischen demPallisadenjDarenchym des Blattes zusammenliegenden, dünnwandigenOogonien, welche im September o
RMPG43TC–. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. ROOT CROPS. 43 reduce its vitality considerably. When artificial cultures were exposed to a temperature of —17° C. for one day, the organisms were completely destroyed. An E.M.F.i of 3'3 volts (at 17° C.) destroyed B. allii when growing in sterilized pork broth (neutral). Prevention.—Onions, lohen stored, should be kept in a. Fig. 17.— Onion Mildew (Peronospora ScUeideniana). A. The fuBgDS growing from the base of an onion leaf. B. Mycelium ramifying amongst the cells of the ho
RMMCKWHA–. Fig. 54. Onion Diseases. a. Downy mildew, 6. mature conidiophore and conidia of Peronospora schleideni, c. fertilization of the female oogonium by the male antheridium, d. oospore (a. to d. after Wh2tzel), e. onion smut, /. spore ball of the smut fungus, g. spore germina- tion, formation of sporidia at x, h. Vermicularia anthracnose, i. section through acervulis of Vermicularia circinans, j. setas and spore formation in 1-'. circinans {e. to g., i. and i. after Thaxter), k. pink root of onion, healthy and diseased bulbs, /. pink root of onion showing nipple formation, m. a formaldehyde drip
RM2G7W2HD–Beautifully delicate Aquilegia flowering in a natural garden setting in close-up. natural environmental flower portrait
RM2AJ699H–Fungous diseases of plants . tion of Peronospora parasitica. Ann.Bot. 14: 263-279. pi. 26. 1900. This fungus seems to be particularly abundant in England, butit is also found in other parts of Europe and in the United States.Practically all cultivated Cruciferae are more or less subject to it, l62 FUNGOUS DISEASES OF PLANTS as well as many wild species. It frequently causes stem deformi-ties, and in England it is often associated with Cystopiis candidiis on Capsella, while in thiscountry it is perhaps bestknown as a pest in cauli-flower culture under glass,yet occasionally destructivein cabbag
RMPG3RTA–. The essentials of botany. Botany. Fig. 66.âShowing tips of two conidia-beaiing branches of Potato-mildew (Peronospora infestans). Highly magnified. find their way through the breathing-pores, and bear their spores singly upon lateral branchlets (Fig. 66); in the White Rusts (species of Cystopus) the conidia-bearing branches collect under the epidermis and rupture it. Here the coni- dia are borne in chains or bead-like rows (Fig. 67). 292. In some species the conidia germi- nate by forming a tube; in others they divide internally and finally emit many zoospores. The latter eventually protrude
RMMCR849–. (B. 613.) F'L^ I 30ofach. Stück eines Längsschnittes aus u<.in .-iiLu^el des Waldmeisters (Aspcrula odorata) mit 2 Reihen von Parenchymzellen. Zwischen ihnen verläuft ein dicker Mycelschlauch von Peronospora calotheca, welcher in 6 Wirthszellen je ein verzweigtes Haustorium hineingesandt hat. Der plasmatische Inhalt dieser Wirthszellen ist bereits völlig aufgezehrt. II 450 fach. Eine Zelle aus dem Schwammgewebe des Blattes von Kaniincultts Fiavia mit 2 von verschiedenen Mycelfäden entspringenden, knorrig verzweigten stattlichen Haustorien, welche einem Rostpilz (Uroniyces Poae Rabknh.) an
RM2HANTM1–Beautifully delicate Aquilegia flowering in a natural garden setting in close-up. natural environmental flower portrait
RM2AN4J7K–Pflanzenschutz nach Monaten geordnet; eine Anleitung für Landwirte, Gärtner, Obstbaumzüchter &c . Das anerkannh besfi? und billigshe Obshbaum - Carbolingum - Präparat. alle HsTJsrben ScbmaroJ-zerti.SchädlingeBlut.-^Dmma.? Schild,-BjaMläusf. Raupen etc. Wunden Krebs.Brand etc. vollständig.Wpf|jjnj|n[|Krankhpi|en u. Bildung von Schwamm. Pilzen Flechtpn, Moos.Schorf, Fäulnis.insbesondere auch Fusikladium ü. Peronospora (Blatt-fallKrankbeit.) ^ gegen Wild und Frostschäden. ^^^^alle Bäume durch Bildung FrischerRindeWachstum u.Lebensdauer der BäumeGrossg Ernteerträge. Sfhcil•z^WrjüngfFördertSichert
RMPG4H0K–. The fungi which cause plant disease . Plant diseases; Fungi. 84 THE FUNGI WHICH CAUSE PLANT DISEASE timate branchlets arise radially; germ tube produced from the apex of the conidia 7. Bremia, p. 95. Conidiophores without subapical en- largements; conidia germinating from the side 8. Peronospora, p. 95. Phytophthora de Bary (p. 83) This genus is of especial interest on account of its one exceed- ingly destructive representative, P. infestans, which occupies an historic position in phytopathology as one of the earliest of para- sitic fungi to receive study in any way complete or adequate; stu
RMMCTK67–. Fig. 93. Oosporenbildung bei Peronospora Älsinearum, a jugendlicher Zustand, 6 Bildung der Oosphäre und des Befruclitnngsschlaucfies, c nach der Befruchtung, n Antheridium, o Oogouium (350/1). (Nach De Bary.) eines Keimschlauches. Die Schwärmsporen sind nierenförmig, mit 2 seitlich stehenden Cilien. — Die sexuellen Sporen werden intercellular gebildet. Antlieridien und Oogonien(Fig. 93) entstehen an den Enden kurzer Seitenzweige unter Abgrenzung durch eine Scheidewand. Die Antheridien sind keulenförmig, legen sich einzeln mit breiter Fläche an das Oogon an und senden einen Befruchtungsschlau
RM2K7P0MH–Beautifully delicate Aquilegia flowering in a natural garden setting in close-up. natural environmental flower portrait
RM2BXBYX1–Aquilegia flowering in a London urban garden in bright sunshine, natural flower portrait
RM2AXF88A–Text-book of structural and physiological botany . Fig.397.—Compound Fig. 398.—I. c Basidiospores of an Agaric; a cells of the spore {sporides- hymenium ; b basidium (x 300): II. ^ basidiospores of miu7ii) of Sphceria Geaster hygroinetHcus ; 7n mycelial filament; b basidium Scirpi (after De (after De Bary; x 390) ; III. a three basidia or sterigmata Bary ; x 390). of ^Jirz^/a ^/zVz^/,^?^.^:; <5 basidiospore (strongly magnified). the oldest on the basidium. In a few cases, as Cystopus 268 Structural and Physiological Botany, and Peronospora^ sporangia are formed instead of sporeson the basid
RMPFYEK3–. A text-book of botany for secondary schools. Botany. FUNGI 145 as apple, pear, cherry, rose, hop, grape, wheat, gooseberry, cucumber, pea, verbena, sunflower, aster, etc. In fact, very few seed-plants seem to escape their attacks. Being exter- nal parasites, mildews are not necessarily destructive; but they often cause the death of the host. An examination of the my- celium shows that its filaments have partition walls; and hence the body is not ccenocytic, as in Mucor and Peronospora, but made up of a row of cells as in the Conferva forms among the green Algae. Small disk-like outgrowths ar
RMMCX0DD–. Figure 2. Some fungi that cause tobacco diseeises, all greatly magnified. A-E, the mildew fungus Peronospora tahacina. A, Sporophore with developing summer spores at tips. B, Mature summer spores. C, Germination of the summer spores. D, Cross- section of a winter spore. E, Haustorium inside a leaf cell and a segment of mycelium between the leaf cells. F, Spores of the fungus Aliernaria tenuis, causing brown-spot and freckle rot. G, Mycelium of the same fungus. H, Sporophore and heads of the spores of one of the pole rot fungi, Botrytis cinerea. I, Spores of the blotch fungus, Fusarium affine
RM2BXBYX8–Aquilegia flowering in a London urban garden in bright sunshine, natural flower portrait
RM2AN3PT3–Danish fungi as represented in the herbarium of ERostrup . bes-holm Skov!; F. Vejstrup Aaskov. Vicia sativa. F. Vejstrup Aaskov; L. Vester-borg. Fjcia angustijolia. J. Skive!, Viborg!. Ficia lathyroides. J. Skive!. Pisumsativum. Common in the gardens. J. F. (Skaarup ^^/e 71), S. L. etc. Pisumarvense. J. Tylstrup!. Lathyrus pratensis. F. Klingstrup. Lathyrus Silvester. J.Horsens!, F. Vejstrup Aaskov, Trolleborg; S. Vejenbred (R. Fejlberg); L. Gron-negade. Orobus tuberosus. J. Viborg!; S. Brede. Orobus niger. F. Svenborg. 72. Peronospora trifoliorum de By., Syll. VII ^ Fisch. IV ^,KWerens Bladsk
RMPG4CGC–. Diseases of truck crops and their control . Vegetables. Fig. 54. Onion Diseases. a. Downy mildew, b. mature conidiophore and conidia of Peronospora sckleideni, c. fertilization of the female oogomum by the male antheridium, d. oospore (a. to d. after Wh^tzd), e. onion smut, /, spore ball of the smut fungus, g. spore germina- tion, formation of sporidia at x, h. Vermicularia anthracnose, i. section through acervulis of Vermicidaria cirdnans, j. setae and spore formation in V. circinansXe. to g., *. and j". after Thaxter), k. pink root of onion, healthy and diseased bulbs, I. pirJc root o
RMMCTKGW–. Fig. 34. Oosporenbildung von Peronospora Alsinearum (350/1). (Nach De Bary.) I'erotiosporineac sind die Antheridien schon frühzeitig durch ihre bedeutendere Kleinheit viel deutlicher von den Oogonien verschieden als bei den vorhergenannten Klassen, ihr Inhalt wandert durch einen Befruchtungsschlauch mit Ausschluss eines geringen Teils, der im Antheridium zurückbleibt, in das Oogon über und verschmilzt bei Pijthiwn und Phytophthora deutlich, bei Peronospora und Cystopus aber nicht deutlich wahrnehmbar, mit dem Inhalt des Oogons, der sich schon vorher in der Mitte desselben zur Eikugel (Oosphä
RM2BXBYX4–Aquilegia flowering in a London urban garden in bright sunshine, natural flower portrait
RM2AN3PHW–Danish fungi as represented in the herbarium of ERostrup . Nibe!, Knudby!; F. Klingstrup; S. Frede-rikssund!. 74. Peronospora cytisi Rostrup (92 j &. p), Syn: Per. cytisi Mag-nus (Hedwigia 1892 ), Syll. XI ^ Per. trifoliorum de By. form,laburni vulgaris Voss in Thiim. Mycot. No. 2219, Guldregn-skimmel (R 02 a ^02 a R 04 a ^). At the same time as RostrupO. Kirchner (92) found it inWiirtemberg and P. Magnus inFrance (P. Mg. 93); about 10years before W. Voss found itin Laibach in Austria; Rostrupw^as, however, the first to deno-minate and describe it. It hasbeen found several times innurseries o
RMPG4CTP–. Diseases of truck crops and their control . Vegetables. Fig. 20. Beet Diseases. fl. Crown gall, b. scab, c, downy mildew, d. Conidiophore of Peronospora schachtii arising from a stomate of an infected beet leaf, e. germinating zoospore of P. schach- tii,/. oospore of P. schachtii, g. Cercospora leaf spot (after Halsted), ft. conidiophore and conidia of Cercospora beticola (after Duggar), i, Phoma leaf spot (after Pool and McKay), k, pycnidium of Phoma beta (after T. Johnson) {d.-f. after PrilUeux).. Please note that these images are extracted from scanned page images that may have been digit
RMMAB5TF–. Dr. L. Rabenhorst's Kryptogamen-Flora von Deutschland, Oesterreich und der Schweiz . Peronospora. — a—g Letzte Gabelzweige der Conidienträger. a—dDivaricataeraP.Schachtii, h P. Eadii, c P. leptosperma, d P. Eumicis; e lutermediae: P. Eupliorbiae; f und g Undu- latae: /"P. Linariae, gr P. parasitica; Näheres über die genannten Gruppen auf pag. 446 dieses Bandes (Vergr. 360). /* P. effusa. Keimende Conidien mit beliebigen Austrittsstellen des Schlauches (Vergr. 190). / P. calotheca. Inter- cellularer Mycelschlauch mit kräftigen, faden- förmigen Haustorien, Längsschnitt durch den Stengel v
RM2BXBYX7–Aquilegia flowering in a London urban garden in bright sunshine, natural flower portrait
RM2AX2X4M–Bulletin . un nom spécial. » Maxgix, qui avoue navoir pas vuces suçoirs 1) dans le tubercule de Pomme de terre les qualifie,d après de Barv. de « masse remplissant la cavité cellulaire »;il a évidemment dénaturé la pensée de de Bary. Ces suçoirs,en effet, rameaux de mycélium, mais rameaux bien différenciés,méritent le nom de suçoirs au même titre que les organesanalogues du Peronospora viticola ou du Cystopus candidus.par exemple. Ils ont, dans le Phytophthora infestans, desformes très variées ; ils peuvent être arrondis ou ovoïdes, unpeu allongés et droits ou légèrement courbés en crosse à le
RMPFBP85–. Der gegenwrtige Standpunkt der Mycologie mit Rcksicht auf die Lehre von den Infections-Krankheiten. Pathogenic fungi. 91 wickluncf dieser Sporen ist nur in we- nigen Fällen beobachtet worden; ent- weder zerfällt ihr Inhalt in Zoosporen oder bei Peronospora Valerianellae wird das Exosporium gesprengt und es tritt ein sich reich verzweigender Keimschlauch heraus, dessen Eindrin- gen in die Nährpflanze übrigens nicht beobachtet werden konnte. Auf zahlreichen Cruciferen, beson- Fig. 31. Peronospora densa; a. und b. " "^.•x.vv.-^».v^*i v^mv/.tv^iv^xij Ausschlüpfen des Protopias- ders au
RMMCKWKE–. , n ^i;" Fig. 54. Onion Diseases. a. Downy mildew, b. mature conidiophore and conidia of Peronospora schleideni, c. fertilization of the female oogonium by the male antheridium, d. oospore (a. to d. after Wh^tzel), e. onion smut, /. spore ball of the smut fungus, g. spore germina- tion, formation of sporidia at x, h. Vermicularia anthracnose, i. section through acervulis of Vermicularia cirdnans. j. setae and spore formation in V. circinans {e. to g., i. and j. after Thaxter), k. pink root of onion, healthy and diseased bulbs, I. pink root of onion showing nipple formation, m. a formald
RM2BXBYX0–Aquilegia flowering in a London urban garden in bright sunshine, natural flower portrait
RM2CE636A–. Journal of botany, British and foreign . wc.5. ad.nat.del. Fig. 2. Peronospora infestans.—Oogonia and antheridia from badly-diseased leaves ofPotato after a weeks maceration in water x 400. (Gard. Chron., p. 69.)K. Eesting-spore with coat of cellulose. L. Eesting-spore washed out ofcoat by maceration. M. Semi-mature resting-spores. N. Antheridia.
RMMCR7TM–. Fig- 44- (B. 653.) I 250 fach. Conidienträger von Peronospora parasitka aus einer Spaltöffnung der Stengel- Epidermis von Cnrdammc pratensis hervortretend (der Träger rechts ist abgeschnitten). II—VI ca. 800 fach. Oosporenbildung und Befruchtungsvorgang bei Pythhtm gracile in ihren successiven Stadien, nach de Bary: II Oogon und Antheridienast zu definitiver Grösse gelangt. III Das Antheridium durch eine Querwand abgegrenzt. IV Im Oogon hat sich die Eiballung vollzogen, zwischen Ei und Oogoniumwand eine dünne Periplasmazonc; das Antheridium hat einen Be- fruchtungsschlauch in das junge Ei hi
RM2BXBYX6–Aquilegia flowering in a London urban garden in bright sunshine, natural flower portrait
RM2CDDMTE–. Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . FIG, 6. SURFACE OF POTATO LEAF GREATLY MAGNIFIED, SHOWINGGERMINATING SPORE ENTERING BREATHING PORE AT a,AND GOING THROUGH EPIDERMIS AT C. developed to a considerable extent they collectively formthe mycelinm of the fungus. After the Peronospora plant has reached this stagein its existence it is ready to prepare for reproduction.It sends out through the breathing pores of the leafbranching threads, and on these develops the conidia, asalready described. By
RMPFG7PC–. Das Mikroskop; ein Mittel der Belehrung und Unterhaltung für Jedermann sowie des Gewinns für Biese. Microscope and microscopy. «ig. OS.. Äiq. 07. giq. 69. ein ^o^tranm entfielt (bei 3;.? Später lutrr tae^ ^etntb(äecf)en unD ter i(;r benacftbarte 2:6ei( bee! @c^(aurf;ei^ gan; teer -'in 4', faßt Jig. 67. 3^urd)i'dinitt cince f artcffc(t(attcö, ircl*c-j von Pei-ouospora tmi)-- macbfcn xfi, circa 300 m. tcrgrcpcrt. o o ^io CK'rhauucücn tcr unteren Stattfläc^c p p nocf) grüne 'l^arendn^m^cüen, (£f)lürophiiüförncficn entliattcnb. ui m DJUjcetium ter Peronospora, irclchce [icfr im 'ßarendiDm »erjnj
RMMECNH1–. Die Gartenwelt . Linde mit Maserung. Nach einer vom Verfasser für die „Gartenwelt** gefertigien Aufnahme. verheerendsten Weise um sich greifen. Man denke z. B. nur an die gefürchtete Peronospora der Weinberge, an die Phytophthora der Kartoffelfelder u. a. Die fördernden und hemmenden Bedingungen und Ein- flüsse im einzelnen kennen zu lernen, ist eine ebenso not- wendige und fruchtbare wie schwierige Aufgabe. Man muß sich dabei vor willkürlichen Schlüssen hüten und kann nicht leicht genug skeptisch und kritisch sein. Sehen wir z. B. in einem „feuchten" Jahr das Fusicladium in Ostpreußen
RM2CDCERK–. Fungous diseases of plants, with chapters on physiology, culture methods and technique . on of Peronospora parasitica. Ann.Bot. 14: 263-279. pi. 26. 1900. This fungus seems to be particularly abundant in England, butit is also found in other parts of Europe and in the United States.Practically all cultivated Cruciferae are more or less subject to it. l62 FUNGOUS DISEASES OF PLANTS as well as many wild species. It frequently causes stem deformi-ties, and in England it is often associated with Cystopits candidus on Capsella, while in thiscountry it is perhaps bestknown as a pest in cauli-flowe
RMME83MF–. Die Krankheiten der Pflanzen; ein Handbuch für Land- und Forstwirte, Gärtner, Gartenfreunde und Botaniker . 1. Zoospori- parae. aSIattfaUfranr- ^eit Des ffiein- ftocfeö. ftorfö. Sie]er ^arafit be- gig. 11. Peronospora yiticola, ein 33üfc^cl Don (5oni« Mcuträi]ern, auä einer Spaltöffnung ber 33(att= epiDernii» be§ SBeinftorfeiö l^eruürQeiüadjfen, juni 2:cil nod) (Sporen tragenb, 250fad; uergrüfeert. ^^X^s.^) dornu. fäUt Siebenarten, faft alle ainerifani)d}en nauient» lid) Vitis aestivalis, La- brusca, vulpina unb cor- difolia, foiüie Den europäi= fdjen iüeinftüd. 2^ie i^ranff)eit beginnt bei
RM2CE632H–. Journal of botany, British and foreign . wc.5. ad.nat.del. Fig. 2. Peronospora infestans.—Oogonia and antheridia from badly-diseased leaves ofPotato after a weeks maceration in water x 400. (Gard. Chron., p. 69.)K. Eesting-spore with coat of cellulose. L. Eesting-spore washed out ofcoat by maceration. M. Semi-mature resting-spores. N. Antheridia.. Fig. 3. The -(4r^6/ro^7<sofMontagneand Berkeley X 400. (Gard. Chron., p. 69. From Journ. Hort. See, vol. i.) been formed in the stem of the Potato. Oogonia (FF) and anthe-ridia (G) are seen in contact, as well as the resulting spore with itscell
RMMAB5TE–. Dr. L. Rabenhorst's Kryptogamen-Flora von Deutschland, Oesterreich und der Schweiz . ^ / Peronospora. â a P. arborescens. Ein Oogon mit heranreifender, von Peri- plasma (pZ) umgebener Oospora, a Antheridium (Vergr. 500, nach de Bary). 6â/" Keife Oosporen von verschiedener Structur: h P. calotheca, c P. Myoso- tidis, d P. Valcrianellae, e P. Corydalis, die verhältnissmässig dünn- wandige Oospore (osp) bleibt hier in das dickwandige Oogon (o//) eingeschlossen, /â P. Ho lost ei (bâf nach der Natur, Vergr. 300). mit Warzen oder zu einem Netzwerk vereinigten kräftigen Leisten besetzt ist
RM2CDF3WJ–. Allgemeine Pflanzenkaryologie . B 1. B2 Fig. Hl 1. Vauchtria pachyderma. A Oogoii mit„Wanderplasma, die Kerne am Rücken desOogons gesammelt. B die Kerne sind größten-teils aus dem Oogon ausgewandert. Die Figurist in zwei Schnitten dargestellt; in 2 findetsich der bleibende Eikern. (Nach Heidinger.) in ganz bestimmter Entfernungfinden (F. L. Stevens 1899,Wager 1900, Davis 1900,Ruhland 1903, King 1903für Alhugo, Peronospora, Araio-spora usw.). Die „Strahlungen,die dabei vorhanden sein kön-nen, sind wohl von keinerprinzipiellen Bedeutung undhängen vielleicht nur mit derCytoplasmaverdichtung sel
RMMA7EY0–. Einführung in die Biologie . Fig. 65. a Erysiphe auf Lithospermuin arvense, b Faden von Peronospora parasitica im Stengelmarli des Hirtentäschel. 150/1. Das trifft z. B. für die mit den Rostpilzen verwandten Brandpilze (Ustilagineen) zu, die vor allem in Gräsern zuerst zwischen den Zellen leben und erst als sporenbildendes Gefäde die Zellen des Wirtes aus- füllen; die Sporen sind kugelig, schwärzlich gefärbt und bilden ein stäubendes Pulver. Die häufigste Einwi rkung des Schmarotzerpilzes auf das befallene lebende Gewebe ist die, daß die Plasmakörper der ausgebeuteten Zellen infolge von Ersc
RMRPXB33–. Album der Natuur. . Fig, 6. Afgesnoerde knopjes van Peronospora in- festans; SS vertoont de verdeeling van den inhoud, zz vrije bewegelijke lichaampjes, door die verdeeling ontstaan.. 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.. Haarlem
RMMAB5TJ–. Dr. L. Rabenhorst's Kryptogamen-Flora von Deutschland, Oesterreich und der Schweiz . Bremia. — Br. Lac tue ae. a Krone eines Conidionträgers mit den charakte- ristisch verbreiterten Astenden (Vergr. 2^0). h Zwei Astenden mit 4 und 5 kurzen Sterigmen am Kande, die je eine Conidie gebildet haben (Vergr. 570). c Keimende Conidie, deren Keimschlauch hier regelmässig am Scheitel hervortritt (Vergr. 400). a und h nach der Natur, c nach de Bary. De Bary vereinigte die von Eegel aufgestellte Gattung mit Peronospora und stellte sie hier in eine besondere Section, die der Acroblastae. Schröter (Kryptf
RMRE2N66–. Elementary botany. Botany. Branching hj-pha of Peronospora alsinearum, Branched hypha of downy mildew of grape shoeing peculiar branching (Plasmopara viticola).. 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.. Atkinson, George Francis, 1854-1918. New York : H. Holt
RMMCTK4F–. Fig. 101. Brcnüa Lactucae Regel. A Conidieu- träger mit Conidien; B Endverzweiguug; C reife Conidie; D Keimung. [A 25G/I, B 40lVi.) (A,B nach der Natur; C, D nach De Bary.) Fig. 102. A, B Peronospora leptosperma DeBary. 1 Conidien- träger; B keimende Conidie; C, D Oosporen. C von P. al- süiearuin Casp.; JD von P. effiisa (Grev.) (A etwa 150/1, BâD 300/1.) (JJach De Bary.) träger sehr lang, bis SOO a, 7â9fach dichotom geteilt, Endäste gerade oder schwach gekrümmt. Conidien ellipsoidisch, von sehr verschiedener GröÃe, 15â33 i. lang, 11â22 ). breit; Membran hell violett. Oosporen 45 [
RMRDWGA0–. Elementary botany. Botany. Fig- i37. Branching hypha of Peronospora alsinearum. Fig. 138. Branched hypha of downy mildew of grape showing peculiar branching (Plasmopara viticola).. 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.. Atkinson, George Francis, 1854-1918. New York, H. Holt
RMRDHGBE–. Plant studies; an elementary botany. Botany. Fig. 'SA'.. a hrancti of Peronospora in contact with two cells of a host ])lant, and sending into them its large hanstoria.—After DeBakt.. 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.. Coulter, John Merle, 1851-1928. New York, D. Appleton and Company
RMRD2HHA–. Elementary botany. Botany. Fig- i37. Branching hypha of Peronospora alsinearum. Fig. 138. Branched hypha of downy mildew of grape showing peculiar branching (Plasmopara viticola).. 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.. Atkinson, George Francis, 1854-1918. New York, H. Holt and company
RMRE0P8P–. Elementary botany. Botany. Fig. 137. Branching hypha of Peronospora alsinearum. Fig. 138. Branched hypha of downy mildew of grape shov.'ing peculiar branching (Plasmopara viticola).. 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.. Atkinson, George Francis, 1854-1918. New York, H. Holt
RMRE1GHY–. Fungi; their nature, influence, and uses;. Fungi. 130 FUNGI. tbose whicli influence the dispersion of the minute sporidia from the terminal cysts. Probably they are more perennial in their character, and are assimilated more to the oogonia of Cystopus and Peronospora, being rather of the nature of resting spores, inasmuch as the same threads usually bear the terminal fruits. Thecaspokes is a term which may be applied generally to all sporidia produced in asci, but these are in turn so innumerable and variable that it will be necessary to treat of some of the groups individually. The Thecaspo
RMRE1GG6–. Fungi; their nature, influence, and uses;. Fungi. GERMINATION AND GEOWTH. 151. â Pseudospore of UsHlago recep- Ustilago as have been remarked in the sporules of the first generation in Tilletia. Returning to Ci/stopus, as the last of the Uredines, we must briefly recapitulate the observations made by Professor de Bary,* â who, by the bye, claims for them an affinity with Peronospora (Mncedines but too well known in connection with the potato disease), and not with the Ure- dines and their allies. In this genus there are two kinds of reproductive organs, those pro- duced on the surface of the
RMRDXT8M–. A manual of poisonous plants, chiefly of eastern North America, with brief notes on economic and medicinal plants, and numerous illustrations. Poisonous plants. 206 MANUAL OF POISONOUS PLANTS side of the oogonium; the antheridium. This pierces the oogonium and the protoplasm of the antheridium passes into the oosphere. In the species that have been studied like Peronospora parasitica, and Al- bugo Candida, the oosphere or egg cell contains a single nucleus, situated about at the center, the remaining nuclei having passed into the peripheral layer of the protoplasm of the periplasm. A single
RMREFCYK–. Comparative morphology and biology of the fungi, mycetozoa and bacteria. Fungi -- Morphology; Bacteria -- Morphology. FIG. 8. Mycelial tubes m creeping about in the intercellular spaces with their haustoria penetrating into the cells z—z; A of Cystopus candidus, from the pith of Lcpidium sativum, B of Peronospora catotheca from the pith of Asperula odorata. Magn. 390 times.. 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..
RMRE1GG5–. Fungi; their nature, influence, and uses;. Fungi. â Pseudospore of UsHlago recep- Ustilago as have been remarked in the sporules of the first generation in Tilletia. Returning to Ci/stopus, as the last of the Uredines, we must briefly recapitulate the observations made by Professor de Bary,* â who, by the bye, claims for them an affinity with Peronospora (Mncedines but too well known in connection with the potato disease), and not with the Ure- dines and their allies. In this genus there are two kinds of reproductive organs, those pro- duced on the surface of the plant bursting through the c
RMRPXP4B–. Text-book of botany, morphological and physiological. Botany. 2?6 THALLOPHYTES. (C. candidus), or the terminal conidium of each chain gives rise to a germinating filament, if it is capable of germinating, while the other cells of the conidial chain produce zoogonidia (C. Portulaca;). After the swarming is finished the zoogonidia become firmly attached to the cuticle of the host, invest themselves with a thin cell-wall, and, in the case of Peronospora infestans, put out a delicate germinating filament directly into an epidermal cell, piercing through its outer wall. After it has entered the c
RMREE49J–. Comparative morphology of Fungi. Fungi. 74 COMPARATIVE MORPHOLOGY OF FUNGI ally fill up the whole host cell like a knot. Biologically, from the simpler to the higher forms, there is an increased adaptation to parasitism. Pythium and Phytophthora kill the infected tissue, Albugo and Perono- spora only stimulate it to hypertrophy or to storage of food. Some species of both these genera winter over in the rhizomes of the host and penetrate the whole shoot. Some species of Peronospora in flowers seem to grow up the stem as intercellular parasites and only develop their conidiophores on the corol
RMREFCNN–. Comparative morphology and biology of the fungi, mycetozoa and bacteria. Fungi -- Morphology; Bacteria -- Morphology. CHAP. II.—DIFFERENTIATION OF THE THALIUS.—SIMPLE SPOROPHORES. 4J. FIG. 20. Phytophtkora infestans, extremity of two simple sporophores. a forma- tion of the first gonidia on the tip of each branch, b two ripe gonidia on each branch, with the beginning of the formation of a third. Magn. about 200 times. put out branches bearing new sporangia. There is here therefore a cymose branching of the sporangiophores. The gonidiophores in Peronospora, which are also without transverse s
RMRDD1MG–. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. iia DIVISION I.—GENERAL MORPHOLOOr. A more noteworthy special case which recalls the formation of swarm-spores is that of the germination of the acrogenously formed spores (gonidia) of the plasmato- parous Peronosporeae (Peronospora densa, Rab. and P. pygmaea, Unger); here when a spore is placed in water the whole of the protoplasm suddenly swells and issues from the papilla-like tip of the spore which opens to admit its passage, and assumes the form of a spherical bo
RMRDXNPK–. Botany of the living plant. Botany. Fio. 357. Fertilisation of thie Peronosporeae. I. Peronospora parasitica, young multi- nucleate oogonium {og), and antheridium {an). 2. Albtigo Candida. Oogonium witli the central, uni-nucleate egg {os), and the fertiUsing tube (a) of the antheridium which introduces the male nucleus. 3. The same. The fertilised egg (0) surrounded by periplasm ip). (After Wager, x 6G6.) {From Strasburger.) such an antheridium as is seen in Vaitcheria into the polHnodium of the Peronosporeae, is acomparativelyshght one: the latter does not hberate. I'lo. 358. MonobtepJiaris
RMREFCAB–. Comparative morphology and biology of the fungi, mycetozoa and bacteria. Fungi -- Morphology; Bacteria -- Morphology. I I 2 DIVISION I. GENERAL M< ilil'lIOLOGV. A more noteworthy special case which recalls the formation of swarm-spores is that of the germination of the acrogenously formed spores (gonidia) of the plasmato- parous Peronosporeac (Peronospora densa, Rab. and P. pygmaea, Unger); here when a spore is placed in water the whole of the protoplasm suddenly swells and issues from the papilla-like tip of the spore which opens to admit its passage, and assumes the form of a spherical
RMRDD1TY–. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. 72 DIVISION I.—GENERAL MORPHOLOGY. one belonging to the sixth youngest spore in the chain. Phenomena essentially the same occur in other species of the Uredineae, but with considerable variations in form in the different species'. Where filiform sporophores rise free into the air, a further mechanical arrange- ment is found which greatly assists the shedding and scattering of the abscised spores. It may be readily observed in the Hyphomycetes, in Peronospora, for exam
RMRDYG2W–. A textbook of botany for colleges and universities ... Botany. THALLOPHYTES 67 of zoospores, a feature which distinguishes the genus from Peronospora, under which the grape mildew was placed formerly. In the life history of Plasmo- para, therefore, zoospores, characteristic of Oomycetes, have been eliminated. This disease is of American origin and was unknown in Europe until American grape stocks were introduced as a protection against the destructive phylloxera. Peronospora. — These forms are very common parasites on ordinary vegetables, as peiis, beans, spinach, etc., and differ from Plasm
RMREFCG0–. Comparative morphology and biology of the fungi, mycetozoa and bacteria. Fungi -- Morphology; Bacteria -- Morphology. 7- DIVISIOX 1. -GENERAL MORPHOLOGY. one belonging to the sixth youngesl spine in the chain. Phenomena essentially the same occur in other species of the Uredineae, but with considerable variations in form in the different species1. Where filiform sporophores rise free into the air, a further mechanical arrange- ment is found which greatly assists the shedding and scattering of the abscised spores. It ma) be readily observed in the Hyphomycetess in Peronospora, for example, Ph
RMRDXT8W–. A manual of poisonous plants, chiefly of eastern North America, with brief notes on economic and medicinal plants, and numerous illustrations. Poisonous plants. EUTHALLEPHYTA—EUM YCETES—OOM YCETES 205 Many members of this group are destructive parasites to cultivated plants like the potato rot fungus {Phytopthora infestans), the onion mildew (Peron- ospora Schleideniana), the lettuce mildew {Bremia Lactucae), the mildew of the sunflower (Plasmopara Halstedii), the Clover mildew {Peronospora tri- fcliorum) which may be injurious to animals, the millet mildew (^Sclerospora gra,:.inicola) which
RMRE1JJK–. Plant studies; an elementary botany. Botany. JPt 'â Fig. 240. Peronospora, one of the Phycomycetes, ehowing at a an oogonium (o) con- taining an egg, and an antheridium (n) in contact; at o the antheridial tube pene- trating the oogonium and discharging the contents of the antheridium into the egg; at c the oogonium containing the oospore or resting spore.âAfter DeBaet.. In certain conditions special branches arise from the mycelium, which organize antheridia and oogonia, and remain within the host (Fig. 240). The oogonium is of the usual spherical form, organizing a single egg. The an-. Ple
RMRDGX69–. The diseases of crops and their remedies : a handbook of economic biology for farmers and students. Plant diseases. 52 DISEASES OF CROPS. 22) is examined beneath the microscope,^ the mycelium of the fungus will be seen ramifying among the cells of the leaf. "Wherever the mycelium comes in contact with the cells of the host-plant, they become discoloured. This is. Fig. 22.^PoTATO FcNans {Peronospora infestans). A to B. Transverse section of potato leaf, showing mycelium (spawn) of fungup. A. Lower surface with two stomata (C) and conidiophores passing tiirough them. D. Conidium (spore).
RMRJ6M1G–. Grasses of North America [microform] : chapters on the physiology, composition, selection, improving and cultivation of grasses, management of grass lands, also chapters on clovers, injurious insects and fungi. Grasses; Forage plants; Graminées; Plantes fourragères. 480 CLOVER PERONOSPORA. SEEDLING ROT. 13. Clover poronospora, {Peronospora irifoUorum, DeBary). A dirty white or purple-brown mold, often completely covering the lower surface of the leaves of clover, alfalfa, none-such, etc. (See Fig. 175.) The life history of this species is quite similar to that of the last, though they differ
RMRE0C83–. Experimental morphology. Protoplasm; Growth. 420 EFFECT OF LIGHT [Ch. xvn observers in the early half of the century, and, more recently, NoBBE ('82), Adrianowsky ('83), and others, have shown that germination of seeds takes place slightly earlier in the dark than in daylight. Among fungi, also, we have the assur- ances of Hoffmann ('60, p. 321) that the spores of the mush- room Agaricus campestris germinate more slowly in the light; and of DE Baey ('63, p. 40) that the spores of the potato fungus, Peronospora infestans, and its allies do germinate with difficulty in the daylight, and not at
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