Part 3: Fungi - Orchids-World

<strong>Part</strong> 3: <strong>Fungi</strong><br />

WORK IN PROGRESS<br />

<strong>Fungi</strong> are members of a very large group of eukaryotic organisms and have cell<br />

walls that contain chitin and not cellulose like the cell walls of plants. Please, for<br />

details check your online encyclopedia.<br />

Most fungi have a symbiotic relationship with other life forms, some are mutualistic,<br />

some are antagonistic and some show no advantages or disadvantages to the host.<br />

Many fungi compete for nutrients and space with bacteria or other fungi. These<br />

fungi are capable of wipe out or restrain the growth of harmful pests such as insects,<br />

mites, nematodes, other fungi, etc. that may cause diseases. <strong>Fungi</strong> are commonly<br />

used in biological control of agricultural pests.<br />

Entomo-pathogenic fungi are used as bio-pesticides as they actively kill insects.<br />

Fungal diseases can be controlled through the use of fungicides; however, overusing<br />

fungicides may result in the creation of new fungi strains that are resistant to<br />

fungicides.<br />

Of special interest to orchid growers are the mycorrhizal fungi. The mycorrhizal fungi<br />

are recognized by their branching growth pattern as Endomycorrhizal, Arbuscular<br />

mycorrhizae (AM) or Vesicular arbuscular mycorrhizae (VAM)". The symbiosis<br />

between orchid plants and mycorrhizal fungi is well known and significant.<br />

WHY?<br />

<strong>Orchids</strong> produce very small seeds that have limited reserves of nutrients. After<br />

germination, mycorrhyzal fungi help the "embryos" and later the adult plants, to<br />

increase their uptake of carbon and inorganic compounds (nutrients), such as<br />

nitrates and phosphates from soils with low concentrations of these nutrients. The<br />

mycorrhizal fungi invade the roots, grow within cells and form protective "coils" that<br />

have a limited life. When dead, the coils degenerate and leave behind nutrients for<br />

the orchids to absorb. Host orchid plants allow this to happen.

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Table 1: The Best known <strong>Fungi</strong> that cause fungal diseases on orchids.<br />

Aecidium graebnerianum<br />

Alternaria spp.<br />

Bloom Shoot Necrosis; Blossom Flecks;<br />

Bipolaris setariae<br />

Blossom Flecks<br />

Bipolaris sorokiniana<br />

Blossom Flecks<br />

Bipolaris spp<br />

Blossom Flecks<br />

Botryodiplodia oncidii<br />

Dieback<br />

Botryotinia fuckeliana<br />

Gray Mold<br />

Floral Spot; Floral Blight; Petal Blight;<br />

Botrytis cinerea<br />

Soft Rot;<br />

Capnodium citri<br />

Sooty Mold<br />

Cephaleuros virescens<br />

Algal Spot<br />

Cercospora angreci<br />

Leaf Spot<br />

Cercospora cypripedii<br />

Fungal Leaf Spot<br />

Cercospora dendrobii<br />

Fungal Leaf Spot<br />

Cercospora epipactitis<br />

Fungal Leaf Spot<br />

Cercospora odontoglossi<br />

Fungal Leaf Spot<br />

Cercospora peristeriae<br />

Fungal Leaf Spot<br />

Chaetodiplodia sp.<br />

Leaf Spot<br />

Colletotrichum bletae<br />

Anthracnose (Bletia)<br />

Colletotrichum coccodes<br />

Anthracnose<br />

Colletotrichum crassipes<br />

Anthracnose<br />

Colletotrichum dicheae<br />

Anthracnose<br />

Colletotrichum gloeosporioides<br />

Anthracnose<br />

Colletotrichum orchidearum<br />

Anthracnose<br />

Colletotrichum roseolum<br />

Anthracnose (Bletia)<br />

Coniothyrium sp.<br />

Leaf Spot<br />

Corynespora cassiicola<br />

Leaf Spot<br />

Curvularia sp.<br />

Leaf Necrosis<br />

Diplodia bulbicola<br />

Leaf Spot<br />

Diplodia laelio-cattleyae<br />

Leaf Spot; Stem decay;<br />

Diplodia paraphysaria<br />

Leaf Spot<br />

Diplodia sobrali<br />

Leaf Spot<br />

Fusarium cattleyae<br />

Fusarium Wilt<br />

Fusarium moniliforme<br />

Soft Rot;<br />

Fusarium oxysporum<br />

Pseudobulb Rot; Root Rot<br />

Fusarium oxysporum f. Sp. Cattleyae Pseudobulb Rot; Root Rot<br />

Gloeodes pomigena<br />

Sooty Blotch<br />

Gloeosporium affine<br />

Anthracnose European<br />

Gloeosporium cattleyae<br />

Anthracnose<br />

Gloeosporium epidendrii<br />

Anthracnose<br />

Gloeosporium laeliae<br />

Anthracnose<br />

Gloeosporium oncidii<br />

Anthracnose<br />

Gloeosporium pallidum<br />

Anthracnose<br />

Gloeosporium stanhopeae<br />

Anthracnose<br />

Gloesporioides<br />

Anthracnose<br />

Glomerella cincta<br />

Leaf Die-Back (American Anthracnose)

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Glomerella cingulata<br />

Guignardia spp.<br />

Hemileia oncidii<br />

Lasiodiplodia theobromae<br />

Macrophoma cattleyicola<br />

Macrophoma oncidii<br />

Nectria behnickiana<br />

Nectria bolbophyli<br />

Nectria bulbicola<br />

Phoma spp.<br />

Phyllosticta capitalensis<br />

Phyllosticta pyriformis<br />

Phyllostictina pyriformis<br />

Physalospora cattleyae<br />

Physalospora orchidearum<br />

Phytophthora cactorum<br />

Phytophthora cinnamomi<br />

Phytophthora nicotianae<br />

Phytophthora palmivora<br />

Pleospora orchidearum<br />

Pseudocercospora spp.<br />

Puccinia cypripedii<br />

Pythium splendens<br />

Pythium ultimum<br />

Rhizoctonia solani<br />

Schizothyrium perexiguum<br />

Schizothyrium pomi<br />

Sclerotinia fuckeliana<br />

Sclerotium orchidearum<br />

Sclerotium rolfsii<br />

Septoria selenophomoides<br />

Sphenospora kevorkianii<br />

Sphenospora mera<br />

Sphenospora saphena<br />

Stibella bulbicola<br />

Tubercularia cattleyicola<br />

Uredo behnickiana<br />

Uredo epidendri<br />

Uredo guacae<br />

Uredo nigropuncta<br />

Volutella albido-pila<br />

Volutella Concentrica<br />

Volutella pachysandra<br />

Zythia nepenthis<br />

Anthracnose<br />

Leaf Spot<br />

Rust<br />

Leaf blight<br />

Leaf<br />

Fungal<br />

Fungal<br />

Fungal<br />

Dry Rot<br />

Leaf Spot; Leaf Lesions; Chlorotic spots<br />

Yellow Leaf Spot<br />

Fungal Leaf Spot<br />

Anthracnose; Fungal Leaf Spot<br />

Anthracnose<br />

Black Rot; Leaf Rot; Crown Rot;<br />

Leaf & Pseudobulb Rot; Stem & Root<br />

Rot<br />

Leaf & Pseudobulb Rot; Stem & Root<br />

Rot<br />

Root Rot; Black Rot;<br />

Fungal<br />

Leaf & Heart Rot<br />

Black Rot; Leaf Rot; Crown Rot;<br />

Root Rot; Stem Rot<br />

Flyspeck<br />

Flyspeck<br />

Petal Blight<br />

Fungal<br />

Leaf Rot; Basal Rot; Stem Rot;<br />

Southern Blight;<br />

Leaf Spot; Stem Decay;<br />

Rust<br />

Rust<br />

Rust<br />

Rust<br />

Rust<br />

Rust<br />

Rust<br />

Fungal Stem Decay;<br />

Leaf Spot<br />

Volutella Blight