Dr. Sristisri Upadhyaya DEUTEROMYCETES Dr. Sristisri Upadhyaya Assistant Professor Dept. of Botany Mangaldai College Darrang-784125, Assam

“Deuteron” – secondary or second Deuteromycetes “Deuteron” – secondary or second - Also known as Fungi inperfecti or Imperfect fungi or Anamorphic fungi - The sexual stage/perfect stage is unknown. - Only the asexual or imperfect stage is known. - Sexual stage is either non-existant or has not been discovered. - Life cycle is thus incompletely known. - Many of them live as saprophytes and many more as parasites.

-Parasitic deuteromycetes are the causative agents of diseases of plants and animals including man, some cause spoilage of stored products. –Mycelium is septate and profusely branched septate. –Reproduction chiefly by conidia; also reported oidia and chlamydospore.

Some special structure found in Deuteromycetes Synnema: In some Deuteromycetes the branched or unbranched conidiophores arise very close to each other and are often united along a grater part of their length to form dense fascicles. This type of arrangement of conidiophore is called synnema. Sporodochium: It is a hemispherical or barrel shaped asexual fruiting body of some deuteromycetes. The upper part of this structure is the conidiophores and the lower part is a cushioned stroma like mass of hyphae.

Picnidium: It is a flask shaped structure which consisting of the cavity, the wall and the fertile layer (consists of short conidiophores). Acervulus: It is a saucer shaped structure consisting of stromatic mass of hyphae and a fertile layer of conidiophore.

Deuteromycetes is divided into four form orders- Moniliales Sphaeropsidales Melanconiales Mycelia sterilia Example of form genus- Fusarium, Alternaria, Cercospora, Colletotrichum.

Cercospora There are about 3,800 form species according to Chupp, 1953. Majority cause leaf spot diseases of higher plants . Eg. Leaf spot (tikka) disease of groundnut (Arachis hypogea) by C. personata and C. arachidicola. Mycelium: Entirely internal in some species, but in some species consists of both external and internal hyphae. Hyphae ramify in the intercellular spaces between the mesophyll cells of the host leaf obtaining nutrition by sending branced haustoria into the spongy and palisade cells.

Asexual reproduction takes place by means of long, cylindrical usually hyaline, multiseptate conidia. The conidiophore arise in tufts from a stroma. The conidiophore are geniculate.

Collectotrichum The mycelium is internal, branched and septate. The hyphae are both intercellular and intracellular. The conidia form singly, sometimes in chains at the tips of conidiophores. The conidiophores are unseptate and usually unbranched. Terminal or intercalary thick walled chlamydospores are formed by septation of hyphae.

The acervuli are characterised by the presence of long, rigid, dark brown bristles or setae. The setae are septate. Number of species cause serious diseases of plants. Eg. Red rot of sugarcane disease caused by Colletotrichum falcatum, Ripe fruit rot and die back of chillies caused by C. capsici.

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