CERCOSPORA - CLASSIFICATION, VEGETATIVE STRUCTURE, REPRODUCTION

CERCOSPORA - CLASSIFICATION, VEGETATIVE STRUCTURE, REPRODUCTION

A.CLASSIFICATION 

Division - Mycotina

Sub-Division - Eumycotina

Class - Deuteromycetes

Order - Moniliales

Genus - Cercospora

The genus Cercospora includes about 3800 species. Majority of the species are plant pathogens which cause leaf spot diseases of higher plants of economic value. Commonly the leaf spot diseases is called the Tikka diseases.


C.personata and C.arachidicola are of two commonly know form species which is responsible for the leaf spot disesase of groundnut. 

B.STRUCTURE OF THE VAGETATIVE BODY 

The Mycelium in many species is entirely internal. The byphae ramify in the intercellular spaces between the mesophyll cells of the host leaf obtaining  nutrition by sending branched haustoria into the spongy and palisade cells. In some form species (C.arachidicola) the Mycelium consists of both internal end external hyphae.


The letter in the beginning are intercellular but later on become intracellular. They do not produce haustoria. Before the Mycelium enters the reproductive phase, the hyphae accumulate and become compacted to farm brown to black globular mass of hyphae, the stroma immediately beneath the Epidermis of the host leaf in a sub stomatal cavity. 

Source Wikipedia

C.REPRODUCTION

The perfect stage of Cercospora is rare. However, perfect stage observed in Cercospora personata and Cercospora archidicola. It is microsphaerella berkleyi in the former.

Reproduction takes place by means of long, Cylindrical, usually hyaline, multiseptate conidia, which are produced at the tip of un-branched, dark conidiophores. The later arise in fruits from a stroma lying in a sub stomatal cavity and emerge by rupturing the overlying Epidermis. The conidiophores are geniculate (knee-jointed) and 1-2 septate. The conidium, as it fall off leaves a scar on the conidiophore.