There is a single class, Oomycetes, which is further divided into 7 orders. We shall study some genera belonging to the orders Saprolegniales, Pythiales and Peronosporales. Order Saprolegniales (Water Molds): The term 'water molds' is generally used for genera belonging to this order. The zoospores are formed in zoosporangia. A peculiar feature of this order is the production of two [...]
In this article we will discuss about the characteristics and classification of peronosporales. General Characteristics of Peronosporales: The order is represented by 12 genera and about 325 species. In habit they range from aquatic to the terrestrial ones through the species with amphibious way of life. Many of the terrestrial species are highly specialized obligate plant parasites which cause serious [...]
In this article we will discuss about the life cycle of saprolegnia with the help of suitable diagrams. Mycelium of Saprolegnia (Fig. 6.2 A): The mycelium is coenocytic and branched. During the vegetative phase it is composed of two kinds of hyphae: (i) Rhizoidal or intramatrical hyphae: These are short hyphae which penetrate the substratum. They anchor the mycelium and [...]