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Asian Journal of Agriculture and Development (AJAD) - Call for papers!

Phytophthora Fruit Rot of eggplant

(Thailand), Master of Science (University of the Philippines Los Baños)

Thesis Abstract:

 

The study was conducted to re-evaluate the identity of Phytophthora  species causing fruit rot of eggplant in the Philippines, to ascertain the role of the zoospores of P. parestica  in infection, and to determine the mode of penetration and histopathological development of fungus in eggplan fruit.

Four isolates Phytophthora  eggplant fruit rot were found identical with P. parestica   (Dastur) Waterhouse.

Chalmydosphores were not produced on oatmeal agar nor in water. No oogania nor oospores were formed on oatmeal agar, potato dextrose broth culture, infected eggplant fruits. Nor in pairings between the different isolates in hemp seed broth.

Zoospores of P. parestica   showed chemotaxis but not chemotropism in susceptible eggplant like the Dumaguete strain. More spores and longer sperm germ tubes were formed by zooperes that encysted near the fruit. Fruit extract stimulated zoospores germination, but germination was less at concentrations above 5% and completely inhibited at 30% and above.

Zoopores germinated on the Dumaguete strain fruits after 25 minutes and penetrated the host after 2 hours, with the hyphal spreading intra and intercellurly. The fungus infected all tissues, expect the xylem vessels. In fruits of the Long Purple strain however, a corky layer was formed below the infected region showing a histological reaction defense reaction to infection by P. parestica .