Investigations into cultural variability of grapevine anthracnose pathogens in southern peninsular India

Anthracnose of grapevine or "bird's eye spot" caused by Elsinoe ampelina (de Bary) Shear has been found to involve three fungal pathogens in asexual forms viz, Sphaceloma ampelinum, Gloeosporium ampelophagum and Colletotrichum gloeosporioides isolated from different grape growing tracts of northern Karnataka, Maharashtra, and Andhra Pradesh. The in-vitro investigations into cultural variability carried out at Horticulture Research Station (Tidagundi), Bijapur, during 2006–07 revealed considerable variability among these incitants of grapevine anthracnose. Morphologically six groups were identified based on the colony characters on Sabouraud's agar. The isolates belonging to G-I and II were predominant (68.0% frequency) producing vigourous growth with circular, creamy white floccmlent smooth colonies. G. ampelophagum isolates were found more aggressive as compared to S. ampelinum and c. gloeosporioides. Host extract medium among liquid media supported maximum growth of Colletotrichum gloeosporioides (0.277g) responding weakly as compared to Gloeosporium ampelophagum (0.358g) and Sphaceloma ampelinum (0.397g).