Variation in Phenol Content of Sorghum Lines after Inoculation with Colletotrichum graminicola

Phenolic compounds accumulate in numerous plant species following infection by plant pathogens (Kuk 1972). Many of such compounds, or their oxidation products are toxic to pathogenic and non-pathogenic fungi, and have been considered an important factor in induced resistance to plant pathogens. The variation in phenol content following infection with Colletotrichum graminicola, the causal fungus of anthracnose of sorghum was studied using six sorghum lines, resistant (A 2267-2, IRAT204); moderately resistant (IS 3758, IS 8354); and susceptible (IS 3089, IS 18442) to anthracnose. The lines were selected based on their disease reactions in the International Sorghum Anthracnose Virulence Nursery conducted at 10-12 locations in India and Africa during 1992 and 1993. Plants of each genotype were grown in 13-cm square plastic pots in a Vertisol mix (Vertisol, farmyard manure, and sand, 2:1:1 by volume, steam sterilized at 105°C) in a greenhouse at ICRISAT-Patancheru