A survey of anthracnose resistant sorghum germplasm lines to identify additional resistance genes

Abstract

Anthracnose, caused by the fungus Colletotrichiim gtaminicola (Ces.) Wils,, is one of the most common. and destructive diseases of Sorghum bicolor (L.) Moench in the warm, humid regions of the world. Breeding for stable host plant resistance has been challenged by the variable nature of the pathogen and an incomplete understanding of the host/pathogen interaction. To develop new and possibly more stable forms of resistance, different sources of genetic resistance must be identified and their inheritance characterized. The objectives of this study were (1) to determine if different sources of genetic resistance exist among a selected set of 13 resistant sorghum germplasm lines, and (2) to determine the inheritance of the different resistance genes identified among the 13 resistant germplasm lines. Inoculated field studies were conducted in 1996 and 1997 at College Station, TX. Four different sources of genetic resistance were identified among the 13 resistant sorghum germplasm lines. A single dominant gene was identified in each of two sources, and a third source was identified as a single recessive gene.