Submitted to: Biennial Grain Sorghum Research and Utilization Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 16, 2003
Publication Date: N/A
Technical Abstract: Three hundred sorghum accessions from the Sudanese germplasm collection were screened for resistance against Colletotrichum sublineolum, causal agent of sorghum anthracnose. Evaluations were conducted during the 2002 growing season in Texas and Puerto Rico using an augmented (replicated control) experimental design. Field inoculations were conducted 30 days after planting by placing C. sublineolum colonized grain into plant whorls in the Texas experiment and infected leaf material for the Puerto Rico experiment. A total of 137 accessions exhibited highly resistant response while 47 accessions exhibited susceptible response at both locations. Variation in the disease response between locations was observed for 82 accessions. Sixty-one accessions that showed resistant reactions in Puerto Rico exhibited susceptible reactions in Texas. While 21 accessions that were resistant in Texas exhibited susceptible reactions in Puerto Rico. These results indicate the existence of different pathotypes or ecotypes of the pathogen at the two locations. Isolates of the pathogen from the two locations will be evaluated to determine the different pathotypes.