Genetic variation of grain sorghum germplasm for resistance to Pseudomonas andropogonis

Pseudomonas andropogonis is the causal agent of bacterial leaf stripe of sorghum (Sorghum bicolor (L.) Moench). Fifty grain sorghum accessions were evaluated for genetic variation to P. andropogonis over a 2-year period. Plants were inoculated at the 7 to 8 leaf stage of juvenile growth with an Idico filler-plug gun calibrated to deliver one mi of inoculum. Disease severity ratings were noted 2 weeks after inoculation on a 0 to 5 scale. For 1993 and 1994, disease severity ratings were significantly different (P < 0.01) among accessions and groups of resistant, intermediate, and susceptible germplasm. Significant differences (P < 0.05) were also observed between years. Resistant accessions included SC326-6, SC414-12E, BTX378, B35-6, and TX2862. Susceptible entries included TX2767, TX430, TAM428, BTx623, R9117, and 90B2662.