Characterization of grain mold resistant sorghum germplasm accessions for physio-morphological traits

One hundred and fifty-six sorghum germplasm accessions that were identified resistant to grain mold in 1988 were reevaluated during the 2006 and 2007 rainy seasons in grain mold nursery at ICRISAT, Patancheru, India to confirm their resistance and characterize them for various physio-morphological traits that are likely to be associated with grain mold resistance. The visual panicle grain mold rating (PGMR) of the 156 test accessions varied from 1 to 3.5 (on a 1–9 scale) compared to 8.5 to 9.0 of the susceptible checks. During the 2006 screen, of the 156 test accessions, 19 were highly resistant (1.0 score), 134 resistant (1.1 to 3.0 score) and 3 moderately resistant (3.1–3.5 score). These accessions varied for various traits, such as time to 50% flowering (47 to 86 days), plant height (90 to 375 cm), panicle type (loose to compact), glumes coverage of grains (25 to 75%), glumes color (straw to black) and grain color (white to dark brown). Of 69 single-plant selections, from as many agronomically desirable grain mold resistant accessions, screened during 2007, two were highly resistant and the remaining 67 were resistant. Some of these lines that have desirable agronomic traits could be preferred for utilization in grain mold resistance breeding