Studies on combining ability of leaf blight (Exserohilum turcicum) resistance in sorghum (Sorghum bicolor (L.) Moench)

K. K. Durga, B. Reddy, M. S. S. Reddy, R. Bandyopadhyay, 'Studies on combining ability of leaf blight (Exserohilum turcicum) resistance in sorghum (Sorghum bicolor (L.) Moench)', International Journal of Tropical Plant Diseases, 19, 1-2, pp.83-95, 2005

Sorghum hybrids of 20 cytoplasmic-male steriles and six restorers and the parents were evaluated in 1996 and 1997 for leaf blight disease (caused by Exserohilum turcicum (Setosphaeria turcica)) resistance parameters (disease damage score, and length, width and area of the lesions, and number of lesions and flecks), and yield components (days to flower, plant height, agronomic desirability, grain yield plant, and test weight). Combining ability analysis revealed significant genetic variation among the parental lines and the hybrids for various characters studied. The significant line × tester mean squares indicated that the A-lines do not appear to behave consistently over different R-lines and vice versa. Specific combining ability (SCA) variances played an important role in the inheritance of various disease related characters and yield attributes. These results indicate that scope exists for producing superior hybrids with heterotic effects for these traits. The parents and the hybrids with significant favourable general combining ability (GCA) and SCA contributions for area of the lesion, number of lesions and number of flecks coupled with desirable mean performance are useful. The most desirable male-sterile lines having desirable effects for more than one disease resistance parameters and yield components were: MS 7, MS 9, MS 11 and MS 16 and the restorer R1. The hybrids, MS 16 and R1 and MS 15 × R6 were found desirable as they possessed desirable SCA effects for resistance in both years for more than one trait