Gamma ray induced genetic improvement of sorghum landraces for grain yield and charcoal rot tolerance

Abstract

Sorghum is an important cereal crop used for food, livestock feed and biofuel. In order to improve rabi sorghum (post-rainy season), which are mainly used for human consumption, physical and chemical mutagens are used to create genetic variability for quantitative traits. Two advanced sorghum mutant populations, TJP 1-5 and TC-2 were subjected to gamma ray irradiation (300 Gy) and treated with 0.2% EMS. Selections were carried out for grain yield and charcoal rot tolerance from M2 generation onwards along with check varieties. In M3 generation, 300 mutant lines were selected and screened for charcoal rot disease using tooth pick method. Based on the field screening, TCM-38, TCM-95, TJM-6-1 and TJM-35 showed less sclerotial growth (1.92, 2.08, 1.92 and 1.61 nodes crossed respectively) with high grain yield. Among all the mutants screened, TJM-35 had least mean length of fungal growth (13.47 cm) which translated into less lodging (21.74%) and better grain yield (2583 kg/ha) compared to check. Wide genetic variability was created for grain yield (354-2874 Kg/ha as against SPV-86 check, 1499 kg/ha) with mean value of 1833 Kg/ha). Among all the mutants studied, TJM-35, TJM 6-1 and TCM-95 were not only high yielding but also possess tolerance to charcoal rot disease.

Keywords

• induced mutations
• gamma rays
• sorghum landraces
• charcoal rot
• grain yield