Evaluation of Stay-Green QTL Introgression Lines for Drought Tolerance in Sorghum [<i>Sorghum bicolor</i> (L). Moench]

Abstract

Stay-green QTL introgression lines (plus the parents and checks) were evaluated during the 2004/05 and 2005/06 post-rainy sorghum cropping season at the International Crops Research Institute for the Semi Arid Tropics (ICRISAT), Patancheru, India. The staygreen introgression lines (BC2F2/BC1F3) were  field evaluated for their agronomic and stay-green related characters under well watered and water-stress conditions. The introgression lines had high  green leaf area (%) and chlorophyll content compared with the senescent lines showing the relationships among these traits. Moreover, many of the  introgression lines had grain yields statistically similar to grain yields of the recurrent parent (R16). The introgression lines such as RSG04001 were good  both in terms of green leaf area (%) and grain yield indicating the contribution of stay green to grain yield. This has also been evidenced by the highly  significant (R² = 0.47 in 2004/05 and R² = 0.77 in 2005/06) correlations of relative grain yield to relative green leaf area (%) in the moisture stress  environments. Overall, the results showed promise for utilization of the stay-green trait for better grain yield in drought-prone environments.