Heterosis in yield attributing and physiological traits of rice hybrids involving male sterile lines.

摘要

Twenty line tester rice hybrids were obtained by crossing 5 IRRI MS lines (23A, 29A, 86A, 88A and 97A) and 4 high yielding restorer cultivars (Heera, Lalat, Konark and Gouri) in an experiment conducted during the kharif season of 2000 in Orissa, India. The crosses showed high variation for physiological parameters such as leaf area index, specific leaf area, leaf area ratio, relative growth rate, net assimilation rate and crop growth rate. The extent of heterosis for physiological traits was high in crosses involving MS lines 97A and 29A, and testers Heera and Lalat. Among the 5 MS lines used for hybrid production, 97A and 29A showed higher heterosis than the others for the yield components. High heterosis (more than 15%) observed in the crosses 29A x Konark, 97A x Gouri, 29A x Lalat and 29A x Heera can be attributed to very high heterosis for relative growth rate and net assimilation rate, and moderate heterosis in leaf area index, specific leaf area, leaf area ratio, relative growth rate, panicle number/plant and panicle length..