Study on Standard Heterosis for Yield, Quality and its Attributing Characters in Rice (Oryza sativa L.) Hybrids under Aerobic Cultivation

Field experiments were conducted for development and evaluation of aerobic rice hybrids during2015-16 to 2016-17 years. In the first experiment sufficient amount of variability was observed for grain yield per plant and its components among 125 genotypes evaluated in aerobic condition. Among these eight genotypes were the top ranking yield in aerobic conditions and good restorers tested by Test Cross Nursery and Rf3, Rf4 fertility restorer gene screening. Than 32 hybrids were produced involving 4 CMS lines (CMS23A, CMS59A, CMS64A and IR68897A) and 8 testers (SVHR-3005, NH-12-103R, KMP-128, MTU-1001, KMP-175, SV-315-081R, RNR-21280 and MTU-1075) and evaluated along with three checks (viz., hybrid check, KRH-2, inbred checks, MTU-1010, MAS-946) under aerobic situation and carryout standard heterosis analysis, to identify best heterotic hybrids over local checks. CMS23A x SV-315-081R manifested high heterotic effects (>20%) for grain yield per plant over the standard checks, besides for important components. Few more CMS59A x KMP-175, CMS59A x RNR-21280, CMS23A x MTU-1001, IR-68897A x MTU-1075 and CMS23A x MTU-1075 were also identified as potential hybrids in view of higher amount of heterosis. For quality, CMS64A x RNR-21280 (hulling percentage, milling percentage, head rice recovery and kernel elongation ratio) and CMS23A x SV-315-081R (head rice recovery, kernel length, L/B ratio and Kernel length after cooking) were best heterotic hybrids. Two crosses viz., CMS59A x SVHR-3005 and CMS64A x SVHR-3005 expressed negative heterosis for kernel breadth and positive heterosis for kernel L/B ratio which was desirable.