Effect of Wild Abortive and ARC Sources of Male Sterile Cytoplasms on Yield and Yield Components of Rice Hybrids

摘要

Thirty- two aF_1 and thirty- two bF_1 rice hybrids were evaluated in two seasons to study the effects of wild abortive and ARC sources of male sterile cytoplasms on grain yield and yield components. The study indicated that in general, sterile cytoplasm exerted more negative effects on plant height and spikelet fertility percent, while positive effects were predominant on panicle length, 1000-grain weight and harvest index. Eleven aF_1 hybrids viz., IR62829Ax Samba Mahsuri, IR62829Ax IR46, IR62829AXWGL3962, IR58025AX Vajram, IR58025A X Samba Mahsuri, IR67683A X Vajram, IR67683A X Samba Mahsuri, IR67683A X IR64, IR67683A X Vijetha, |R67683A X WGL3962 and APMSlA X WGL3962 consistently showed superiority for yield and yield components when compared totheir fertile counterparts. Wild abortive cytoplasm induced more positive effects on yield and yield components even though it had sporophytic male sterility system. The negative effects of gametophytic male sterility system (ARC) are stronger than thatof sporophytic male sterility system (wild abortive) and this may be attributed to the availability of high frequency of restorer lines to CMS lines of WA cytoplasm. The cytoplasmic effects were found to be cross specific and can be improved through appropriate selection of parents. The negative effects of sterility inducing cytoplasm are only relative when the combination has high combining and restoring ability as observed in APMS1A X WGL3962. Among the three CMS lines of wild abortive cytoplasm, IR67683A was found to be promising as it showed pronounced positive effects on yield and yield components.