Combining Ability Analysis of Yield-Related Traits of Two EliteRice Restorer Lines in Chinese Hybrid Rice
Shiguang Wang†, Haoxiang Wu , Zhanhua Lu, Wei Liu, Xiaofei Wang, Zhiqiang Fang and Xiuying He*
International Journal 必威betways of Molecular Sciences
Abstract
Hybrid rice breeding is an important strategy for enhancing grain yield. Breeding highperformance parental lines and identifying combining abilities is a 必威betway中文版入口 top priority for hybrid breeding. Yuenongsimiao (YNSM) and its derivative variety Yuehesimiao (YHSM) are elite 必威betway中文版入口 restorer lines with a high ability of fertility restoration, from which 67 必威betway中文版入口 derived hybrid combinations have been authorized to different degrees in more than 必威betways 110 必威betway中文版入口 instances in China. In this study, we found that YNSM and YHSM contained three candidate restorer-of-fertility (Rf ) genes, Rf3, Rf4, and Rf5/Rf1a, that might confer their restoration ability. Subsequently, we investigated heterosis and combining ability of YNSM and YHSM using 50 必威betways F1 hybrids from a 5 10 incomplete 必威betways diallelic mating design. Our results indicated that hybrid combinations exhibited significant genetic differences, and the additive effects of the parental genes played a preponderant role in the inheritance of observed traits. The metrics of plant height (PH), 1000-grain weight (TGW), panicle length (PL), and the number of spikelets per panicle (NSP) were mainly affected by genetic inheritance with higher heritability. Notably, the general combining ability (GCA) of YHSM exhibited the largest positive effect 必威betway中文版入口 on the number of grains per panicle (NGP), NSP, PL, and 必威betways TGW. Thus, YHSM had the largest GCA effect on yield per plant (YPP). In addition, the GCA of YNSM exhibited a positive impact on YPP, mainly due to the critical contribution of seed setting percentage (SSP). Moreover, 必威betway中文版入口 YNSM and YHSM exhibited negative GCA effects on PH, implying that YNSM and YHSM could effectively enhance plant lodging resistance by reducing the 必威betway中文版入口 plant height of the derived hybrids. Remarkably, among the hybrids, Yuanxiang A/YNSM (YXA/YNSM), Shen 08S/Yuemeizhan (S08S/YMZ), and Quan 9311A/YHSM (Q9311A/YHSM) represent promising new 必威betway中文版入口 combinations with a higher specific combining ability (SCA) effect value on YPP with a value more than 3.50. Our research thus highlights the promising application for the rational utilization of YNSM and YHSM in hybrid rice breeding.
Keyeords:hybrid rice; Yuenongsimiao; restorer of fertility; GCA; SCA
