Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China (Co-Construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China.
Int J Mol Sci. 2023 Aug 3;24(15):12395. doi: 10.3390/ijms241512395.
Hybrid rice breeding is an important strategy for enhancing grain yield. Breeding high-performance parental lines and identifying combining abilities is a top priority for hybrid breeding. Yuenongsimiao (YNSM) and its derivative variety Yuehesimiao (YHSM) are elite restorer lines with a high ability of fertility restoration, from which 67 derived hybrid combinations have been authorized to different degrees in more than 110 instances in China. In this study, we found that YNSM and YHSM contained three candidate restorer-of-fertility () genes, , , and /, that might confer their restoration ability. Subsequently, we investigated heterosis and combining ability of YNSM and YHSM using 50 F hybrids from a 5 × 10 incomplete 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 on the number of grains per panicle (NGP), NSP, PL, and 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, YNSM and YHSM exhibited negative GCA effects on PH, implying that YNSM and YHSM could effectively enhance plant lodging resistance by reducing the 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 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.
杂交水稻育种是提高粮食产量的重要策略。培育高性能的亲本系和鉴定组合能力是杂交育种的首要任务。Yuenongsimiao（YNSM）及其衍生品种 Yuehesimiao（YHSM）是具有高育性恢复能力的优良恢复系，从这两个品种中衍生出的 67 个杂交组合在中国已获得不同程度的授权，涉及 110 多个实例。在本研究中，我们发现 YNSM 和 YHSM 包含三个候选育性恢复基因、、和/，它们可能赋予了它们的恢复能力。随后，我们使用 50 个来自 5×10 不完全双列交配设计的 F1 杂种，研究了 YNSM 和 YHSM 的杂种优势和组合能力。我们的结果表明，杂交组合表现出显著的遗传差异，亲本基因的加性效应在观察性状的遗传中起主导作用。株高（PH）、千粒重（TGW）、穗长（PL）和每穗小穗数（NSP）的度量主要受遗传影响，具有较高的遗传力。值得注意的是，YHSM 的一般配合力（GCA）对每穗粒数（NGP）、NSP、PL 和 TGW 的影响最大。因此，YHSM 对单株产量（YPP）的 GCA 效应最大。此外，YNSM 的 GCA 对 YPP 有正向影响，主要是因为结实率（SSP）的关键贡献。此外，YNSM 和 YHSM 对 PH 表现出负的 GCA 效应，这意味着 YNSM 和 YHSM 可以通过降低衍生杂种的株高来有效提高植株抗倒伏能力。值得注意的是，在这些杂种中，Yuanxiang A/YNSM（YXA/YNSM）、Shen 08S/Yuemeizhan（S08S/YMZ）和 Quan 9311A/YHSM（Q9311A/YHSM）代表了具有更高的特定配合力（SCA）效应值的有前途的新组合，对 YPP 的 SCA 效应值超过 3.50。因此，我们的研究强调了合理利用 YNSM 和 YHSM 在杂交水稻育种中的应用前景。
