Song XuanChen, Yang Ying, Pu QiuHong, Zhou JiaWu, Lv YongGang, Jiang Xiaohan, Li Jing, Deng XianNeng, Tao DaYun, Zhang Yu
Yunnan Seed Laboratory/Yunnan Key Laboratory for Rice Genetic Improvement, Food Crops Research Institute, Yunnan Academy of Agricultural Sciences (YAAS), Kunming, 650200, China.
College of Agriculture, Yunnan University, Kunming, 650504, China.
Sci Rep. 2025 Apr 19;15(1):13536. doi: 10.1038/s41598-025-98008-w.
Oryza. sativa subsp. indica, a subspecies of Asian cultivated rice, plays a crucial role in global rice production, particularly in the utilization of hybrid vigor. However, the genetic basis of hybrid sterility among indica-indica intrasubspecific hybrids remains elusive, hindering the effective exploitation of heterosis in rice breeding programs. In this study, a near isogenic line (NIL) was developed using the indica variety Swarna as the donor parent and the indica variety IR64 as the recurrent parent. A novel locus, designated S68, responsible for intrasubspecific hybrid sterility was mapped to the region between RM14247 and RM3413 on the short arm of chromosome 3, spanning approximately 190 kb. S68 followed one-locus allelic interaction model. In IR64/NIL-S68 hybrids, the gametes from IR64 exhibit a transmission advantage, while those from Swarna are aborted in the heterozygote. This is the first hybrid sterile locus identified in indica-indica intrasubspecific hybrids, which enhances our understanding of the genetic mechanisms underlying intrasubspecific hybrid sterility and the genetic divergence within indica rice, thereby providing guidance for hybrid breeding programs within the indica subspecies.
亚洲栽培稻的一个亚种——籼稻，在全球水稻生产中发挥着关键作用，尤其是在杂种优势的利用方面。然而，籼稻亚种内杂种不育的遗传基础仍不清楚，这阻碍了水稻育种计划中杂种优势的有效利用。在本研究中，以籼稻品种Swarna为供体亲本、籼稻品种IR64为轮回亲本培育了一个近等基因系（NIL）。一个负责亚种内杂种不育的新位点，命名为S68，被定位到第3号染色体短臂上RM14247和RM3413之间的区域，跨度约为190 kb。S68遵循单位点等位基因互作模型。在IR64/NIL-S68杂种中，来自IR64的配子表现出传递优势，而来自Swarna的配子在杂合子中败育。这是在籼稻亚种内杂种中鉴定出的第一个杂种不育位点，它增进了我们对亚种内杂种不育遗传机制以及籼稻遗传分化的理解，从而为籼稻亚种内的杂交育种计划提供指导。
