Huang Xuehui, Yang Shihua, Gong Junyi, Zhao Yan, Feng Qi, Gong Hao, Li Wenjun, Zhan Qilin, Cheng Benyi, Xia Junhui, Chen Neng, Hao Zhongna, Liu Kunyan, Zhu Chuanrang, Huang Tao, Zhao Qiang, Zhang Lei, Fan Danlin, Zhou Congcong, Lu Yiqi, Weng Qijun, Wang Zi-Xuan, Li Jiayang, Han Bin
National Center for Gene Research, Collaborative Innovation Center for Genetics and Development, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200233, China.
State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China.
Nat Commun. 2015 Feb 5;6:6258. doi: 10.1038/ncomms7258.
Exploitation of heterosis is one of the most important applications of genetics in agriculture. However, the genetic mechanisms of heterosis are only partly understood, and a global view of heterosis from a representative number of hybrid combinations is lacking. Here we develop an integrated genomic approach to construct a genome map for 1,495 elite hybrid rice varieties and their inbred parental lines. We investigate 38 agronomic traits and identify 130 associated loci. In-depth analyses of the effects of heterozygous genotypes reveal that there are only a few loci with strong overdominance effects in hybrids, but a strong correlation is observed between the yield and the number of superior alleles. While most parental inbred lines have only a small number of superior alleles, high-yielding hybrid varieties have several. We conclude that the accumulation of numerous rare superior alleles with positive dominance is an important contributor to the heterotic phenomena.
杂种优势的利用是遗传学在农业中最重要的应用之一。然而，杂种优势的遗传机制仅得到部分理解，且缺乏来自代表性数量杂交组合的杂种优势全局观点。在此，我们开发了一种综合基因组方法，为1495个优良杂交水稻品种及其自交亲本系构建基因组图谱。我们研究了38个农艺性状并鉴定出130个相关位点。对杂合基因型效应的深入分析表明，杂种中仅有少数位点具有强超显性效应，但产量与优良等位基因数量之间存在强相关性。虽然大多数亲本自交系仅有少量优良等位基因，但高产杂交品种有多个。我们得出结论，大量具有正向显性的稀有优良等位基因的积累是杂种优势现象的重要促成因素。
