亚热带生态所揭示东乡野生稻越冬耐寒性的遗传机制
剖析野生稻种群适应当地生态环境的机制将有利于培育出耐气候逆境的水稻品种。东乡野生稻是迄今为止生长纬度最北的野生稻，具有很强的耐寒性，能越冬再生。然而，迄今为止，依然不清楚它是如何进化出对寒冷环境的适应性，这限制了东乡野生稻在耐冷水稻分子育种中的利用。
为此，中国科学院亚热带农业生态研究所研究员陈彩艳领衔的研究团队结合数量性状遗传位点(QTL)作图和进化分析剖析东乡野生稻耐寒性的遗传机制。通过在两个东乡野生稻遗传群体中分别进行高通量SNP的区间作图和单标记分析，证实在东乡野生稻中至少存在13个QTL位点同时控制耐冷性。利用与耐冷QTL连锁的分子标记以及全基因组均匀分布的分子标记对多个野生稻和栽培稻进行进化分析，确定东乡野生稻与其他耐寒性强的野生稻与较耐低温的粳稻亚种具有较近的遗传距离，属于Or-III类野生稻;而耐寒性弱的野生稻与低温敏感的籼稻亚种有较近的遗传距离，属于Or-I类野生稻。此外，东野1号是利用东乡野生稻与栽培稻杂交选育出的第一个耐寒品种。通过对其进行全基因组的基因型鉴定，确定在东野1号种富集了多个东乡野生稻的耐寒位点，这证实了这些耐寒QTL的应用价值。因此，该研究全面阐述清楚东乡野生稻对高纬度地区低温环境适应性的遗传本质，所发掘的耐寒QTL位点将有助于耐冷水稻的分子育种。
上述成果以Multiple cold resistance loci confer the high cold tolerance adaptation of Dongxiang wild rice (Oryza rufipogon) to its high-latitude habitat 为题发表于国际期刊Theoretical Applied genetics(Mao et al. 2015. doi:10.1007/s00122-015-2511-3)。该研究得到了国家自然科学基金青年项目资助并顺利结题。后续工作正以东乡野生稻的最为主效的耐冷QTL为研究重点，在国家自然科学基金面上项目的资助下，开展该基因的图位克隆与功能分析。
原文链接：
Multiple cold resistance loci confer the high cold tolerance adaptation of Dongxiang wild rice (Oryza rufipogon) to its high-latitude habitat
原文摘要：
Understanding the nature of adaptation in wild populations will benefit crop breeding in the development of climate-resilient crop varieties. Dongxiang wild rice (DXWR), the northernmost common wild rice known, possesses a high degree of cold tolerance and can survive overwintering in its native habitat. However, to date, it is still unclear how DXWR evolved to cope with low-temperature environment, resulting in limited application of DXWR in rice breeding programs. In this study, we carried out both QTL mapping and phylogenetic analysis to discern the genetic mechanism underlying the strong cold resistance. Through a combination of interval mapping and single locus analysis in two genetic populations, at least 13 QTLs for seedling cold tolerance were identified in DXWR. A phylogenetic study using both genome-wide InDel markers and markers associated with cold tolerance loci reveals that DXWR belongs to the Or-III group, which is most closely related to cold-tolerant Japonica rice rather than to the Indica cultivars that are predominant in the habitat where DXWR grows. Our study paves the way toward an understanding of the nature of adaptation to a northern habitat in O. rufipogon. The QTLs identified in DXWR in this study will be useful for molecular breeding of cold-tolerant rice.
作者：生物帮
