海南普通野生稻优质基因的发掘利用与种质创新

Studies show that 40% genes in modern cultivated rice have missed in the course of domestication from wild rice, and 50% of which could improve cultivated rice. So through mining and utilization of desirable genes in wild rice to broaden genetic basis of cultivated rice will have an significant impact on rice breeding. This study will focus on primary mapping, genetic analysis, and gene transferring of QTLs underlying elite traits in wild rice W3005. The main contents as follows: 1) With hybridization and molecular marker assisted selection, a set of chromosome segment substitution lines (CSSLs) covering entire genome of wild rice W3005 will be developed with good restorer line 9311 as recurrent parents. 2）Agronomic characters (related to yield, grain quality, and resistance etc) of the CSSLs and 9311 will be investigated and then combined with genotype of the CSSLs, QTL mapping and genetic analysis will be carried out.3) Desirable CSSLs will be used for breeding new hybridized combination and applied to rice production. All above will be carried out at fundamental research level and application level respectively. Firstly, this study will provide primary near-isogenic lines for fine mapping and cloning favorable genes; Secondly, it will broaden rice gene pool uesed for improving cultivated rice; Lastly, elite germplasm resource will be obtained for breeding. This programme will realize the sustainable exploitation and utilization of rice resource and promote the steady growth of the rice yield.

研究表明野生稻驯化为现代栽培稻的过程中丢失了近40%的等位基因，其中的50%能改善栽培稻的农艺性状，因此,挖掘、利用野生稻优良基因资源、拓宽栽培稻遗传基础将对水稻育种产生深远影响。本项目将展开对控制野生稻W3005优良性状QTL的初级定位、遗传分析及基因转移。具体研究内容包括：1）利用常规杂交、分子标记筛选构建一套覆盖野生稻W3005全基因组、以强优恢复系9311为受体的染色体片段代换系；2）考察各代换系及受体亲本产量、品质、抗性等相关性状，结合基因型进行QTL定位及遗传效应分析；3）对优良代换系即改良版9311测配新的杂交组合应用于生产。以上内容分别从基础研究层面及应用层面进行，首先为优异基因的精细定位与克隆提供初级近等基因系；其次为现有栽培稻品种的分子改良提供新的基因来源；最后为育种提供能直接应用的优异品种。项目的实施将有利于水稻资源的可持续开发利用,促进水稻产量稳步增长。

目前水稻育种中由于定向栽培和人为选择导致水稻遗传背景日益狭窄，水稻增产潜力及抗逆性大受影响，水稻产量徘徊不前。野生稻驯化为现代栽培稻的过程中丢失了近 40%的等位基因，因此，挖掘、利用野生稻优良基因资源、 拓宽栽培稻遗传基础将有利于水稻资源的可持续开发利用，促进水稻产量稳步增长。. 本研究以海南普通野生稻为研究对象，通过构建染色体片段代换系展开了对其抗性、品质、产量等优良基因的挖掘工作。通过多代杂交、回交、分子标记选择与精准性状鉴定，我们获得了控制稻米品质的Waxy基因位点的一个新的等位基因，并通过测序及等位性测定等方法开发了该位点功能基因标记，发表SCI 1篇，获得授权专利1项；另外，我们还通过测序及序列比对获得了两个抗稻瘟病基因位点的特异性分子标记，并分别发表了中文核心期刊论文及申请了发明专利。..在应用研究层面，我们获得了多个部分性状得到改良的染色体片段代换系，比如部分代换系表现出比轮回亲本米质更优异，部分表现出较高的抗性，我们对于部分综合性状优异的株系进行了测配，并选育出多个苗头组合，目前有1个组合在参加湖北省水稻区试。..因此，本研究产出与预期一致，较好的完成了项目制定的任务目标，无论在基础研究层面还是应用研究层面均取得了不错的成绩。