花生重组近交系群体的遗传变异与高油种质的创新

Genetic Diversity of Peanut RILs and Enhancement for High Oil Genotypes

花生是世界上食用植物油脂的重要来源之一,提高含油量是花生育种的重要目标。以不同遗传背景的亲本远杂9102与中花5号杂交构建的花生重组近交系（recombined inbreed lines,RIL）群体,进行含油量的系统测试和DNA多样性分析。结果表明,RIL群体家系的含油量范围（50.85%-62.11%）大于两个亲本的差异,最高含油量家系比高油亲本中花5号高5个百分点以上。通过SSR技术分析RIL群体的DNA多样性,发现家系间存在较大的遗传变异,杂交重组产生的超亲高油种质分布在不同类群中,含油量高低与荚果大小和青枯病抗性无明显连锁关系。鉴定获得了3组SSR遗传距离为0、含油量和主要农艺性状相似但青枯病抗性不同的家系。农艺性状和抗病性等鉴定试验筛选出了3份含油量高、农艺性状优良、高抗青枯病的新种质并已进入品种比较试验。

Peanut （Arachis hypogaea L.） is one of the important sources of vegetable oil and enhancement of peanut oil content is a key objective of breeding. In this study, peanut recombined inbreed lines （RILs） were constructed from Yuanza 9102 × Zhonghua 5 using a seed descent method and oil content and DNA polymorphism among the RILs were analyzed. The oil range of the RILs was 50.85-62.11%, which was much wider than the two parents of 53.13-57.07%, indicating that there was heterobeltiosis for oil content. The highest oil content in the RILs was higher than that of the high oil parent Zhonghua 5 by 5%. Through DNA diversity analysis using SSR approach, there was wider DNA polymorphism among the RILs. The high oil recombined lines existed in various clusters with considerable genetic distance. The high oil content was found not linked with other important traits such as 100-pod weight and resistance to bacterial wilt. Three line-pairs with zero genetic distance and similar oil content and agronomic characteristics but different in resistance to bacterial wilt were found, which might be desirable genetic materials for molecular marker research or gene cloning. Three elite lines with high oil content, desirable agronomic characters and bacterial wilt resistance were identified and they would be soon tested in regional varietal trials.