野生花生含油量分子标记的建立

The oil content of peanut varieties released is low and not stable from year to year. There are some hindrances including shortage of elite germplasm with high oil, scarce knowedge on the genetic background of oil, and complexity of oil testing technique in peanut oil improvement. In the present project, the oil content and its variation of the wild Arachis species A. appressipila and A. villosa and their offsprings including F1 population, F2 population and recombined inbred lines (RILs) will be tested and analyzed. The genetic nature of the oil content in wild Arachis species will be studied through quantitative genetic model. The genetic diversity of RILs from A. appressipila and A. villosa separately will be detected by SSR technique. The molecular markers linked oil content and genetic linkage maps in A. appressipila and A. villosa will be identified and constructed through the software Mapmaker/Exp and QTL Cartographer. The synteny and collinarity of the QTLs linked to oil content will be compared. The derivatives from wide cross between cultivated peanut and wild Arachis species will be detected by the markers linked to oil content and tested for oil content. Therefore, the QTLs linked to the high oil content and elite germplasm with high oil content will be identified. The results from the present project will be useful for peanut oil enhancement.

我国生产上应用的花生品种含油量偏低且不稳定，优良高油资源缺乏、含油量遗传基础研究薄弱以及测试选择技术复杂等是花生高油育种进展缓慢的主要原因。本项目拟以含油量高且稳定的野生花生A.appressipila和A.villosa及其后代群体为材料，系统测试和分析含油量的变异，应用相关遗传模型分析野生花生含油量的遗传特性。用SSR技术检测RIL群体的遗传多样性，通过连锁分析方法获得含油量分子标记，并构建遗传连锁图。比较不同野生花生之间(A.appressipila与A.villosa)含油量QTL区段的同线性和共线性；用所得标记检测栽培种与野生种间杂交后代材料，鉴定高油后代分子标记，同时鉴定这些后代材料的含油量及其稳定性，分析相关标记与含油量的关系，获得含油量高且稳定的种质材料和分子标记。研究结果将为花生高油育种中优良种质创制、优异亲本组合选配及后代标记辅助选择提供材料基础和理论依据。

本项目针对我国生产上应用的花生品种含油量偏低且不稳定、优良高油资源缺乏、含油量遗传基础研究薄弱等问题，对72份野生花生资源含油量进行了重复测试，获得了含油量高而且稳定的材料7份，其中匍匐区组的appressipila和花生区组的villosa含油量在多年重复鉴定中均稳定在60%以上。通过136对多态性SSR数据与含油量的关联分析，获得了9个显著关联位点，其中5个表现增效，有3个增效位点在野生花生中存在而栽培种中缺失。对appressipila和villosa的后代群体含油量和脂肪酸进行重复鉴定，应用数量性状模型的统计分析结果表明，这2个二倍体种的含油量遗传均符合E-1-9模型，受2对主基因+加性多基因控制。利用8300对SSR引物对appressipila和villosa的高油与低油种质杂交构建的2个RIL群体进行鉴定，应用JoinMap3.0软件，构建了分别包含583和428个标记位点均由10个连锁群组成的遗传连锁图，结合2个RIL群体的含油量和脂肪酸测试结果，在appressipila的RIL群体中获得相关QTL59个，在villosa的RIL群体中获得相关QTL40个。在villosa的RIL群体含油量相关QTL中，2个主效QTL（qvoil.1和qvoil.2）能在多年试验中重复检测到。通过比较2张连锁图上的标记信息和QTL位置及效应，发现2张图谱之间存在同源性，但是与含油量、山嵛酸和廿四碳烷酸相关QTL不同，表明appressipila与villosa含油量遗传基础不同，可通过不同材料的杂交聚合不同QTL，从而提高花生品种的含油量。用获得的含油量主效QTL的相关标记对栽培种与野生种间的杂交后代进行鉴定，结合含油量测试结果，获得了含油量达58%以上的优良高油四倍体材料11份，其中ZY208含油量达61.43%。