利用RIL群体和自然群体检测与花生含油量相关的SSR标记

以远杂9102×中花5号杂交后代衍生的重组近交系F₈代家系为材料,在含油量测试的基础上,选用10份低油材料(平均含油量52.91%)、12份高油材料(平均含油量58.85%)以及亲本进行SSR引物筛选,通过631对SSR引物扩增,筛选出来源于7对引物的13个有显著差异的片段可以有效区分低油材料和高油材料。以这7对差异引物在F₈ RIL群体中扩增,对20份低油家系材料(含油量<55%)和45份高油家系材料(含油量>56%)进行统计分析,获得1个与花生含油量相关的分子标记2A5-250/240,其中,标记2A5-250为低油材料(含油量<55%)所拥有,相符率为95.0%,标记2A5-240为高油材料(含油量>56%)所拥有,相符率为88.9%。用SSR标记2A5-250/240检测11份高油(平均含油量为55.93%)栽培种花生和11份低油(平均含油量为48.41%)栽培种花生,结果表明,标记2A5-240与高油栽培种花生的符合率为63.6%,2A5-250与低油栽培种花生的符合率为90.9%。在19份高油(平均含油量为58.60%)野生花生中,10份野生花生能检测到标记2A5-240。综合分析RIL群体和自然群体的研究结果表明,标记2A5-250/240可用于花生含油量分子标记辅助选择。

Identification of SSR Markers Linked to Oil Content in Peanut (Arachis hypo-gaea L.) through RIL Population and Natural Population

Oil content has been an important quality trait for peanut. However, the progress in genetic improvement of oil content is slow. This is mainly due to the complex genetic basis, the high cost in oil content testing, and difficulty in phenotypic selection because of environmental influence. Therefore, marker assisted selection (MAS) is necessary for oil content improvement in peanut breeding. In the present study, F₈ RILs derived from a cross of Yuanza 9102×Zhonghua 5 were selected as materials. Ten RILs with extremely low oil content (about 52.91% on an average), twelve RILs with extremely high oil content (about 58.85% on an average) and the two parental lines were used to screen 631 simple sequence repeat (SSR) primers. Thirteen polymorphic bands of seven SSR primers were able to distinguish the extremely high and low oil content lines. Subsequently, the seven SSR primers were used to genotype the total RIL population. Based on the statistics of the SSR data from 20 lines with low oil content (less than 55%) and 45 lines with high oil content (more than 56%), we identified that a SSR marker, 2A5-250/240, was tightly linked to the oil content trait. The band 2A5-250 appeared almost in all low oil content lines with the match rate of 95.0%, while the band 2A5-240 appeared almost in all high oil content lines with the match rate of 88.9%. Detection of the marker 2A5-250/240 was conducted in 11 high oil (55.93% on an average) and 11 low oil (48.41% on an average) content peanut cultivars. The results showed that the match rates of the band 2A5-250 to low oil content materials and 2A5-240 to high oil content materials was 90.9% and 63.6%, respectively. In addition, the band 2A5-240 appeared in 10 of the 19 wild peanut (Arachis) lines with high oil content (about 58.60%). The results based on the analyses using RIL and natural populations demonstrated that the SSR marker 2A5-250/240 was useful for marker-assisted selection of oil content in peanut.