Mapping of a southern root-knot nematode resistance gene in pepper and marker-assisted selection | 辣椒抗南方根结线虫基因的定位及标记辅助选择

chinois. 用对南方根结线虫具有稳定抗性的辣椒材料09C649与感病材料09C108杂交并构建F2分离群体,遗传分析表明,09C649中对南方根结线虫的抗性由一对显性基因控制,将其暂命名为Me8。用236对SSR标记、1对SCAR标记、1对SSCP标记、8对EST-SSR标记及2对COSII标记对Me8进行基因定位。该基因被定位在辣椒第9号染色体上,与其距离最近的4个标记SSCPB322、COS710、SCAR315和COS970,分别与该基因相距0、0.1、1.3和3.3cM。抗南方根结线虫基因N、Me1、Me3及Me7也都位于这一染色体区域,因此这4个分子标记可运用于对目前已发现的所有抗南方根结线虫基因的辅助选择中。用标记SCAR315对37份辣椒材料进行辅助选择,结果表明标记鉴定结果与抗性鉴定结果具有高度的一致性。

anglais. A southern root-knot nematode resistant inbred line 09C649 was crossed with a susceptible line 09C108. TheF2 segregating population was obtained. Disease investigatLon and heredity analysis revealed that the resistance to southern root-knot nematode in 09C649 was controlled by a dominant gene, tentatively named as MeS. Two hundreds and thirty six pairs of SSR markers, 1 pair of SCAR marker, 1 pair of SSCP marker,8 pairs of EST-SSR markers and 2 pairs of COSII markers were used to map MeS. It was located on the chromosome 9 of pepper. The four molecular markers SSCP B322, COS710, SCAR_315 and C0S970, were the nearest markers away from Me8 with geneticdistances of 0,0. 1,1.3 and 3.3 cM respectively. Southern root-knot nematode resistance genes N, Me1, Me3 and Me7 were also located in this genomic region. These markers could thus be used in marker-assisted selection for all the southern root-knot nematode resistance genes that were found currently. The SCAR_315 was used in marker-assisted selection of 37 pepper lines. And the molecular identification was well in agreement with the southern root-knot nematode resistance tests.