利用SRAP标记构建甘薯分子连锁图谱

以高淀粉甘薯品种漯徐薯8号为母本,低淀粉甘薯品种郑薯20为父本,杂交得到的F1分离群体的240个单株为作图群体,利用SRAP标记技术,共得到770个母本的多态性标记和523个父本的多态性标记,用JoinMap3.0软件和"双假测交"策略,分别构建了2个亲本的分子连锁图谱。其中漯徐薯8号的图谱包括由473个SRAP标记组成的81个连锁群,总图距为5802.46cM,标记间平均图距为10.16cM;郑薯20的图谱包括由328个SRAP标记组成的66个连锁群,总图距为3967.90cM,标记间平均图距为12.02cM。该高密度分子连锁图谱的构建,为甘薯分子标记辅助选择、基因定位及克隆研究奠定了基础。

Establishment of Molecular Linkage Maps Using SRAP Markers in Sweet Potato

Sweet potato [Ipomoea batatas (L.) Lam.] is an important vegetative reproduction crop. Despite its worldwide importance, molecular biology researches in sweet potato have lagged behind other crops due to its characteristics including polyploidy, outcrossing behavior and high heterozygosity. As a result, it is difficult to make a breakthrough for the improvement of sweet potato using conventional methods. In this study, sequence-related amplified polymorphism (SRAP) markers were applied to establish molecular genetic linkage maps with F₁ population consisting of 240 individuals derived from a cross of sweet potato cv. Luoxushu 8 (high starch content cultivar) × cv. Zhengshu 20 (low starch content cultivar). A total of 770 and 523 SRAP markers were generated, respectively, in Luoxushu 8 and Zhengshu 20. Using the software of JoinMap 3.0 and the ‘double pseudo testcross strategy’, a molecular linkage map containing 81 linkage groups was established with 473 SRAP markers in Luoxushu 8, and the map covered 5 802.46 cM with an average marker interval of 10.16 cM. In Zhengshu 20，the molecular linkage map containing 66 linkage groups was constructed using 328 SRAP markers, and the map covered 3 967.90 cM with an average marker interval of 12.02 cM. The results will provide a powerful tool to facilitate the introgression of desired traits into cultivars, gene localization and map-based cloning techniques, and greatly increase breeding efficiency through marker-assisted selection (MAS) techniques.