Construction of Molecular Linkage Maps Using SRAP Markers in Sweetpotato

The objective of this study was to construct a linkage map of sweetpotato [Ipomoea batatas (L.) Lam.] based on Chinese cultivars with higher marker density than previous maps. Cultivars Luoxushu 8 (female parent) and Zhengshu 20 (male parent) with obvious differences in starch content, yield, β-carotene content, and disease resistance were crossed to produce a segregation population with 240 F1 individuals. Among the total 800 sequence-related amplified polymorphism (SRAP) markers, 770 and 523 markers showed polymorphism in the female and male parents, respectively. Using the “double pseudo testcross” strategy, 2 linkage maps were constructed by means of JoinMap 3.0. The linkage maps were composed of 473 markers in 81 linkage groups for Luoxushu 8 and 328 markers in 66 linkage groups for Zhengshu 20. The former map covered 5802.46 cM with an average marker interval of 10.16 cM, and latter one covered 3967.90 cM with an average of 12.02 cM. Both linkage maps may facilitate marker-assisted selection, gene localization, and gene cloning in sweetpotato.

摘 要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5 802.46 cM, 标记间平均图距为10.16 cM; 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3 967.90 cM, 标记间平均图距为12.02 cM。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。