黄瓜心皮数基因CsCLAVATA3近等基因系的构建及遗传评价

Construction and genetic evaluation of CsCLAVATA3 introgression line of cucumber cardiac number gene

以综合性状优良的3心皮栽培黄瓜(Cucumis sativus L.,2n=14)‘津春4号’(JC4)和‘长春密刺’(CCMC)为受体亲本,以5心皮基因黄瓜‘True Lemon’(TL)为供体亲本,通过多代回交和自交,结合SSR标记辅助选择构建了以JC4和CCMC为遗传背景的黄瓜心皮数基因CsCLAVATA3回交渗入系,并对中选单株及每条染色体的遗传背景恢复率进行评价。结果表明:在轮回亲本JC4的BC_1、BC_2、BC_3回交群体中,平均遗传背景恢复率分别为73.9%、89.8%、98.8%;在轮回亲本CCMC的BC_1、BC_2、BC_3回交群体中,平均遗传背景恢复率分别为71.1%、88.3%、98.1%,由此可见,JT(JC4×TL)群体比CT(CCMC×TL)群体的背景恢复率相对较高,通过回交世代的增加,后代恢复为轮回亲本的比率也显著增加,并且都高于理论值,说明采用分子标记辅助选择策略在黄瓜多心皮品种筛选中十分有效。该研究已完成了构建黄瓜心皮数基因回交渗入系的前期大部分工作,这为后期渗入系的纯化奠定了坚实基础。

With the three-carpel cucumbers ‘Jinchun No. 4’(JC4) and ‘Changchun Mici’(CCMC) that are excellent in comprehensive traits as the parent receptor, and ‘True Lemon’(TL) as the donor parent, the CsCLAVATA3 introgression line of cucumber cardiac number gene with JC4 and CCMC as the genetic background was constructed with SSR marker assisted selection through multi-generational backcross and self-cross. The recovery rate of genetic background of the selected individual plant and each chromosome were evaluated. The results indicated that, in the backcrossing groups of BC1, BC2 and BC3 of recurrent parent JC4, the average recovery rate of genetic background was 73.9%, 89.8% and 98.8%, respectively. In the backcrossing groups of BC1, BC2 and BC3 of the recurrent parent CCMC, the average recovery rate of genetic background was 71.1%, 88.3% and 98.1%, respectively. It can be concluded that the background recovery rate of JT group is relatively higher than that of CT group, and with the increase of backcross generation, the ratio of the JT and CT offsprings recovering to the recurrent parent increased significantly, both of which were higher than the theoretical value, indicating that the molecular marker assisted selection strategy was very effective in the selection of cucumber poly-carpels. This study has completed most of the work in the early stage of the construction of the pericarp gene of cucumber, which has laid a solid foundation for the purification of the late pericarp.