分子标记辅助玉米自交系京24抗南方锈病的改良

Study on the Improvement of Maize Inbred Line Jing24 to Resist Corn Southern Rust with Molecular Marker-assisted Selection

近年来,南方锈病对中国玉米生产的危害日益严重。本研究选用齐319为供体亲本,利用分子标记辅助前景选择和背景选择,结合回交转育技术,改良骨干系京24的南方锈病抗性。利用荧光毛细管电泳检测系统,从13对引物中最终筛选出与抗病基因遗传距离较近,扩增稳定、分别位于抗病基因上下游的两对引物Phi118和P2,用于目标性状的前景选择,230个BC1代单株室内分子标记检测结果和海南自然发病情况的比较,验证了前景选择标记的有效性。同时,从100对SSR引物中,筛选出在供受体间具有明显差异的42对引物用于回交群体的背景选择。单色荧光标记引物的多重电泳检测,可显著提高背景选择的效率。

In recent years, Southern Rust harms China＇s corn production increasingly. In this research, Qi319 was selected as donor parents, and the molecular makers were used to assist foreground selection and background selection. Then, by using the backcrossing technology, Jing24 was improved to resist the Southern Corn Rust. Two pairs of primers-Phill8 and P2 were finally screened from 13 pairs of primers with the detection system of Fluorescence. These two pairs of primers are close at the genetic distance of the resistance gene and can be amplified stablely, and they are located in the upstream and downstream of the resistance gene respectively. Phil 18 and P2 are used for foreground selection of the target trait. 230 individual indoor molecular markers of BC1 generation plants werecompared to the natural occurrence of corn southern rust in Hainan, and this verified the validity of the foreground selection markers. Meanwhile, 42 pairs of primers, which have obvious differences between donors and aeceptors, were screened from 100 pairs of SSR primers, and these primers were used to make background selection of the backcross population. Multiplex capillary electrophoresis using fluorescent-labeled primers can significantly improve the efficiency of the background selection.