利用分子标记辅助选择聚合水稻Pi-ta、Pi-b和Wx-mq基因

摘要

近年来, 优良食味粳稻品种南粳46、南粳5055和南粳9108在江苏等地大面积推广, 促进了优质稻米产业的发展.但这些品种均不抗稻瘟病, 且缺乏适合在淮北地区种植的中熟中粳型优良食味粳稻品种.本研究以同时携带稻瘟病抗性基因Pi-ta和Pi-b的江苏抗病、高产粳稻品种武粳15为母本,携带低直链淀粉含量基因Wx-mq的优良食味粳稻品种南粳 5055 为父本配置杂交组合进行聚合育种.利用 Pi-ta和 Pi-b 基因的分子标记多重 PCR 体系以及Wx-mq基因的四引物扩增受阻突变体系PCR检测技术,分别在不同的分离世代对目标基因位点进行检测,结合田间多代选育、抗性鉴定和籽粒胚乳外观鉴定, 成功地将Pi-ta、Pi-b和Wx-mq基因聚合于一体, 选育出稻瘟病抗性好、食味品质优、产量高的水稻新品系"南粳0051", 适合在江苏省淮北地区种植.本研究将三套自主研发的PCR检测体系成功应用于分子标记辅助选择, 不仅为水稻多基因聚合育种提供了快捷、高效的选择方法, 也为水稻抗病、优质育种创制了新的种质资源.%In recent years, japonica rice varieties Nanjing 46, Nanjing 5055, and Nanjing 9108 were planted in a large area in Jiangsu province because of their good eating quality. However, these varieties are not resistant to rice blast, and there is no japonica rice variety with good eating quality and suitable for planting in Huaibei area,Jiangsu province.The goal of modern rice breeding is to develop new varieties with good quality, high yield and multi-resistance. Marker-assisted selection combined with traditional breeding methods can greatly improve breeding efficiency. In this study, the high yield rice variety "Wujing 15" con-tained two blast resistance genes of Pi-ta and Pi-b was used as gene recipient to be crossed with the rice variety"Nanjing 5055", which carries the low-amylose content gene Wx-mq.We developed two multiple PCR systems to identify resistance and suscepti-ble alleles on Pi-ta and Pi-b loci and the Tetra-primer Amplification Refractory Mutation PCR System for Wx-mq gene. MAS technique was adopted in combination with field phenotyping of agronomic traits, blast resistance identification, and classification of the grain endosperm appearance.Finally,a new japonica line,tentatively designated"Nanjing 0051",was bred,which showed excellent agronomic traits and adaptation in the Huaibei area. The results indicate that the three PCR systems developed in this study are applicable and effective in rice breeding to improve blast resistance and grain quality. The success of breeding "Nanjing 0551" is an example for using MAS technique to pyramid favorable genes and facilitate breeding process in rice.