摘要
Fungi blast is one of the most serious diseases of rice worldwide. Breeding resistant varieties have been proved to be the most effective and economical means to control the disease. This paper describes the molecular marker-assisted selection (MAS) procedure for a broad-spectrum blast resistant gene Pi1 integrated into an elite hybrid maintainer line, Zhenshan 97. A simple sequence repeat (SSR) based on molecular marker-aided selection system for Pi1 segment was established. Using a backcross population and a blast isolate F1829, Pi1 gene was mapped on the top of chromosome 11 between markers RZ536 and RM144, with a distance of 9.7 cM and 6.8 cM, respectively. Seventeen families derived from the recurrent parent Zhenshan 97 were obtained with homozygous Pi1 gene. The background of the 17 families was identified with inter simple sequence repeat (ISSR) amplification, the highest recovery of the Zhenshan 97 genetic background was 97.01% after the assay of 167 polymorphic bands.
利用同交育种中产生的回交群体,结合前人的研究结果构建了Pil基因区域的局部分子标记连锁图,通过BC1F2家系的接种结果判断其基因型。将Pil定位在RFLP标记RZ536与SSR标记RM144之间,图距分别为9.7cM、6.8 cM,从而建立了一套完整的以PCR为基础的分子标记辅助选择体系。通过分子标记和抗性验证两种选择方式相结合,经过三代回交将Pil区段快速导入受体亲本珍汕97B中。在BC3F1中利用15条ISSR引物扩增的167条随机分布在基因组中的多态性带筛选背景,得到4个背景较好的单株。经过纯合筛选及抗性验证后共得到17个带有抗性基因Pil的改良珍汕97株系。试验表明微卫星标记在正向选择、负向选择及背景选择中都起到极大的作用。
基金
国家高技术研究和发展计划(863)项目(2001AA211091)
国家转基因植物研究与产业化专项(J001-B-013)
