长江2号多花黑麦草主要形态性状的回交改良分析

采用回交的方法对长江2号多花黑麦草（Lolium multiflorum‘Changjiang No.2’）的主要形态性状进行改良。结果表明：杂交组合C2，C7及C8的茎粗及节间长表现优于亲本长江2号。经过一轮回交，各回交组合除含有目标性状外，其他性状也发生了不同程度的回复。SSR分析表明，20对SSR引物在7个育种群体中共扩增出217个条带，多态性条带比率为92.2%。SSR分子标记水平上的遗传相似性分析表明，回交组合形态性状上的变化是发生在遗传物质变化上的。这将为长江2号多花黑麦草的进一步改良提供基础信息。

A Study on Improving the Main Morphological Traits of Annual Ryegrass by Backcross

In this study, backcross method was used to improve the main morphological traits of annual ryegrass ‘Changjiang No.2’. The analyses of agronomic traits of 14 tested materials showed that stem diameters and internode lengths of hybridized combination C2, C7 and C8 had significant heterobeltiosis. After backcross, agronomic traits of backcross combination were recovered at different degrees. The genetic analysis by SSR markers showed that a total of 217 bands were detected in the tested populations with 20 selected primer pairs, the percentage of polymorphic bands was 92.2%. The genetic similarity analysis by SSR markers showed that the variation of agronomic traits in backcross was caused by the changes of genetic materials. Results of this study provide some basic information for the backcross breeding of ryegrass.