Abstract: The influencing factors on the seed yield component of Medicago truncatula Gaertn.were analyzed based on its seed yield characteristics in field.The results show that significant difference existed in seed yield of 38 germplasms tested(P<0.05) and average seed yield of Line J1.12 was higher than other materials.There were significant differences in seed yield components including branch number,branch length,pods number,and 100-pod weight.The relevancy analysis of seed yield and its components of M.truncatula germplasm indicates that the branch length and seed yield was highly correlated and the correlation coefficient was 0.719;the relevancy of seed number per pod and seed yield was least.M.truncatula germplasm were divided into 3 groups by cluster analysis,6 parents with highest differences in seed yield characters were selected as hybrid parents.Detecting with SSR,EST-SSR and SRAP primers,there were significant polymorphism differences among the 6 parents.The heredity of seed yield of RILs population from cross A17×A20 was under the control of two additive-epistatic major genes according to the major gene plus poly gene inheritance analysis.The major gene heritability played a major role and the genetic variance of poly gene was lower,additive effect of the second major gene was larger than that of the first major gene.

Key words: Medicago truncatula Gaertn., Seed yield, Major gene plus poly gene inheritance analysis, EST-SSR maker, SRAP maker

摘要： 通过对蒺藜苜蓿(Medicago truncatula Gaertn.)种子产量相关性状的田间调查,解析影响蒺藜苜蓿种子产量的主要构成因素。结果表明:搜集的38份蒺藜苜蓿种质资源在种子产量方面存在显著差异(P<0.05),选系J1.12单株平均种子产量明显高于其他材料;不同种质在分枝数、伸展长度、小花数、结荚数和百荚重等构成因素上存在显著差异(P<0.05);对蒺藜苜蓿种质种子产量与其构成因素间的相关性进行分析发现,伸展长度与种子产量相关性最大,相关系数为0.719,每荚种子数与种子产量相关性最小。通过系统聚类,参试蒺藜苜蓿种质可分为3个类群,并从中筛选6份种子产量特性差异大的蒺藜苜蓿种质作为杂交亲本,利用SSR、EST-SSR和SRAP引物检测亲本的多态性,发现6份亲本多态性差异明显;通过应用主基因+多基因遗传模型发现蒺藜苜蓿A17×A20组合的RILs群体种子产量性状的最佳遗传模型是2对加性-上位性主基因模型,该组合群体种子产量遗传以主基因为主,多基因遗传率较低,第二对主基因的加性效应值高于第一对主基因的加性效应值。

关键词: 蒺藜苜蓿, 种子产量, 主基因+多基因遗传分析, EST-SSR标记, SRAP标记