紫花苜蓿多元杂交后代产量和品质一般配合力分析及遗传参数的估算

Determination of general combining ability and estimation of genetic parameters for yield and quality in alfalfa

为培育高产优质紫花苜蓿新品种,以筛选出的16个苜蓿优良株系的半同胞后代为材料,研究其产量和品质的一般配合力,并在此基础上进行聚类分析,结果表明,一般配合力高的株系有白花3号和速生4号,一般配合力中等的株系有速生15号、速生12号、白花1号、白花2号和速生1号等,这些株系都具有高产、优质等特点,均可作为优良亲本,参与下一步优良株系杂交组合的配置育种应用。16个株系组合的广义遗传力由大到小顺序是:相对饲用价值>干草产量>叶茎比>粗蛋白>分枝数>节间长>株高>生长速度,其中,除了株高和生长速度,其余性状的广义遗传力都较高,均在80%以上,可以作为进行早代选择的指标。该研究可为杂交育种正确评价亲本和组合提供科学依据。

To breed high yielding high quality alfalfa cultivars,seeds of 16 half-sib lines with good performance, obtained from the progeny of multiple crosses,were selected.General combining ability (GCA)and the broad-sense heritability (H2 )for yield and quality were analyzed and evaluated.Cluster analysis was conducted based on GCA.Two genotypes with high GCA (White flower No.3 and Fast-growing No.4)and eight strains with moderate GCA (Fast-growing No.15,Fast-growing No.12,White flower No.1,White flower No.2 and Fast-growing No.1 etc.).Strains with high yield and quality can be used as parents in the next crossing cycle.The estimated H2 values for attributes affecting relatively feeding value were in the order>hay yield>leaf-stem ra-tio>crude protein > branch number > internode length > plant height > growth rate.Most H2 values were>80%,which means they could be used as early generation selection indicators in a breeding programme.