苜蓿总皂甙含量的遗传变异及其与农艺性状的相关分析

 【目的】通过对苜蓿总皂甙含量与农艺性状的相关分析找出一个能快速标记总皂甙含量高低的性状,探索总皂甙含量的遗传变异规律。【方法】以耐湿热苜蓿新品种渝苜一号为材料,测定100个苜蓿单株,从中选出5个高皂甙植株和5个低皂甙植株。【结果】通过各单株后代系的试验确定了这10个植株的总皂甙遗传力在0.118到0.745之间变化,后代系的变异系数在15.54%到28.81%之间变化,高低皂甙群体的遗传力分别为0.636和0.208,高皂甙群体的遗传力明显高于低皂甙群体。苜蓿总皂甙含量与株高、叶色、虫害程度、干重和干物质率的相关分析及通径分析的结果表明：叶色与总皂甙含量呈极显著负相关（r=-0.405**）,且叶色与总皂甙含量的的相关关系主要是直接效应（P=-0.422**）;干重与总皂甙含量的相关主要是通过株高、叶色和干物质率的间接作用。【结论】通过常规育种方法要育成低皂甙苜蓿品种较为困难,而一些高皂甙含量的后代系可作为高皂甙苜蓿品种的育种材料;苜蓿的叶色可以作为快速识别苜蓿总皂甙含量高低的标记。

Correlation Analysis of Agronomic Characters and Heritability of Saponins Content in Medicago sativa L

Objective] Through correlation analysis between saponins content and agronomic characters in alfalfa, the authors try to find out one trait which can sign saponins content quickly and explore the rule about heritability and variation of saponins content. Method] A new cultivar of Hot-wet alfalfa named Yumu No. 1 was used as materials in this research, one hundred alfalfa plants were determined, five high saponin plants and five low saponin plants were selected. Result] Saponins heritability of these 10 alfalfa plants changed from 0.118 to 0.745 through experiments on the lines of offsprings of every plant, and variation coefficient of the lines of offsprings changed from 15.54% to 28.81%, the heritability of high and low saponin groups was 0.636 and 0.208, respectively, and the heritability of high saponin group was obviously higher than low saponin group. The result of correlation and path analysis between the saponins content and plant height, leaf color, pest extent, dry weight as well as the dry matter content showed that there was an extremely significant relationship (r=-0.405~(**)) between leaf color and saponins content, and the saponins content was affected by leaf color directly (P=-0.422~(**)). The correlation between dry weight and saponins content was affected by plant height, leaf color and dry matter indirectly. Conclusion] It is difficult to breed low saponin cultivar in alfalfa through general breeding method, but some lines of offsprings with high saponin content can be used as materials for breeding of high saponin content alfalfa cultivar. Leaf color of alfalfa can be used as a marker to identify saponins content in alfalfa quickly.