不同品种紫花苜蓿产量性状分析及其综合评价

[Objective]The study evaluates phenotypic indicators related to yield traits of 19 domestic and foreign alfalfa(Medicago sativa L.)cultivars at the initial flowering stage,and provides a reference for screening the high-yielding,nutritious and adaptable alfalfa cultivars.[Method]19 different cultivated varieties of alfalfa grown in Changping,Beijing were used as tested materials,and 12 major yield traits were determined,including the plant height,the number of branches and tillers,the dry/fresh weight,the stem thickness,the leaf length/width/area,and the stem-leaf ratio,and were comprehensively evaluated by the correlation analysis,principal component analysis and affiliation function.[Result]1)In terms of yield traits,there were large differences among different alfalfa cultivars,in which a minimum coefficient of variation was 13.43%in stem thickness and a maximum coefficient of variation was 57.41%in dry weight.2)The results of correlation analysis showed that there were significant positive relationships(p<0.05)between the stem thickness,stem-leaf ratio,dry/fresh weight and the plant height of alfalfa,indicating a positive relationship between the plant height and them.3)The results of principal component analysis suggested that the top three principal component factors were highly representative of the alfalfa yield,with their contribution rates of 37.404%,30.246%,and 15.133%,respectively.The eigenvalue of each principal component was greater than 1,with a cumulative contribution rate of 82.783%.Among of them,the eigenvectors of the stem thickness,plant height and fresh weight in the 1st principal component had a larger proportion;the area of trifoliate leaves and single leaf,the length and width of single leaf in the 2nd principal component had a larger proportion;and the eigenvectors of the number of tillers and the dry/fresh weight in the 3rd principal component were relatively large.[Conclusion]The comprehensive analysis combined with the affiliation function method shows that the top three alfalfa cultivars with comprehensive scores are'Alola','218TR'and'Zhao Dong',which can be selected as fine varieties for promotion and application in production.