264份梨种质资源枝条、叶片表型多样性评价OA

Using 264 pear germplasm accessions preserved in the Pear Germplasm Repository of Nanjing Agricultural University as the research materials,22 descriptive traits,including one-year-old shoot color and lenticel density,and 10 quantitative traits,including petiole length and leaf length,were investigated.The Shannon-Wiener diversity index,coefficient of variation,comparative analyses of inter-and intra-population diversity,correlation analysis and principal component analysis of quantitative traits,and cluster analysis were conducted.The results showed that the diversity indices of the descriptive and quantitative traits ranged from 0.025 to 1.637 and from 2.004 to 2.087,the diversity of quantitative traits was markedly higher than that of descriptive traits.Among the descriptive traits,young leaf color had the highest diversity index(H'=1.637).The coefficients of variation of the 10 quantitative traits ranged from 11.18％to 36.56％,with leaf area showing the highest value(CV=36.56％).Both inter-and intra-population variation of the nine quantitative traits related to shoots and leaves were relatively high,indicating that both contributed substantially to the phenotypic diversity of pear germplasm resources.Based on the comprehensive analysis of correlation and principal component analysis,leaf area,one-year shoot length,and flower bud length can serve as important indicators for evaluating the variation in shoot and leaf traits.Cluster analysis divided the 264 pear germplasm accessions into five groups.Pyrus communis could be distinguished from most Oriental pears,whereas P.bretschneideri and P.pyrifolia within the Oriental pear group did not form independent clusters but showed an intermingled distribution.