Abstract: The study on the diversity and variation of fruit phenotypic characters of walnut germplasm resources can provide valuable based data and theory foundation for construction of walnut germplasm resources and variety breeding, and promote the efficient utilization of walnut germplasm resources. The study was conducted in order to evaluate 13 qualitative characters and 11 quantitative characters on 99 walnut germplasm resources, which were designed with hierarchical classification and then were done with analysis of variations and systematic cluster analysis. The results showed that the coefficient of variation of the 13 qualitative characters ranged from 16.57% to 54.46%, especially, coefficient of variation concerning 7 out of 13 characters including sweet, texture of crisp, number of kernel, number of pockmark, degree of difficulty taking kernel, astringency and smooth of shell. The Shannon-weaver index of the 13 qualitative characters ranged from 0.49 to 1.51, especially, Shannon-weaver index concerning 5 out of 13 characters including degree of difficulty taking kernel, number of kernel, smooth of shell, color of shell and astringency. The coefficient of variation of the 11 quantitative characters ranged from 8.38% to 26.91%, especially, coefficient of variation concerning 2 out of 11 characters including weight of kernel and thickness of shell. The Shannon-weaver index of the 11 quantitative characters ranged from 1.89 to 2.27, especially, Shannon-weaver index concerning 3 out of 11 characters including equatorial diameter of nut(2.27), side diameter of nut(2.27), thickness of shell(2.27). There were significant differences among and within populations(except nut weight and equatorial diameter of fruit), and phenotypic differentiation coefficient among and within populations were 15.66% and 58.13% respectively. The degree of difficulty taking kernel had extremely significant correlation with thickness of shell(r=-0.618), kernel rate(r=0.573), number of kernel(r=0.790), degeneracy of crisp(r=0.733), texture of crisp(r=0.659). The systematic cluster analysis showed that 99 test materials could be divided into 3 categories based on the variation of phenotypic characters and in which there were differences. There were abundant genetic diversity based on the phenotypic characters of fruit of walnut, and these characters were worth mentioning such as degree of difficulty taking kernel, number of kernel, smooth of shell, astringency, thickness of shell, degeneracy and texture of crisp in the variety breeding. The variation within populations was more abundant(except the fruit shape index), and we can pay attention to the genetic improvement within populations.

Key words: Walnut, Phenotypic characters, Among populations, Within populations, Diversity

CLC Number: 

• S664.03