Research on the Phenotypic Diversity of Walnut Germplasm Resources in Qinghai
Abstract
Phenotypic diversity of walnut germplasm resources were investigated from main characters through variation analysis,clustering analysis and principal component analysis based on 152 superior trees from 6cities/counties in Qinghai.The results showed that,variation coefficients of many economic indicators,such as fruit weight,nuclear shell thickness,kernel situation,take the kernel were difficult,nucleolus plumpness was in a relative high level.Consequently,those could be considered as reference guides in walnut variety breeding.The variation extent of all walnut characters was the greatest in Xunhua area among all 6walnut growing areas,where the genetic diversity showed great abundance.In general,the walnut from Jianzha area was ranked first in the 6walnut areas;the result from cluster analysis showed that the 6walnut areas could be clustered into 3classes when the distance was 5.Different geographical location,climate and rainfall conditions leaded to walnut phenotypic variation degree different,richness of genetic diversity.