Assessment and exploitation of genetic divergence in pecan nut

Abstract

Sixty genotypes of pecan nut having unknown seedling origin were selected after thorough survey to assess the nature and magnitude of genetic divergence. Genetic divergence was analyzed in these 60 bearing trees of pecan nut growing at various geographical locations in Jammu Division of UT of Jammu and Kashmir. The data were subjected to non- hierarchical Euclidean cluster analysis based on seven nut and kernel characters viz nut length, lateral nut width, ventral nut width, shell thickness, kernel weight, kernel length and nut weight High heritability coupled with higher genetic advance was observed for kernel length (94.80% and 46.61 %).Further kernel weight showed positive and significant correlation with nut length and nut weight. Clustering of selected genotypes was done by using D² statistics and dendrogram was made as per Ward’s method. All the 60 seedling pecan nut genotypes were grouped into 8 clusters. The maximum inter cluster distance was recorded between selections of cluster VII and V. Cluster VII was the most diverse as more clusters showed maximum inert cluster distance with it. Considering high magnitude of genetic advance and heritability (broad sense) in various traits of horticultural interest, the existing biodiversity was gainfully exploited by direct selection and three genetically diverse genotypes were selected and compared with three commercial cultivars and out of these five genotypes one was selected for commercial cultivation based on yield and nut characters. The selected genotype has been released as variety for cultivation in North West Himalayan region and the same has been notified by Central Variety Release committee and released under name SKJPP 25 /Jammu pecan nut.