Cluster analysis for fruit yield components in grapes

Abstract

For any plant improvement programme, different genotypes are to be classified into clusters based on genetic diversity. Further the extent of genetic divergence between them needs to be estimated. D2 statistics is one of the powerful tools to assess the relative contribution of different component traits to the total diversity, to quantify the degree of divergence and to choose genetically diverse parents for obtaining desirable recombinants. The present study was conducted at Punjab Agricultural University, Regional Research Station, Bathinda from 2011-13 on 20 genotypes of grapes for genetic divergence with respect to nine yield contributing traits viz., bunch length, bunch breadth, bunch weight, berry length, berry breadth, berry weight, TSS (%), acidity (%) and fruit yield per vine. The analysis of variance exhibited significant differences among genotypes for all the nine characters studied. Twenty genotypes were grouped into five clusters. The cluster size varied from single genotype (cluster V) to seven genotypes (cluster I). Cluster II, III, IV had 4, 5 and 3 genotypes respectively. No relationship between geographic and genetic diversity was revealed as genotypes from same geographic area fell in different clusters and vice versa. The intercluster distances were more than intracluster distances. The highest intercluster distance was observed between cluster I and cluster IV followed by clusters I and V. The other intercluster distances were of low magnitude. Hence crossing between genotypes of cluster I with those from cluster IV and V will be rewarding. Based on intercluster distances and cluster mean for different characters, parents were identified which upon crossing may yield desirable recombinants.

Keywords

• grapes
• fruit yield components
• d2 analysis