Phenetic relationship of rubber tree clones

Abstract

Twenty clones of the breeding population of Hevea brasiliensis were evaluated for phenetic diversity. The test-clones included six clones developed in Nigeria, ten Malaysian clones, two clones from Indonesia and a clone from each of Brazil and Sri Lanka. Data collected on fifteen seed characters in 1998 and 1999 were utilized for multivariate analysis. Cluster analysis of data matrix of clonal mean seed characters was conducted to produce principal component axes, dendrograms and Tocher's clusters in 1998, 1999 and the combined data. There was taxonomic isolation of the recent collection from Brazil (IAN 710) from the other clones that are either members or descendants of the Wickham collection of 1876. There was a continuum of phenetic diversity from the highly divergent to the closely related pairs of clones. The highly divergent clones are expected to produce heterotic progenies in crosses while crosses among clones with close phenetic similarity should be avoided. This will guide against inbreeding depression and genetic erosion.