Repeatability of yield and girth growth traits in rubber tree clones of series IAC 300

Abstract

This study aimed to estimate the repeatability coefficients, to compare the efficiency of methodologies used inthe estimation process, and further to determine the minimal number of evaluations in the selection of rubber tree [Heveabrasiliensis (Willd. ex Adr. de Juss.) Muell. - Arg.] clones. The following methodologies were used: analysis of variance;principal component analysis based on the correlation matrix together with the phenotypic variances and covariance matrix;and the structural analysis. The r values for girth growth varied from 0.77 to 0.79 and rubber yield from 0.39 to 0.52. It wastherefore admitted that the principal component method based on the correlation matrix as well as for the phenotypicvariances and covariance matrix are the most efficient to estimate the coefficient of repeatability. At an accuracy of 90% and80%, two measurements of girth growth and four to six measurements of rubber yield would be necessary for the selection ofrubber tree clones, respectively.

Keywords

• Hevea brasiliensis
• plant breeding
• clone selection
• rubber yield.