Optimising selection in full-sib progeny of the cashew

Abstract

In Brazil, the productivity and quality of the peduncle and nut of the cashew have increased significantly due to the use of binomial hybridisation-cloning. In the present research, genetic parameters (variance components – individual REML) and genetic values (mean components – individual BLUP) were estimated in a test of full-sib segregating progenies, aiming at the selection of superior cashew progenies and individuals. A controlled-pollination, segregating population from the cashew genetic breeding program of Embrapa Agroindústria Tropical, comprising four different progenies, each represented by 48 full-sib (FS) individuals, were evaluated over six consecutive crops. The following traits were evaluated: nut yield, mean nut weight, reaction to Anacampsis phytomiella, and reaction to oidium (powdery mildew). The experimental design was of randomised blocks, with four replications and 12 plants per plot. The REML/BLUP geneticstatistical procedure was used to optimise the selection process. It seems reasonable to opt for a selection limit of 14 individuals with superior behaviour to comprise the recombination unit of the next cycle of recurrent selection using the remaining seeds from this breeding population. Plants 25 and 27 from the progeny identified as having the best performance (FS 13/3) for direct cloning were selected to comprise the local trial of the cashew genetic breeding program.