Progresso e variabilidade genética com a seleção recorrente para produtividade de grãos no feijoeiro / Progress and genetic variability through recurrent selection for grain yield of common bean

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Recurrent selection (RS) is a breeding cyclic process which involves the obtainment of progenies, the evaluation and recombination of the best ones. RS is expected to enhance the selected trait average without losing the genetic variability for future progresses which will be eventually achieved by selection. The objective of this work was to estimate the genetic progress through selection for carioca bean grain yield after eight cycles as well as to verify if there is still enough genetic variability to continue attaining future progress through selection. The RS program was launched in 1990 at Universidade Federal de Lavras. The base population was obtained from ten genitors having many different traits. For each cycle, S0:1 and S0:2 progenies were evaluated, then S0:3 progenies were recombined. This selection process was carried out until the lines could be attained; those were then more thoroughly evaluated along with lines originated from other programs involving experiments for the evaluation of elite lines. The data originated from the evaluation results made for lines obtained through recurrent selection were collected in the county of Lavras. Such data were used to conduct the group analysis of variance per harvest comprehending lines of the same selective cycle. As the experiments had three common controls, a combined analysis of variance of all lines was done. Adjusted averages of lines from each cycle were used to estimate the genetic progress. The linear regression coefficient estimated between the lines average (y) and the number of cycles (x) was 68.58 kg/ha, in other words, 3.3% per cycle. In order to check for any possible population variability, phenotypic and genetic parameters estimates for cycles VIII and IX were obtained from S0:2 progenies. It was verified that heritability estimate for selection on progenies average was similar in both cycles, thus foreseeing any continuous genetic progress for future cycles.

ASSUNTO(S)

recurrent selection seleção recorrente genetica vegetal bean breeding phaseolus vulgaris l. phaseolus vulgaris l. melhoramento do feijoeiro

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