Seleção recorrente no melhoramento de feijão vermelho

• Autor(a) principal: Menezes Júnior, José ângelo Nogueira de
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1321
• topic: Phaseolus vulgaris; Genética quantitativa; Progresso genético; Phaseolus vulgaris; Quantitative genetics; Genetic progress; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL

This work was carried out to obtain an estimate of genetic progress after two cycles of recurrent selection in red bean breeding and to obtain lines aiming at the composition of the tests of Value for Cultivation and Use (VCU) in Minas Gerais, Brazil. The base population was obtained from the cross of the cultivar Vermelhinho, the only one with shiny red grains adapted to the cultivation conditions of the state of Minas Gerais, with elite lines and sources of resistance to diseases. The recurrent selection program was conducted by evaluating the families of two generations and recombination of the best ones to obtain the next cycle. At cycle zero (C0) were evaluated families F3:5 and F3:6 and recombined families F3:7. As for cycle one (CI), the families were extracted in generation F5 and evaluated in generations F5:6 and F5:7, with the recombination being carried out using the families F5:8. After selecting the best families for recombination, these continued being evaluated aiming to obtain lines. During the recombination phase, in order to obtain the cycle one population, besides the 17 families selected in cycle zero, three new parents were included (VR-3, VR-2 and BRS Timbó). In the two selection cycles, the families were evaluated in Coimbra-MG using a simple or triple lattice design. Since the families were evaluated in different years and generations, the genetic progress estimate was obtained by comparing the 30 best lines obtained at the end of the cycle. The lines were evaluated together with the checks Ouro Vermelho and Vermelhinho in a randomized block design, with three repetitions and plots of two 2-meter long lines during the 2008 winter season (sowing Jun/Jul) and 2009 dry season (sowing Feb/Mar) and winter season. After two cycles of recurrent selection, genetic progress was 7.5% for grain yield, 7.0% for grain aspect, 33.4% for rust severity and 13.2% for angular leaf spot severity. Inclusion of new lines during the recombination phase was found to be efficient for recurrent selection programs for bean plant culture. Red bean lines superior to the cultivars Vermelhinho and Ouro Vermelho were obtained, with the potential to be included in future VCU trials in the state of Minas Gerais. The existence of genetic variability for all the characteristics evaluated shows the possibility of obtaining a successful selection in the following cycles, and that the recurrent selection program must be continued.