Dois ciclos de seleção recorrente no melhoramento de feijão carioca

• Ano de defesa: 2012
• Autor(a) principal: Alves, Anatércia Ferreira
• Orientador(a): Carneiro, José Eustáquio de Souza
• Banca de defesa: Oliveira, Lucimar Rodrigues de , Oliveira, Marciane da Silva
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Phaseolus vulgaris; Seleção recorrente; Progresso genético; Melhoramento do feijoeiro
• Palavras-chave em Inglês: Phaseolus vulgaris; Recurrent selection; Genetic progress; Breeding of bean
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1186

The Brazilian population s preference for one of the several commercial types of bean is a regional characteristic. The bean of the carioca type is the most cultivated and consumed in Brazil, standing for over 70% of the national production. Thus, the main bean plant breeding programs in Brazil have given emphasis to the improvement of that type of grain. In bean plant breeding, in addition to the methodologies traditionally utilized in self-pollinating plants, the use of recurrent selection is common. Promising results have been obtained through this strategy in the increase of yield, disease resistance and bettering of other traits of interest in the bean plant. By means of this work, it was intended to estimate the genetic progress of two recurrent selection cycles of Carioca bean by utilizing different strategies and identify families with greatest genetic potential to generate superior lines in the different cycles. The base population (C0) was obtained by the combination of 20 parents of carioca grains, carriers of phenotypes favorable for several traits of agronomic interest. At first, the parents were crossed according to the scheme proposed by Bearzoti (1997), in circulant diallel scheme, with each parent participating in two crosses. So, 20 populations coming from single crosses were generated. From these populations were derived the families evaluated by three crops in different generations (F2:3, F2:4 and F2:5). The same crossing and evaluation procedure of C0 was done in CI. The genetic progress was estimated on the basis of the simultaneous evaluation of the 40 best families of each cycle and also from the evaluation experiment of families (F2:3, F2:4 e F2:5) in each cycle with average controls. The genetic gain ranged from 8 to 9% for grain yield when estimated from the simultaneous evaluation of the best families of each cycle; when the families were evaluated in different cycles, with average controls, there was an overestimate of the gains, varying from 14,2 to 23,7%. Families with the potential to generate lines superior to cultivars Pérola, BRSMG Majestoso and BRSMG Madrepérola, especially among the families of cycle one (CI), were identified.