Controle genético de caracteres e estratégias de seleção no maracujazeiro-azedo

• Ano de defesa: 2008
• Autor(a) principal: Santos, Carlos Eduardo Magalhães dos
• Orientador(a): Bruckner, Claudio Horst
• Banca de defesa: Sediyama, Tuneo , Moura, Waldênia de Melo
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Maracujá; Melhoramento; Seleção recorrente
• Palavras-chave em Inglês: Passion fruit; Breeding; Selection
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/1276

Heterosis in hybrids were evaluated, the selection strategies for plant vigor and scab resistance, the adequate fruit number to be sampled for selection and the association of fruit weight classes with other fruit traits. Twelve F1 hybrids obtained according to the diallel II design of Comstock and Robinson and half-sib progenies were evaluated at the Department of Plant Science of Universidade Federal de Viçosa (Federal University of Viçosa, Brazil). The results evidenced dominance effects and therefore heterosis in the yield of the first year in the traits of fresh mass, pulp mass, skin mass, and equatorial diameter of the fruit. In the second yield season only the equatorial diameter of the fruit presented variance due to dominance effects. The presence of additive effects was observed for number of fruits and mass of the fruit. The heritability values are an indication of the potentiality of the population for genetic improvement. The evaluated population at the present study can be inserted in popular genetic improvement programs, aiming heterotic hybrids. The combined selection promoted superior expected gains than the direct and indirect selection and the applied selection indexes. The indexes of Pesek & Baker and Mulamba & Mock provided satisfactory and similar expected gains for plant vigor and scab resistance selection when 1 and -3 (Pesek & Baker) or higher than 4 and lower than 2 (Mulamba & Mock) were used as economical weights, respectively. Differences were found among the estimates of the repeatability coefficients obtained by the method of ANOVA and by the multivariate methods. The method of the main components based on the covariance matrix always presented larger estimates, mainly for thickness of the skin and longitudinal length of the fruit. Eighteen measurements will be enough to predict the individuals' real value of the fresh mass of the fruit, pulp, skin mass, longitudinal length and equatorial diameter with 90% of accuracy in the first year of production. The thickness of the skin varies with the mass of the fruit, so that the evaluation of the skin thickness in fruits with different mass can cause misunderstandings in the evaluations. Interactions were found between the progenies and the classes of mass of the fruit for mass of the skin and mass of the seeds. The equatorial diameter of the fruit presented higher correlation with the fresh mass of the fruit, when compared to the longitudinal length, indicating the viability of indirect selection of progenies with higher fruit mass by evaluation of the fruit diameter.