Semina: Ciências Agrárias (Aug 2015)
Selection of full and half brothers families of yellow passionfruit resistant to Tetranychus mexicanus
Abstract
The goal of this study was to assess the behaviour of the full and half brothers families of yellow passionfruit with respect to resistance to mites (Tetranychus mexicanus), and study the alternatives of selection based on the estimated genetic gain. The 113 families of full and half brothers were assessed using randomized block designs arranged in sets, with respect to productivity of first flowering (g 21 m-2), which was defined from the average weight of the fruit, the number of fruits harvested in the first flowering, and the main character, which corresponded to the average number of mites per plot. The F-test showed genetic variability in the number of mites with respect to male families, and in the productivity of first flowering linked to female/male families and male families. It was observed that male variance was greater than female variance with respect to the number of mites. Consequently, there was no gene effect attributed to dominance in this character. The coefficient of male heritability regarding the number of mites was half the heritability of productivity in the first flowering, indicating that it was highly influenced by the environment. Regarding the two characters assessed, the combined selection was the one that provided the greatest selection gains.
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