Evaluation of F1 populations from a 4 x 4 diallel in pineapple and estimation of breeding values of parents

Y. K. Chan

Abstract

A complete diallel cross in pineapple was carried out using four parents from three diverse groups, i.e. Sarawak (Cayennc), Moris (Queen), Masmerah (Spanish) and Johor (Spanish). Analyses ol the F₁ populations for eight characters showed wide variation, often exceeding twice that of the parents, and this represents scope for selection and improvement. Identifying the parents most likely to generate the best F₁ populations was relatively straight forward when characters were consideted one at a time. For each character, more promising F₁ populations may be produced by using the parent with the best mean if there was no female parent x male parent interaction, or by using the best combination of  parents when interaction was significant. In this study, Sarawak was found to be the best parent for increasing fruit size. Masmerah was effective for reducing core diameter, but Johor was a poor parent in so far as improvement. of tolerance to marbling and cork spot discases was concerned. For increasing TSS content, the best cross was Sarawak-Moris, while the best for improvement of flesh colour were Moris-Masmerah and is reciprocal. Estirnation of breeding values of parents was more complicated when all the characters were considcred simultaneously for selection.The computation of an overall breeding value for each cultivar was described. This was based on the product of the proportion of progenies that qualified for selection in each character.

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