Simultaneous selection for yield and stability in papaya (Carica papaya L.)

Y. K. Chan and C. Mak

Abstract

Twenty-one genotypes of papaya consisting of six inbreds and their 15 half-diallel hybrids were tested over six environments to study their performance in yield and stability. Significant G x E interaction was obtained, indicating that yield performance of genotypes was environment-dependent. Therefore, selection cannot be based on mean yield alone and stability in performance has to be considered as well. Four methods were used for simultaneous selection of genotypes for high yield and good stability. Results indicated that there were certain discrepancies in selection decisions among the various methods. The C.V. and mean distribution method gave emphasis to selection for genotypes with high mean yields while the non-parametric ranking indices favoured genotypes with high stability. The rank-sum and rank-product indices appeared to be well-balanced and unbiased in selection between mean and stability. Between the two indices, however, the rank sum appeared to lean towards selection for stability.

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