Genetic control of resistance to Liriomyza sativae by antixenosis in the melon accession

Abstract

In melon, characterizing germplasm allows identification of genotypes resistant to leafminers; knowing the genetic control of this resistance is indispensable for use in breeding. In this study, the genetic inheritance of resistance to L. sativae by antixenosis was investigated in the melon accession CNPH 94-244 (P_R) in crosses with the susceptible hybrids ‘Goldex’ (P_S) and ‘Iracema’ (P_S’), generating two populations. The plants were infested by the insect in screened plant enclosures and in the field. In the enclosures, the number of leaf mines and pupae per plant were evaluated; and in the field, a subjective score was attributed and the number of mines per leaf were counted. The genetic studies were based on the mean values and variances in the different generations (P_R, P_S or P_S’, F₁, F₂, BC₁, and BC₂), in each population. Genetic inheritance of resistance to L. sativae by antixenosis in the accession CNPH 94-244 has predominantly additive effects and is oligogenic for the subjective score variable and polygenic for number of mines and pupae per plant variables in both populations. By the number of mines variable, it was polygenic in the CNPH 94-244 × ‘Goldex’ population and oligogenic in the CNPH 94-244 × ‘Iracema’ population.