Identification of ssr markers associated with resistance to Liriomyza sativae in Cucumis melo

Abstract

ABSTRACT Melon is an economically important crop worldwide, but pest infestations limit fruit yield and quality. The leafminer fly (Liriomyza spp.) is a major pest of melon crops. Therefore, resistant genotypes carrying specific alleles are highly desirable. This study aimed to identify SSR markers associated with melon resistance to the leafminer fly. Crosses were performed between resistant (Rutênio) and susceptible (Vedrantais) plants, generating F₁, F₂, and backcross populations that were evaluated for resistance. Molecular markers were used for genotyping, and segregation tests based on chi-square analyses were conducted to assess genetic distortions. Regression analyses were used to estimate marker effects on phenotypic variation. Among the 192 F₂ plants evaluated, phenotypic segregation followed a 3:1 ratio, consistent with monogenic dominant inheritance. Of the 100 SSR markers tested, 19 were polymorphic, and 13 were selected because they showed no significant segregation distortions. Three markers (CMTA166, CMCT170B, and CMTA134A) explained 5.73%, 4.46%, and 3.32% of the phenotypic variation, respectively. Multiple regression analysis indicated that CMTA166 and CMCT170B jointly explained 9.42% of the variation. Although the identified SSR markers accounted for a relatively small proportion of the phenotypic variation, CMTA166 and CMCT170B showed the strongest association with resistance to Liriomyza sativae and may contribute to future marker-assisted selection studies in melon breeding programs.