Herança genética da resistência por antibiose à mosca-minadora na linhagem de meloeiro EATMEL 20230024

Abstract

The leafminer fly (Liriomyza sativae Blanchard) is one of the main pests of melon (Cucumis melo L.), causing significant damage to the crop and increasing production costs due to the intensive use of insecticides. In this context, genetic resistance constitutes a sustainable alternative for managing this pest. The present study aimed to elucidate the genetic inheritance of antibiosis resistance to the leafminer fly in the melon line EATMEL 20230024. To this end, a population was structured from the cross between the resistant line EATMEL 20230024 (P1) and the susceptible line EHMEL 200910 (P2). Parental generations (P1 and P2), filial generations (F1 and F2), and backcrosses (RC1 and RC2) were evaluated under cage and field conditions, considering the number of mines per plant, larval and pupal viability of the insect, and the phenotypic classification of the plants regarding resistance. Statistical analysis, performed using the GENES program, employed the Chi-square test to assess the fit of the data to the proposed genetic models. The results showed phenotypic uniformity in the F1 generation, an approximate segregation of 3:1 in F2, and 1:1 in the backcross with the susceptible parent, confirming that resistance is controlled by a single dominant gene. The reduction in larval and pupal viability of the leafminer fly in resistant plants indicated that the resistance mechanism acts predominantly through antibiosis, with no antixenosis-type resistance observed. Validation under field conditions confirmed the stability of the trait expression. It is concluded that the genetic inheritance of the EATMEL 20230024 lineage is conditioned by a single gene with two alleles and a complete dominance relationship, constituting a promising source of genetic resistance to L. sativae, with potential application in melon breeding programs and integrated pest management strategies.