The adoption of melon hybrids by the productive sector necessitates a prior evaluation of the productivity, quality and shelf life of their fruits. Due to the different environmental conditions under which the hybrids are evaluated, an accentuated genotype-environmental interaction is expected to become apparent and likewise play important role in manifestation of phenotypic traits. The objective of the present work was to evaluate melon hybrids in the state of Rio Grande do Norte. The adaptability and stability of the genetic values were estimated by the HMRPGV method (Harmonic Mean of the Relative Performance of Genetic Values) for the following traits: yield, and soluble solids (SS) content in the period between 2010 to 2015. In 2017, the more promising melon hybrids from previous trials were evaluated under commercial conditions to determine the fruit’s yield, quality and shelf life. The predominance of the complex part of the genotype-environmental interaction was verified for both yield and SS content. Hybrids HC-02 and HC-11 show promising traits when grown under the conditions of the Mossoró-Assu Agricultural Complex owing their high stability, adaptability, yield, and fruit quality. Hybrids HC-02, HC-11, and ‘Hy Mark’ are suitable as international exports due to their long shelf life.

Melon (Cucumis melo L.) is cultivated worldwide, with prominence in the Northeast region of Brazil, due to its favorable soil and climate conditions. However, over the years, the genotype × environment (GxE) interaction phenomenon has been occurred, which can complicate the selection process depending on its extent (whether it is a simple or complex interaction). In this context, melon breeding programs aim to identify adaptable and stable genotypes, capable of reaching their maximum potential. Therefore, the objectives of this study were to investigate GxE interactions and identify cultivars with greater adaptability and phenotypic stability using various methods for comparison. Thirteen melon hybrids were assessed in four municipalities in the state of Rio Grande do Norte, across two planting dates, totaling eight distinct environments. The experiments were conducted in randomized complete blocks with three replications. The traits evaluated included the number of fruits per plant and total soluble solids. Several adaptability and stability methods were employed and compared including Wricke, Eberhart and Russell, Lin and Binns, Annicchiarico, GGE Biplot, and Resende (harmonic mean of relative performance of genotypic values). Significant GxE interaction for the number of fruits per plant was found to be simple, whereas for soluble solids, it was crossed. The methods of Linn and Binns, Annicchiarico, and Resende showed strong correlations among them and were all correlated with the trait mean. The HA-08 hybrid emerged as the most promising, exhibiting high number of fruits per plant, high soluble solids content, and exceptional adaptability and stability.

The main quality parameters of melon are related to sucrose accumulation and soluble solids content. Understanding the genetic control of these traits is essential to help breeders in the selection process. The aim of this study was to evaluate the inheritance of sucrose accumulation and soluble solids content in melon. A randomized block design with three replicates was used to evaluate AC-16 and Vedrantais parents, and F1, F2, BC1 and BC2 generations. We verified that sucrose is the main factor which is related to genetic and environmental variability observed in sugar content between parents. The inheritance of sucrose content involves a major effect gene with additive and dominance effects associated with polygenes with additive effects. The inheritance of soluble solids involves a major gene with additive and dominance effects associated with polygenes, with additive effects, and the presence of epistasis.

The use of resistant cultivars is an efficient and recommended method for the management of leafminers, which are the main phytosanitary problem in melons. The objectives of this study were to identify the sources of resistance to the leafminer in yellow melon accessions and to determine the resistance inheritance in acession AM-RT. Two field experiments were conducted in the municipalities of Baraúna, RN and Icapuí, CE, Brazil, to identify the sources of resistance. The design adopted was completely randomized blocks with 22 treatments and four replications. In this evaluation, the number of mines per leaf was quantified. The heterogeneity of the studied materials allowed for the identification of the accessions AM-RT and AM-TM as sources of resistance, considering that they revealed zero mines in the two evaluation environments. The accession AM-RT was selected and used to obtain the S1 population (by self-fertilization), S1:2 population derived from S1, and crossing between AM-RT and ‘Goldex’, which were evaluated in a third laboratory trial to determine the genetic control of resistance in that material. By the segregation pattern of the populations S1, S1:2, and the crossing (AM-RT and ‘Goldex’) and the estimation of the chi-squared (χ2) values, which were 1.33, 3.14, and 0.36, respectively, it was determined that the inheritance of resistance was controlled by only one gene with complete dominance. Therefore, in this study, two sources of resistance to the leafminer were identified, and resistance was conditioned by a gene with complete dominance in the accession ‘AM-RT’.

Limited knowledge exists on the impact of environmental covariates on the genotype-by-environment (G × E) interaction in melon cultivated under semi-arid conditions. This study assessed the influence of environmental covariables on G × E interactions and identified melon genotypes demonstrating adaptability and stability. Thirteen yellow melon hybrids were evaluated in randomized blocks with three replications across four municipalities in Rio Grande do Norte State during two distinct seasons. Traits investigated included the number of fruits per plant and soluble solids. Factor regression and principal component analysis were employed to quantify the influence of maximum and minimum temperature, relative humidity, and radiation on the G × E interactions. The Harmonic Mean of Relative Performance of the Genotypic Values method identified adapted and stable genotypes. The covariate-biplot model established relationships between crucial environmental covariables and their impact on the number of fruits per plant and soluble solids. Minimum temperature, relative humidity, and solar radiation significantly contributed to the G × E interactions in melon. Hybrids exhibited distinct sensitivities to environmental covariates, with HA-08 emerging as the most stable and adapted hybrid for both the number of fruits per plant and soluble solids.