Avaliação morfoagronômica de germoplasma de melão do nordeste brasileiro

Abstract

Melon (Cucumis melo L.) has the Brazilian Semiarid region as a highlight in national production from improved cultivars that generate uniformity, but are susceptible to various abiotic and biotic stresses, such as yellowing melon caused by the MYaV and CABYV viruses, and that it decreases the production and quality of the fruits. On the other hand, many locations in the Semiarid region cultivate melon in family farming, from traditional populations, where there is a great diversity of germplasm that has been selected for several generations, and which carry genes of importance for genetic improvement, including genes for resistance to various diseases and pests. Samples from these locations were collected and stored in the Active Germplasm Bank (BAG) of Cucurbitaceae for the Northeast of Brazil, requiring in-depth studies for a better understanding of the variability and resistance to various stresses that exist for the crop. Thus, this study aimed to estimate the variability between and within accessions and sub-accessions of melon, in the parental and S1 generations, belonging to this BAG, using morpho-agronomic descriptors, identifying the botanical groups present in this sample, as well as to examining the S1 progenies to biotic stress "amarelão do meloeiro". From the quantitative and qualitative morpho-agronomic descriptors used in this work, the univariate and multivariate analyzes in sequential generations allowed an in-depth study of the variability between and within the evaluated accessions and sub-accessions, making it possible to identify the botanical groups makuwa subg. nashi-uri, momordica and cantalupensis subg. prescott, however, some sub-accessions have not been identified because they have variations in their morphological characteristics, and are also attributed to the probable existence of allele introgression among different groups. In addition, the study of variability has inferred the existence of genotypes that can be inserted in breeding programs. From the analysis of the "amarelão do meloeiro", the sub-accessions were not resistant to viruses, however, within these sub-accessions there were resistant progenies that could be used in an improvement melon program. It was also possible to infer that melon yellow disease probably does not interfere in the quality of the fruit, mainly related to the mass characteristics of the fruit and the soluble solids content.