<b>Interference of genotype-by-environment interaction in the selection of inbred lines of yellow melon in an agricultural center in Mossoró-Assu, Brazil

Abstract

ABSTRACT. The aims of this study were to i) identify the influence of the GxE interaction in the selection of inbred lines of melon, and ii) test the efficiency of different indexes in the selection of inbred lines with a higher yield potential and better quality fruit. For these purposes, 98 inbred lines of yellow melon and two commercial controls, Vereda and AF-646, were evaluated in a randomized block design with two replications, at the conditions present in Mossoró and Baraúna. Analyses of the following traits were performed: fruit yield, mean fruit weight, pulp thickness, pulp firmness and soluble solids content. A complex portion of the GxE interaction was predominantly detected for all traits. The recommendation in this case is to promote selection in each environment. Alternatively, selection based on the average behavior of the inbred lines is the strategy that generates the greatest gains, approaching those obtained through direct selection in each specific environment. The selection indexes aimed at reducing the expression of all traits proved to be best for both locations. The index constructed for Baraúna allowed the selection of a greater number of inbred lines with a higher yield potential and better quality fruit and, thus, greater efficiency.Keywords: Cucumis melo L, segregant populations, genetic gains, inbred lines extraction, hybrids, selection indexes.Interferência da interação genótipo por ambiente na seleção de linhagens de melão amarelo no agropolo Mossoró-Assu, Brasil RESUMO. Objetivou-se com esse estudo: i) identificar a interferência da interação GxE no processo de seleção de linhagens de melão e; ii) testar a eficiência de índices na seleção de linhagens com maior potencial produtivo e melhor qualidade de fruto. Para isto, avaliaram-se 98 linhagens de melão amarelo e duas testemunhas, Vereda e AF-646, em blocos casualizados com duas repetições, em Mossoró e Baraúna, localizadas no Agropolo produtor desta hortaliça. Avaliaram-se os caracteres produtividade de frutos, massa média de frutos, espessura de polpa, firmeza de polpa e sólidos solúveis. Detectou-se uma predominância da porção complexa na interação GxE em todos os caracteres. A recomendação, neste caso, é promover a seleção em cada ambiente. Alternativamente, a seleção baseada no comportamento médio das linhagens é a estratégia que gera ganhos mais próximos àqueles obtidos pela seleção direta em cada ambiente específico. Os índices de seleção, com o propósito de reduzir a expressão de todos os caracteres, se mostraram melhores para ambas as localidades. Àquele construído para Baraúna permitiu selecionar um maior número de linhagens com elevado potencial produtivo e com melhores qualidades de fruto, sendo assim, mais eficiente. Palavras-chave:Cucumis melo L, populações segregantes, ganho genético, extração de linhagens, híbridos, índices de seleção.

Stability, adaptability and shelf life of Cantaloupe melon hybrids

“…In this case, the best options for selection were verified in groups 1 and 2 for productivity, and in group 2, for SS content, with estimates ≥60%. Estimates of heritability for productivity and SS content are within the ranges observed in some melon crops in the Mossoró-Assu Agricultural Complex (MELO et al, 2011;ARAGÃO et al, 2015, GUIMARÃES et al, 2016.…”

“…This indicates that there was a predominance of the complex part of the interaction for the two traits evaluated, thereby making the selection process difficult. Previous studies in the Mossoró-Assu Agricultural Complex indicated the predominance of the complex interaction for productivity and SS content in Yellow melons (ARAGÃO et al, 2015;GUIMARÃES et al, 2016;NUNES et al, 2006;. Only Nunes et al (2011b) found a predominance of the simple part of the interaction when measuring SS content in Galia melon hybrids evaluated across nine environments in the Mossoró-Assu Agricultural Complex.…”

“…The interaction shows the different behavior of the hybrids in different environments. The genotypeenvironment interaction in melon crops has been verified in the evaluation studies of melon hybrids (FREITAS et al, 2007, NUNES et al, 2005, NUNES et al, 2011a, as well as in the evaluation of families (ARAGÃO et al, 2015, GUIMARÃES et al, 2016. In evaluations of cultivars, genotype-environment interaction plays a key role and may greatly influence the selection process, though the logical difficulty is found in the selection of promising genotypes.…”

“…Moreover, 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 an important role in the manifestation of phenotypic. This event has occurred in many trials aimed at the evaluation of melon cultivars in the Mossoró-Assu Agricultural Complex (ARAGÃO et al, 2015;FREITAS et al, 2007;GUIMARÃES et al, 2016;NUNES et al, 2006). Once the presence of the interaction is detected, measures must be promptly taken so as to mitigate this effect.…”

Adaptability and Phenotypic Stability of Lettuce Cultivars in a Semiarid Region

“…This is explained by the different response of genotypes to different environments (YAN et al, 2007). Genotype -environment interaction affects phenotypic manifestation and may hinder plant breeding and the recommendation of cultivars from the selection process (GUIMARÃES et al, 2016).…”