Abstract This study evaluated the phenotypic variation in Total Soluble Solid (TSS) quantified in different environments, together with allelic diversity and genetic-population structure based on 18 microsatellites loci (SSR) in QTLs (Quantitative Trait Loci). The phenotypic characterization in 41 Brazilian accessions of melon and three commercial cultivars revealed a wide variation in TSS, with values higher than 9.0 % for commercial cultivars and lower than 4.0 % in traditional melon accessions. The genetic parameters inferred by the phenotypic analysis revealed low variances but high heritability, indicating that the expression in TSS is highly related to the genotypic potential. In contrast, the significant effect of genotype and environment interaction (G x E) on the studied trait suggests that the selection or recommendation of promising plants for breeding should be based on the behavior of these accessions in more than one environment. High allelic diversity was verified with amplification of SSR loci, ranging from two to ten alleles per locus. High polymorphic content indicates the use of markers such as CMATN22 for mapping and binding analysis. The graphical representation of genetic diversity revealed the formation of two large groups of variation, both in the main components analysis graph and in the weighted neighbor-joining dendrogram. The certification of the distribution was validated by the inclusion of two genotypes of the Spanish access “Piel de Sapo” (PS) in a group different from the exotic Korean access “Songwhan Charmi” (PI161375) and the hybrid PI161375 X A16. The genetic-population structure was inferred using the ad hoc and ΔK method, indicating two well-defined populations and corroborating the graphical information of genetic diversity distribution. However, eight subpopulations were defined, structuring genetic diversity in the analyzed germplasm. The distribution of PS and PI161375 varieties in different subpopulations, despite the structural similarity between the two PS genotypes, indicates an expected pattern in the population structure. The results show the studied germplasm is structured but diversified both from the phenotypic point of view and from the variation in alleles in QTLs for TSS.

中文翻译：

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甜瓜 (Cucumis melo L.) 的表型变异性、多样性和遗传种群结构与总可溶性固体相关

摘要 本研究基于 QTL (Quantitative Trait Loci) 中的 18 个微卫星位点 (SSR)，评估了在不同环境中量化的总可溶性固体 (TSS) 的表型变异，以及等位基因多样性和遗传种群结构。41 个巴西甜瓜种质和 3 个商业品种的表型特征揭示了 TSS 的广泛变化，商业品种的值高于 9.0%，而传统甜瓜种质的值低于 4.0%。表型分析推断的遗传参数显示低方差但高遗传力，表明 TSS 中的表达与基因型潜力高度相关。相比之下，基因型和环境相互作用 (G x E) 对研究性状的显着影响表明，选择或推荐有前途的育种植物应基于这些种质在不止一种环境中的行为。通过 SSR 基因座的扩增验证了高等位基因多样性，每个基因座有 2 到 10 个等位基因。高多态性表明使用标记如 CMATN22 进行定位和结合分析。遗传多样性的图形表示揭示了在主要成分分析图中和加权相邻连接树图中形成了两大组变异。分布的认证通过将西班牙访问“Piel de Sapo”（PS）的两种基因型包含在与异国情调的韩国访问“Songwhan Charmi”（PI161375）和杂交PI161375 X A16不同的组中来验证。使用 ad hoc 和 ΔK 方法推断遗传种群结构，表明两个明确定义的种群并证实了遗传多样性分布的图形信息。然而，定义了八个亚群，在分析的种质中构建了遗传多样性。尽管两种 PS 基因型之间的结构相似，但 PS 和 PI161375 品种在不同亚群中的分布表明了种群结构的预期模式。