A selection of tomato (Solanum lycopersicum L.) genotypes with diverse origin and breeding history including 33 landraces, eight modern varieties and two commercial hybrids has been characterized using a set of 25 qualitative descriptors and six quantitative traits. A wide range of variation was evident for the majority of traits, highlighting their utility for characterizing tomato germplasm collections. A plethora of qualitative traits including type of leaf blade, depression and ribbing at peduncle end, fruit shape at blossom end, number of locules and flowering time, as well as measured traits with economic importance such as fruit fresh weight, firmness and total yield per plant, were found to be highly variable within the collection, with a diversity index greater than 0.8. Strong correlations were detected among several traits related to fruit yield and quality. Two-dimensional principal component analysis as well as the unsupervised hierarchical clustering grouped genotypes according to their phenotypic resemblance and morphological characteristics to a great extent. Landraces from different origins were scattered across the whole variation spectrum of PC1 and PC2. A set of six qualitative traits could efficiently discriminate cultivars in PCA (explaining 75% of total variation), suggesting that it can serve as a valuable breeding tool for the germplasm characterization. The evaluation of the phenotypic diversity in the collection as well as the identification of traits that contribute most to heterogeneity have important implications for establishing core collections with high diversity, as well as designing breeding schemes across the Mediterranean basin.

中文翻译：

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使用多元统计探索番茄 (Solanum lycopersicum) 种质资源的形态生理学特征

番茄的选择（番茄L.) 具有不同起源和育种历史的基因型，包括 33 个地方品种、8 个现代品种和 2 个商业杂交种，已使用一组 25 个定性描述符和 6 个数量性状进行了表征。大多数性状明显存在广泛的变异，突出了它们在表征番茄种质收集方面的实用性。大量的定性性状，包括叶片类型、花序梗末端的凹陷和棱纹、开花末端的果实形状、室数和开花时间，以及具有经济重要性的测量性状，如果实鲜重、硬度和每单位的总产量植物，被发现在集合中是高度可变的，多样性指数大于 0.8。在与果实产量和质量相关的几个性状之间检测到强相关性。二维主成分分析以及无监督层次聚类在很大程度上根据基因型的表型相似性和形态特征对基因型进行分组。来自不同来源的地方品种分散在PC1和PC2的整个变异谱中。一组六个定性性状可以有效区分 PCA 中的品种（解释总变异的 75%），表明它可以作为种质表征的有价值的育种工具。对馆藏表型多样性的评估以及对异质性贡献最大的性状的鉴定对于建立具有高多样性的核心馆藏以及设计整个地中海盆地的育种计划具有重要意义。