Exploring morpho-physiological profiles of a collection of tomato (Solanum lycopersicum) germplasm using multivariate statistics

Abstract

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.

Evaluation of a dill (Anethum graveolensL.) gene bank germplasm collection using multivariate analysis of morphological traits, molecular genotyping and chemical composition to identify novel genotypes for plant breeding

“…Non-parametric Spearman correlations were used for the determination of the relations between the morphological traits ( Mellidou et al, 2020 ). Principal component analysis (PCA), which provides the multivariate statistical analysis of a dataset, was used to identify the main traits included in the dataset obtained.…”

Utilization of Tomato Landraces to Improve Seedling Performance under Salt Stress

“…The collection of tomato germplasm (Solanum lycopersicum) used to study seedling responses to salt stress included five landraces (cvs 'Santorini', 'Zakynthos', 'Paxoi', 'HL073', 'Agiou Orous', named V1 to V5, respectively), one modern variety (cv 'Makedonia'-V6), the salt-sensitive cv 'Ailsa Craig' (AC), the salt-tolerant accession LA1579 (a wild species of Solanum pimpinellifolium), as well as the Solanum pennellii introgression line IL12-4 (LA4120), rich in vitamin C content (Table S1). More details on the origin and the phenotypic characterization of the selected landraces can be found elsewhere [61]. Seeds were obtained either from the vegetable collection preserved at the Hellenic Agricultural Organization (HAO) Demeter, originated from different districts in Greece (Makedonia, Ionian Sea, Aegean Sea, Crete), or from the Tomato Genetics Resource Center (TGRC).…”

Multivariate analysis unravels genetic diversity and relationship between agronomic traits, protein, and dietary fiber in yardlong bean (Vigna unguiculata subsp. sesquipedalis Verdc.)

“…Apart from the contribution of each trait to total variability, PCA was also able to dissect the genotypes contribution to total diversity. Genotypes are said to have meaningful contributions if they exhibit principal component scores of more than 1 (Mellidou et al 2020). A list of genotypes with a significant contribution based on the principal component score in PC1 and PC2 are tabulated in Table 4.…”