Genotype and environmental interaction for fruit quality traits in vintage tomato varieties

Tomato (Solanum lycopersicum L.) is the second most highly consumed vegetable in the world after potato. Traits including physicochemical (lycopene, total titratable acid (TTA), total soluble solids (TSS) and vitamin C), morphological (fruit shape and size) and colors contribute to the overall fruit quality of tomato. The primary objective of the present study was to evaluate vintage tomato varieties representing a wide genetic background for fruit quality including physicochemical, morphological and color traits in multiple environments and to analyze consistency of their performances across locations. In order to achieve this objective, we acquired 44 vintage tomato varieties and evaluated them in five environments (NC, NY, OH in 2009, and NC and OH in 2010). Analysis of the data revealed that there was a significant (p < 0.01) difference among genotypes and environments for all quality traits, Genotype x Environment interaction was significant (p < 0.01) for all quality traits except for TSS. Broad-sense heritability of physicochemical traits ranged from 5.8 % (lycopene) to 35.7 % (TTA) whereas that for morphological traits ranged from 8.1 % (proximal eccentricity) to 97.3 % (fruit shape index external 1), and color from 69.0 % (a*-value) to 99.3 % (b*-value). Pearson's correlation analysis indicated that estimated lycopene content was negatively correlated with the other physicochemical traits whereas vitamin C, TSS and TTA were positively correlated with each other. Principal component analysis (PCA) based on phenotypic data identified five components explaining at least 82 % of the total variation. Cluster analysis based on phenotypic data revealed the clusters of vintage tomato varieties were not distinct whereas single nucleotide polymorphism data revealed three distinct populations. This information including heritability and correlation coefficients from the present study may be useful to tomato breeding programs to choose germplasm, improve the response to selection and simultaneously improve multiple traits for tomato fruit quality.