Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 18, 2013
Publication Date: April 24, 2013
Citation: Panthee, D., Labate, J.A., Mcgrath, M., Francis, D., Breksa III, A.P., Robertson, L.D. 2013. Genotype and environmental interaction for fruit quality traits in vintage tomato varieties. Euphytica. 193:169-182. Interpretive Summary: Tomato is the second most commonly consumed vegetable in the world, after potato. There is a growing demand for quality tomato in the market place in terms of texture, flavor and nutritional value. Traits such as lycopene (the red pigment), sugars, vitamin C and acidity all contribute to quality of tomato fruit. We studied a diverse set of 44 vintage (heirloom) tomato varieties in four different environments. The purpose was to 1) measure differences in the four traits among the varieties and 2) discover whether the performance of each variety was consistent across different environments. We found highly significant differences in each of the four quality traits among the varieties. We also found that different environments interacted with the varieties to influence the trait values. The results of this study will help breeders to select parents for developing improved varieties of vintage tomatoes.
Technical Abstract: Tomato (Solanum lycopersicum L.) is the second most commonly consumed vegetable after in the world, after potato. There is a growing demand for quality tomato in the market place. Traits such as lycopene, total soluble solids (TSS), vitamin C and titratable acid (TA) content contribute to the overall quality of the fruit. In order to address these concerns through breeding, evaluation of a broadly diverse set of tomato germplasm is the first step. The objective of the present study was to evaluate vintage tomato varieties representing a wide genetic background in multiple environments and to analyze their consistent performances across locations. In order to achieve this objective, we acquired 44 vintage tomato varieties of diverse origins and evaluated them in a total of four environments (NC, NY, OH in 2009 and OH in 2010). Analysis of the data revealed that there was a significant Genotype, and Genotype x Environment (GxE) interaction (p<0.01) for lycopene, TSS, vitamin C and TA. Significant differences among the genotypes indicated that some of those may be of interest to use as parents in tomato breeding programs aiming to improve fruit quality whereas significant GxE interactions indicated that the performance of the vintage tomato varieties may be location specific. Heritability of these traits ranged from 49.8% (lycopene) to 88.7% (TSS). Both genetic and phenotypic correlation analysis indicated that lycopene was negatively correlated with the other traits whereas vitamin C, TSS and TA were positively correlated among each other. Positive correlation between TSS and vitamin C was also supported by the detection of same molecular markers associated with these traits. The 44 vintage tomato varieties were grouped into three distinct clusters on the basis of phenotypic data. Cluster analysis based on 18 single nucleotide polymorphisms (SNPs) was inconclusive with the exception of a separate clade consisting of two cherry tomato varieties. SNP diversity (average expected heterozygosity = 0.110 plus or minus 0.0351) showed that this set of vintage varieties was slightly less diverse than two geodiversity panels. This information may be useful to select the parent(s) for a tomato breeding program aiming to develop improved quality tomato varieties.