CONSERVATION AND CHARACTERIZATION OF GERMPLASM OF SELECTED VEGETABLE CROPS
Location: Plant Genetic Resources
Title: Magnitude of genotype x environment interactions affecting tomato fruit quality
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 13, 2012
Publication Date: June 1, 2012
Citation: Panthee, D., Cao, C., Debenport, S., Rodriguez, G., Labate, J.A., Robertson, L.D., Breksa Iii, A.P., Van Der Knaap, E., Mcspadden-Gardener, B. 2012. Magnitude of genotype x environment interactions affecting tomato fruit quality. HortScience. 47:721-726.
Interpretive Summary: Fruits and vegetables of high quality and high nutritional value are increasingly in demand by U.S. consumers. Government guidelines currently recommend that fruits and vegetables account for 50% of our dietary intake at each meal (http://www.choosemyplate.gov/). Some of the major compounds that affect flavor, quality and nutritional value of fresh tomatoes are sugars, acids, vitamin C and the red pigment lycopene. The quantities of these compounds are determined both by genes and the growing environment. To better understand the genes and environmental factors influencing the levels of these compounds, we grew 42 different tomato varieties in three diverse environments (OH, NY and NC), in replicated plots. We used statistical methods to estimate the effects of genes (G), the environment (E) and their interactions (GxE). We found significant differences in the amounts sugars, acids, vitamin C and lycopene among different tomato varieties, among the three environments, and a strong GxE effect. Understanding these influences will help breeders develop varieties that are of consistently high quality, despite where they are grown to be sent to market.
There is a growing interest by consumers to purchase fresh tomato with improved quality traits including lycopene, total soluble solids (TSS), vitamin C and titratable acid (TA) content. Therefore, there are considerable efforts by tomato breeders to improve tomato for these traits. However, suitable varieties developed for one location do not perform the same across different locations. This causes a problem for plant breeders since it is too labor-intensive to develop varieties for each specific location. The objective of this study was to determine the extent of genotype x environment (GxE) interaction that influences tomato fruit quality. To achieve this objective, we grew a set of 42 diverse tomato genotypes with different fruit shapes in three locations: North Carolina (NC), New York (NY) and Ohio (OH) in replicated trials. Fruits were harvested at red ripe stage and analyzed for lycopene, TSS, vitamin C and TA. Analysis of variance (ANOVA) revealed that there was a significant difference (p<0.05) among tomato genotypes, location and their interaction. There was also a significant difference among fruit shape categories for all quality traits except lycopene. However, there was no interaction between fruit shape and quality traits. Further analysis of quality traits from individual locations revealed that there was as much as 211% change in performance of some genotypes in a certain location compared to the average performance. Lycopene was found to be most influenced by the environment whereas TA was the least influenced. This was in agreement with heritability estimates observed in the study for these quality traits, as heritability estimate for lycopene was 16% whereas that for TA was 87%. The extent of GxE interaction found in the fruit quality traits of the tomato varieties included in this study may be useful in identifying optimal locations for future field trials by tomato breeders aiming to improve tomato fruit quality.