Varietal differences in sugar contents and their stability to growing and environmental conditions in tomato

Abstract

Varietal differences in glucose and fructose contents were evaluated in mature fruits of 30 genotypes grown under different cultivation systems. Varietal differences of glucose and fructose contents were comparatively stable among the cultivation systems. Although there is a high correlations between glucose and fructose contents, the percentage fructose to total sugar content was lower in the genotypes containing higher sugar content. There are no genotypes which has a high stable sugar content. Regression analysis of mean genotype and individual genotype contents of glucose and fructose reveals that the tomato genotypes were divided to four groups as follows. 1. Genotypes with regression coefficient almost equal to the mean genotype content. 2. Genotypes with significantly higher regression coefficient than the mean genotype content. 3. Genotypes with significantly lower regression coefficient than the mean genotype content. 4. Genotypes whose regression coefficient were not significant.