Abstract
Relationship between fruit weight and seed content within and among varieties in the tomato fruit was studied by two variety tests in order to clarify how environmental condition or tomato breeding influences on the relationship between these two characters.
Within-variety correlation and within-variety regression between the two characters were about 0.60 and 0.95 in the average of variety and experiment, respectively, but the within-variety correlations and regressions showed considerably large. variations among varieties near to the significant level. From these results it was inferred that on the whole there was positive correlation between fruit weight and seed content within variety, and hence environmental conditions positively affected the two characters and caused the increase of one accompanied with that of the other. Furthermore, it was also inferred that there was varietal difference, namely, genotypic difference among the degrees of the association expressed by correlation and the directions of the association expressed by regression.
Subsequently, phenotypic, genotypic and environmental correlation were estimated from the analyses of variance and covariance in order to examine the relationship between the two characters among varieties. From the phenotypic correlations it was also confirmed that environmental conditions could produce positive correlation between thee two characters. On the other hand, genotypic correlation was about 0.60 in the average of experiment. The genotypic correlations were considered to be statistically significant. This suggests that the direct improvement of fruit weight by tomato breeding has been accompanied with the indirect increase of seed content and various types of varieties have been differentiated, some developing heavy fruits with fewer seeds, while others producing plenty of seeds in smaller fruits.
High heritability values were obtained in both the characters.
