Genetic variation and heritability of blossom-end scar size in tomato

Large blossom-end scar is a disorder in tomato fruit which reduces its marketability. The disorder is affected by genotype and by environment. This study was donducted in order to identify genotypes with small blossom-end scar and to estimate the genetic variation and the heritability of the trait. The blossom-end scar size (BSS) of 27 genotypes, 18 open pollinated varieties and breeding lines and 9 F1's, grown in 3 fields representing spring, summer, and winter production, was recorded. The genotypes' BSS was distributed in a continuous bi-modal fashion. A few genotypes exhibited consistently small BSS, and line N-643 the smallest one. The genetic variance component for BSS was 3, 2.1, and 2.5 in fields 1, 2, and 3, respectively. The other major source of variation was fruits within plants. Single plant heritability estimates were 0.71 and 0.72 in fields 1 and 2. Single plot heritability estimates were 0.92, 0.75, and 0.81, in fields 1, 2, and 3, respectively. Joint analysis of all the fields revealed relatively small, though significant genotype by environment interaction. It was concluded that it should be possible to select for genotypes with small blossom-end scar. Such genotypes are likely to have small BSS in a wide range of environments.