Genetic Variability and Character Association Analysis in Tomato

Abstract

Genetic variability, heritability (h2), genetic advance, character association and path analysis were carried out in
17 accessions of tomato (Solallum tycopersicllnl Mill.) during 2000-2001. Significant genotypic differences were
observed for all characters under study as indicated by the high genotypic eocfticient of variation for number of
fruits per plant, average fruit weight, number of locules per fruit, acidity percentage. length of fruits and yield
of fruits per plant. The characters with high genotypic coefficient of variation had also high heritabilities. This
indicates the possibility of genetic improvements for such traits through selection based on phenotype. Association
studies indicated that the yield of fruits per plant positively correlated with plant height. number of branches per
plant. number of fruits per plant. average fruit weight, fruit length, number of locules, TSS and ascorbic acid content.
Pericarp thickness and acidity percentage are negatively correlated with yield. Path cocfficient analysis revealed
that plant height. number of branches per plant, width of fruit, number of fruits per plant and average fruit weight
exhibited the maximum positive direct effect on yield. Thus an increase in selection on these traits may lead to
an over all increase in the yield. Quality trait~ except pericarp thickness and TSS did not play any signiticant
dircct and indirect role. Therefore, a genetic improvement of yield can be initiated by putting positive selection
pressure on plant height, number of branches per plant, width of fruit, number of fruits per plant and average
fruit weight.