Estimating the pleiotropic effect of the jointless-2 gene on the processing and agronomic traits of tomato by using near-isogenic lines

Two near-isogenic lines of the processing tomato cv. ‘IPA-5’, pheno-typically distinct from each other only in terms of the presence or absence of a jointless fruit pedicel, were used to estimate pleiotropic effects of the recessive gene j-2 on 15 processing and agronomic parameters. Total yield, total yield of mature fruit, total yield of green fruit, total number of fruit, total number of mature fruit, total number of green fruit, mean weight of mature fruit, mean weight of green fruit, mean weight of mature plus green fruit, soluble solids, fruit colour, pH, titratable acidity, sugar: acid ratio, and fruit firmness were compared in jointed (J-2/J-2) and jointless pedicel (J-2/J-2) lines. Statistically significant differences were detected between both isolines for the following parameters: total number of fruit, total yield, total yield of green fruit, and total number of green fruit. In all cases, smaller values were observed in the isoline with the genetic constitution J-2/J-2. These data reinforce the view that they j-2 gene may cause, in some specific tomato backgrounds, significant yield constraints. Furthermore, it was demonstrated that this gene cannot exert any important pleiotropic influence on any of the processing characteristics evaluated.