Abstract

A study was conducted in a 8 × 8 half diallel cross set of tomato excluding reciprocals to estimate the general combining ability and specific combining ability for marketable fruit yield per plant (kg) and yield components, namely number of fruits per plant, individual fruit weight (g) fruit length (cm), fruit diameter (cm) and fruit thickness (cm) including some quality traits as TSS, pH and pericarp thickness. The experiment was conducted from December 2019 to March 2020 at Wollega University Experiment Field, Shambu and Hareto sites. Simple lattice design was used for field trial. Data from Fl generation and parents were analyzed using the Griffing Method II of Model I. Significant differences among genotypes were obtained for all the traits except for number of primary branches per plant. The effects of general combining ability (GCA) and specific combining ability (SCA) were highly significant indicating the presence of additive as well as non-additive gene effects except for fruit length and fruit diameter. The genotype P8 is selected a parent with the best general combining ability for marketable fruit yield per plant, individual fruit weight, fruit density, and fruit thickness. The tomato genotype P5×P7 followed by P3×P6 and P3×P7 were proved to be the best specific combiner for marketable fruit yield and number of fruits per plant.

Key words: Combining ability, diallel, general combining ability (GCA), tomato, specific combining ability (SCA).