Combining ability and heterosis for yield and some fruit traits of tomato

Abstract

This study was conducted to estimate heterosis and combining ability for yield and some economic-related characteristics in tomato. For this purpose, six tomato lines with their 15 direct hybrids resulted from half-diallel mating were cultivated during the 2017 and 2018 seasons in Al-Jamasah station, Tartous agricultural research center, Syria. Results showed that most of the hybrids were characterized by significant desirable heterosis compared to mid-parents and the best-parent for most of the studied traits. Heterosis reached 49.03 and 33.4% for single plant yield, -31.2 and -29.27 for the number of days to the beginning of flowering, 89.73 and 61.77% for the number of fruits per cluster, 15.72 and 9.30% for fruit height, 27.29 and 24.18% for fruit diameter, 32.55 and 24.18% for the number of locales per fruit comparing to mid-parents and best-parent, respectively. The hybrids T2×T6, T2×T8, and T8×T16 were significantly superior and could be promising hybrids for improving yield potential. Variations related to general and specific combining ability were highly significant, indicating the role of additive and non-additive gene action in the inheritance of the studied traits. Furthermore, the ratio (σ2GCA/σ2SCA) showed the control of additive gene action in the inheritance of fruit weight, fruit height, fruit diameter, and the number of fruits per cluster, while non-additive gene action controlled the inheritance of single plant yield, the number of days to flowering and the number of locales per fruit.

Keywords

• solanum lycopersicum
• general combining ability
• specific combining ability
• diallel
• hybrid