Heterosis and inbreeding depression was studied in tomato under low temperature regime. A total of six parental lines comprising of two cold set (Pusa Sheetal and Pusa Sadabahar) and four non-cold set (Booster, DT-39, Pusa Uphar and Chiku) were crossed in a diallel fashion without reciprocals to obtain 15 F1s. Significant positive as well as negative heterosis over better and mid-parent for first fruit set was recorded in most of the crosses. Maximum heterosis over better parent was recorded in cross PSH × DT 39 (−7.55%). Hybrids PS × CH (51.92%) followed by PSH × PU (46.88%) had the maximum heterosis over better parent in desirable positive direction. Hence, PSH × PS and PSH × CH F1 hybrids could be recommended for growing successfully under low temperature regime because of their ability to set fruit, early and higher total yield.
Heterosis, imbreeding depression low temperature, tomato
