Dry matter, leaf area, leaf area ratio (LAR), specific leaf mass (SLM), and chlorophyll (Chi) a and b contents in different cultivars, lines and Fj hybrids of tomato plants (Lycorpersicon esculentum Mill.) were studied under constant in vitro conditions. Plant biomass and Chi content heterosis were observed in all breeding combinations regardless of genotypic features of initial forms. No differences in leaf area were found among cultivars, lines and Fj hybrids. High significant correlations were established among dry matter production, LAR and SLM values.