Effect of 1-methylcyclopropene on ripening and associated parameters in tomato fruits

Tomato (Lycopersicon esculentum Mill.) cv. Pusa Ruby and Pusa Gaurav fruits were harvested at mature green stage and exposed to 1-MCP evolved from ethylbloc at concentrations of 1l/l and 5l/l for 4 hours, at 28±2°C. The fruits were then stored at room temperature (28±2°C). The treatment of 5l/l of 1-MCP delayed ripening by four days in both the varieties. Respiration rate, chlorophyll, lycopene, carotenoid contents and polygalacturonase activity were determined in mature green fruits just before treatment and at half ripe and full ripe stages. 1-MCP treatment not only delayed lycopene accumulation but also significantly reduced its magnitude. However, total carotenoids content was enhanced by 1-MCP treatment. Polygalacturonase activity was highly inhibited by 1-MCP at half ripe stage, but did not affect it at full ripe stage. The results imply that 1-MCP could be effective in delaying the ripening process in tomato fruits under tropical condition.