Effects of Exogenous ABA on Contents of Lycopene and Endogenous Hormone in Tomato Pericarp

Abstract

Aims: This research studied the regulatory effect of ABA (Abscisic acid) on the contents of lycopene and endogenous hperipheral pericarp of tomato fruit during ripening, and provided an effective measure for improving the quality of tomato fruits. Study Design: When the second cluster of toormone in mato fruits reached green mature stage, fruits were labeled and sprayed ABA (100 mg·L-1) over fruit surface, with spaying water as control, avoiding polluting the leaves. After treatment for 0, 4, 8, 12, 16, 20d, 10 fruits were sampled and dissected, peripheral pericarp for measuring the contents of lycopene, GA3 (Gibberellic acid), ABA, ZT (Zeatin) and ETH (Ethylene). Place and Duration of Study: Horticultural College, between February 2014 and March 2015. Methodology: The contents of lycopene, GA3, ABA and ZT were determined using HPLC (High Performance Liquid Chromatography). The content of ETH was determined using GC (Gas Chromatography). Results: The effect of exogenous ABA on the lycopene content in peripheral pericarp of tomato fruits was firstly inhibited then promoted during fruit mature period.  Exogenous ABA decreased the content of endogenous GA3, but the endogenous ABA content was inhibited firstly, and then promoted, inhibited finally, and promoted the content decrease of endogenous ZT. The peak value was appeared early, but a little effect on the amount of ETH release. Conclusion: This work proved the feasibility of elevating of lycopene levels in tomato fruit by the application of exogenous ABA. ABA promoted the accumulation of lycopene by the decreasing of endogenous GA3, ZT and ABA contents, and by releasing peak appear of endogenous ETH.