EFFECT OF FLURIDONE ON SOME PHYSIOLOGICAL AND QUALITATIVE FEATURES OF RIPENING TOMATO FRUIT

摘要

In tomato fruits, chlorophyll, lycopene and ?-carotene are mostly responsible for the color. During ripening oftomato fruits, the color of the pericarp changes from green to red as chlorophyll is degraded and carotenoids accumulate.These changes are associated with an increase in respiration and ethylene production. Carotenoid biosynthesispathway in plants can be disturbed by herbicide fluridone (1-methyl-3-phenyl-5-[3-trifluoromethyl(phenyl)]-4(1H)-pyridinone), which inhibits the activity of phytoene desaturase, an enzyme responsible for conversion ofphytoene to phytofluene. Fluridone is also used as an inhibitor of biosynthesis of abscisic acid (ABA) and strigolactones,and it reduces chlorophyll production in plants. In our research we studied the effect of fluridone on somephysiological parameters, such as color, firmness, ethylene production, lycopene and chlorophyll content duringripening of the tomato fruit. Tomato plants cv. Altadena (Syngenta) were cultivated in a greenhouse in controlledtemperature and both immature and mature fruits were used for the experiments, performed between August andNovember 2016. Fluridone at concentrations of 0.1% and 1.0% in lanolin paste was applied as a 2-3 mm stripefrom the top to the base of tomato fruits, and as a control a stripe of lanolin was applied in the same way on theopposite side of the fruits. Fluridone at a concentration of 1.0% greatly inhibited lycopene accumulation in thepericarp of tomato fruits from the treated side. The measurements of fruit firmness have shown no significantdifferences between firmness of the part of the tomato fruits treated with fluridone, and the non-treated ones.Tomato fruits treated with fluridone produced amounts of ethylene similar to those found in control tissues onthe opposite side of the same fruit. Fluridone delayed chlorophyll degradation in tomato fruits. The metabolicsignificance of these findings is discussed with the role of carotenogenesis inhibition in tomato fruit ripening.