Abstract:

The effects of foliar application of silicon on growth，yield，accumulation of sugar and vitamin C in fruit and activities and gene expression of the related enzymes of cucumber were studied. The results showed that foliar application of silicon significantly promoted the growth and yield of cucumber plants，and increased activities of neutral invertase（NI），sucrose phosphate synthase（SPS），sucrose synthase（SS）and galactose dehydrogenase（GaILDH）and contents of fructose，glucose and vitamin C in fruits of cucumber. Among all treatments，foliar application of 1.420 g · L^-1 monosilicic acid showed the most significant effect. Compared to the control，contents of fructose，glucose and vitamin C of the fruits increased by 13.79%，18.08% and 75.11%，respectively. Real-time quantitative PCR results indicated that the genes expression of neutral invertase-3（NI-3），sucrose phosphate synthase（SPS）and galactose dehydrogenase（GaILDH）were significantly increased in fruits under 1.420 g · L^-1 monosilicic acid treatment.

Key words: cucumber, silicon application, sugar accumulation, sugar metabolism enzyme, vitamin C, galactose dehydrogenase, gene expression