Abstract:

The effects of foliar application of calcium and silicon on Solanum lycopersicum ‘Hongshuangxi’fruits firmness，cell wall components and activities of cell wall-degrading enzymes were studied. The results showed that foliar application of 7 mmol · L^-1 H₄SiO₄，7 mmol · L^-1 K₂SiO₃，7 mmol · L^-1 H₄SiO₄ + 45 mmol · L^-1 CaCl₂ and 7 mmol · L^-1 K₂SiO₃ + 45 mmol · L^-1 CaCl₂ significantly increased the fruit firmness at the time of harvest and 7 days after harvest. The contents of protopectin and cellulose were higher，while the content of soluble pectin was lower，and the activities of polygalacturonase（PG），pectin methylesterase（PME） and cellulose enzyme（Cx）reduced in the fruits of these four treatments. Among the treatments，foliar application of 7 mmol · L^-1 H₄SiO₄ and 7 mmol · L^-1 K₂SiO₃ showed the most significant effect. Compared to the control，in the fruits of these two treatments at 7 days after harvest，the firmness increased by 14.31% and 13.84%；protopectin increased by 75.00% and 68.10%；cellulose increased by 68.66% and 80.60%；soluble pectin decreased by 28.41% and 29.55%；polygalacturonase（PG）activity decreased by 18.70% and 20.87%；pectin methylesterase（PME）activity decreased by 13.61% and 17.66%；and cellulose enzyme（Cx）activity decreased by 31.42% and 31.38%，respectively.

Key words: tomato, silicon, calcium, fruits firmness, cell wall component, cell wall-degrading enzyme