Abstract: By the methods of laboratory and field tests, this paper studied the effects of different concentrations (0, 0.01, 0.05, 0.10, 0.50, and 1.00 mmol·L^-1) 2,4-di-tert-butylphenol on the tomato leaf mould, seed germination, and seedling growth. At the early stage of culturing tomato leaf mould, 2,4-di-tert-butylphenol had significant inhibition effect on the mycelium growth. When the mycelium growing to 7 d, 0.1 mmol·L^-1 of 2,4-di-tert-butylphenol had the best inhibition effect. Field test showed that 2,4-di-tert-butylphenol at all test concentrations enhanced the disease resistance of tomato seedlings. The best effect was observed at 0.1 mmol·L^-1 of 2,4-di-tert-butylphenol, and the disease index decreased by 54%, as compared to the control. 2,4-di-tert-butylphenol at low concentration promoted the seed germination, increased the plant height, stem diameter, plant fresh weight, leaf chlorophyll content, root activity, and plant defense enzyme activities, but decreased the leaf MDA content and relative electricity conductivity. With the increasing concentration of 2,4-di-tert-butylphenol, its promotion effect decreased while its inhibition effect increased, being the strongest at 0.1 mmol·L^-1. It was concluded that 2,4-di-tert-butylphenol at 0.1 mmol·L^-1 was the most suitable concentration to enhance the resistance of tomato plant against leaf mould and to regulate tomato seeding growth.

Key words: pollen limitation, experimental level, pollen quality, resource reallocation, Sagittaria trifolia.