Abstract:
Abstract: Silicon plays an important role in improving crop drought resistance. The irrigation of alternate wetting and drying condition is a method that can achieve the goal of saving water resources and increasing production, through the inducement of the drought regulation potential by exposure of the plant roots to drought stress. Signal feedback control in the root zone can be performed adequately under alternate wetting and drying condition, and therefore physiological water conservation can be achieved. However, the conclusions on the effects of water-saving irrigation on the physiological characteristics of crops are different. With regard to the research about applicability of alternative irrigation method on tomato (Solanum lycopersicum L.) cultivation. In order to investigate the impacts of application of exogenous silicon on tomato under alternate wetting and drying condition, the effects of silicon on the silicon mass fraction in plant, plant growth, fruit yield and quality of tomato under alternate wetting and drying condition simulated. The simulation system was achieved by the use of a self-designed ebb-and-flow irrigation system. The results showed that the application of exogenous silicon in culture solution resulted in the increase of silicon mass fraction in tomato plants. The silicon mass fraction of tomato roots, stems, leaves and fruits increased by 494%, 444%, 246% and 631%, respectively. During the period of seedling stage and the period of flowering and fruit bearing stage of tomato, the irrigation of alternate wetting and drying condition can be used to control the growth and nurture strong seedlings. From the period of early fruiting stage to the period of later fruiting stage of tomato, especially fruit flourish stage, it is not appropriate to use the irrigation of alternate wetting and drying condition. Dry and wet alternation resulted in a serious decline in tomato production and a decline in lycopene mass fraction, vitamine C mass fraction, titratable acid mass fraction, but significantly improved other quality indicators of tomato fruit, such as soluble protein mass fraction, free amino acids mass fraction, soluble solid mass fraction, soluble sugar mass fraction, titratable acid mass fraction, fruit rigidity, sugar-acid ratio. Especially, sugar and acid ratio increased by 30%. The application of exogenous silicon can alleviate the adverse effects of alternate wetting and drying condition on fruit yield and quality in the late growth and development period of tomato. To this end, the combination of the irrigation of alternate wetting and drying condition and the application of exogenous silicon, in the promotion of stable production of tomatoes under the premise of high quality, can cause water conservation up to 23%. Based on this study, how exogenous silicon regulated the yield and quality of tomato under the condition of alternate wetting and drying was investigated, and the role of exogenous silicon in mediating changes of some physiological parameters of tomato planted under variable water conditions was made a thorough inquiry. The theoretical contents that refer to how exogenous silicon improved plant drought resistance were expanded. Irrigation method of alternate wetting and drying condition in tomato water-saving cultivation was further optimized. The result of this paper is of great significance to a reasonable water saving and to the improvement of the commodity rate of tomato.