| Seed vigor is an important index to measure seed quality.The results show that physical treatment can improve seed vigor,and the research of corona discharge field(CDF)on its treatment effect and mechanism is relatively few,which also leads to the limitation of this technology in application.The purpose of this study is to explore the suitable conditions for corona discharge field treatment to improve the vigor of pepper and tomato seeds,and to analyze the physiological mechanism of vigor improvement,so as to provide a theoretical basis for improving the vigor of pepper and tomato seeds in agricultural production.In the early stage of this study,the corona discharge field treatment conditions were optimized by selecting the"golden pepper"pepper seeds with medium vigor.Five seed samples of pepper and tomato were treated under suitable optimum conditions,and the effects of treatment on the related indexes of seed vigor and the changes of physiological indexes were analyzed.The main results are as follows:1.Through the preliminary screening of the treatment conditions,we predicted that the better treatment conditions of"Jinjiao"pepper seeds were obtained:"under 175 kv/m conditions,corona discharge field treatment was 4.5 minutes".On this basis,orthogonal experiments were carried out and binary quadratic regression equation related to treatment effect(activity index)was fitted by generalized multiple linear regression analysis:VI=0.035448+0.000127837*X+0.000293503*Y+0.00020825*X*Y-0.001033188*X~2-0.000796188*Y~2.(X=treatment time,Y=field strength).After that,the equation was optimized and the maximum value was obtained.Finally,the optimum treatment conditions were obtained:"Under 185 kv/m condition,the corona discharge field was treated for 4.7minutes".All samples were treated with this condition,and the vigor of"golden pepper"pepper seeds and"pink fruit"tomato seeds were improved to a certain extent.Corona discharge field treatment increased the seed vigor of different vigor levels differently.The experimental results showed that the seed vigor of different vigor levels increased by corona discharge field treatment had the following rules:medium vigor seeds were larger than high vigor seeds and low vigor seeds.Therefore,the seeds with medium vigor should be the most suitable vigor grade for corona discharge field treatment.2.After seeds were treated by corona discharge field,the vigor index of seeds with different vigor levels increased differently.The increasing range of"Jinjiao"pepper seeds was as follows:medium vigor seeds(10.39%)were higher than high vigor seeds(6.47%).The increasing range of"pink fruit"tomato seeds was as follows:medium vigor seeds(19.42%)were higher than low vigor seeds(8.77%).After corona discharge field treatment,the conductivity of external extracts of three pepper seeds with different vigor and two tomato seeds with different vigor was lower than that of the control,and the activities of protective enzymes(SOD,POD,CAT)were higher than that of the control.At the same time,the physiological indexes of seeds with medium vigor level were better than those of seeds with high and low vigor level.3.Under low temperature treatment,the germination index of the treated seeds was significantly higher than that of the control.In the seedling morphological index,five samples showed obvious root length growth and accelerated root elongation process.The seeds showed good low temperature resistance,which indicated that the vigor of seeds treated by corona discharge field had been improved to a certain extent.4.After corona discharge field treatment,the conductivity of external extracts of three pepper seeds with different vigor and two tomato seeds with different vigor was lower than that of the control,and the activities of protective enzymes(SOD,POD,CAT)were higher than that of the control in different degrees.At the same time,the physiological indexes of medium vigor seeds were significantly better than those of high and low vigor seeds. |
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