| Under the condition of nutrient solution cultivation,different Na Cl concentration gradients were set.Salt stress treatments were carried out on five pepper rootstock seedlings of "Graft","Weizhuangbeier","Youzhuang","Cat 188" and "Root".After 9days,growth and physiological indexes of each treatment were determined,and salt tolerance of each rootstock variety was evaluated comprehensively.By grafting the selected salt tolerant capsicum rootstock and "yangjiaohong No.1",the salt tolerance characteristics of self rooted and grafted seedlings were compared under the stress of90mmol·L-1Na Cl.The rootstock with more developed roots was selected to overcome the obstacles of continuous cropping of vegetables.And the trial planting was carried out in the arch shed.Experiments were conducted to explore the production benefits of self-rooted seedlings and grafted seedlings.The results are as follows:1.In this study,different concentrations of Na Cl treatment on pepper seedlings showed low promotion and high inhibition.When Na Cl concentration was less than60 mmol·L-1,the growth index of root system,chlorophyll content and biomass accumulation of pepper seedlings were significantly higher than those of the control group,and the seedlings were not affected by salt damage,indicating that low Na Cl concentration could promote the growth of pepper seedlings;when Na Cl concentration was higher than 60 mmol·L-1,the growth of pepper seedlings was inhibited significantly,and with the increase of salt concentration,the seedlings of all rootstock varieties were affected by salt.The accumulation of dry matter in plants decreased significantly,and the membrane permeability and MDA content in leaves increased significantly.The results of comprehensive evaluation showed that "Graft" pepper Rootstock Varieties had the least inhibition and the strongest salt tolerance.2.Selecting the most salt-tolerant "Graft" cultivars as rootstocks and "Yangjiaohong 1" as scions,the growth,photosynthetic parameters,osmotic regulation ability and membrane peroxidation of grafted and self-rooted pepper plants under 90 mmol·L-1 Na Cl stress were studied.The results showed that under salt stress,the biomass accumulation of grafted seedlings and self-rooted seedlings decreased significantly,growth was inhibited,and photosynthetic parameters such as net photosynthetic rate and stomatal conductance of leaves decreased.With theprolongation of salt stress time,the relative conductivity and MDA content of grafted and self-rooted seedlings increased,the peroxidation degree of plasma membrane increased,and the osmotic regulation ability decreased.Under the same Na Cl stress,the degree of inhibition of grafted pepper plants was significantly lower than that of self-rooted pepper plants.The results showed that the application of grafting technology alleviated the salt damage to a certain extent and improved the salt tolerance of pepper.3.Compared with self-rooted seedlings,using "Graft" as rootstock could significantly increase the soluble sugar content and improve the quality of pepper fruit.The number of fruit per plant,yield per plant and total yield of grafted seedlings were significantly higher than those of self-rooted seedlings. |
