Study On The Physiological Characteristics Of Tomato Plants Salt Tolerance Improved By Grafting

Tomato is one of the main vegetable facility cultivation,because tomato with weak salt resistance,seasonal or perennial of soil are covered and natural leaching of soil can not get the rain,this coupled with the excessive application of chemical fertilizer,easily in the surface soil salt accumulation,eventually leading to soil secondary salinization.So make the tomato quality and production,of limiting greenhouse tomato production the main factor.Studies at home and abroad have shown that the grafting cultivation of vegetables using good rootstocks can enhance the resistance of plants and improve the yield and quality.Nutrient solution culture method is applied in this experiment,the five commonly used tomato root stock breed on the market"Ala Mu","Guozhen NO.1","Aozhen NO.1","Yedage NO.1","Jiuliu Dazuo"seedlings of different concentrations(0mmol·L^-1（CK）,20mmol·L^-1,40mmol·L^-1,60mmol·L^-1,80mmol·L^-1,100mmol·L^-1)Ca（NO₃）₂ stress processing,after 10d began to investigate different varieties of plant seedlings growth physiological indexes,salt resistance selection evaluation.The optimum and the stock and scion"saipeng"were used for grafting,rootstock grafting and scion grafting and two grafting methods were analyzed under Ca（NO₃）₂ of80mmol·L^-1 stress.The results can be summarized as follows:1.It was found that Ca（NO₃）₂ showed the effect of low promotion and high inhibition at the experimental treatment concentration.When the concentration was 40mmol·L^-1,the plant height,stem diameter and biological value of tomato rootstock seedling reached the maximum.When the concentration was higher than 40 mmol·L^-1,the plant height,stem diameter and biomass of tomato rootstock seedlings of all varieties were significantly decreased,and the relative electrical conductivity and MDA content of leaves were significantly increased.The results showed that low concentration Ca（No₃）₂ promoted the growth of rootstock.The salt tolerance of different rootstocks was different,and the salt tolerance order of the five tomato rootstocks was’Ala Mu’>’Guozhen NO.1’>’Aozhen NO.1’>’Yedage NO.1’>’Jiuliu Dazuo’.2.Under the 80 mmol·L^-1ca（NO₃）₂ stress,the decreased biomass of the stock grafted seedlings was significantly lower than that of the root grafted seedlings,indicating that the stock grafted seedlings could maintain better growth potential under the same conditions.Changes in the membrane system can directly reflect the degree of salt damage suffered by plants.Under the stress of Ca（NO₃）₂,the scion grafting blade relative electrolyte permeability and MDA in the rising trend of grafting significantly below the root,POD,SOD is significantly higher than the root grafting,showed that grafting reduces the injury to the plant high salt concentration,the membrane lipid peroxidation degree obtained certain inhibition,improved the activity of antioxidant enzymes.By using polyacrylamide gel electrophoresis to compare the tomato plants treated with four treatments,CT₂ were obviously different from other treatments.The results showed that under the same Ca（NO₃）₂ concentration stress,the grafting of superior rootstock could improve the antioxidant enzyme activity of tomato leaves,alleviate the membrane peroxidation induced by salt stress,reduce the inhibition and improve the adaptability of tomato plants.3.Under the 80 mmol·L^-1Ca（NO₃）₂ stress,the grafted seedlings of rootstock had significantly higher transmissibility and expression of different proteins than those of the grafted seedlings from root,indicating that grafting reduced the damage to plants caused by high salt concentration.At the same time,the content and expression of soluble sugar,proline and soluble protein be improved,the ability of osmotic adjustment is enhanced,and the salt tolerance is obviously improved.In particular,it has strong tolerance to Ca（NO₃）₂ stress,and it is a better tomato graft rootstock.