| Silicon(Si)is one of the most abundant elements in the earth,its contents after oxygen.In many higher plants,although Si has not been as one of the essential elements for plant growth,but the function that it can improve the plant response to biotic and abiotic stresses has aroused widespread concern.Tomato is one of the main vegetables are indispensable to human life,Xinjiang tomato products production capacity has accounted for more than 90% of the our country,the China has become the world's third largest producer of tomato products after the United States and Italy.With the rapid development of intensive agricultural production technology,the drip irrigation technology applicated in most crop production,and lead to soil salinization increasingly serious.Soil salinization is an important problem limiting crop production in the world,the world there are about 5 billion 700 million acres of land have different degree of salinization,accounting for about 10% of the arable land,secondary salinization land in cultivated of our country is 1/10 in arable land,which Xinjiang Salinization Soil Area first in the country,as the main agricultural products of Xinjiang tomato production is also different extent by the harm of saline alkali soil and secondary salinization of soil.Therefore,selection of strong salt tolerant tomato varieties,research and develop the material or technology that could to decrease the salt damage to tomato have very important theoretical and practical significance to the sustainable development of tomato production in Xinjiang.In this paper the processing tomato varieties Riegel 87-5 as test material,and studied the effects of exogenous silicon(Si)on growth parameters,membrane lipid peroxidation and activity of protective enzymes,root activity and partial ion absorption and distribution,changes in the content of osmotic adjustment substances in leaves,photosynthetic pigment content and photosynthetic indexes of processing tomato seedling under salt stress by hydroponic culture.The main results are as follows:1.With the increase of NaCl concentration,the Riegel 87-5 total biomass decreased and the rate of dry matter accumulation rise instead.When NaCl concentration was at 50 m M conditions,dry matter accumulation rate of seedling under Si plus treatment was significantly higher than that in non Si,high 13.44%.2.The leaf relative conductivity and MDA content of Riegel 87-5 seedling were increased with increasing of NaCl concentration,when Si was added,the relative electrical conductivity and MDA content of tomato under NaCl 50 m M treatment were decreased 72.33%,19.00%,respectively,here in the SOD activity was significantly enhanced,but Si addition to deal with the effects on the activity of POD and CAT were not significant.3.The root activity of tomato cultivar Riegel 87-5 showed a trend of first increasing and then decreasing with the increase of NaCl concentration.Based on the NaCl concentration of treatment,after added the exogenous Si,except the root activity of NaCl concentration 50 m M treatment was significantly higher than that of the addition of Si treatment,the root activity of control treatment and the NaCl concentration 100 m M treatment were increased significantly.4.With the increase of NaCl concentration,Na ion content in leaves and roots of 87-5 Riegel has been on the rise,Ca,K and Mg ion content in leaves,Ca ion content in roots showed decreased first and then increased trend,K and Mg ions content in root have been showed a downward trend,among them the Na,Ca and Mg content in root were significantly lower than those of leaf,K ion content in root was higher than that of leaves.NaCl treatment plus Si,all of the Na,K,Ca and Mg content has changed,and the K/Na and Ca/Na in the leaves of NaCl concentration 50 m M treatment are very significantly increased.5.Soluble protein,soluble sugar content,proline content and starch content in leaf Riegel 87-5 tomato showed a somewhat different trend with increasing of concentration of NaCl.After the Si treatment,soluble protein,soluble sugar content,proline content and starch content in leaves of each NaCl treatment also change,among them the soluble protein,soluble sugar content,proline content and starch content in leaf of NaCl 50 m M treatment maintained a consistent level of control after plus Si.6.Under different NaCl concentration conditions,compared with the no Si treatment,the chlorophyll content and carotenoid content of Riegel 87-5 leaves were affected by the addition of Si treatment,but the difference was not significant between the two.However,the Si treatment had different effects on the diurnal variation of photosynthesis,and the water use efficiency was improved to a certain extent.When the concentration of NaCl was 50 m M,the net photosynthetic rate of tomato treated with Si was for 10.257 ?mol·m-2·s-1,compared with the no Si treatment higher than 42.08%.All in all,under the NaCl concentration was 50 m M condition,the exogenous Si treatment could increase the salt tolerance ability of the processed tomato Riegel 87-5. |
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