Study On Migration Of Chlorine In Soil And Accumulation And Distribution In Tobacco Leaves

To solve the problem of henan tobacco chloride content on the high side,with over 87 varieties tested,first of all,the relationship between the physiological characteristics of chlorine and flue-cured tobacco were studied,based on this,to carry out the chloride ion in different soil texture of chlorine reduction test,migration and accumulation in tobacco plant distribution series research,so as to achieve effective control on agricultural and industrial purpose of flue-cured tobacco chloride ions.The main research results are as follows:1.When chlorine concentration increased,osmiophilic particles in leaf cells increased significantly and chloroplast matrix gradually disintegrated,but high chlorine concentration had little effect on mitochondria and other organelles.Secondly,the activities of superoxide dismutase(SOD)and peroxidase(POD)increased gradually,while the activities of catalase(CAT)decreased,and the content of malondialdehyde(MDA)increased.During the culture period,the activties of POD,SOD,CAT and MDA content in tobacco leaves were significantly different from those without chlorine application when chlorine concentration was 120 mg/L,while the activities of POD,SOD,CAT and MDA content were not significantly different when chlorine concentration was 0-30 mg/L.2.After winter irrigation,the chlorine leaching rate of sandy soil was higher than that of clay soil.When the soil depth was greater than 100 cm,the variation range of clay water content and soil chlorine content was smaller than that of sandy loam.When the amount of soil chloride was 0-100 m2/hm2,the total amount of soil chloride was lower than that before winter irrigation.When the amount of winter irrigation was higher than 100 m3/hm2,the content of chlorine in soil 0-100 cm of both germplasm increased compared with that before winter irrigation.3.Different soil chlorine concentrations(15-60 mg/kg)could promote the increase of plant height,stem circumference,maximum leaf length and maximum leaf width of flue-cured tobacco,but the increase was not significant.The agronomic traits of flue-cured tobacco in sandy soil texture were better than those in clay texture.4.Among the two soil textures,the migration rate of chloride ions was the fastest in 0-40 cm soil layer,and the migration rate slowed down in deep soil When the soil chlorine content was more than 30 mg/kg,the chlorine leaching rate of 1 m3 soil in sandy loam increased with the increase of the soil chlorine content in 0-20 cm soil layer,while the soil chlorine leaching rate showed irregular changes between clay treatments.Affected by rainfall,the chlorine leaching rate of both soil texture was small.The adsorption capacity of chlorine ions on clay was stronger than that on sand loam,which could promote the accumulation of chlorine in tobacco plants.Sand loam was more conducive to reducing chlorine content in tobacco leaves.5.With the increase of soil chlorine concentration,the accumulation of chlorine in the whole plant and all parts of tobacco plant showed an upward trend,and the proportion of chlorine accomulation in the root to the total plant first increased and then decreased with the time of transplanting.while the accumulation of chlorine in the leaves was opposite to that in the roots.At 100 after transplanting,the accumulation of chlorine in sand loam and clay tobacco plant was leaf>stem>root,and the distribution ratio of chlorine accumulation in root stem and leaf was 1:1.80:6.62 and 1:1.90:7.10,respectively he distribution ratios of chlorine accnmulation in basal,lower,middle and upper leaves were 1.93:2.13:1.19:1 and 1:2.14:2.14:1.86,respectively.The distribution ratios of chlorine accumulation in stem cortex and stem pith were 1:6.19 and 1:5.78,respectively.6.The tobacco leaves were divided into 15 locations,and the distribution rules of chlorine content and potassium content in leaf locations were consistent,showing the following patterns:leaf base>near base>middle of leaf>near tip>leaf tip,near main>near middle>near edge.In a single location,the content in near main-leaf base location was the largest and that in near edge-tip location was the smallest.he distribution pattern of nicotine content and k/C ratio was opposite to that of chlorine content.The ratio of glycobase increased first and then decreased from leaf base to leaf tip.Chlorine agpplicatioi promoted the accumulation of potassium,chlorine and nicotine in tobacco leaves,and affected the accumulation of reducing sugar and total sugar.The content of chlorine potassium and nicotine in sandy soil was lower than that in clay soil.The technology can be further optimized to improve the utilization level of tobacco raw materials.In conclusion,high chlorine conditions have adverse effects on chloroplast of fine-cured tobacco leaf cells and enhance the expression of antioxidant enzymes and MDA.Suitable winter irrigation can reduce soil chlorine content.In view of the present situation of high chlorine content in the soil of henan tobacco-growing area,choosing sandy soil teature when optimizing the distribution of tobacco-growing area is more conducive to reducing the chlorine content of flue-cured tobacco.The negative effects of high chlorine content in tobacco leaves can be reduced and the utilization level of tobacco raw materials can be improved by optimizing the process technology according to the differences of chemical components in each region of leaves during leaf opening and rebaking.