Effect Of Nutrient Conditions In Cd-Pb High Geological Background Area On Potato Antioxidant System

Heavy metal pollution in terrestrial soil has caused serious harm to human life and safe agricultural production.In a stressful environment where heavy metals exist,plants will selectively absorb heavy metal particles in part of the environment.The heavy metals entering the plant will have a certain impact on the physiological and biochemical indicators of the plant,which will affect the normal growth of the plant.Solanum tuberosum is one of the most important crops in the world as the main crop for grain,economics and feed.Its planting area is only after wheat,rice,and corn.Potatoes have been planted in Guizhou Province for more than 400 years and have a long history;they are also important crops for Guizhou Province to ensure food security,promote targeted poverty alleviation,and increase farmers’ income.Nowadays,Guizhou’s potato planting area and fresh potato production ranks second in the country,and it has entered the ranks of the country’s major potato provinces.This study was carried out using the method of plant tissue culture,combined with the risk control value of agricultural land soil pollutants in GB 15618-2018,to simulate the Cd-Pb compound pollution environment,and set the culture medium with different overall infertility levels and different N and Fe content levels.Nutrient situation.Heavy metal pollution and two different nutrient conditions were combined separately to stress different genotype potato test-tube seedlings.Samples were taken to investigate some morphological and physiological and biochemical indexes of potato test-tube seedlings,and to explore the response of different genotype potato test-tube seedlings to the test conditions.The main findings of the experiment are as follows:1.As the degree of nutrient infertility increases,morphological indicators: different genotypes of potato test-tube plantlet all have leaf expansion inhibition,the leaf area becomes smaller,the stem and leaf color becomes lighter,and even yellow,the number of roots in the test-tube plantlet base decreases,and the length Shorter and thinner roots;the height of potato test-tube plantlets of different genotypes increased first and then decreased with the increase in the degree of infertility.The mildly infertile condition of halving the nutrient content,on the contrary,promotes the height of the seedlings to the maximum,and the height of the seedlings is proportional to the level of nutrient infertility.Negative correlation;the dry-to-fresh ratio of different genotypes of potato test-tube plantlet showed an overall upward trend,which was positively correlated with the level of nutrient infertility.2.With the increase of nutrient infertility intensity,physiological and biochemical indicators: SOD activity: Favorita,British Red and Zhongshu 3 are first reduced and then increased;Atlantic is first reduced,then increased,and then decreased;Zhongshu 5 is increased first,then decreased,then increased;POD activity: Favorita,Atlantic and Zhongshu3 are first decreased and then increased;British Red and Zhongshu 5 are continuously increased;CAT activity: Favorita and British Red are increased first and then decreased;Atlantic continued to decline;Zhongshu 5 is first increased,then decreased,and finally increased;Zhongshu 3 is first decreased,then increased;MDA content : Favorita,Atlantic and Zhongshu 3 are first increased and then decreased;British Red and Zhongshu 5 are keep increased;ASA content: Favorita and Zhongshu 3 are first decreased and then increased;Atlantic is continuously increased;British Red is first increased and then decreased;Zhongshu 5 is first increased,then decreased,and then increased;GSH content: British Red,Zhongshu 3 and Atlantic are first decreased,then increased;Zhongshu 5 is constantly increasd;Favorita is first increased,then decreased slightly,and then increased;GSSG content: As the degree of nutrient infertility increases,except for the slight decrease in the degree of moderate infertility of British Red,the GSSG content of potato seedlings are increased.3.Through the membership function analysis method,it is concluded that the growth ability of the 5 genotypes of potato under the combined effect of Cd-Pb and nutrient infertility is ranked as follows :British Red > Atlantic > Fevureta > Zhongshu 5 > Zhongshu 3.4.In the orthogonal design experiment of genotype,N level and Fe level,the morphological index: the test results show that the new leaves are dark green,and the color of the test tube seedlings under 3*N conditions will be darker than other levels.Under 3*N conditions,Stalk and node spacing are the thickest and shortest between treatments of this genotype,respectively;seedling height is negatively correlated with N level and negatively correlated with Fe level;dry-to-fresh ratio is positively correlated with N level,and it is significant with Fe level Positive correlation.5.In the orthogonal design experiment of genotype,N content and Fe content,the physiological and biochemical indicators: When potato seedlings are under heavy metal stress,the correlation between N level and SOD activity,POD activity,CAT activity,ASA content and GSH content is positive,and it is positive with GSSG The correlation between content and MDA content is negative,Fe level is positively correlated with SOD activity,POD activity,CAT activity,MDA content,GSH content and GSSG content,and negatively correlated with ASA content.6.In the orthogonal design experiment of genotype,N level,and Fe level,the order of the effect of the experimental factors is that the potato genotype is the primary influencing factor;the morphological index,the effect of Fe level is greater than the N level;physiological and biochemical indicators,The effect of N level is greater than that of Fe level.Comprehensive analysis In a heavy metal environment,the order of the effects of test factors is as follows : Genotype > N level > Fe level.