Study On Prediction Model Of Cadmium Enrichment In Potato

In this study,7 soil types and 9 common potato varieties mainly distributed in Guizhou Province were selected,and potted plants were grown on these 7 soils by adding different concentrations of exogenous Cd.This paper mainly studies the effect of different potato varieties on cadmium accumulation and transport,and the effect of cadmium accumulation and transport in potato under cadmium stress in different soils.Then,the Cd-BCF prediction equation of the main cultivar is used for interspecific extrapolation,and finally the ecological risk probability based on ecological risk probability is established.Distribution of cadmium critical threshold models.The main conclusions are as follows:（1）There are great differences in agronomic traits,physiology and quality among potato varieties with different genotypes;Among them,the cultivar with the higher cadmium enrichment coefficient of tubers is Weiyu 5,and the lower ones are Xingjia 2 and Feiwu Ruita;The concentration of cadmium increased,and the accumulation of cadmium in each part also increased,and the cadmium enrichment coefficient of each part of potato in the two soils was Nayong yellow soil>Guiyang lime soil.（2）The plant height,stem diameter and tuber quality of potato have no relatively consistent laws under different soil types,but the overall performance is the law of low concentration promotion and high concentration inhibition.The growth of potatoes grown on Leishan brown soil is better;The cadmium content and enrichment coefficient of each part of potato on Luodian red soil were higher,followed by Nayong yellow soil,the cadmium content and enrichment coefficient of root,stem and leaf on Panzhou yellow brown soil were lower,and the cadmium content of tubers on Maotai calcareous purple soil and the lowest enrichment coefficient;pH was the main soil factor affecting cadmium accumulation in tubers,with a very significant negative correlation.（3）The empirical regression equations obtained by fitting the 7 soil physicochemical properties with potato tuber Cd-BCF have good prediction effects under the total method and the exogenous method（except for the T1 and T2 treatments under the exogenous method）.Based on the theory of interspecific extrapolation,the tuber Cd-BCF prediction equation(（Model 2 in the full volume method）derived from the main potato variety Qingshu 9 was extrapolated to other varieties,and the extrapolation effect was good（both the measured BCF and the predicted BCF were within the2-fold interval and close to the 1:1 solid line）.（4）The ecological effect method was used to deduce the cadmium threshold,and the results showed that the soil cadmium threshold calculated by the prediction equation fitted in this paper was higher than the current national standard（the threshold calculated by the full method was between 2-4 times of the current standard,The highest predicted value of the exogenous method is4.7 times higher than the current standard,and the lowest is 2.65 times higher than the current standard）.（5）The species sensitivity curve method was used to derive the cadmium threshold.When the cumulative probability was 5%,the cadmium critical thresholds calculated by Log-normal and Burr III were at pH=5.5,7,and 7.5,and their values were 1.02,1.08,and 1.09 mg,respectively./kg,1.43,1.56,1.62 mg/kg.The Cd critical thresholds HC₁,HC_5,and HC₁₀ calculated by the SSD curve of each standard soil after normalization were fitted with the corresponding soil physical and chemical properties,and a linear regression equation was established.Compared with the current standard,the HCx value calculated by the regression equation using the two functions showed a relatively loose trend.