Differences In Absorption And Distribution Of Soil Heavy Metals In Rice Cultivars

Rice is one of the most important food crops in China.At the same time it is also one of the strongest crops to absorb the accumulation of cadmium.Cadmium pollution of rice has attracted people's attention.The article had potted plants by heavy metal contaminated paddy soil where Maba Zhen,Qujiang,Shaoguan,Guangdong to study the difference of Cd uptake and distribution in different rice varieties,screened out the rice varieties with low accumulation of heavy metals to provide reference for the safe production of heavy metals in rice.The following conclusions are obtained:(1)The yield and the dry weight of each organ of the 16 rice varieties had significant difference among different cultivars.The overall trend of Cd content in different organs of rice was: root > stem > leaf > brown rice,and there was a very significant positive correlation between Cd content in different organs of the same rice variety.(2)There were significant differences in Cd content between the different organs of rice.The lower content of Cd in different organs of rice varieties were Kenong,Huahangsimiao and Tianyou 998,the high varieties were Xinyinzhan,Meixiangzhan and Xiangyazhan;The transport coefficients of Cd in different organs of rice: stem>leaf>brown rice,The lower transfer coefficient of varieties were Huanghuazhan and Huahangsimiao,the higher transfer coefficient varieties were Qujiangzhan and Meixiangzhan.(3)The contents of Cd,Pb,Cu,and Zn in brown rice of 16 rice varieties were 0.33~0.92 mg.kg-1,0.08~0.19 mg.kg-1,5.36~8.13 mg.kg-1,36.51~61.43 mg.kg-1.Compared with the national food hygiene standards(NY861-2012),the content of Pb and Cu is in line with the standard of limited quantity,there are 11 varieties of Zn content is lower than the standard,all varieties Cd content exceeded the limited standard.Correlation analysis showed that there was a significant negative correlation between Pb and Zn?Cu and Zn in brown rice,and there was a significant positive correlation between Pb and Cu.(4)The correlation analysis of 16 rice varieties was made that their absorption of four kinds of heavy metal is relatively smaller which Jinglongzhan ? Wuxingsimiao and Tianyou998 three varieties of rice.Combined with agronomic measures,they can be wholesome producted in the middle and low heavy metal compound pollution farmland.