Cadmium(Cd), a common toxic heavy metal in soil, has relatively high bioavailability, which seriously threatens agricultural products. In this study, 8 different soils with contrasting soil properties were collected f...Cadmium(Cd), a common toxic heavy metal in soil, has relatively high bioavailability, which seriously threatens agricultural products. In this study, 8 different soils with contrasting soil properties were collected from different regions in China to investigate the Cd transfer coefficient from soil to Chinese cabbage(Brassica chinensis L.) and the threshold levels of Cd in soils for production of Chinese cabbage according to the food safety standard for Cd. Exogenous Cd(0–4 mg kg^(-1)) was added to the soils and equilibrated for 2 weeks before Chinese cabbage was grown under greenhouse conditions. The influence of soil properties on the relationship between soil and cabbage Cd concentrations was investigated. The results showed that Cd concentration in the edible part of Chinese cabbage increased linearly with soil Cd concentration in 5 soils, but showed a curvilinear pattern with a plateau at the highest dose of exogenous Cd in the other 3 soils. The Cd transfer coefficient from soil to plant varied significantly among the different soils and decreased with increasing soil p H from 4.7 to 7.5. However, further increase in soil pH to > 8.0 resulted in a significant decrease in the Cd transfer coefficient. According to the measured Cd transfer coefficient and by reference to the National Food Safety Standards of China, the safety threshold of Cd concentration in soil was predicted to be between 0.12 and 1.7 mg kg^(-1) for the tested soils. The predicted threshold values were higher than the current soil quality standard for Cd in 5 soils, but lower than the standard in the other 3 soils. Regression analysis showed a significant positive relationship between the predicted soil Cd safety threshold value and soil p H in combination with soil organic matter or clay content.展开更多
以国内外207份小麦种质为材料,利用660K SNP芯片对其进行基因型检测,并结合不同环境下表型数据和最佳线性无偏预测值(BLUP,Best linear unbiased prediction)对小麦籽粒镉元素含量进行全基因组关联分析。结果表明:与小麦籽粒镉元素含量...以国内外207份小麦种质为材料,利用660K SNP芯片对其进行基因型检测,并结合不同环境下表型数据和最佳线性无偏预测值(BLUP,Best linear unbiased prediction)对小麦籽粒镉元素含量进行全基因组关联分析。结果表明:与小麦籽粒镉元素含量显著关联的SNP 310个,这些SNP分布于除3D和4D外的19条染色体上,单个SNP解释变异率为10.95%~14.66%。不同环境下检测到的关联SNP结果存在差异,其中在原阳地区检测到186个SNP,开封地区检测到71个SNP。基于BLUP值分析获得53个SNP。基于SNP物理位置,将距离较近的SNP进行整合,共获得有效QTL位点52个。同时发现了7个在多环境下表现稳定的SNP,并对其进行单标记效应分析。最后对基于获得的关联SNP进行了候选基因预测,共获得7个与小麦籽粒镉元素含量相关的候选基因,其中TraesCS1B01G321700和TraesCS1B01G320200可能与镉元素调控相关基因转录有关,而TraesCS7B01G459000和TraesCS7B01G456900可能与镉元素的吸收和转运等代谢过程有关。还筛选出了对镉具有良好避性的部分小麦优异种质,如‘云麦51’‘郑麦379’‘白穗白’‘云麦53’‘双丰收’。展开更多
基金supported by the Special Fund for Environment-Scientific Research in the Public Interest of China (No. 201409041)the Special Fund for Agro-Scientific Research in the Public Interest of China (No. 201403015)the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institute, China
文摘Cadmium(Cd), a common toxic heavy metal in soil, has relatively high bioavailability, which seriously threatens agricultural products. In this study, 8 different soils with contrasting soil properties were collected from different regions in China to investigate the Cd transfer coefficient from soil to Chinese cabbage(Brassica chinensis L.) and the threshold levels of Cd in soils for production of Chinese cabbage according to the food safety standard for Cd. Exogenous Cd(0–4 mg kg^(-1)) was added to the soils and equilibrated for 2 weeks before Chinese cabbage was grown under greenhouse conditions. The influence of soil properties on the relationship between soil and cabbage Cd concentrations was investigated. The results showed that Cd concentration in the edible part of Chinese cabbage increased linearly with soil Cd concentration in 5 soils, but showed a curvilinear pattern with a plateau at the highest dose of exogenous Cd in the other 3 soils. The Cd transfer coefficient from soil to plant varied significantly among the different soils and decreased with increasing soil p H from 4.7 to 7.5. However, further increase in soil pH to > 8.0 resulted in a significant decrease in the Cd transfer coefficient. According to the measured Cd transfer coefficient and by reference to the National Food Safety Standards of China, the safety threshold of Cd concentration in soil was predicted to be between 0.12 and 1.7 mg kg^(-1) for the tested soils. The predicted threshold values were higher than the current soil quality standard for Cd in 5 soils, but lower than the standard in the other 3 soils. Regression analysis showed a significant positive relationship between the predicted soil Cd safety threshold value and soil p H in combination with soil organic matter or clay content.
