基于大田试验的铅镉复合污染土壤中甜糯玉米低积累特性

为筛选适合在铅（Pb）、镉（Cd）复合污染土壤种植的低积累特性甜糯玉米品种，选取39个玉米品种，通过大田试验，研究其籽粒和秸秆对Pb和Cd的富集特性和差异.将玉米产量、富集系数和基于土壤Pb和Cd风险阈值的方法作为筛选低积累玉米品种的评价指标.结果表明，不同品种玉米的产量、籽粒和秸秆的Pb和Cd含量之间存在显著差异（P<0.05）.籽粒对Pb和Cd的富集系数分别为0.00003~0.00230和0.01~0.15，秸秆对Pb和Cd的富集系数分别为0.003~0.065和0.64~4.28.通过对不同玉米富集系数的聚类分析，综合不同品种玉米的土壤Pb和Cd风险阈值得出，惠甜5号、新美甜818和玉糯9号可在Pb和Cd含量超风险管制值的耕地安全生产，天贵糯937和金萬糯2000可在Cd含量超风险筛选值的耕地安全生产.惠甜5号、新美甜818和玉糯9号作为Pb和Cd复合低积累品种，适宜在广西铅镉复合污染土壤上推广种植，天贵糯937和金萬糯2000作为籽粒低积累、秸秆Cd高积累品种，建议将其作为植物修复资源加以利用.

Low Accumulation Characteristics of Sweet-waxy Maize in Pb and Cd Complex Contaminated Soils Based on Field Trials

To screen out sweet-waxy maize varieties with low accumulation characteristics suitable for planting in lead (Pb) and cadmium (Cd) complex contaminated soils, 39 maize varieties were selected, and the enrichment characteristics and differences of grains and straws on Pb and Cd were studied through field trials. Maize yield, bioaccumulation factors, and soil Pb and Cd risk thresholds were used as evaluation indicators for screening low accumulation maize varieties. The results showed that there were significant differences between the yield and Pb and Cd contents in grains and straws of different varieties of maize (P<0.05). Bioaccumulation factors of grains for Pb and Cd were in the range of 0.00003-0.00230 and 0.01-0.15, respectively, and those of straws for Pb and Cd were in the range of 0.003-0.065 and 0.64-4.28, respectively. Through the cluster analysis of bioaccumulation factors, the soil Pb and Cd risk thresholds of different varieties of maize were comprehensively obtained:Huitian 5, Xinmeitian 818, and Yunuo 9 could be safely produced in the farmland with Pb and Cd content exceeding the risk control value, and Tianguinuo 937 and Jinwannuo 2000 could be safely produced in the farmland with Cd content exceeding the risk screening value. Huitian 5, Xinmeitian 818, and Yunuo 9, as low Pb and Cd accumulation varieties, were suitable to be popularized on Pb and Cd polluted soil in Guangxi, China. Tianguinuo 937 and Jinwannuo 2000, as low grain and high Cd accumulation varieties, are suggested to be used as phytoremediation resources.