玉米(Zea mays)对镉积累与转运的品种差异研究

Variety Difference of Cd Accumulation and Translocation in Zea Mays

通过田间实验，研究了25个玉米（Zea mays）品种在Cd质量分数为50 mg·kg-1胁迫条件下，Cd对不同玉米品种生长的影响，以及不同玉米品种对Cd积累和转运的品种差异，以期筛选出Cd低积累玉米品种。结果表明：25个玉米品种的生物量和产量对Cd胁迫的响应，以及不同品种根、茎叶和籽粒对Cd的吸收、累积及转运能力存在显著差异（P＜0.05）。有20个品种生物量和19个品种产量下降；有2个品种籽粒的Cd质量分数超过了国家规定的食品卫生标准（≤0.1 mg·kg-1），占供试品种的8.0%，所有品种茎叶的Cd质量分数均超过了国家规定的饲料卫生标准（≤0.5 mg·kg-1），超标率为100%；25个玉米品种的富集系数范围为0.063~0.899、茎叶转运系数范围为0.038~0.554、籽粒转运系数范围为0.000~0.111，均小于1，其中有8个品种富集系数〉0.5，1个品种茎叶转运系数〉0.5，而所有品种的籽粒转运系数均〈0.5，说明玉米对土壤Cd仍有一定的吸收能力，但地下部向地上部转运能力以及由茎叶向籽粒的转运能力较弱；根据玉米生物量、产量、籽粒Cd含量以及对Cd的富集系数和转运系数等指标进行评价，认为云瑞8号、会单4号、路单7号3个品种可作为Cd低累积玉米品种，可在云南Cd重度污染土壤上推广种植。

In Cd （50 mg·kg-1） stress conditions, the effects of Cd on the grown of 25 maize varieties and the difference of Cd accumulation and transfer between different maize varieties was studied in field experiments, to screen out Cd low accumulation maize varieties. The results showed that there was significant difference between 25 maize varieties of biomass, yield Cd uptake by root, stem and leaf, Cd accumulation and translocation ability （P〈0.05） response to Cd stress. Biomass of 20 maize varieties decreased, and yield of 19 maize varieties decreased. The seed Cd contents of 2 varieties were more than the food sanitation standards set by the state （≤0.1 mg·kg-1）, accounting for 8% of the tested cultivars. The stem and leaf Cd contents of all varieties were more than the national feed hygiene standard （≤0.1 mg·kg-1）. The range of enrichment coefficients of 25 maize varieties was 0.063~0.899, and the stem and leaf transfer coefficient was in the range of 0.038~0.554, meanwhile the seed transport coefficient was in the range of 0.000~0.111, but all the coefficients were less than 1, of which the enrichment coefficients of 8 maize species 〉 0.5, the stem and leaf transfer coefficient of 1 maize specie 〉 0.5, the seed transport coefficients of all the varieties 〈 0.5. Data analysis results showed that there were still certain absorption capacity of the maize to soil Cd, but the transport capacity from root to shoot and stem and leaf to grain was weak. Evaluated according to the index of maize biomass, grain yield, Cd content , Cd enrichment coefficient and transfer coefficient, 3 varieties of Yun Rui 8, Hui Dan 4, and Lun Dan 7 could be used as Cd low accumulation Maize Varieties, and were fit to be planted in Cd heavily polluted soil in Yunnan.