不同玉米(Zea mays)品种对镉锌积累与转运的差异研究

选取20个玉米(Zea mays)品种作试验材料,通过田间试验研究了镉-锌(Cd-Zn)复合胁迫下玉米的生长发育及其积累和转运Cd、Zn的差异,以期筛选出Cd、Zn低积累的玉米品种。结果表明,Cd-Zn复合胁迫下,玉米的株高、叶面积、生物量、产量以及玉米根、茎叶和籽粒中Cd、Zn含量在品种间均表现出显著差异。有2个品种籽粒的Cd含量超过国家食品卫生标准(≤0.2 mg·kg-1),13个品种茎叶的Cd含量超过国家饲料卫生标准(≤0.5 mg·kg-1),所有品种籽粒和茎叶的Zn含量均符合国家食品卫生标准(≤50mg·kg-1);有7个品种的Cd富集系数1,13个品种茎叶转运系数1,所有品种籽粒转运系数均1;20个玉米品种Zn的富集系数均1,有18个品种茎叶转运系数1,6个品种籽粒转运系数1。根据玉米生物量、产量、籽粒Cd和Zn含量、富集系数、转运系数等指标进行评价,认为红单6号、红育1号、云优78、平单2号、屏单2号5个品种可作为Cd低积累玉米品种,雅玉98可作为Zn低积累玉米品种,可分别在个旧地区Cd、Zn中、轻度污染土壤上推广种植。

Differences of cadmium and zinc accumulation and translocation in different varieties of Zea mays

In the heavy metal contaminated soil of cadmium-zinc(Cd-Zn), the effects of Cd and Zn on the growth of 20 maize varieties a-long with differences of Cd and Zn accumulation and transfer between different maize varieties were studied in field experiments. The pur-pose of the field experiments was to screen out maize varieties with low accumulation ability of Cd and Zn. The results showed that there were significant differences among 20 maize varieties of plant height, leaf area, biomass as well as yield under combined stress of Cd and Zn. Meanwhile, there were significant differences among 20 maize varieties of Cd and Zn uptake by root, stem and leaf, kernels Cd and Zn accu-mulation and translocation ability(P<0.05). The seed Cd contents of 2 varieties were more than the food sanitation standards set by the state (≤0.2 mg·kg-1). The stem and leaf Cd contents of 13 varieties were more than the national feed hygiene standard(≤0.5 mg·kg-1). The kernel stem and leaf Zn contents of 20 varieties conformed to the food sanitation standards(≤50 mg·kg-1). The Cd enrichment coefficients of 7 maize species<1, the stem and leaf transfer coefficient of 13 maize species<1, and all the seed transport coefficients were less than 1. 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 from stem and leaf to grain was weak———The Zn enrichment coefficients of 20 maize species<1,the stem and leaf transfer coeffi-cient of 18 maize species<1, and the seed transport coefficients of 6 maize species<1.Data analysis results showed that the absorption capac-ity of the maize to soil Zn and the transport capacity from shoot and stem to grain were strong. Evaluated by the index of maize biomass, grain yield, Cd and Zn content , Cd and Zn enrichment coefficient and transfer coefficient, 5 varieties of Hong Dan 6, Hong Yu 1, Yun You 78, Ping Dan 2 and Ping Dan 2 could be used as Cd low accumulation Maize Varieties, and Ya Yu 98 could be used as Zn low accumulation Maize Varieties, and were fit to be planted in Cd, Zn polluted soil in Gejiu lightly and moderately.