不同小麦品种对大田中低量镉富集及转运研究

为解决Cd污染带来的粮食安全问题及为小麦品种推广应用提供品种特征数据资料,采用田间调查的方法,于黄淮海平原9个小麦种植区采集了59个小麦品种,共计91组土壤-植物点对点样品,基于小麦不同部位Cd含量、茎叶Cd转移系数(TF)及籽粒Cd富集系数(BCF)值等指标对不同小麦品种Cd富集能力进行比较研究;采用聚类分析,以不同基因型小麦的BCF为筛选条件,对59个小麦品种进行了分类。结果表明:除济源外(2.292 mg·kg~(-1)),研究区表层土壤Cd污染状况整体尚好(0.107~0.212 mg·kg~(-1));济源小麦品种籽粒Cd含量范围为0.119~0.150 mg·kg~(-1),其他样点为0.005~0.030 mg·kg~(-1);TF变化区间为0.093~0.500,最大与最小值间相差约4.4倍;BCF变化区间为0.047~0.165,最大与最小值间相差约2.5倍。经聚类分析把不同品种小麦Cd的BCF值分为五类,并筛选出冀麦518、衡0628、衡09观29三个低Cd富集小麦品种。通过BCF推算,在保障籽粒Cd含量不超过食品安全限量标准的前提下,59个小麦品种基本上都可以在国家规定的二类Cd污染土壤上种植,其中,有27个小麦品种还可以在三级Cd污染土壤上种植。

Accumulation and translocation of cadmium in different wheat cultivars in farmland

It is relatively easy for wheat to absorb cadmium(Cd) from the soil, resulting in high Cd levels in the seeds. Preferential selection of low Cd wheat varieties is important for the production of safe wheat production in Cd-contaminated areas. For the selection of low Cd wheat varieties, a study on Cd absorption, transport and enrichment ability by different wheat varieties was carried out. A total of 59 wheat varieties were collected in the field, and a total of 91 pairs of soils and grains, and stems and leaves, were collected from nine wheat planting areas of the Huanghuaihai Plain, and the Cd content in soil, wheat stems, leaves, and grain were analyzed, and the stem and leaf translocation factor(TF) and grain bioconcentration factor(BCF) were calculated. The results showed that the surface soil Cd content was low,with a range of 0.107~0.212 mg·kg^-1; Jiyuan''s soil Cd content exceeded the standard, up to 2.292 mg·kg^-1. The grain Cd content in wheat varieties ranged from 0.005~0.030 mg·kg^-1(Jiyuan:0.119~0.150 mg·kg^-1), with an average of 0.016 mg·kg^-1(except Jiyuan). The variation range of TF was 0.093~0.500, with a 4.4 folds difference between extremes.The range of BCF change was 0.047~0.165, with a 2.5 folds difference between extremes. Using a cluster analysis, the Cd BCF values of different wheat varieties were divided into five categories, and 29 wheat varieties with low Cd concentrations were identified, which were Ji Mai 518, Heng 0628, Heng 09 Guan 29. Based on the results of the BCF calculation, on the premise that the Cd content in grain should not exceed the standard of food safety limits, 59 wheat varieties could be planted in grade two Cd-contaminated soil prescribed by the state. Among them, 27 wheat varieties could also be planted in grade three Cd-contaminated soil.