不同小麦品种灌浆期生长和镉积累的差异研究

为了解不同小麦品种灌浆期在镉污染农田中的生长情况和重金属镉积累的差异,本研究以30个小麦品种为材料,探明其在镉污染农田上的生长情况以及镉积累情况。结果表明,30个小麦品种在镉污染条件下能正常生长。不同小麦品种在灌浆期其株高、地上部和根部的生物量均存在着显著的差异,变化范围分别为48.87～77.47 cm、0.89～1.92 g·plant~(-1)、0.05～0.22 g·plant~(-1)。此外,不同小麦品种之间各部位吸收、积累镉的能力也存在明显差异。地上部和根部镉含量的变化范围分别为0.07～0.26、0.37～1.57mg·kg~(-1)。灌浆期镉在小麦体内的分配规律总体上为根地上部。地上部和根部镉积累量的变化范围分别为0.12～0.38、0.04～0.24μg·plant~(-1)。不同小麦品种各部位转运镉的能力存在明显差异,变化范围分别为0.08～0.47,其中淮麦23、冀麦738、宁麦17具有最低的根-地上部转运系数。成熟期的数据表明,淮麦23、冀麦738、宁麦17籽粒中镉的含量均远低于0.1 mg·kg~(-1)DW的国家限量标准,并具有很低的根-地上部转运系数,符合镉低积累小麦的标准。本文初步确定淮麦23、冀麦738、宁麦17作为低转运小麦品种的候选者,为低积累小麦品种的筛选提供科学依据。

Variations in growth and cadmium accumulation among 30 wheat(Triticum aestivum L.) cultivars during the grain filling stage

In this study, 30 wheat cultivars planted in Cd-contaminated farmland were used as materials to study the growth and differences in Cd accumulation among different wheat cultivars during the grain filling period. The results showed that the 30 wheat cultivars all grew well under Cd pollution, and there were significant differences in plant height and biomass during the filling period. Different tissues of different wheat cultivars showed clear variations in their ability to uptake and accumulate Cd. At the filling stage, the pattern of Cd distribution in wheat was generally roots > shoots. The Cd translocation ability among different tissues varied clearly among different wheat cultivars. Huaimai23, Jimai738, and Ningmai17 exhibited lower shoot to leaf translocation factors. The maturity results indicated that the above three wheat cultivars could be identified as low-Cd wheat cultivars; the Cd concentrations in the grains were below the limit values(0.1 mg·kg^-1 DW) set by China''s Ministry of Environmental Protection, and they also showed lower TF_rs values(< 1). In this study, Huaimai23, Jimai738, and Ningmai17 were initially identified as candidates for low-transport wheat cultivars, thereby providing a scientific basis for screening low-accumulation wheat cultivars.