蔬菜对重金属的积累差异及低积累蔬菜的研究进展

从种间差异、种内差异和器官分布等方面总结了蔬菜对重金属的积累差异,对低积累蔬菜的筛选标准、筛选方法和目前筛选到的品种进行了归纳,分析了不同蔬菜品种积累重金属存在差异的机制,为低积累蔬菜的安全生产和研究提供了较为系统的参考资料。

Variation in accumulation of heavy metals in vegetables and low accumulation vegetable varieties: A review

Heavy metals in soils can be easily accumulated by various vegetables. The problem of metal pollution in vegetables should be of concern due to health risks. Low heavy metal accumulation vegetable cultivars (LAVCs) refer to some cultivars where the concentration of heavy metals in their edible parts should not exceed the maximum limits of the national or international standards when they are grown in heavy metal contaminated soils. The growth of LAVCs is a practicable and cost-effective approach to minimize the influx of heavy metals to the human food chain, and to utilize low or moderate heavy metal contaminated soils reasonably and effectively. In this review, research progresses involving variation in the accumulation of heavy metals in vegetable species, various cultivars, and different vegetable organs were summarized. Leafy vegetables accumulated more heavy metals compared with other vegetables. The low and high heavy metal accumulation cultivars coexisted among various cultivars within a species, and the accumulation property of vegetables was genotype-dependent at the cultivar level. This review also included the screening criteria, screening methods, and selected LAVCs. The main methods for screening LAVCs included pot-culture experiments and field-testing. Many LAVCs were selected from the candidate cultivars, and a majority of the selected LAVCs was low-Cd accumulating cultivars of leafy vegetables. Furthermore, the mechanisms of variation in vegetable accumulation of heavy metals among various cultivars within a species were analyzed. They might be attributed to the morphology and physiological responses of plant roots, differential gene expression, and the transport coefficient, chemical forms, bioavailability, and sub-cellular distribution of heavy metals in different plant parts. In summary, this review provides important reference materials for the application and study of LAVCs, which should help in ensuring human health and the safe production of vegetables.