Genotypic variation of cadmium accumulation and distribution in rice
Genotypic variation of cadmium accumulation and distribution in rice
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DOI：
10.1007/s12892-010-0036-5
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发表时间：
2010-08
影响因子：
--
通讯作者：
Yong-feng Yan;Doug-Hwan Choi;Do-Soon Kim;Byun-Woo Lee
中科院分区：
文献类型：
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作者：
Yong-feng Yan;Doug-Hwan Choi;Do-Soon Kim;Byun-Woo Lee
减少镉(Cd)进入食物链的风险的有效方法是使用低Cd积累量的水稻品种，特别是在亚洲。选育低Cd积累量品种的根本要求是了解Cd积累量的遗传变异和控制水稻籽粒Cd积累量的生理过程和遗传基础。本试验以35个水稻品种为材料，研究了Cd在水稻各器官中积累和分配的遗传变异。2007年在大田条件下，在整个水稻生长季节，用含2ppm Cd的灌溉水种植它们。收获时，对植株进行采样，分析Cd在水稻各器官中的浓度和积累情况。在35个水稻品种中，水稻各器官中Cd的浓度和积累量存在显著差异，表现出籽粒Cd浓度和地上部Cd积累量的8倍以上的品种差异。籽粒中Cd含量和积累量在不同品种组间差异显著，表现为籼稻最高，温带粳稻最低。同类型水稻和热带水稻的Cd含量介于温带水稻和籼稻之间。水稻籽粒对Cd的高积累量与其对Cd的吸收能力较强有关。热带粳稻较强的根冠运转能力和桐桂类型的地上部再分配能力，导致这些品种群体的籽粒Cd含量显著高于温带粳稻。在供试的35个品种中，籽粒Cd浓度与根Cd浓度、地上部Cd浓度和积累量呈显著正相关，与根冠运转因子和地上部再分配比无显著相关。但各品种组内相关分析表明，籽粒Cd浓度与籼稻根冠运转因子显著相关，与桐桂型根Cd浓度显著相关，与热带粳稻地上部Cd浓度和积累量显著相关，与温带粳稻地上部Cd积累量和地上部籽粒再分配比显著相关。这些结果表明，籽粒Cd积累的遗传变异总体上受三个生理过程的控制，但品种群内控制其遗传变异的主要生理过程因品种群而异。
An effective way to reduce the risk of cadmium (Cd) entering the food chain is to use low Cd-accumulation rice cultivars, particularly in Asia. The fundamental requirement for breeding low grain Cd-accumulation cultivars is to know the genotypic variation in Cd accumulation and the physiological processes and genetic basis governing the Cd accumulation in rice grain. In this experiment, genotypic variation in Cd accumulation and distribution among rice organs was studied using thirty-five rice varieties. They were grown with irrigation water containing 2 ppm Cd throughout rice growing season under field condition in 2007. At harvest, plants were sampled and analyzed for Cd concentration and accumulation in each rice organ. Significant variation of Cd concentration and accumulation in rice organs were found among thirty-five rice cultivars, revealing more than 8-fold varietal differences in grain Cd concentration and shoot Cd accumulation. Cd concentration and accumulation in grain were significantly different among cultivar groups, showing the highest in indica and the lowest in temperate japonica. Tongil-type and tropical japonica rice showed a Cd concentration intermediate to that of temperate japonica and indica rice. The higher Cd accumulation in grain of indica rice was attributable to the greater ability of Cd uptake. The greater ability of root-shoot translocation in tropical japonica and shoot-grain redistribution in tongil-type resulted in the significantly higher grain Cd concentration in these cultivar groups than in temperate japonica. For over 35 cultivars tested, grain Cd concentration revealed a significant positive correlation with root Cd concentration and shoot Cd concentration and accumulation while no significant correlation with root-shoot translocation factor and shoot-grain redistribution ratio. However, correlation analyses within each cultivar group showed that grain Cd concentration was significantly correlated with root-shoot translocation factor in indica, with root Cd concentration in tongil-type, with shoot Cd concentration and accumulation in tropical japonica, and with shoot Cd accumulation and shoot-grain redistribution ratio in temperate japonica. These results indicate that genotypic variation in grain Cd accumulation, in general, is controlled by all the three physiological processes but the major physiological process governing its genotypic variation within cultivar group is different depending on cultivar groups.