中国稻米

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不同镉积累型水稻品种苗期镉积累及转运变化特征

  1. 1湖南农业大学农学院,长沙 410128;2湖南省水稻研究所,长沙 410125;3国家杂交水稻工程技术研究中心,长沙 410125
  • 出版日期:2018-07-20 发布日期:2018-07-20
  • 基金资助:

    湖南省重金属污染耕地修复及农作物种植结构调整试点项目

Cadmium Accumulation and Transfer Capacity among Different Types of Rice Cultivars at Seedling Stage

  • Online:2018-07-20 Published:2018-07-20

摘要:

稻米镉污染成为国家和社会广泛关注的问题,为了解不同水稻品种对土壤中镉离子的吸附特性,本研究通过水培试验分析了不同镉积累型水稻品种(高镉积累品种:玉针香、天优华占;低镉积累品种:湘晚籼12号、金优59)在苗期的镉吸收及转运时间动力学特征。结果表明,4个品种苗期根系和地上部的镉积累时间动力学特征均符合米氏方程,根系和地上部分的α值均表现为高镉积累品种大于低镉积累品种;镉胁迫72 h之后各品种镉总累积量表现为玉针香>金优59>天优华占>湘晚籼12号,其中高镉积累品种天优华占苗期累计量未达到饱和状态。4个品种镉转运速率随着胁迫时间延长均呈显著下降趋势,72 h后表现为高镉积累品种大于低镉积累品种。相关分析表明,参试品种根系镉含量、地上部分镉含量及根部向地上部的镉转运速率三者之间均呈显著正相关关系。可见,水稻高、低镉积累特性的显现具有一定的时限性,其中,以湘晚籼12号等为代表的低吸收、低转运品种类型在镉污染田块种植具有较高应用价值。

关键词: 水稻, 镉, 苗期, 时间动力学

Abstract:

Cadmium pollution incidence in rice had become a widespread concern of the state and society. In order to understand the soil Cd2+ adsorption characteristics in the different types cultivars, a water culture experiment was established with the high Cd accumulation cultivars (HCAs) Yuzhenxiang (A1)and Tianyouhuazhan (A2) and the low Cd accumulation cultivars (LCAs) Xiangwanxian 12 (B1)and Jinyou59 (B2) as materials, to examine the Cd absorption and transfer time kinetic characteristics at seedling stage. The results showed that the root and shoot Cd accumulation time kinetic characteristics of the 4 cultivar were all described with Michaelis-Menten equation, α value of their root and shoot all showed like HCAs> LCAs. After 72 h of Cd stress, the total Cd accumulation in all cultivars followed the order of A1> B2> A2> B1, in which the cumulative amount of A2 did not reach the saturation level at seedling stage. The Cd translocation efficiency showed a significant downward trend with prolonging of stress time, and HCAs were higher than those of LCAs. The correlation analysis showed that there was a significant positive correlation among Cd concentration in shoots and roots and Cd translocation efficiency of root to shoot in different rice varieties. It can be seen that the characteristics of high and low cadmium accumulation in rice have a certain time limit, and the low cadmium and low transport types represented by low cadmium varieties, such as Xiangwanxian 12, have high practical value in the cadmium polluted paddy fields planting.

Key words: rice, Cd, seedling stage, time kinetic

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