不同生育期镉胁迫对两种水稻的生长、镉吸收及糙米镉含量的影响  

Effects of cadmium exposures in different stages on plant growth ,cd uptake and cd concentrations in brown rice of a hybrid and conventional rice variety

作　　者：王凯荣[1] 龚惠群[2] 

机构地区：[1]莱阳农学院农业生态与环境健康研究所,山东青岛266109 [2]中国科学院亚热带农业生态研究所,湖南长沙410125

出　　处：《生态环境》2006年第6期1197-1203,共7页Ecology and Environmnet

基　　金：农业部农业结构调整重大研究专项(04-01-03B)资助

摘　　要：采用分阶段加镉水培试验，对杂交水稻“威优1126”和常规水稻“浙辐802”不同生育期对Cd胁迫的生长反应及其对Cd吸收、积累与分配特性进行了比较研究。结果表明，水稻对Cd胁迫的反应因生育期不同而异，幼穗分化之前（前期），镉毒害主要表现为降低光合生产力；幼穗分化至抽穗期（中期）主要抑制幼穗的分化与发育过程；抽穗之后（后期）主要阻碍碳水化合物和NP养分向穗部迁移和转化。从对产量形成影响来看，幼穗分化-抽穗期是水稻对Cd胁迫反应最敏感时期。水稻吸Cd速率为中期〉后期〉前期。糙米中Cd的含量受水稻植株吸收Cd的总量和茎叶Cd向籽粒转移效率的双重影响。杂交稻对Cd的吸收能力与常规水稻相近，但Cd在地上部分累积的比例比常规水稻高4．9％-21．8％，籽粒部分的镉与茎叶部分镉的比例比常规稻高49%-95％，糙米Cd含量比常规稻高33％～72％。从减产效应和对稻米卫生品质损害来看，杂交水稻对环境Cd污染比常规水稻更加敏感。A comparative study was conducted on the responses of hybrid rice ＂Weiyou 1126＂ and conventional rice ＂Zhefu 802＂ in plant growth, dry matter production, and cadmium （Cd） uptake, accumulation and distribution under Cd exposure in various growth stages through a water culture pot experiment with split addition of Cd reagent. Results showed that there were different responses of rice plants on Cd exposure in various growth stages. In the stage before spikelet initiation （the early stage）, the major response of Cd toxicity was the reduction of photosynthetic potential. In the stage from spikelet initiation to flowering （the middle stage）, Cd toxicity mainly reflected on inhibition of the process of spikelet initiation and development. In the stage after flowering （the later stage）, Cd exposure mainly resulted in an obstacle in transfer, as well transformation of carbohydrates and NP nutrients from the straw to the ear. Considering the aspect of grain yield, the middle stage was the most sensitive one of the two types of rice to the Cd stress. The sequence of Cd uptake rate was the middle stage 〉 the later stage 〉 the early stage of both rice varieties. Concentrations of Cd in the brown rice was related to both, the amount of Cd uptake by rice plants as well the rate of Cd transfer from the straw to grains. There was a comparative potential of Cd uptake by the hybrid and the conventional flee. However, ratios of Cd in the upper ground parts to the total uptake by the hybrid flee was 4.9-21.8 % higher than that of the conventional rice, while the ratio of Cd accumulated in grains to that in straw of the hybrid rice was 49-95 % higher that that of the conventional flee. Finally, concentration of Cd in brown flee of the hybrid rice was 33-72 % higher than that of the conventional flee. From this experiment, it can be concluded that the hybrid flee is more sensitive to an environmental Cd pollution than the conventional rice in aspects of the reduction of yield and the damage effect on hygieni

关 键 词：镉 植物毒性 杂交水稻 常规水稻 稻米镉含量 

分 类 号：X171.5[环境科学与工程—环境科学]