重金属镉对8个水稻（Oriza sativa L.）品种（系）种子萌发的影响

Effects of Cadmium Tolerance on Seed Germination of eight diffrent rice (Oriza sativa L.) varieties

摘要:

为了探明不同品种水稻间抗镉能力差异及不同浓度镉胁迫对水稻种子萌发的影响，[方法]采用水培方法，对8个水稻品种轻，中，重度镉胁迫下种子萌发时期的相关性状指标进行收集，并通过聚类分析法对8个水稻品种的抗镉胁迫能力进行分析评价。[结果]表明：不同品种水稻其表型及生理机制各异，抗镉能力存在较大差异。轻度重金属镉胁迫对水稻种子萌发的影响，更多的体现为对水稻种子活力的单抑制效应。随着胁迫浓度的增大，水稻种子萌发受影响越大。中重度胁迫水稻的种子萌发敏感型品种生长表现为根芽尖脆弱易断，芽色不能及时转绿等现象。轻度重金属胁迫下的指标其综合性状表现更符合相关性拟合曲线。故选择轻度重金属胁迫下水稻的相对性状表现筛选重金属抗性品种，与实际环境情况最为相符合。聚类分析结果显示，三个杂交水稻主要亲本保持系亲本岗46B，保持系亲本Ⅱ-32B，和恢复系亲本成恢3203都属于高抗型。三个常规籼稻桂朝2号，桂育7号及五山丝苗都属于敏感型。本实验结果为培育重金属抗性品种提供了有价值的线索和材料。

Abstract:

To explore the ability of cadmium resistance between the different rice genotypes and to find the effects on the rice germination when exposed to the different concentration of cadmium. Method: Eight kinds of rice were planted by using hydroponic and we conducted a comprehensive evaluation on the ability of resistance to cadmium stress between the different rice genotypes through the clustering analysis. Results: On account of the various genotypes and different physiological mechanism, there were a large difference on their cadmium resistance. The effect of mild cadmium stress on the seed germination of rice was more significant at the single inhibitory effect on rice seed vigor.With the increase of stress concentration, the effect of rice seed germination was greater.Sensitive varieties seems to be more brittle of rice root tip and bud color can not be timely turn to green phenomenon when under midle Cd stress. The comprehensive character of the index under mild heavy metal stress was more consistent with the correlation curve. Therefore, the selection of heavy metal resistant varieties under the condition of mild heavy metal stress was the most suitable to the actual situation.These eigth varieties of rice for experiment were divided into three types through the cluster analysis, which were tolerant respectively,sensitive and intermediate.The hybrid rice including G46-B,Ⅱ-32B,and R3203 were proved to be tolerant, which had the strongest ability of cadmium resistance.While the Wushansimiao, Guichao-2 and Guiyu-7 were the sensitive type and the cadmium resistance were the weakest.The results of this study provide valuable clues and materials for the breeding of heavy metal resistant varieties.