不同品种水稻种子萌发和幼苗生长的耐镉性评价

【研究目的】为了明确不同品种水稻种子萌发和苗期对镉胁迫反应的差异，为小麦品种耐镉性筛选和耐镉育种提供理论参考；【方法】采用室内生物测定方法，在不同浓度镉胁迫下，通过对贵州省常见的12个水稻品种的发芽率、发芽指数、活力指数、根长、芽长、根鲜重、芽鲜重、耐镉半致死浓度和耐镉致死浓度进行比较研究，并采用模糊数学隶属函数法对水稻的耐镉性进行综合评价。【结果】结果表明，随着镉胁迫浓度的增加，12个水稻品种种子萌发受到的抑制作用明显增强，发芽率、发芽指数、活力指数、根长、芽长、根鲜重、芽鲜重呈下降趋势，其中活力指数、根长、根鲜重对镉胁迫的反应更敏感；不同水稻品种间种子萌发受镉胁迫抑制的程度存在明显差异。耐镉半致死浓度为208~955 μmol/L、耐镉致死浓度940~3678 μmol/L。【结论】在供试的12个水稻品种中，II优808和川江优3号的耐镉性较强，而中优9801、宜香优101、冈优725和宜香1979的耐镉性较差，其他为耐镉性中等品种。

Cadmium-resistance Evaluation on Seed Germination and Seedling Growth of Different Rice Varieties

In order to elucidate the different responses of different rice cuhivars to cadmium and provide theoretical reference for selecting cadmium-tolerant varieties and breeding cadmium-tolerant species, the seeds of 12 varieties of rice mainly cultivated in the province of Guizhou were treated with Cd solution of different concentrations by using the techniques of laboratory bioassay. The germination rate, germination index, vigor index, root length, shoot height and fresh weight of root and shoot, semilethal cadmium concentration and lethal cadmium concentration were measured to assess the cadmium-resistant ability of rice by Membership Function. The results showed that the inhibitive effects on the seed germinations obviously increased with the increase of Cd concentrations. And the germination rate, germination index, vigor index, root length, shoot height and fresh weight of root and shoot were reduced. The vigor index, root length and root fresh weight were more sensitive to Cd stress. There were significant differences in seed germination among different rice cultivars. Semilethal Cd concentration was 208-955 μmol/L, and lethal Cd concentration was 940-3678 μmol/L. In all the 12 cuhivars, II You 808 and Chuanjiangyou 3 were tolerant to Cd, Zhongyou 9801, Yixiangyou 101, Gangyou 725 and Yixiang 1979 were sensitive and the others were moderately tolerant.