镉胁迫对不同水稻品种种子萌发和幼苗生长的影响

Effects of Cadmium Stress on Seed Germination and Growth Characteristic of Different Rice Cultivars

为研究不同浓度镉胁迫对水稻种子萌发和幼苗生长的影响及其不同水稻品种的镉胁迫抗性差异,采用52个不同遗传背景的水稻品种(系)种子,研究了0(蒸馏水,CK)、0.5、1.0、2.0 mmol/L等4种不同镉胁迫浓度对不同水稻品种(系)种子发芽率、发芽势、发芽指数、活力指数、胚芽长、胚根长、胚芽鲜重与干重等萌发期性状的影响。结果表明:(1)镉胁迫对水稻种子的萌发及幼苗生长具有抑制作用,且随着镉胁迫浓度的增高,其受到的抑制作用逐渐加强;(2)不同镉胁迫浓度对幼苗根生长的影响大于对幼苗芽生长的影响;(3)镉胁迫下,各水稻品种(系)种子各萌发性状指标间的相互关系密切;(4)镉胁迫对水稻种子的活力指数、幼苗根长的抑制程度较大,而对发芽势、发芽率的抑制程度较小;(5)不同水稻品种(系)对不同镉胁迫浓度的耐受性存在显著差异,根据镉胁迫各浓度处理条件下各供试水稻品种(系)在萌发期内的各项萌发性状指标与对照的相对值用聚类方法进行分析,可将52个参试水稻品种(系)分为镉胁迫敏感型、中间型和耐受型等3种类型。

In order to study the resistance differences of different rice cultivars to cadmium stress,fifty-two rice cultivars( strains) with different genetic back ground were used to analyze the effects of 4 different cadmium concentration( 0,0. 5,1. 0,2. 0 mmol/L) on seed germination rate,germination energy germination index,vigor index,germ length,radicle length,germ fresh weight and bud dry weight of all the cultivars. The results showed that:( 1) Cadmium stress inhibited seed germination and seedling growth,and the inhibition was increased as the increasing of cadmium concentration.( 2)The radicle growth of rice seed was in habited more serious than that of the bud sat different cadmium concentrations.( 3)There was highly significant correlation among indexes of all the rice cultivars under cadmium stress.( 4) There was difference in the in hibitory degree of all the indexes due to cadmium stress,the vigor index and radicle length were in habited more than that of germination energy and germination rate.( 5) There was significant difference in the resistances to cadmium stress among different rice cultivars. According to the results of cluster analysis about the relative values of each trait during germination at cadmium stress,the fifty-two rice cultivars were classified into three types: sensitive,intermediate,tolerant.