镉胁迫对不同基因型水稻生长和镉吸收的影响

Effects of Cadmium Stress on Growth and Cadmium Uptake of Different Rice Genotypes

采用盆栽试验,以水稻不育系、恢复系以及水稻品种为研究对象,探索了在土壤中不同浓度镉胁迫下水稻各生长期状况以及镉的吸收特性。结果表明:镉胁迫促进了川33B水稻的分蘖;低浓度镉胁迫促进S527与Lemont水稻分蘖,高浓度则抑制分蘖;分蘖期对镉胁迫不敏感的品系为Ⅱ-32B。同一基因型水稻在不同镉浓度胁迫下,株高和穗长差异均不显著。低浓度镉胁迫能提高水稻有效穗的形成和增加千粒重,高浓度则起抑制作用。除不育系Ⅱ-32B外,供试的其余品系水稻籽粒和秸秆中镉含量均随土壤镉浓度增加而升高。恢复系T3028和水稻品种岗优725的籽粒富集镉的能力较强,不育系川33B籽粒不易富集镉。不同基因型水稻耐受镉的浓度约为0.3 mg/kg。

In this pot experiments,taken a rice cultivar,its sterile lines and restorer lines as tested objects,the status of rice growth in different stages and the Cd uptake characteristic of different rice genotypes were studied under the concentrations of different cadmium（Cd）.The results showed that Cd stress improved tillering of the sterile line Sichuan 33B;the tillering of the restorer line Lemont and S527 enhanced at low Cd concentration but depressed at higher Cd concentrations,while the steril line Ⅱ-32B was not sensitive to Cd stress during rice tillering stage.The plant height and the ear length of the same genotype cultivars were not significantly affected by Cd concentrations.Effective ear number and 1000-grain weight enhanced at low Cd concentrations but depressed at higher Cd concentrations.Cd content in seed or straw increased along with the increase of Cd concentrations in soils except II-32B.Restorer line T3028 and cultivar Gangyou 725 could enrich more Cd in grain than others,but the sterile line Sichuan 33B was on the contrary.Different genotype rice tolerance to Cd concentrations in soils was about 0.3 mg/kg.