Cd^(2+)胁迫对籼稻和粳稻不同生育期生长发育的影响

Effects of Cd^(2+) Stress on Growth and Development of Rice Indica and Japonica

来自于采矿废物的重金属镉,由于其在土壤中的高移动性和食物链上的生物可获得性已经污染了越来越多的稻田,导致人类受到潜在的毒害而受到人们高度关注。研究采用盆栽试验,以籼稻和粳稻2个水稻类型为材料,比较研究了6种不同浓度Cd2+对籼、粳稻植株生长发育和叶片生理活性的胁迫效应。结果表明:低Cd2+浓度(10 mg/kg)对籼稻CG132R生长发育具有一定的促进作用。随着土壤Cd2+浓度的增加,CG132R(籼稻)和粳925(粳稻)生长发育均受到抑制。生育前期是CG132R生长发育对Cd2+胁迫最敏感的时期;生育后期,CG132R对Cd2+胁迫表现出一定适应性。CG132R和粳925对Cd2+胁迫耐性存在显著差异。在不同浓度Cd2+胁迫下,CG132R都表现出比粳925更好的适应性。水稻叶片生理活性受Cd2+胁迫主要表现为水稻叶片叶绿素含量下降、丙二醛(MDA)含量升高、细胞膜透性增加。综合比较,籼稻CG132R比粳稻粳925有更强的抗镉胁迫能力,镉污染土壤种植粳稻将更好表现镉污染状况。

Due to the fact that more and more paddy fields have been polluted by cadmium which is mostly coming from mining waste,pot-culture experiments were conducted focusing on the stress effects of Cd2＋ of six different concentrations in soil on two species of rice,Indica（CG132R） and Japonica（Jing925）. Results of the experiments indicated that though Cd2＋ in low concentration（10 mg/kg）could promote growth of Indica,with the increases of cadmium concentration in soil both Indica and Japonica were negatively effected,i.e. their growth were restrained. Indica was more sensitive to cadmium in the early growing stage but became slightly adapted to it in later stage;and in general,Indica was more tolerant of Cd2＋ in different concentrations than Japonica. In addition,it was found cadmium stress resulted in a decrease of chlorophyll content in leaves of rice,while concentration of MDA in leaves increased.