钙和钾对延胡索幼苗镉毒害的缓解作用  

Alleviation of cadmium toxicity in Corydalis yanhusuo seedlings by exogenous calcium or potassium

作　　者：张静[1] 余顺慧[1] 祁俊生[1] 梁克中[1] 陈书鸿[1] 刘雷[1] 陈华华[1] 陆亚萍[1] 

机构地区：[1]重庆三峡学院三峡库区水环境演变与污染防治重庆高校市级重点实验室,重庆404100

出　　处：《草业学报》2017年第8期123-130,共8页Acta Prataculturae Sinica

基　　金：重庆市应用开发计划项目(cstc2014yykfA110024);三峡库区水环境演变与污染防治重点实验室项目(WEPKL2012MS-01)资助

摘　　要：通过探讨外源钙(Ca^(2+) )、钾(K^+)对重金属镉(Cd)(0~25mg/kg)胁迫下延胡索幼苗的缓解作用,为延胡索经济高效优质高产的栽培模式提供理论依据和实践指导。以大叶延胡索为材料,采用土培法,研究外源Ca^(2+) 、K^+处理对不同浓度Cd胁迫下延胡索幼苗株高、生物量、生理特征、重金属含量及药用品质的变化。结果表明,各浓度Cd胁迫下外源Ca^(2+) 、K^+处理的最适缓解浓度分别为100和200mg/kg,在该浓度下Ca^(2+) 、K^+能明显缓解Cd对延胡索幼苗的抑制作用。在低浓度Cd胁迫下,添加最适浓度的外源Ca^(2+) 处理后幼苗可溶性糖、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性相比未添加外源Ca^(2+) 处理的对照组升高,而丙二醛(MDA)含量低于对照。添加最适浓度的外源K^+处理后幼苗上述各指标无明显变化。高浓度Cd胁迫下,添加最适浓度的外源Ca^(2+) 处理后幼苗可溶性糖、SOD、POD和CAT活性显著高于对照,MDA含量显著降低。在各浓度Cd胁迫下,添加最适浓度的外源Ca^(2+) 、K^+处理后幼苗根部细胞微核率降低,从而缓解了Cd对延胡索幼苗的毒害。因此,在Cd胁迫(尤其是25mg/kg浓度Cd胁迫)下,外源Ca^(2+) 、K^+通过提高延胡索幼苗的抗氧化能力来缓解Cd对幼苗毒害和细胞染色体损伤。此外,外源Ca^(2+) 、K^+影响Cd胁迫下延胡索幼苗地上及地下部分Cd的积累,其影响机制比较复杂。25mg/kg Cd胁迫下添加Ca^(2+) 能够显著改善延胡索的药用品质,延胡索乙素比25mg/kg Cd胁迫下增加了27.52%。在Cd污染的土壤上种植延胡索,可加入适量的外源Ca^(2+) 通过改变延胡索幼苗的抗氧化酶活性等方式达到缓解Cd毒害,降低块茎中Cd含量,改善药用品质。In this study, we explored the alleviating effects of exogenous calcium （Ca2＋） and potassium （K＋） on Corydalis yanhusuo seedlings under cadmium （Cd） stress. Seedlings of C. yanhusuo were grown in soil containing Cd （〇-25 mg/kg） and their plant height, biomass and physiological characteristics, heavy metal content, and medicinal quality were determined. At all levels of Cd stress, the optimal concentrations of exoge-nous Ca2＋ and K＋ to alleviate Cd stress were 100 and 200 mg/kg, respectively. Under low-Cd and high-Cd ＊ ＊stress, the addition of 100 mg/kg Ca2＋ increased the soluble sugars content in seedlings, increased the activities of superoxide dismutase （SOD）,peroxidase （POD） and catalase （CAT）,and decreased the malondialdehyde （MDA） content, compared with those in plants without exogenous Ca2＋ treatment. There were no changes in these parameters in plants under low-Cd stress treated with K＋ at 200 mg/kg. Under all levels of Cd stress, the addition exogenous Ca2＋ and K＋ at the optimal concentrations decreased the rate of micronucleus formation in the roots, indicating that there was a significant alleviation of Cd poisoning. Under Cd stress （especially high-Cd stress at 25 mg/kg） , exogenous Ca2＋ and K＋ alleviated Cd poisoning of seedlings and relieved chromo-somal damage by increasing the antioxidant capacity of C. yanhusuo seedlings. Exogenous Ca2＋ and K＋ also af-fected Cd accumulation in above-ground and below-ground parts of the plant, but the effects were complex. Under 25 mg/kg Cd stress, the tetrahydropalmatine content increased by 27. 52% after adding exogenous Ca2＋ , indicating a significant increase in the medicinal quality of C. yanhusuo. Therefore, when growing C. yanhusuo in soil contaminated with Cd, the addition of an appropriate amount of Ca2＋ can alleviate Cd poison-ing via its effects on the activity of antioxidant enzymes. This leads to a decrease in the Cd content in tubers, there

关 键 词：镉污染 延胡索 钙 钾 抗氧化酶 细胞微核率 品质 

分 类 号：S567.239[农业科学—中草药栽培]