【摘要】 为了揭示不同硒源和浓度对饲用苎麻幼苗生理生化特性的影响，以中饲苎1号为试材，通过盆栽试验，研究亚硒酸钠(Se⁴⁺)和硒酸钠(Se⁶⁺)及其不同浓度(0、0.9、1.8、2.7 mg·kg^-1)对苎麻生物量、硒含量、硒积累总量、光合色素含量、抗氧化酶活性、超氧阴离子含量和产生速率及丙二醛（MDA）和可溶性蛋白含量的影响。结果表明，土壤施硒能够显著增加苎麻硒含量和硒积累总量，且随施硒量的增加苎麻硒含量和硒积累总量逐渐增加。苎麻地上部对硒酸钠的吸收远远高于对亚硒酸钠的吸收，其中0.9 mg·kg^-1 Se⁶⁺处理中苎麻叶片和茎秆硒含量分别是相同浓度下Se⁴⁺处理的71.9和54倍。当硒酸钠施用量为0.9 mg·kg^-1时，虽然提高了苎麻植株体内超氧化物歧化酶（SOD）、过氧化物酶（POD）、谷胱甘肽过氧化物酶（GSH-PX）和谷胱甘肽还原酶（GR）活力，但超氧阴离子含量和释放量显著增高，叶绿素和类胡萝卜素含量明显降低，使苎麻幼苗地上部分干物质降低90.3%；而当硒酸钠施用量为1.8和2.7 mg·kg^-1时，则造成苎麻幼苗死亡。亚硒酸钠对苎麻地上部生物量和过氧化氢酶（CAT）与GR活性有显著性影响，其中0.9、1.8和2.7 mg·kg^-1 Se⁴⁺处理中CAT和GR活性较CK处理分别提高130.6%和37.6%、41.5%和131.4%、176.7%和117.4%，但2.7 mg·kg^-1 Se⁴⁺处理使苎麻地上部生物量降低了24.7%。施用前期，亚硒酸钠对光合色素和可溶性蛋白无显著性影响，而施用后期显著增加叶绿素和可溶性蛋白含量，降低叶绿素a/b的值。因此，硒酸钠对苎麻生理生化特性的影响程度远远大于亚硒酸钠，其在植株体内易迁移，生物有效性强，更易造成植株伤害。施用0.9 mg·kg^-1 Se⁴⁺在不影响苎麻生物量的同时能够显著提高硒含量和硒积累总量，并且缓解植株衰老。更多还原

【Abstract】 In order to reveal the effects of different selenium（Se）sources and concentrations on physiological and biochemical characteristics of forage ramie seedlings,the pot experiment was conducted to study the difference between sodium selenite(Se⁴⁺)and sodium selenate(Se⁶⁺),using zhongshi Ramie No.1 as the test material.Concentration(0,0.9,1.8,2.7 mg·kg^-1)had significant effects on plant biomass,Se content,total Se accumulation,photosynthetic pigment content,antioxidant enzyme activity,superanion radical content and production rate,malondialdehyde（MDA）and soluble protein content of forage ramie were analyzed.The results showed that soil Se application significantly increased Se content and its total accumulation in ramie,and it gradually increased with the increase of the Se dose.The absorption of Se⁶⁺on the above-ground of ramie was much higher than that of Se⁴⁺,among which the Se content of ramie leaves and stems under the treatment of 0.9 mg·kg^-1 Se⁶⁺was 71.9 times and54 times of that under the treatment of the same concentration of Se⁴⁺.0.9 mg·kg^-1 Se⁶⁺treatment improved superoxide dismutase,peroxidase（POD）,glutathione peroxidase（GSH-PX）and glutathione reductase（GR）activity,but increased strongly super anion radical content and release amount,reduced significantly the contents of chlorophyll and carotenoid,and the overground dry matter of ramie seedling was reduced by 90.3%,while the ramie seedlings died when the dosage of Se⁶⁺was 1.8 and 2.7 mg·kg^-1.The biomass,CAT and GR enzyme activity of ramie were significantly affected by selenite at different concentrations.Compared with the control group,the activity of CAT and GR in 0.9,1.8 and 2.7 mg·kg^-1 Se⁴⁺treatments increased by 130.6%and 37.6%,41.5%and 131.4%,176.7%and 117.4%,respectively,but 2.7 mg·kg^-1 Se⁴⁺reduced the overground dry matter weight by 24.7%.In the early stage of application,Se⁴⁺had no significant effect on photosynthetic pigment and soluble protein,but chlorophyll content and soluble protein content were significantly increased and chlorophyll a/b ratio was decreased in the late stage of application.Therefore,the effect of Se⁶⁺on the physiological and biochemical characteristics of ramie is far greater than that of Se⁴⁺,which is more easy to migrate in the plant and has strong bioavailability which can cause damage to the plant.Without affecting the biomass of ramie,the application of 0.9 mg·kg^-1 sodium selenite could significantly increase the Se content and total Se accumulation,and alleviate the senescence of ramie.更多还原