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作 者 ：魏 明,杨超英,孔 芳,柴瑞娟

期 刊 ：西北植物学报 2015年 2期 页码：309~314

关键词：铁皮石斛；硝酸镧；兰科菌根真菌；生理特性；

Keywords:Dendrobium officinale, lanthanum nitrate, orchid mycorrhizal fungi, physiological characteristic,

摘 要 ：利用盆栽的方式研究了不同硝酸镧水平(0、1.0、3.0、5.0和7.0 mg·L^-1)下接种兰科菌根真菌对铁皮石斛生物量、多糖和蛋白质合成的影响,并分析了叶绿素含量、丙二醛(MDA)含量以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性的变化,以探讨硝酸镧和兰科菌根真菌对铁皮石斛生理特性的影响。结果表明:(1)添加适量的硝酸镧有利于菌根真菌侵染和菌根发育,提高铁皮石斛幼苗生物量。(2)在接种菌根真菌的同时添加5.0 mg·L^-1的硝酸镧,铁皮石斛的根重、茎叶重和总生物量均达到最大,分别是未添加硝酸镧以及未接种对照组的4.26倍、4.98倍和4.87倍,其菌根侵染率也高达92.8%;而且可显著提高叶片中叶绿素含量,并显著降低细胞内的丙二醛含量。(3)在适量(5.0 mg·L^-1)的硝酸镧水平下接种菌根真菌能促进铁皮石斛幼苗多糖和蛋白质的合成,并显著提高细胞内SOD、CAT和POD活性。研究认为,菌根真菌与适宜浓度硝酸镧(5.0 mg·L^-1)联合使用能显著促进铁皮石斛菌根的形成,增强植株的生理活性和适应能力,提高其生物量和多糖等活性成分的积累,有效改善铁皮石斛的药用品质。

Abstract:In order to investigate the physiological effects of lanthanum nitrate and orchid mycorrhizal(OM) fungi on Dendrobium officinale,we investigated the effects of inoculation with OM fungi under different lanthanum nitrate application levels (0,1.0,3.0,5.0 and 7.0 mg·L^-1) on the biomass of D.officinale seedling and synthesis of polysaccharides and proteins using a pot experiment.The chlorophyll content,malondialdehyde (MDA) content and the activities of SOD,CAT and POD in cells were analyzed.The results were as follows:(1)Appropriate concentration of lanthanum nitrate was beneficial to the development of mycorrhiza and promoted the biomass of D.officinale seedling.(2)D.officinale inoculated with OM fungi and applied with lanthanum nitrate 5.0 mg·L^-1 had the largest mass of roots,mass of shoots and biomass of D.officinale seedling which were of 4.26,4.98 and 4.87-fold,respectively,compared to control.The infection rate of OM fungi to the roots of D.officinale seedling reached 92.8%.The contents of chlorophyll increased,whereas the content of MDA decreased in cells.(3)The contents of polysaccharides and proteins increased in cells.SOD,CAT and POD activities were found to increase significantly in cells too on the same conditions.Therefore,the development of D.officinale mycorrhiza,the physiological activity and adaptability of plants,the biomass of D.officinale seedling and accumulation of polysaccharides could be improved by inoculation with OM fungi and application with appropriate concentration of lanthanum nitrate (5.0 mg·L^-1).It indicated that the medicinal qualities of D.officinale could be promoted too.

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