目的研究不同产区、不同生长期明党参内生真菌的种群结构与生态分布, 以及内生真菌诱导子对明党参细胞生长与多糖积累的影响。方法采用微生物分离、培养与鉴定等生物学方法、植物细胞悬浮培养方法以及统计分析方法。结果从4个产地明党参植株中共分离到8属116株内生真菌, 其中镰孢属(Fusarium LK.exFR.)、地霉属(Geotrichum LK.)和链格孢属(Alternaria Nees)为优势种群。随着明党参生长期的不同, 内生真菌种群结构出现明显的动态变化。在苗期和孕蕾期, 内生真菌种群丰富, 数量较多, 尤其是在孕蕾期3种优势种群的分离率和分离频率分别达到30%和19%以上。部分内生真菌种群还具有明显的区域专一性和组织专一性。此外, 内生真菌Fusarium sp.3诱导子处理组, 明党参细胞生长量和多糖量分别比对照提高了31.86%和38.01%。结论明党参内生真菌具有丰富的生物多样性, 种群结构及分布与其生态环境具有密切的相关性, 且部分明党参内生真菌诱导子对其细胞生长和多糖积累均具有显著的促进作用。

Objective To study the effect and action rules of five allelochemicals on protective enzyme activity of Panax ginseng roots.Methods By the method of solution culture, the effects of benzoic acid,diisobutyl phthalate, diisobutyl succinate,palmitic acid,and 2,2-bis(4-hydroxyphenyl) propane on the activity of peroxidase(POD),catalase(CAT),and phenylalanine ammonia-lyase(PAL) of P.ginseng roots at seedling stage were studied.Results Benzoic acid inhibited POD activity at three concentration tested,diisobutyl phthalate and diisobutyl succinate inhibited POD activity at low concentration only,palmitic acid,and 2,2-bis(4-hydroxyphenyl) propane enhanced POD activity at three concentration tested,which was positively correlated to alle-lochemical concentration.Except for diisobutyl succinate and palmitic acid,the other allelochemicals enhanced CAT activity,and their concentration was positively correlated to the activity.Benzoic acid and diisobutyl succinate inhibited PAL activity at low concentration,and the enhancement of PAL activity at middle concentration was higher than that at high concentration.Palmitic acid at low concentration and 2,2-bis(4-hydroxyphenyl) propane at high concentration enhanced the PAL activity most,and the PAL activity was positively correlated to concentration for 2-benzenedicarboxylic acid bis(2-methylpropyl) ester.Furthermore,the activities of POD,CAT,and PAL fluctuated with time at both control and five allelochemical treatments,but no significant correlation among them.ConclusionFive allelochemicals identified from of P.ginseng roots could significantly influence the activities of POD,CAT,and PAL.

江苏省自然科学基金 (BK2007241);南京中医药大学青年科学基金 (09XZR19);江苏省方剂研究重点实验室资助项目