接种后共培养时间对丛枝菌根喜树幼苗喜树碱含量的影响  

Effect of co-cultivation time on camptothecin content in Camptotheca acuminata seedlings after inoculation with arbuscular mycorrhizal fungi

作　　者：于洋[1] 于涛[1] 王洋[1] 阎秀峰[1] 

机构地区：[1]东北林业大学盐碱地生物资源环境研究中心,东北油田盐碱植被恢复与重建教育部重点实验室,哈尔滨150040

出　　处：《生态学报》2012年第5期1370-1377,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金(30771699);高等学校博士学科点专项科研基金(20090062110008)

摘　　要：在前期工作中利用蜜色无梗囊霉(Acaulospora mellea)和根内球囊霉(Glomus intraradices)从接种时期角度分析了喜树碱含量与菌根形成过程对应关系的基础上,通过温室盆栽接种试验,继续观察了这两种丛枝菌根真菌接种后与喜树(Camptothecaacuminata)幼苗的共培养时间对喜树幼苗喜树碱积累的影响。分别用两种菌根真菌每隔7d接种一批喜树幼苗,第5批接种7 d后采样,获得菌根真菌与喜树幼苗共培养时间分别为35、28、21、14、7 d的喜树幼苗样品,测定了菌根浸染状况和喜树碱含量。结果表明:(1)接种两种丛枝菌根真菌均促进了喜树幼苗喜树碱的积累,表现为喜树碱含量和产量(单株幼苗所含的喜树碱量,喜树碱含量与幼苗生物量的乘积)的显著提高。(2)从接种后共培养时间的效果看,两种菌根幼苗各器官(根、茎、叶)及全株喜树碱含量和产量均呈现随着丛枝菌根真菌与喜树幼苗共培养时间的增加而增加的趋势。两种菌根幼苗的根和茎、根内球囊霉菌根幼苗的叶片和全株的的喜树碱含量和产量,在共培养时间增加至21 d时趋于稳定,而蜜色无梗囊霉菌根幼苗的叶片和全株的喜树碱含量和产量在共培养时间增加至28 d时达到最高,其后略有降低。(3)两种丛枝菌根真菌的侵染率和侵染强度同样随共培养时间的增加而增加,至共培养28 d后无显著变化。在一定共培养时间范围内,喜树碱含量和产量的变化与丛枝菌根真菌的侵染及菌根形成之间具有对应性。More than 85% of terrestrial plant species associate with arbuscular mycorrhizal fungi （AMF）. Most plant individuals stimulate nutrient availability through their fungal partner. Highly mycorrhizal-dependent plant species derive more benefits from AMF in comparison with plant species with a relatively low mycorrhizal dependency. Until recently, the effects of AMF on the competition between mycorrhizal and non-mycorrhizal plants （with high phosphate foraging ability） remained largely unclear, particularly in an environment with low phosphate bioavailability. Mycorrhizal effects on plant interactions are most likely due to alterations in the soil nutrient availability. AMF colonization could increase nutrient （particularly phosphate） availability for host plants and consequently increase plant biomass. The larger plants are then expected to be successful competitors. In the present study, maize （Zea mays L.） and rape （Brassica napus L.） plants were cultivated in three different interaction status, namely monoculture, intercropping and nylon net split. All the plants were inoculated with Glomus intraradices, Glomus mosseae or remained uninoculated. The strength of competition is measured as the reduction in biomass caused by the presence of a competitor. The results showed that maize growth and mineral nutrition was suppressed, while the mycorrhizal dependency increased to some extent, in intercropping compared with monoculture system. In intercropping system inoculation with G. intraradices and G. mosseae significantly decreased phosphorus concentration and content of rape roots compared with non-inoculation treatments, while in contrast mycorrhizal association improved phosphorus nutrition of maize plants. The experimental results clearly showed the beneficial effects of mycorrhizal associations on AMF host plants in competition with non-host plants. All these revealed that AMF may play an important role in structuring plant community and influencing plant biodiversity in ecosystems.

关 键 词：喜树幼苗 丛枝菌根真菌 喜树碱 

分 类 号：S792.99[农业科学—林木遗传育种]