【作者】 丁琼；

【导师】 贾桂霞；

【作者基本信息】 北京林业大学 ， 园林植物与观赏园艺， 2004， 硕士

【摘要】 收集了濒危植物沙冬青分布的西北荒漠地区4个样区32份土样，经1-2个周期富集培养后，用湿筛法分离AM真菌孢子。从磴口样区土样中分离到数量上明显占优势的五种类型AM真菌孢子，以高粱为宿主，用盆钵盆养法，将分离得到的单种和混合种类孢子分别进行培养，为下一阶段接种试验准备菌剂。收集到豆科植物根瘤样品23份，发现沙冬青根瘤具有形态多样性。并初步分离到沙冬青根瘤菌菌株3株。 沙冬青容器育苗时作如下三种接种处理：1．添加原产地土样及残根混合物；2．添加1混合物的滤液；3．添加经间歇式湿热灭菌处理的1混合物。结果表明：经1和2处理的沙冬青幼苗株高、地径和叶片数都显著高于灭菌原土；处理1和2之间差异不显著。初步证明原产地土壤中的微生物(包括根瘤菌及其它土壤微生物)对沙冬青幼苗生长有显著的促进作用，而土著AM真菌的单独效应不显著，这可能与本次试验采用的原土中土著AM真菌繁殖体剂量有关，也可能是由于土著AM真菌长期适应极度干旱瘠薄环境，在水分和养分优于原产地的栽培条件下，真菌与植物原有的共生平衡关系被改变。与此同时，对Glomus mosseae，G versiforme，G．etunicatum，G．diaphanum四种AM真菌商业菌剂进行初步筛选，表明：分别以G．mosseae，G versiforme接种后，幼苗株高和干重均显著高于对照。而其它两个菌株接种效应不明显。 另外，本论文研究了沙冬青种子萌发特性及幼苗生长特性，针对北京地区气候和土壤条件，研究了沙冬青育苗、栽培的关键性技术措施。更多还原

【Abstract】 Thirty two soil samples from four field sites, where the endangered evergreen shrub Ammopiptanthus mongolicus resides in the desert region of north-west China, were collected and multiplied on Trifolium pratense under greenhouse condition for one or two cycle. Five kinds of arbuscular mycorrhiza fungi(AMF) spores with higher density were isolated from the multiplied soil sample of DengKou, one of the four study sites, by wet sieving method. The spores extracted were set up monospecific or mix culture in pot using sorghum as host to produce inoculum for further study. The nodule of A. mongolicus are greatly diversified in its shape and, from which 3 strains of rhizobia were isolated on the YAM plate.In the case of container seedling culture, to each pot add a mycorrhizal "inoculum" of one of three types: (l)soil around the roots system of A. mongolicus and its roots mixture collected from the sample field, (2)water filt of the former mixture, (3) the steam sterilized soil mixture. Seedlings of A. mongolicus were significantly increased in plant hight and stem diameter after inoculate with the(1) or (2) inoculum, but with no significant effect between them. It can be infered that once altering the nutrient environment of the indigenous AMF, which is well adapted to the nutrient poor soils of the arid desert region , does alter the mutualistic balance sheet. Another reason for this phenomenon is that the AM propagules in the soil are inadequate for the colonization of the fungi to set up a mutulistic relationship that mostly benefits the host.At the same time, four speices of AM fungi in the genera of Glomus obtained from the Research Institute of Agriculture and Forest Science of Beijing were used in container seedling culture procedure. Results show that the growth of A. mongolicus were significantly enhanced after inoculated with the G. mosseae or G. versiforme compared with the uninoculated, while the G. etunicatum or G. diaphanum were not showing significant effect. Therefore, for the relatively fertile soil, the AM fungi species frequently used in agriculture and horticulture might gain more reasonable result than the native AM fungi.Further, in order to introduce this shrub with beautiful flower to the gardens of north China, this thesis also deals with the cultivation techniques and maintenance of A. mongolicus in Beijing where the precipitation were three times more than its habitat.更多还原