白洋淀湿地植物AM真菌和DSE物种多样性及DSE重金属抗性研究

发布时间：2018-01-06 08:24

本文关键词：白洋淀湿地植物AM真菌和DSE物种多样性及DSE重金属抗性研究　出处：《河北大学》2017年硕士论文　论文类型：学位论文

【摘要】：白洋淀湿地位于河北省中部,地处京津冀腹地,为内陆淡水湿地系统。大陆性气候特点显著,四季分明,物种丰富。近年来由于自然因素和人类活动影响,白洋淀湿地生态系统遭到严重破坏,土壤重金属污染严重。AM(arbuscular mycorrhiza)真菌能与绝大多数维管植物根系形成互惠共生体且在植物矿质营养、水分吸收和生物间相互作用等方面发挥着重要作用。DSE(dark septate endophytes)泛指定殖在植物根细胞间隙或细胞内的一类土壤真菌,能与多数维管植物根系形成互惠共生体,具有类似菌根真菌的生态学功能。本试验于2015年5-6月在河北保定安新县端村镇白洋淀北岸与白洋淀景区随机采集多种湿地植物,系统研究植物与AM真菌和DSE共生状况,DSE分离培养和物种多样性以及筛选重金属镉耐受性菌株,为利用植物-真菌复合体修复白洋淀湿地土壤重金属污染提供依据。主要试验结果如下:1.从白洋淀湿地共分离鉴定AM真菌6属20种,包括一个未定种。其中球囊霉属(Glomus)9种;无梗囊霉属(Acaulospora)6种;盾巨孢囊霉属(Scutellospora)2种;管柄囊霉属(Funneliformis)1种;巨孢囊霉属(Gigaspora)1种;原囊霉属(Archaeospora)1种。2.所试植物根系可被AM真菌侵染,但侵染频度相对较低;菌根类型以疆南星型(Arum-type)为主,重楼型(Paris-type)和中间型(Intermediate types)均有出现。3.与荒漠和农田环境相比,白洋淀湿地植物丛枝丰富度明显升高,泡囊侵染频度显著下降;较热带植物而言,其丛枝丰富度差异不明显,泡囊侵染率高于热带植物,这与丛枝和泡囊的功能有关,是长期适应环境的结果。4.所试植物根系可被DSE侵染,除菌丝外,泡囊、微菌核都有形成,但侵染情况在不同种间差异明显。大多数DSE菌株自然状态下产孢,未产孢菌株观察到菌丝结合点(Mycelium binging sites)和菌丝圈(Mycelium circle)等特殊结构。5.6种湿地植物共分离5种9株DSE菌株,包括Altemaria sp.,Exserohilum pedicellatum无性型Setosphaeria pedicellata,Cladosporium cladosporioides,Zopfiellalatipes,Lasiosphaeria hispida,其中Zopfiella latipes、Exserohilum pedicellatum无性型Setosphaeria pedicellata、Lasiosphaeria hispida为中国淡水湿地生态系统首次报道的DSE种类。6.从本试验分离所得不同种属DSE菌株中筛选出两株镉胁迫下的抗性菌株XHF(Cladosporium cladosporioides)和LWJ1(Altemaria sp.),在一定Cd2+浓度范围内两菌株菌丝体内黑色素含量随Cd2+浓度升高而增加,说明DSE菌丝体黑色素含量高低与菌株抗镉胁迫能力有关。
[Abstract]:Baiyangdian wetland is located in the middle of Hebei province, located in the hinterland of Beijing-Tianjin-Hebei, and is an inland freshwater wetland system. Baiyangdian wetland ecosystem has been seriously damaged. The soil heavy metal pollution is serious. The fungi can form mutual symbiosis with the root system of most vascular plants and have mineral nutrition in the plant. Water absorption and biological interaction play an important role. DSE dark septate endophytes). Any of various soil fungi that are generally designated to colonize between or within the cells of a plant's root cells. It can form a symbiosis with the root system of most vascular plants. The experiment was conducted from May to June, 2015, in the north shore of Baiyangdian, Duancun Town, Anxin County, Hebei Province, and Baiyangdian Scenic spot to collect a variety of wetland plants at random. The isolation, culture and species diversity of plants with AM fungi and DSE were systematically studied, and cadmium tolerance strains were screened. The main results are as follows: 1. Six genera and 20 species of AM fungi were isolated from Baiyangdian wetland. Including one undetermined species, including 9 species of Glomusus. 6 species of Acaulospora; 2 species of Scutellospora; 1 species of Funneliformis; One species of the genus Gigaspora; One species of Archaeospora, Archaeospora. 2. The roots of the tested plants could be infected by AM fungi, but the frequency of infection was relatively low. Arum-type was the main type of mycorrhizal mycorrhiza. Paris-type) and Intertypes (intermediate type) were found. 3. Compared with desert and farmland environment. In Baiyangdian wetland, the branchlets richness increased obviously, and the frequency of vesicle infection decreased significantly. Compared with tropical plants, there was no significant difference in branchlets richness, and the infection rate of vesicle was higher than that of tropical plants, which was related to the function of arbuscular branches and vesicles. The root system of the tested plants can be infected by DSE, except for hyphae, vesicle and microsclerotia. But the infection conditions were different among different species. Most of the DSE strains produced spore in natural state. Mycelium binging sitesand mycelium circle were observed. A total of 5 species and 9 DSE strains were isolated from 5 species of wetland plants. Includes Altemaria sp. pedicellatum pedicellatum asexual Setosphaeria pedicellata. Cladosporium cladosporioides,Zopfiellalatipes,Lasiosphaeria hispida. Zopfiella latipes. Exserohilum pedicellatum asexual Setosphaeria pedicellata. Lasiosphaeria. Hispida is the first reported species of DSE in freshwater wetland ecosystem of China. Two XHFs resistant to cadmium stress were isolated from different species of DSE strains. Cladosporium cladosporioidesand LWJ1(Altemaria sp.). The melanin content in mycelium of two strains increased with the increase of Cd2 concentration in a certain range of Cd2 concentration, indicating that the melanin content of DSE mycelium was related to the ability of the strain to resist cadmium stress.
【学位授予单位】：河北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948.122.3

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