西北荒漠花棒根系DSE真菌物种多样性和耐盐性研究

发布时间：2018-05-30 17:14

本文选题：深色有隔内生真菌 + 物种多样性　；参考：《河北大学》2017年硕士论文

【摘要】：本研究沿西北荒漠花棒天然分布区,自东向西,于2015、2016年7月,选取内蒙古鄂尔多斯、磴口、乌海、阿拉善,宁夏沙坡头,甘肃民勤、安西7个样地,采集花棒(Hedysarum scoparium Fisch.et Mey.)根际土样和根样,开展深色有隔内生真菌(Dark septate endophyte,DSE)群落组成、物种多样性、生态分布以及DSE耐盐性研究,为阐明花棒与DSE相互关系及其适应极端荒漠环境机理提供依据。主要试验结果如下:1.DSE真菌能够高度侵染花棒根系,形成典型深色有隔菌丝和微菌核结构,2015和2016年DSE平均总定殖率分别是48.32%和63.81%。2.相关性分析表明,土壤磷酸酶、脲酶、速效磷、氨氮与DSE定殖显著正相关,有机质、pH与DSE定殖显著负相关。DSE菌丝直径随氨氮升高而减小。3.共分离鉴定DSE真菌10属20种,即Alternaria,Cladosporium,Embellisia,Hypocrea,Microascus,Paraphoma,Preussia,Schizothecium,Curvularia,Rhizopycnis。其中6种产孢,其余不产孢。Embellisia chlamydospora,Hypocrea lacteal,Microascus cirrosus,Cladosporium oxysporum,Preussia aemulans,Curvularia spicifera和Schizothecium inaequale为荒漠生态系统首次报道的DSE真菌。4.安西和民勤样地共有种为Microascus sp.;磴口和鄂尔多斯样地共有种是Pleosporales sp.3;Embellisia chlamydospora是乌海和鄂尔多斯样地共有种;Paraphoma radicina是阿拉善和鄂尔多斯样地共有种;Paraphoma chrysanthemicola是磴口、阿拉善和沙坡头样地共有种。5.相关性分析表明,Shannon-Wiener指数和Simpson指数与土壤磷酸酶显著正相关。冗余分析表明,Paraphoma和Pleosporales多度分别与土壤磷酸酶和氨氮显著正相关,Hypocrea和Microascus多度与pH显著正相关。线性回归分析表明,土壤湿度与DSE分离率、Shannon-Wiener指数、Simpson指数和均匀度指数显著正相关。6.Embellisia chlamydospora和Cladosporium oxysporum菌株多糖与黑色素显著负相关。过氧化氢酶(CAT)为菌株Embellisia chlamydospora主要影响因子,且与多糖、丙二醛(MDA)显著正相关,与黑色素显著负相关。超氧化物歧化酶(SOD)为菌株Cladosporium oxysporum主要影响因子,与黑色素、MDA显著正相关,与多糖显著负相关。
[Abstract]:In this study, the natural distribution area of flower stick along the northwest desert, from east to west, was selected from Ordos, Dengkou, Wuhai, Alashan, Shapotou, Gansu, Anxi, Inner Mongolia, Inner Mongolia in July, 2015.Hedysarum scoparium Fisch.et Mey.was collected. Studies on the community composition, species diversity, ecological distribution and salt tolerance of DSE were carried out in rhizosphere soil samples and root samples. The results provided a basis for elucidating the relationship between Rhizome and DSE and their adaptation to extreme desert environment. The main results were as follows: 1. The average total colonization rate of DSE in 2015 and 2016 was 48.32% and 63.81%, respectively. Correlation analysis showed that soil phosphatase, urease, available phosphorus and ammonia nitrogen were positively correlated with DSE colonization, and pH of organic matter was negatively correlated with DSE colonization. DSE hyphal diameter decreased with the increase of ammonia nitrogen. A total of 10 genera and 20 species of DSE fungi were isolated and identified, I. e., Cladosporia Alternariae Cladosporiumus Embellisiae, Microascusa Paraphoma PreussiaSch Schizothecium Curvularia, Rhizopycnis. Among them, 6 species produce spore, the rest do not produce spore. Embellisia chlamydospora Hypocrea lactealus Microascus cirrosusCladosporium oxysporum Preussia aemulansus Curvularia spicifera and Schizothecium inaequale are the first reported DSE fungi in desert ecosystem. The common species of Anxi and Minqin are Microascus sp., the common species of Dengkou and Ordos are Pleosporales sp. 3Embellisia chlamydospora is the common species of radicina in Wuhai and Ordos samples, and the common species of chrysanthemicola is Dengkou in Alashan and Ordos, and 5 in Alashan and Shapotou. Correlation analysis showed that Shannon-Wiener index and Simpson index were positively correlated with soil phosphatase. Redundancy analysis showed that the abundance of Paraphoma and Pleosporales were positively correlated with soil phosphatase and ammonia nitrogen, respectively. Hypocrea and Microascus abundance were positively correlated with pH, respectively. Linear regression analysis showed that soil moisture was positively correlated with Shannon-Wiener index and evenness index of DSE isolation rate. 6. Embellisia chlamydospora and Cladosporium oxysporum polysaccharides were negatively correlated with melanin. Catalase (catalase) was the main influencing factor of Embellisia chlamydospora, and was positively correlated with polysaccharides and malondialdehyde (MDA), and negatively correlated with melanin. Superoxide dismutase (SOD) was the main influencing factor of Cladosporium oxysporum, which was positively correlated with melanin and negatively correlated with polysaccharides.
【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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