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1.
通过对塔里木河下游自然和人工植物群落中的15种主要建群种植物根系菌根的定殖状况的调查及对菌根侵染部位、菌根中的泡囊、丛枝和菌丝的观察,其结果显示:其中11种植物可被AM真菌侵染,占所调查植物种总数的73.33%,野生乡土植物表现出较高的菌根侵染率和侵染强度,其中有84.62%的植物为菌根植物,且乔木、多年生草本和灌木类植物全部为菌根植物,一年生草本植物未见AM真菌侵染;人工引入种蓼科的泡果沙拐枣(Calligonum junceum)和藜科的梭梭柴(Haloxylon ammodendron)均未见有AM真菌侵染。丛枝菌根真菌侵染率、侵染强度与植物所属的科属关系较密切,也与真菌群落所处时空环境及土壤深度有关。  相似文献   

2.
丛枝菌根在退化生态系统恢复和重建中的作用   总被引:15,自引:0,他引:15  
丛枝菌根是绝大多数植物根系与土壤真菌形成的共生体。是自然生态系统中的重要组成部分。通过对丛枝菌根在退化生态系统中土壤和植被恢复和重建中的作用的探讨,指出丛枝菌根不仅能够促进土壤营养物质循环和利用,稳定和改良土壤结构。而且能够调节植物种间关系、影响群落的演替和结构以及维持物种多样性。同时。丛枝菌根真菌种类和数量以及生长状况的差异都能对生态系统巾南于自然或人类活动所引起土壤和植被的变化起指示作用。  相似文献   

3.
菌根真菌对CO2浓度升高和N沉降的响应   总被引:1,自引:1,他引:0  
高天鹏 《中国沙漠》2009,29(1):131-135
气候变化是全球普遍关注的环境问题,尤其是工业革命以来,全球CO2浓度升高和N沉降的增加,不仅改变了植物的生长发育、生态系统中碳、N生物地化循环,而且影响着与植物共生的菌根真菌。对外生菌根真菌(Ectomycorrhizal fungi, ECMF)和丛枝菌根真菌(Arbuscular mycorrhizal fungi, AMF)的群落结构、真菌的侵染率以及菌丝生物量等方面如何响应全球CO2浓度升高和N沉降的增加进行了综述,同时对当前存在的问题和未来的发展方向进行探讨。  相似文献   

4.
杉木连栽常导致地力退化,但连栽是否影响丛枝菌根真菌的侵染率并不清楚。以福建三明粉砂岩发育红壤上的连栽杉木为对象,研究了杉木细根丛枝菌根真菌侵染率与土壤性质的关系,分析了杉木连栽影响杉木根系菌根侵染率的主导因素。结果表明,杉木连栽没有显著导致土壤退化现象,二代林杉木细根丛枝菌根真菌侵染率显著高于一代和三代林,一代和三代林之间没有明显差异。通过主成分分析发现,在杉木连栽时,影响杉木丛枝菌根真菌侵染率的主导土壤因子是全氮、容重、SOC和速效磷含量。因此,通过改善土壤结构、提高土壤有机质含量和土壤速效磷含量,在一定程度上可能增加杉木菌根真菌的侵染率,从而有利于提升杉木人工林的生产力。  相似文献   

5.
 以极端干旱区塔里木河下游处于干旱胁迫下的天然胡杨为研究对象,采用传统形态鉴定法和分子生物技术,研究了胡杨根围土壤中丛枝菌根真菌。结果表明:处于干旱胁迫下的胡杨根围土壤中丛枝菌根真菌孢子密度较低,且孢子种类单一,经形态鉴定和分子生物学鉴定,孢子为球囊霉属的摩西球囊霉〖WTBX〗Glomus mosseae[WTBZ] (T.H. Nicolson &; Gerd.),孢子在土壤中单生、根内生或孢子果内形成;圆形,近圆形,直径150~220 μm,浅黄色至黄褐色;孢壁3层,L1和L2无色透明,L3浅黄至黄褐色。连孢菌丝单根,连点漏斗状。胡杨根系内存在丛枝菌根真菌的泡囊结构,分子检测表明摩西球囊霉[WTBX]Glomus mosseae[WTBZ]与胡杨根系形成共生关系,但是胡杨根系的菌根侵染率及根系的菌根侵染强度均不高。  相似文献   

6.
大青山、蛮汗山外生菌根真菌资源调查   总被引:6,自引:0,他引:6  
室外调查与室内观察鉴定结果表明:1.大青山、蛮汗山外生菌根真菌资源极为丰富。其中大青山已知存在78种外生菌根真菌,隶属于15科,3l属;蛮汗山已知存在79种外生菌根真菌,隶属于15科,32属。2.在高海拔阴坡和半阴坡,与青海云杉、落叶松共生的主要为牛肝菌属、乳菇属、红菇属、丝膜菌属;与阔叶树共生的以鹅膏科为最多。3.在中低海拔地区与松属共生频率最高的是乳牛肝菌属;与杨、桦共生最多的是杯伞属、桩菇属、蘑菇属。4.通过分离,在大青山、蛮汗山先后分别获得珍贵菌根菌10种、12种。5.在分离的菌根菌中乳牛肝菌属中的大部分种为油松、樟子松的优秀菌根真菌。  相似文献   

7.
<正> 植物遗传资源的保护与利用是防治荒漠化最关键的因素之一。一方面,它们是提供木材、粮食、油料、纤维和医药等生活生产资料的重要资源;另一方面,它们在为野生动物提供栖息地、保护生物多样性、地理景观美化、退化生态系统恢复与重建等生态环境维护方面具有重要功能。荒漠化地区优良植物选繁和定向培育技术的研究一直是我国的薄弱环节。而国外在保护荒漠化地区植物多样性的  相似文献   

8.
黄河三角洲湿地拥有丰富的微生物资源,明确该湿地的功能微生物群落结构特征及其驱动因素,对黄河三角洲湿地环境保护与土壤微生物资源的合理开发与利用具有重要意义。概述了参与黄河三角洲湿地土壤地球化学循环的功能微生物群落的组成,总结了土壤含盐量、土壤深度、植物类型、水淹状况和湿地类型等因素对微生物群落结构的影响。综述结果表明,黄河三角洲湿地土壤中亚硝基菌属(Nitrososphaeria)和根瘤菌属(Rhizobium)微生物介导的氮循环、真菌、固碳细菌、甲烷氧化细菌和产甲烷菌介导的碳循环、解磷菌和丛枝菌根真菌介导的磷循环、delta-变形菌纲下的硫酸盐还原菌介导的硫循环,在区域地球化学循环和污染物降解中起到重要作用;子囊菌门、变形杆菌门、厚壁菌门和放线菌门微生物是功能微生物群落的优势耐盐微生物;通过分析黄河三角洲湿地土壤中与污染物降解相关的功能微生物,对利用土著植物和耐盐微生物构建被污染土壤的原位生物修复系统进行了展望,以期从微生物角度为黄河三角洲湿地的保护和生态修复提供参考依据。  相似文献   

9.
科尔沁沙地荒漠化土地初析   总被引:32,自引:10,他引:22  
应用1996年TM卫星影像资料得出,科尔沁沙地中心地区荒漠化土地占总土地面积的34.02%,以风蚀荒漠化土地为主。各种荒漠化土地在14个旗(县)的分布不同,按严重程度划分为重度荒漠化地区、中度荒漠化地区和轻度荒漠化地区。对历史时期和近期的分析表明,科尔沁沙地荒漠化土地产生和扩展的根本原因是过度开垦。  相似文献   

10.
藏北草原主要植物AM真菌的初步研究   总被引:2,自引:0,他引:2  
通过调查藏北草原AM真菌种质资源及菌根侵染率,对藏北特定生态环境条件下,各种类型草原主要植物AM真菌的多样性及其与不同生态环境因子之间的相互关系进行了分析。从藏北草原主要植物根围土壤中共分离出4属AM真菌。总体上,孢子密度、分离频度、相对多度和重要值显著的Glomus>Acaulospora>Paraglomus>Scutellospora趋势。其中Glomus、Acaulospora均为优势属,Glomus的优势属地位极为突出;寄主植物、海拔、土壤条件对于AM真菌的种类组成,孢子密度及分离频度均有显著影响。  相似文献   

11.
Mycorrhizas are worldwide symbiotic associations established between certain soil fungi and most vascular plants and are fundamental in optimizing plant fitness and soil quality. Mycorrhizal symbioses improve the resilience of plant communities against environment stresses, including nutrient deficiency, drought and soil disturbance. Since these stresses are paramount in the degradation of semi-arid ecosystems in the SE Spain, a series of basic, strategic and applied studies have been made to ascertain how the activity and diversity of mycorrhizal fungi affect plant community composition, structure and dynamics in this region. These investigations are reviewed here in terms of: (i) analysing the diversity of mycorrhizal fungi; (ii) assessing the ecological and functional interactions among plant communities and their associated mycorrhizal fungal populations; and (iii) using mycorrhizal inoculation technology for the restoration of degraded semi-arid areas in Southeast Spain. Disturbance of the target semi-arid ecosystems decreases the density and diversity of mycorrhizal fungust populations. Nevertheless, the mycorrhizal propagules do not disappear completely suggesting a certain degree of stress adaptation, and these remaining, resilient ecotypes are being used as plant inoculants. Numerous field experiments, using plant species from the natural succession inoculated with a community of indigenous mycorrhizal fungi, have been carried out in revegetation projects in the semi-arid Iberian Southeast. This management strategy improved both plant development and soil quality, and is a successful biotechnological tool to aid the restoration of self-sustaining ecosystems. However, despite a 20-year history of this work, we lack a comprehensive view of the mycorrhizal potential to improve the composition, diversity, structure and functionality of drought-adapted plant communities in the Region.  相似文献   

12.
为了探讨AM真菌对干旱区珍稀濒危植物引种过程中的成活、生长保育的影响研究,在盆栽条件下,选取具有代表性的7个珍稀濒临灭绝植物物种,在引种过程中定向接种AM真菌,通过分析植株的生长状况及AM真菌的侵染率,初步筛选在干旱区珍稀濒危植物引种过程中,具有应用价值的AM真菌与植物最佳共生模式。结果表明:7种濒危植物与AM真菌能形成共生关系,但植物与菌种间侵染率存在显著差异。既形成了良好的共生关系又能促进濒危植物生长的最佳组合有:AM真菌F.mosseae与白麻或乌拉尔甘草或蒙古莸的共生,真菌D.eburnea与新疆沙冬青的共生、真菌C.claroideum或F.mosseae与中麻黄的共生、真菌C.lamellosum与胀果甘草的共生、真菌C.etunicatum与蒙古沙冬青的共生。表明濒危植物与AM真菌之间存在一定的生态适用性选择关系,而且在利用AM真菌对濒危植物引种繁育时,必须要考虑他们间的生态适用性关系,才能充分发挥AM真菌的功能。这对干旱区珍稀濒危植物的引种繁殖意义重大。  相似文献   

13.
Arbuscular mycorrhizal fungi(AMF) are universally mutualistic symbionts that colonize the fine roots of most vascular plants. However, the biogeographical patterns and driving factors of AMF diversity of plant roots in grasslands are not well investigated. In this study, we used high-throughput sequencing techniques and bioinformatics to evaluate the AMF richness of 333 individual plant roots in 21 natural grassland ecosystems in northern China, including the Loess Plateau(LP), the Mongolian Plateau(MP), and the Tibetan Plateau(TP). The AMF richness showed a significant parabolic trend with increasing longitude. In regional situations, the AMF richness in the grasslands of the MP(60.4 ± 1.47) was significantly higher than those of the LP(46.4 ± 1.43) and TP(44.3 ± 1.64). Plant traits(including plant families, genera, and functional groups) explained the most variation in the AMF richness across China's grasslands, followed by energy and water; soil properties had the least effects. The results showed the biogeographical patterns of the AMF richness and the underlying dominant factors, providing synthetic data compilation and analyses in the AMF diversity in China's grasslands.  相似文献   

14.
Numerous human activities constitute threats to biodiversity. The effects of climate change, including increasing drought in already arid lands, pose an additional layer of uncertainty in the fate of rare species. In the case of plants, reintroduction is becoming an important active management practice in species conservation. We hypothesized that even under extreme drought inoculation with mycorrhizal fungi would increase growth rates of an endangered plant in experimental reintroduction. We selected a plant species, Abronia macrocarpa, and conducted the experiment in Texas while the area was experiencing mild and extreme drought intensities. Treatment plots were planted with seed inoculated with arbuscular mycorrhizal fungi and control plots were planted with seed coated with autoclaved inoculant. We analyzed measurements of growth and development of germinated plants. Mean number of leaves was greater in treatment plants (P = 0.005) and mean aerial diameter was larger in treatment plants (P = 0.02) than in control plants. Significantly improved growth suggests that inoculation is a viable technique to increase reintroduction success in plant species especially during periods of drought.  相似文献   

15.
Salinization and alkalinization are increasing problems in the world. Some land has been degraded to bare saline-alkaline soil where vegetation restoration is difficult because high toxic ionic content and pH are harmful to the survival of introduced plants. We grew Leymus chinensis with and without arbuscular mycorrhizal fungi (Glomus mosseae and G. geosporum) in either pots filled with soil from bare saline-alkaline land, or transplanted seedlings into field plots, to determine the influence of AM fungi on the reestablishment of this dominant grass species in bare degraded land. Association with AM fungi increased the absorption of N, P, K+, Ca2+, but decreased Mg2+, Na+ and Cl uptake under saline-alkaline stress. Therefore, higher K/Na, Ca/Na, P/Na, and P/Cl ratios were found in the inoculated plants. Plants inoculated with AM fungi accumulated significantly higher biomass, root/shoot ratio and tiller number than non-inoculated plants. AM fungi also significantly increased the survival of seedlings when they were transplanted into a bare saline-alkaline land in the field. The improvement of survival, growth and asexual reproduction of inoculated plants indicated that the plant-AM fungi mutualism could improve the reestablishment of vegetation in bare saline-alkaline soil, drive the vegetation restoration to a community dominated by original species.  相似文献   

16.
Arbuscular mycorrhizal (AM) fungi convey well documented benefits to plant growth in domesticated species. We investigated AM in Solanum centrale, a desert shrub of central Australia and traditional food for Indigenous Australians. AM were observed in roots of S. centrale from wild and cultivated stands of different ages and management regimes. Greenhouse seedlings grown in sterilised sand were provided with no or minor additions of phosphorus, with or without AM fungi. Inoculated seedlings not fertilised with phosphorus exhibited moderate AM formation. Added phosphorus resulted in an absence of AM. Inoculation did not significantly affect dry weight, root length and plant height of seedlings fertilised with phosphorus but significantly increased the size of unfertilised seedlings. Inoculation significantly increased root phosphorus content, decreased root to shoot ratio and decreased root biomass at all phosphorus additions, despite the absence of observable AM. Thus it appears AM fungi in the root zone influenced certain plant characteristics, regardless of phosphorus nutrition. Overall, S. centrale benefited from the presence of AM through increased phosphorus uptake, but only when the seedlings were growing in soil with extremely low available phosphorus. The response was immediate in our experimental system and is likely to be important in the wild.  相似文献   

17.
Global economic development and increasing human activities have brought great challenges to fragile ecosystems. In order to avoid, reduce, and reverse desertification, Chinese and foreign scientists and ecological governance institutions have developed a series of ecological restoration technologies (ERTs) and models in the past few decades. These technologies can improve residents’ livelihoods, strengthen disaster resilience, and launch a comprehensive review of degraded ecosystems in desertification regions. However, some studies and practices have limited the selection and promotion of good technologies and the assessments of these technologies, resulting in the waste and loss of funds and manpower. The objective of this study is to identify desertification control and restoration technologies and models, summarize the evolutionary features and trends of these technologies under different natural conditions, and evaluate the various ERTs that are now available. The data sources of this study include the databases of international organizations, CNKI, related literature and reports, and questionnaires from institutions and experts. First, the three stages of ERTs evolution were summarized, and the key events and social-economic developments were identified as the driving forces of evolution. Then, the four categories of ERTs were identified as biological, engineering, agricultural, and management ERTs. Finally, the key ERTs were evaluated in the five dimensions of the degree of difficulty, the degree of maturity, effectiveness, suitability, and potential for transfer. The management ERTs scores for the degree of difficulty, the degree of maturity, and potential for transfer are higher. This study provides a reference for adapting to local conditions, the comprehensive management, rational development, and utilization of dryland resources, improving the application of ecological technologies, and promoting the export and import of the excellent technologies.  相似文献   

18.
A survey was made of the spore community of arbuscular mycorrhizal fungi (AMF) and root colonization by AMF in 16 plant species in Lhalu wetland on the outskirts of Lhasa city in Tibet. It was found that 13 of the 16 plant species investigated (81. 5% ) formed arbuscular mycorrhizal structures and dark septate endophytic fungi colonized the roots of most species. Total AMF colonization ranged from 0 to 82. 6% in dicots and 0 to 54. 5% in monocots. Both total AMF and arbuscular colonization were greater in d...  相似文献   

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