中国盐三土壤中AM菌的生态分布

对我国盐碱封中丛枝菌根（Ａｒｂｕｓｃｕｌａｒ Ｍｙｃｏｒｒｈｉｚａ,ＡＭ）菌的种属构成、生态分布状况进行了研究。结果表明,不同地区菌种属构成不同,其种属组成、分布与土壤类型碱化度和土壤有机质含量有关。盐渍化砂土、壤土和粘土中,Ｇｌｏｍｕｓ属的真菌数量最多,Ａｃａｕｌｏｓｐｏｒａ属次这,而Ｇｌｏｍｕｓ属中的Ｇ．ｍｏｓｓｅａｅ则是分布最为广泛的菌种。随土壤碱化度的增加,Ｇｌｏｍｕｓ ｍｏｓｓｅａｅ出现     

黄河三角洲盐碱土壤中AM真菌的初步调查

2000年3月－2001年2月对黄河三角洲盐碱土壤中5种优势植物柽柳（Tamarix chinensis),芦苇（Phragmites communis),碱蓬（Suaeda glauca),獐毛（Aeluropus littralis var.sinensis) 和刺儿菜（Cirsium setosum)根围内丛枝菌根（arbuscular mycorrhiza,AM)真菌进行了长期定点调查,结果表明,AM真菌在这5种植物根围土壤内都有分布,但多样性较低,尤其在冬季,AM真菌种的丰度和孢子密度分别在夏季降低了18．0％和61．6％,不同深度土层中AM真菌的分布存在诸多差异。     

我国北方农田土壤中AM真菌的多样性

AM真菌是农业生态系中一类重要的土壤微生物,它在农田土壤中的发生和分布受多种环境因素的影响。为深入了解我国北方农田土壤中AM真菌的多样性规律,于2000年在河北、山东的农田土壤中采集有代表性的土样127个。通过进一步扩繁、纯化,从中分离出AM真菌5属22种,鉴定了20个种,包括一个国内新记录种沾屑球囊霉(Glomus spurcum)。分析AM真菌的多样性特点及其影响因素发现,农田土壤中以球囊霉属(Glomus)的频度最高,其次为无梗囊霉属(Acaulospora);优势种类为幼套球囊霉(Glomus etunicatum)和摩西球囊霉(Glomus mosseae).土壤速效磷含量、pH状况主要对孢子密度产生影响,对种群分布影响不大。宿主植物类型对AM真菌的侵染状况和多样性影响较大;比较玉米(Zea mays)、甘薯(Ipomoea batatas)根区AM真菌的种群组成后发现两者有所不同,但优势种一致.     

盐碱土壤与非盐碱土壤微生物的抗盐碱特性

为了比较分析盐碱土壤与非盐碱土壤微生物资源抗盐碱性差异,本研究利用含有不同浓度Na2CO3、NaHCO3和pH的培养基对盐碱土壤和非盐碱土壤细菌进行培养计数.结果显示:非盐碱土壤出菌数量随Na2CO3、pH和NaHCO3浓度升高而下降,盐碱土壤细菌出菌数量随着Na2CO3、pH和NaHCO3浓度升高先是升高然后下降,最高值分别出现在200 mmol/L NaHCO3、50 mmol/L Na2CO3和pH 9.0的分离平板上.此外,高Na2CO3、pH和NaHCO3浓度的平板中盐碱土壤出菌数量远高于非盐碱土壤;以上结果可见,耐盐碱细菌资源主要集中分布在盐碱土壤中,在非盐碱土壤中虽有分布,但是仅占有很少一部分.     

接种AM菌对西部黄土区采煤沉陷地柠条生长和土壤的修复效应

以采煤沉陷区柠条为宿主植物,研究接种丛枝菌根真菌(arbuscular mycorrhizal fungi,简称AM菌)对柠条生长和根际土壤的改良效应。结果表明:8月份接种AM菌比不接菌柠条的株高、冠幅和地径显著增加了29.11%,29.83%和14.81%,9月份接菌区柠条的根长、平均直径、根表面积和根体积分别比对照区增加了151.0%,34.2%,116.0%和129.3%。接种AM菌增强柠条的抗逆性,接菌区的柠条叶片可溶性糖含量和过氧化氢酶活性分别比对照区增加了13.4%和111.1%。8月份接种AM菌改善了土壤的生物理化性质,接菌区有机质、碱解氮、速效磷和速效钾比对照区分别增加7.06g/kg,140.0 mg/kg,1.82 mg/kg和16.72mg/kg,接种AM菌显著增加了根际土壤中真菌、放线菌、细菌数量和酸性磷酸酶活性。总之,接种AM菌促进采煤沉陷区柠条的生长和土壤的改良。     

荒漠油蒿（Artemisia ordosica）根围AM真菌分布与土壤酶活性

于2007年10月在油蒿(Artemisia ordosica)集中分布区选取4个典型样地,分别从0～10cm、10～20cm、20～30cm、30～40cm和40～50cm土层采集根围土样,分离其丛枝菌根(arbuscular mycorrhiza,AM)真菌并测定了3种土壤酶活性.结果表明,在各样地0～50cm土层中油蒿根系AM真菌菌丝定殖率均很高,有典型的泡囊与丛枝结构.菌丝定殖率与泡囊定殖率呈显著正相关,但菌丝、泡囊和丛枝定殖率与AM真菌孢子密度和土壤酶活性之间都无相关性;孢子密度在不同样地及采样深度间差异明显,与土壤有机质、速效磷和速效氮含量都呈一定正相关关系.孢子密度与脲酶和酸性磷酸酶活性有显著或极显著相关关系,与碱性磷酸酶活性之间的相关性受到土壤pH的显著影响.孢子密度的峰值出现在0～10cm表层土,并随土壤剖面深度增加而降低.土壤酶活性在土壤垂直剖面显示与孢子密度同样的规律.不同样地间AM真菌分布及油蒿根系定殖率的差异表明,油蒿与AM真菌之间有良好共生性,对维护荒漠生态环境系统结构的完整性具有重要意义.     

盐碱胁迫下AM真菌对羊草生长及生理代谢的影响

利用盆栽控制试验研究了盐碱胁迫下AM真菌对羊草生长及生理代谢的影响。结果表明,盐碱胁迫显著降低了AM真菌的侵染率与侵染强度,且具有高pH的碱胁迫的抑制效应更强。接种AM真菌一定程度上提高了胁迫下羊草幼苗的生物量及光合色素(Chl a,Chl b和Car)含量。随着盐碱胁迫浓度的增加,羊草幼苗积累了大量的Na~+,并抑制了其对K~+的吸收,接种AM真菌一定程度上降低了Na~+的积累,并缓解了胁迫下K~+含量的降低,提高NO_3~-含量从而改善羊草幼苗的离子平衡。在碱胁迫下,柠檬酸、苹果酸含量均显著提高,在盐胁迫下,仅苹果酸含量显著提高,而接种AM真菌使盐碱胁迫下有机酸含量一定程度降低。在盐碱胁迫条件下,接种AM使羊草体内超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)的活性明显提高,增强宿主植物体内氧自由基的清除能力。接种AM真菌明显提高羊草幼苗抗盐碱能力,因胁迫类型不同,抗逆机理有所差异。研究结果为利用羊草进行生物改良退化盐碱草地以及菌肥的应用提供了科学依据,也为探求羊草-丛枝菌根共生体对盐碱胁迫的响应和反馈提供了数据支持。     

不同盐碱度土壤中AM菌根真菌群落结构组成及影响因子

为研究黄河三角洲盐渍土壤中植物根围AM菌根真菌多样性及影响多样性的因素,从东营孤东和孤岛油区采集碱蓬和柽柳植物的根围土壤,鉴定了4种土壤试样中丛枝菌根(Arbuscular mycorrhiza,AM)的群落组成。结果表明:球囊霉属(Glomus)是盐碱地中的优势种,同时还有许多未知真菌;考察不同盐碱度情况下菌根真菌群落结构差异,结果表明:碱蓬根围土壤中AM真菌的多样性高于柽柳,孤东根围土壤AM真菌多样性比孤岛高。相关分析表明,铵态氮含量与AM真菌多样性呈现显著负相关。     

山东省不同植被区内野生植物根围AM菌的生态分布

ＡＭ菌是土壤习居菌 ,生态适应性强 ,可发生在各种生态环境。寄主范围也十分广泛 ,除少量植物如莎草科、苋科、灯心草科、藜科、石竹科等 2 0余科植物不能或不易形成ＡＭ外 ,大多数植物包括苔藓、蕨类、裸子植物、被子植物都能被菌根菌侵染。当前人们十分重视对野生植物上ＡＭ菌的调查[3 ,4 ,1 0 ,1 1 ,1 4 ]。研究发现 ,野生植物上可能有比栽培作物更多的ＡＭ菌种类[1 ]。我国野生植物资源丰富 ,开发和利用野生寄主植物上的ＡＭ菌潜力巨大。由于ＡＭ菌对寄主植物的选择性及对环境条件的适应性不同 ,或进化过程中的历史原因 ,造成了自然生态…     

Biolistic transformation of arbuscular mycorrhizal fungi

Gene transfer systems have proved effective for the transformation of a range of organisms for both fundamental and applied studies. Biolistic transformation is a powerful method for the gene transfer into various organisms and tissues that have proved recalcitrant to more conventional means. For fungi, the biolistic approach is particularly effective where protoplasts are difficult to obtain and/or the organisms are difficult to culture. This is particularly applicable to arbuscular mycorrhizal (AM) fungi, being as they are obligate symbionts that can only be propagated in association with intact plants or root explants. Furthermore, these fungi are aseptate and protoplasts cannot be released. Recent advancements in gene transformation systems have enabled the use of biolistic technology to introduce foreign DNA linked to molecular markers into these fungi. In this review we discuss the development of transformation strategies for AM fungi by biolistics and highlight the areas of this technology which require further development for the stable transformation of these elusive organisms.     

中国大陆地区丛枝菌根真菌菌种资源的分离鉴定与形态学特征

【目的】分离收集保藏中国大陆各个地区不同生态环境的丛枝菌根真菌菌种资源,为丛枝菌根的研究提供资源、奠定基础。【方法】以高粱为宿主植物,采用诱导培养、单孢培养和扩繁培养分离土壤样品中的丛枝菌根真菌菌种并鉴定。【结果】从我国大陆的45个地区50余种宿主植物根区土壤中分离到丛枝菌根真菌135株,隶属于23个种;对各个菌株的形态特征进行了描述。【结论】我国蕴藏着丰富的丛枝菌根真菌菌种资源,文中描述的菌种资源是目前从我国大陆地区获得的种类和数量最多、覆盖范围最广的AM真菌菌种资源。     

Diversity and infectivity of arbuscular mycorrhizal fungi in agricultural soils of the Sichuan Province of mainland China

Knowledge about the presence and diversity of arbuscular mycorrhizal fungi (AMF) in a specific area is an essential first step for utilizing these fungi in any application. The community composition of AMF in intensively managed agricultural soil in the Sichuan Province of southwest China currently is unknown. In one set of samples, AMF were trapped in pot cultures from 40 fields growing legumes in the Panxi region, southeast Sichuan. In a second set of samples, the MPN method with four-fold dilutions and maize as host was used to estimate infective propagules in soil from another 50 agricultural sites throughout the province. Soil types were heterogeneous and were classified as purple, yellow, paddy and red. Crops at each site were either maize, wheat or sweet orange. From this set of soil, AMF spores were also extracted and identified. Including all ninety soils, thirty glomeromycotan species in Glomus (20 species), Acaulospora (four species), Scutellospora (three species), Ambispora (one species), Archaeospora (one species) and Paraglomus (one species) were identified. Yellow, red and purple soils yielded similar numbers of AMF species, while AMF species diversity was clearly lower in paddy soil. In trap culture soils, the most frequent species were Glomus aggregatum or Glomus intraradices, Glomus claroideum and Glomus etunicatum. The species Acaulospora capsicula, Acaulospora delicata, G. aggregatum (or intraradices), G. claroideum, Glomus epigaeum, G. etunicatum, Glomus luteum, Glomus monosporum, Glomus mosseae and Glomus proliferum were successfully cultured as single-species pot cultures in Plantago lanceolata. The three most frequent species in field soils were G. mosseae, Glomus caledonium and Glomus constrictum. MPN values varied between 17 and 3334 propagules 100 g soil⁻¹ among the fifty field sites sampled. Regression analysis, including host&soil, log(P) and pH as explanatory variables explained 59% of the variation in log(MPN). The highest MPN estimates were found in purple soil cropped with maize and citrus, 324 and 278 propagules 100 g soil⁻¹, respectively. The lowest MPN value, 54 propagules 100 g soil⁻¹, was measured in wheat in purple and yellow soil. Despite intensive agricultural management that can include often repeated tillage, our examination of 90 agricultural sites revealed that soils of the Sichuan region have moderate to high numbers of infective AMF propagules as well as a high AMF species diversity. This opens possibilities for further studies and utilization of AMF in agriculture and horticulture in the Sichuan province, People’s Republic of China.     

龙脑香科植物对丛枝菌根真菌的影响

在天然林地和温室盆栽条件下,比较研究了龙脑香科植物对丛枝菌根(Arbuscular mycorrhizas,AM)真菌孢子密度、相对多度、频度、属的组成、丰度和侵染状况等方面的影响.结果表明,用坡垒作盆栽寄主加富培养后,菌根侵染率、泡囊、丛枝和侵入点都低于原采样植物,以原坡垒土壤中栽植苗木的侵染率为最高,可达20.3%;而以望天树根围土壤栽植的苗木为最低,仅为10.6%;坡垒还不同程度地改变了原采样植物根围土壤中AM真菌孢子的密度、相对多度、频度、属的组成、丰度等.在4种土壤中,栽植坡垒苗木后,AM真菌的孢子密度都有不同程度的增长.采用与原采样相同种类的植物作为AM真菌加富培养的寄主更有利于促进AM真菌的生长发育、保持AM的多样性.     

High incidence of arbuscular mycorrhizal fungi in rare and endangered wild grapevine

High levels of arbuscular mycorrhizal fungi colonisation of 90–100%, as well as high vesicular and arbuscular colonisation were found in the roots of the rare and endangered wild grapevine (Vitis vinifera subsp. sylvestris) along the Neretva River in southwestern Bosnia and Herzegovina, surpassing colonisation in region vineyads.     

丛枝菌根真菌的生态分布及其影响因子研究进展

丛枝菌根(arbuscular mycorrhiza,AM)共生体系对于植物适应各种逆境胁迫具有重要积极作用。AM真菌还能够通过根外菌丝网络调节植物群落结构和演替,深刻影响生态系统结构和功能的稳定性。AM真菌生态生理功能的发挥主要取决于其生态适应性,明确AM真菌在不同环境中的多样性、生态适应性以及对各种生态因子的响应机制,是AM真菌资源管理、功能发掘与利用的前提。迄今为止,有关各种生态因子对AM真菌多样性的影响已有不少研究,但是AM真菌生态分布及其形成机制仍缺乏系统的研究和理论分析。综述了生物因子和非生物因子对AM真菌生态分布的影响,结合大型生物空间分布理论探讨了AM真菌生态分布规律和建成机制,分析了当前本研究领域所存在的问题和动向,以期推动相关研究进展。     

Twenty years of research on community composition and species distribution of arbuscular mycorrhizal fungi in China: a review

The biodiversity and distribution of arbuscular mycorrhizal fungi (AMF) in different ecosystems and plant communities in China has received increasing interest over the past decades. This has led to a steady increase in the number of scientific papers published on this topic. Studies have surveyed AMF-colonizing rhizospheres of most families of angiosperms, bryophytes, pteridophytes, and gymnosperms. China has about 30,000 plant species (one eighth of the plant species worldwide). A total of 104 AMF species within nine genera, including 12 new species, have been reported in environments such as croplands, grasslands, forests, and numerous disturbed environments. In this paper, we review data published over the past 20 years on AMF community composition and species distribution, the mycorrhizal status of plants, AMF spore communities in different habitats, and germplasm collections in China. Possible future trends in the study of the biodiversity of AMF are also briefly discussed. In particular, the aim of our review is to make some of the recent work published in the Chinese literature accessible to a wider international audience.     

Effects of mowing on fungal endophytes and arbuscular mycorrhizal fungi in subalpine grasslands

In French subalpine grasslands, cessation of mowing promotes dominance of Festuca paniculata, which alters plant diversity and ecosystem functioning. One of the mechanisms underpinning such effects may be linked to simultaneous changes in the abundance of fungal symbionts such as endophytes and arbuscular mycorrhizal fungi. In field conditions, mowing reduced the abundance of the endophyte Neotyphodium sp. in leaves of F. paniculata by a factor of 6, and increased mycorrhizal densities by a factor of 15 in the soil. In greenhouse experiments, the mycorrhizal colonization of Trifolium pratense and Allium porrum increased 3- fold and 3.8- fold respectively in mown vs unmown grassland soil. Significantly reduced growth of the two host plants was also observed on soil from the unmown grassland. Such opposite effects of mowing on the two functional groups of fungal symbionts could suggest interactions between these two groups, which in turn could contribute to structuring plant communities in subalpine grasslands.     

Genetic processes in arbuscular mycorrhizal fungi

Arbuscular mycorrhizal (AM) fungi (Glomeromycota) colonize roots of the majority of land plants and facilitate their mineral nutrient uptake. Consequently, AM fungi play an important role in terrestrial ecosystems and are becoming a component of sustainable land management practices. The absence of sexual reproductive structures in modern Glomeromycota combined with their long evolutionary history suggest that these fungi may represent an ancient asexual lineage of great potential interest to evolutionary biology. However, many aspects of basic AM fungal biology, including genome structure, within-individual genetic variation, and reproductive mode are poorly understood. These knowledge gaps hinder research on the mechanisms of AM fungal interactions with individual plants and plant communities, and utilization of AM fungi in agricultural practices. I present here the current state of research on the reproduction in AM fungi and indicate what new findings can be expected in the future.     

丛枝菌根真菌和生物质炭对连作西瓜土壤肥力的影响

【背景】作为土壤改良剂生物质炭能够改善土壤条件,促进丛枝菌根(arbuscular mycorrhizal,AM)真菌侵染和植物生长发育。【目的】探究接种AM真菌配合施加生物质炭对连作土壤肥力和西瓜生长的效应。【方法】盆栽‘圆佳’西瓜(Citrullus lanatus)嫁接苗[砧木为‘全能铁甲’南瓜(Cucurbita maxima×C. moschata)],栽培基质为西瓜连作土壤,试验设接种或不接种AM真菌变形球囊霉(Glomus versiforme)并施加0%、1%、2%和4%的生物质炭,共8个处理,测定土壤理化特性、土壤酶活性、土壤微生物数量和植株生长量。【结果】接种AM真菌并施加生物质炭,可显著促进土壤大颗粒团聚体的形成和有机质的矿化,稳定土壤pH,增加土壤细菌和放线菌数量,降低真菌数量,提高土壤蔗糖酶、过氧化氢酶和脲酶的活性,活化土壤矿质养分,最终促进西瓜植株的生长发育。其中,以接种变形球囊霉并施加2%?4%生物质炭组合的效应最大。两者互作在一定程度上提高了连作土壤的pH、饱和含水量及孔隙度,降低了土壤容重,有利于土壤大颗粒团聚体的形成,提高了土壤酶活性,改善了根围土壤微生物组成。【结论】 AM真菌接种配合施加2%?4%的生物质炭可以显著改善连作土壤的肥力状况。