土壤因子对西藏高原草地植物AM真菌的影响

于西藏高原中部地区就土壤因子对草地植物AM真菌的影响进行的研究表明：AM真菌孢子密度与菌根侵染率、菌根侵染强度无相关性；土壤质地对AM真菌孢子密度的影响明显大于土壤类型，壤土、粉砂土中AM真菌对植物根系的侵染率高于砂壤土；土壤pH与植物根围土壤孢子密度、菌根侵染率分别呈显著正相关和正相关，与菌根侵染强度则呈负相关；土壤有机质与AM真菌孢子密度呈负相关，菌根侵染效果则随土壤有机质含量的增加而提高；高磷土壤环境对AM真菌产孢和侵染均具不同程度的抑制作用，其中植物菌根侵染率随土壤有效磷含量的提高而呈显著下降；AM真菌对莎草科植物矮生嵩草、扁穗莎草根系具有良好的侵染效应。     

AM真菌生长发育影响因素及其对植物作用的研究

由真菌与植物根系共生形成的AM菌根在自然界中分布广泛，其牛长发育受温度、土壤湿度等条件的影响；AM菌根可以促进宿主植物的生长已经在许多植物上得到证实，此外。此类菌根对提高植物的耐盐性、抗旱性及抗重金属毒性方面都有显著的作用。     

AM真菌与地上草食动物的互作及其对宿主植物的影响

丛枝菌根是自然生态系统中广泛存在的一种植物根系与菌根真菌的共生体.放牧是草原生态系统的一种重要生态学功能.目前,关于AM真菌和植物的关系,以及草食动物与植物的相互作用研究已经非常深入,但有关AM真菌-植物-草食动物的多重相互作用研究尚处于发展初期.本文从揭示AM真菌-植物-草食动物三者相互作用机理的角度出发,围绕动物采食作用对AM真菌的侵染、孢子群落组成的变化及其作用机理,丛枝菌根对动物采食行为的影响,以及植物个体与群落对二者共同作用的响应等方面,对AM真菌-植物-草食动物研究领域最新的成果进行综述,并在此基础上,提出AM真菌-植物-草食动物相互作用领域未来的研究方向.     

丛枝菌根真菌在植物修复重金属污染土壤中的作用

菌根是真菌与植物根系所建立的互惠共生体,其中以丛枝菌根(AM)真菌在自然界中分布最广。在重金属污染条件下,AM真菌可以减轻重金属对植物的毒害,影响植物对重金属的吸收和转运,在重金属污染土壤的植物修复中显示出极大的应用潜力。文章通过讨论菌根植物对重金属修复的作用机制,提出菌根技术在重金属植物修复中应在通过广泛调查、筛选超积累植物的基础上,不断探索植物-菌根体系修复问题,以促进重金属污染土壤的生物修复。     

菌根植物适应低磷胁迫的分子机制

丛枝菌根 (AM) 真菌能够和绝大多数陆生植物建立共生体系,对于植物适应低磷胁迫具有重要作用。已有很多研究从不同角度揭示了宿主植物和AM真菌协同适应低磷胁迫的生理机制,并已深入到分子和信号水平。本文归纳了近年来相关研究成果,从磷胁迫信号感知、有机酸分泌、磷酸酶与激素合成相关基因、磷酸盐转运蛋白基因、转录因子与小分子物质miRNA等若干方面讨论了菌根共生体系响应和适应磷胁迫的分子机理,重点介绍了1) 环境磷浓度作为营养信号诱发菌根植物的生理响应过程及其在共生体系建立中的关键作用;2) AM真菌调节植物激素平衡进而影响植物生长发育和根系构型的生理机制;3) 丛枝菌根涉及的植物、真菌以及菌根特异诱导植物产生的磷酸盐转运蛋白基因在磷酸盐摄取中的特殊作用及可能调控机制;4) 转录因子作为感知磷胁迫信号和调控转录表达水平的枢纽,在增强植物适应磷胁迫能力方面的重要贡献。这些因素既单独作用又相互关联,共同构成菌根植物适应磷胁迫的分子调控网络。未来需要着重加强菌根共生界面的磷转运机制、菌根植物适应低磷胁迫的转录因子调节,以及各调控因子相互作用研究,从而全面揭示菌根植物适应低磷胁迫的分子调控网络,为发展和应用菌根技术调控植物磷营养奠定理论基础。     

烟草与丛枝菌根真菌的共生效应研究进展

丛枝菌根(Arbuscular mycorrhiza,AM)真菌是陆地生态系统中广泛存在的一类专性共生土壤微生物,是根系土壤区域中重要的功能菌群之一。AM真菌可侵染植物根系形成丛枝菌根共生体,改变植物根系形态和改善营养状况,从而提高宿主植物的生长发育、产量、质量和抗逆性。目前从烟草根系土壤分离报道的AM真菌已达13属54种,显示出烟草(Nicotiana tobacum L.)栽培的潜在AM真菌资源较为丰富。围绕烟草与AM真菌的共生效应,总结了影响AM真菌侵染和定殖烟草根系的主要因素,阐述了AM真菌对烟草生长、抗性生理及品质的影响,并对PGPR与AM真菌的协同作用进行了简要回顾,最后讨论了该领域存在的不足及今后展望;旨在为菌根技术运用于烟草栽培提供参考。     

不同外源碳对AM真菌吸收氮源合成精氨酸的影响

本文意在探究外源碳对丛枝菌根（arbuscular mycorrhiza, AM）真菌吸收氮源合成精氨酸(Arg)的影响。采用三室隔离盆栽培养系统,以高粱（Sorghum bicolor L. Moench）为宿主植物,接种AM真菌Glomus intraradices,在菌丝室施加4 mmol/L的NH4NO3,同时在根室施加不同形式的碳源,测定分析不同外源碳条件下根外菌丝体（ERM）、菌根和植物茎叶中的Arg含量和总氮含量。结果表明ERM和菌根中的Arg含量远远高于茎叶中;虽然不同形式外源碳提高了AM真菌的ERM干重和菌根侵染率,但是葡萄糖降低了ERM、菌根和茎叶中的Arg含量,蔗糖和甘油对Arg含量没有显著的影响,只有外源Arg和谷氨酰胺（Gln）使ERM中的Arg含量显著增加;不同外源碳对菌根和茎叶的总氮含量没有显著影响。由上述结果分析可知在根室施加外源碳对AM真菌的氮代谢和宿主植物氮素营养水平没有显著影响,Arg合成所需的碳可能大多来自宿主植物供给的碳水化合物;但是施加外源碳能够促进AM真菌的生长繁殖。     

松嫩盐碱草地植物丛枝菌根的初步调查

对松嫩盐碱草地主要植物的丛枝菌根(AM)真菌共生状况进行了初步调查,在观察的9科20种植物中,所有植物均能被AM真菌侵染。在过去认为不被侵染的莎草科、藜科和蓼科植物中,发现球序苔草、碱蓬、灰绿藜、碱地肤、萹蓄蓼和碱蓼有侵染现象。丛枝菌根结构类型以Arum类型(A-型)为主,占75%,少数为Paris类型(P-型),占15%。根际土壤中AM真菌孢子密度范围为0.23～4.71个g-1。在不同质地土壤条件下,根际土壤中AM真菌孢子密度、AM真菌侵染率和侵染强度均有差异,松嫩盐碱草地的壤土比砂壤土更适宜AM真菌的生存。植物根际土壤的pH值和全盐含量对AM真菌侵染和AM真菌均有一定的影响。     

关中地区葡萄根际土壤中AM真菌特点研究

丛枝菌根是植物根系及AM真菌产生的互惠共生体,是生态系统中较为重要的一部分。AM真菌不仅可以帮助植物吸收营养及水分的效率,也可以提升植物的逆生长能力。由此,从分析AM真菌及简述关中地区的葡萄根系AM真菌的情况入手,概述了检测关中地区葡萄AM真菌的方法     

共生丛植菌根减轻番茄黄化卷叶撒丁岛病毒症状和降低病毒浓度

正共生丛枝菌根(arbuscular mycorrhizal,AM)对生物和非生物胁迫经常表现出较高的耐受力,被认为是一种能够改善植物健康和提高植物产量的天然工具,然而AM与病毒感染的关系一直很少被人们关注和深入研究。意大利国家研究委员会的G.Maffei团队通过一系列试验,探索了共生菌根(funneliformis mosseae)与番茄黄化卷叶撒丁岛病毒(Tomato yellow leaf curl Sardinia virus,TYLCSV)的相互作用,为防治在地中海地区肆虐的番茄黄化卷叶病毒病提供了新途径,具有重要的理论和实际意义,其相关研究结果于2013年9月发表在《Mycorrhiza》上。许多研究表明,AM除了可以改善无机营养,还能够提高共生植物耐受不良生物和非生物环境的耐受力,从而增进植物健康。AM还可以影响植物与病原物的互作,目前已在很多土传病害病原菌上观察到了有益效果。但是关于植物病毒与共生菌根互作却鲜有报道。     

Altered amino acid profile of arbuscular mycorrhizal maize plants under low temperature stress

We investigated the effect of arbuscular mycorrhiza (AM) on amino acid concentration and composition of maize plants under low‐temperature stress. The AM plants had higher amino acid concentrations than the non‐AM pants. The concentrations of Thr, Lys, Gly, Ala, His, and Ile of the AM plants were higher than non‐AM plants. The results show that low‐temperature stress decreased the concentrations of amino acids and altered their composition.     

丛枝菌根真菌对棉花耐盐性的影响研究

盆栽灭菌试验研究丛枝(AM)真菌对棉花耐盐性的影响结果表明,自然盐渍化土壤和人工模拟盐渍条件下接种AM真菌处理的生物产量显著高于不接种处理,相同土壤下菌根真菌对棉花植株生长的促进作用随盐水平的提高而增大,表明AM真菌与植株建立的共生关系有利于棉花在盐渍土壤中生长。盐胁迫下棉花植株对P的需要量增加,接种AM真菌可提高植株含P量,促进植株生长,提高棉花的耐盐性。     

Reaction of Mycorrhizal and Nonmycorrhizal Leucaena leucocephala to Charcoal Amendment of Mansand and Soil

A series of experiments were conducted to evaluate the influence of charcoal on the development of arbuscular mycorrhiza (AM) on Leucaena leucocephala roots and the contribution of the symbiosis to the phosphorus (P) nutrition and growth of the legume. Arbuscular mycorrhizal fungal colonization of plants raised in Mansand (crushed basalt) in the first experiment was reduced if the medium was amended with fine charcoal and not with coarse charcoal. Charcoal amendment had no effect on AM fungal colonization, AM symbiotic effectiveness measured as pinnule (subleaflet) P content, or on growth of L. leucocephala in soil in the first experiment and in Mansand and in soil in subsequent experiments. However, AM fungal colonization of L. leucocephala roots, P content of pinnules, and growth of the legume were significantly enhanced (P < 0.05) by AM fungal inoculation in all experiments regardless of the growth medium used or charcoal amendment.     

丛枝菌根提高植物耐盐性的研究进展

近年来,土地盐渍化越来越多的引起人们的关注,已成为最常见的农业问题之一,其对人类造成的危害主要是使农作物减产甚至绝收,并间接造成生态环境恶化。研究表明丛枝菌根真菌(Arbuscular Mycorrhiza Fungi,AMF)在盐胁迫下能与很多种植物共生,能够提高植物的耐盐性,促进植物在盐胁迫中生长。因此,探索AMF缓解盐胁迫对植物的危害是近年来生态学和农业生产中的热点问题。综述了AMF在植物干物质的积累、营养吸收、渗透调节、抗氧化酶系统、叶绿素浓度、水分状况、植物激素信号以及一些耐盐相关基因方面国内外最新的研究成果,并对利用AMF提高植物耐盐性相关研究提出了展望,以期为盐碱地的改良及农业生产提供参考依据。     

Brassinosteroid (BR) and arbuscular mycorrhizal (AM) fungi alleviate salinity in wheat

This study was conducted to assess the impacts of brassinosteroide (BR), arbuscular mycorrhizal (AM) fungi, Glomus mosseae and their interactions on salt stress tolerance in Triticum aestivum L. After foliar spraying of mycorrhizal and non-mycorrhizal plants by 5 µM epibrassinolide, they were subjected to 0 and 150 mM sodium chloride (NaCl) for 2 weeks. The experiment was conducted in a randomized complete block design, replicated 4 times. Our results showed a probable potential of BR and/or AM fungi in improving salt tolerance of plants. Total phenol and proline content increased in BR and/ or AM treatments. AM fungi promoted plant growth, including leaf area, shoot and root dry weights, and lengths under saline condition. Moreover, BR improved growth parameters except root dry weights and lengths. This study indicated that BR and/or AM fungi may contribute to improve salt tolerance of the plant.     

Soil and weed management for enhancing arbuscular mycorrhiza colonization of wheat

Tillage and weed control are critical components of cropping systems that need to be combined such that crops benefit from reduced competition. However, weeds may also contribute to the biological diversity within the agro‐environment. This greenhouse study investigated whether common weeds of arable cropping systems were suitable host plants for arbuscular mycorrhizal fungi (AMF), allowing the development of extraradical mycelium (ERM) that can contribute to the early colonization of a following wheat crop, especially in the absence of soil disturbance. Weeds were allowed to grow for up to 2 months before being controlled by soil disturbance or herbicide application (glyphosate or paraquat). Pregerminated wheat seeds were then planted. Chemical control of the weeds prior to sowing enhanced the early arbuscular mycorrhiza (AM) colonization rate of wheat roots, whereas mechanical disturbance was less acceptable as a method of weed control for rapid AM colonization. The type of herbicide (contact or systemic) had no impact on colonization of the wheat crop. Enhanced AM colonization promoted early P acquisition and growth of the crop. Appropriate management of weeds emerging between two consecutive cropping seasons coupled with no‐till soil management could ensure a quick and efficient AM colonization of the following wheat plants.     

Interactive effect between Cu‐adapted arbuscular mycorrhizal fungi and biotreated agrowaste residue to improve the nutritional status of Oenothera picensis growing in Cu‐polluted soils

The interactive effect of sugar beet (SB) agrowaste and arbuscular mycorrhizal (AM) fungi inoculation in response to increasing Cu levels was evaluated in the metallophyte Oenothera picensis. Plants were grown in a Cu‐added soil (0, 100, or 500 mg Cu kg^?1), in presence or absence of SB, and inoculated with: (1) indigenous Cu adapted mycorrhiza (IM) isolated from Cu‐polluted soils; (2) Claroideoglomus claroideum (CC); or (3) maintained uninoculated (control). Sugar beet application produced an increase in shoot biomass of 2 to 7 times, improving plant nutritional status and allowing their survival at the highest Cu concentrations. Moreover, AM fungi utilization had a positive effect promoting the plant establishment; nevertheless, Cu plant concentration as well as the mycorrhizal development in terms of AM colonization, AM spore density, and glomalin production were strictly dependent of the AM fungi strains used. Remarkable differences between AM fungi strains were observed at the highest soil Cu level where only plants colonized by IM were able to survive and grow when no SB residue was added. An interactive effect between AM fungi and SB produced a higher plant growth than plants without the amendment application, improving the plant establishment and allowing their survival at highest copper concentrations, suggesting that this combination could be used as a biotechnological tool for the phytoremediation of Cu‐polluted soils.     

Interactions between arbuscular mycorrhizal fungi and fungivorous nematodes on the growth and arsenic uptake of tobacco in arsenic-contaminated soils

The effects of inoculation with two AM fungi (M1, Glomus caledonium; M2, Glomus spp. and Acaulospora spp.) and a fungivorous nematode Aphelenchoides sp. on growth and arsenic (As) uptake of Nicotiana tabacum L. were investigated in soils contaminated with a range of As. The reproduction of Aphelenchoides sp. was triggered by the co-inoculation of AM fungi regardless of AM fungal isolates and As levels. Stimulative effects of Aphelenchoides sp. on the development of mycorrhiza, slightly different between two AM fungi, were found particularly at the lowest As level. Irrespective of mycorrhizal inoculi, increasing soil As level decreased plant growth, but increased plant As uptake. Co-inoculation of AM fungi and Aphelenchoides sp. led plants to achieving further growth and greater As accumulation at the lowest As level. Results showed that the interactions between AM fungi and fungivorous nematodes were important in plant As tolerance and phytoextraction at low level As-polluted soil.