AM真菌对君迁子水分状况、保护酶活性和膜脂过氧化的影响

在盆栽条件下,研究了3种丛枝菌根真菌Glomus mosseae(Nicol.&Gerd.)Gerd.&Trappe,Glomus in-traradicesSchenck&Smith和Glomus versiforme(Karsten)Berch对君迁子(Diospyros lotusL.)幼苗生长、水分状况、叶片SOD、POD活性及MDA含量的影响。结果表明,接种丛枝菌根真菌显著促进了植株生长,接种处理的苗高、叶数、地径、单株叶面积、茎和叶鲜重、干重、叶绿素含量都显著高于对照,苗高提高了25%~43.8%,叶干重增加了64.6%~79.7%,叶面积为对照的1.72~1.99倍。同时,接种后也提高了叶片自由水、束缚水和总含水量,束缚水含量提高了12.5%~20.6%,并显著提高了离体叶片的保水力;在干旱胁迫下,君迁子推迟15.4~32.2 h出现萎蔫,重新复水后,提前10~15 min恢复正常。干旱胁迫各接种处理SOD、POD活性显著提高;MDA的含量显著降低。     

氮、磷添加对青藏高原高寒草甸丛枝菌根真菌群落的影响

【目的】探究青藏高原高寒嵩草草甸生态系统中丛枝菌根真菌(AMF)群落对氮、磷添加的响应及其驱动因子,补充目前高寒草甸AMF对施肥响应研究的不足。【方法】通过常规分析和高通量(Illumina-Miseq)测序,分析氮(0、7.5、15.0 g·m~(-2))、磷(0、7.5、15.0、30.0 g·m~(-2) P_2O_5)添加3年对青藏高原高寒小嵩草草甸土壤化学性质、AMF侵染率、OTU丰度、 Shannon多样性指数和AMF群落组成的影响。【结果】测序共发现36个AMF的OTU,归属于7个科。氮、磷的添加及其交互作用对AMF侵染率、OTU丰度和Shannon多样性指数均无显著影响。相对于低施氮处理,高施氮处理显著降低球囊霉门的相对丰度。土壤有机碳、硝态氮、有效磷和全磷含量均是影响AMF群落的土壤因子。【结论】青藏高原高寒嵩草草甸根系AMF群落不受氮、磷添加的影响,群落分布与土壤因子有显著相关性。     

长春花接种丛枝菌根真菌对柑橘黄龙病菌的抑制效果

通过筛选获得具有显著促生和抗病能力的AM真菌菌株,为防治柑橘黄龙病提供理论依据和基础,并探索防治新途径。采用盆栽法,于长春花幼苗期分别接种17株AM真菌进行长春花农艺性状和对柑橘黄龙病的抗病性比较试验,研究不同丛枝菌根真菌菌株对长春花的促生效果及对柑橘黄龙病的抑制效果。结果表明,长春花接种AM真菌后,菌株GZ10、GZ5和JX70能显著促进植株生长,其中接种GZ10的株高和茎径分别比CK增加了23.1%和12.1%,接种GZ5的叶片数比CK增加了12.9%;接种菌株GZ1、BNMJ和PWJ有效提高了长春花对柑橘黄龙病的抗病和耐病能力,其相对防效分别为78.39%、66.87%和69.75%。     

AMF对铅锌矿区农田土壤部分理化性质、玉米生长和镉铅含量的影响

为研究重金属污染胁迫下丛枝菌根真菌（Arbuscular mycorrhizal fungi,AMF）对土壤部分理化性质、玉米生长、光合生理、养分与镉铅含量的影响,以云南会泽、兰坪铅锌矿区周边重金属污染农田土壤为供试土壤,玉米为宿主植物,设置接种和不接种AMF处理,开展室内盆栽试验。结果表明：接种AMF显著增加土壤易提取球囊霉素相关蛋白（EE-GRSP）与总球囊霉素相关蛋白（T-GRSP）的含量;降低土壤有效态镉、铅含量,降幅为34.6%~79.5%;增加土壤中碱解氮和速效磷的含量,增幅为30.9%~206%。接种AMF显著增加玉米植株氮磷养分含量,增幅为17.6%~38.5%;增强叶片光合作用,提高植株生物量;降低植株镉铅含量,降幅达30.0%~68.7%。相关性分析发现,土壤T-GRSP与碱解氮、速效磷含量呈极显著正相关;EE-GRSP、T-GRSP与有效态铅含量呈显著负相关;玉米植株镉、铅含量与土壤有效态镉、铅含量呈显著正相关;玉米根系氮与土壤碱解氮含量、植株磷与土壤速效磷含量呈显著正相关。研究表明,接种AMF增加土壤球囊霉素相关蛋白含量,降低污染土壤镉、铅生物有效性,减少玉米植株镉、铅的含量;增加土壤速效养分含量,改善玉米矿质营养和光合生理,提高玉米植株生物量。     

接种AM真菌对不同盐度土壤中向日葵生长的影响

采用温室盆栽的方法,模拟不同程度盐渍化土壤（外源添加NaCl 0、0.5、1.0 g·kg^-1和1.5 g·kg^-1）,研究接种AM真菌Funneliformis mosseae（F.mosseae）对向日葵菌根侵染率、生物量、矿质营养元素吸收、Na⁺吸收、抗氧化酶活性和膜系统、渗透平衡物质含量、光合作用以及水分利用率的影响。结果显示,NaCl浓度可显著影响AM真菌F.mosseae对向日葵根系的侵染,平均菌根侵染率为51.99%~68.85%;随着NaCl浓度的增加,向日葵地上部干质量和总干质量显著降低,地上部和根部Na⁺含量和积累量显著增加,叶片过氧化物酶（POD）活性显著降低,丙二醛（MDA）和脯氨酸含量显著增加,净光合速率（Pn）、蒸腾速率（Tr）和水分利用率显著降低;不同浓度NaCl胁迫下,接种AM真菌使向日葵总干质量显著增加了16.95%~28.97%,地上部和根部磷含量分别显著增加了33.77%~54.29%和36.07%~52.63%,地上部和根部Na⁺含量显著增加,叶片POD活性显著增加,脯氨酸含量显著降低了80.26%~87.05%,净光合速率和蒸腾速率分别增加7.70%~80.00%和7.27%~32.53%,水分利用率显著增加了8.93%~14.97%。研究表明,AM真菌能够增强向日葵对盐胁迫的抵抗能力并促进其生长。研究为利用AM真菌联合耐盐作物修复盐渍化土壤以及拓宽盐渍土的开发和利用,提供基础数据和技术支持。     

Arbuscular mycorrhizal fungi and their response to pesticides

Arbuscular mycorrhizal fungi (AMF) form symbioses with the majority of plant species and can provide multiple benefits to the host plant. In agro‐ecosystems, the abundance and community structure of AMF are affected by agricultural management practices. This review describes and discusses current knowledge on the effects of inorganic and organic chemical pesticides on AMF in the conflicting area between agricultural use and environmental concerns. Variable effects have been reported following chemical pesticide use, ranging from neutral to positive and negative. Moreover, a species‐specific reaction has been documented. The reported effects of pesticides on arbuscular mycorrhizal symbiosis are very diverse, and even when the same substance is investigated, the results are often contradictory. These effects depend on many parameters, such as the active substance, the mode of action, the mode of application and the dosage. In the field, determinants such as the physico‐chemical behavior of the active substances, the soil type and other soil microorganisms contribute to the fate of pesticides and thus the amount of active substances to which AMF are exposed. This review highlights that the fate of AMF following pesticide use needs to be addressed in a broader agro‐ecosystem context. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Phosphorus Fertilization and Fungal Inoculations Affected the Physiology,Phosphorus Uptake and Growth of Spring Wheat Under Rainfed Conditions on the Canadian Prairies

Some fungal species have been shown to improve plant growth under drought conditions and to increase plant phosphorus (P) uptake from the soil. How moisture limitation, P availability and fungal inoculation interact to affect plant physiology and growth is, however, poorly understood. Here, we studied the combined effects of fungal (arbuscular mycorrhizal fungi (AMF) or Penicillium spp.) inoculations and phosphorus (P) fertilization (0, 45 and 90 kg ha^?1) on the net rate of photosynthesis, water‐use efficiency, P uptake and growth of spring wheat (Triticum aestivum var. Superb) under field conditions at two locations (Castor and Vegreville) in Alberta, Canada. Both fungal inoculation and P application increased the rate of photosynthesis. Under the same P level, AMF inoculation had a greater positive effect on the rate of photosynthesis than Penicillium inoculation. The AMF inoculation increased the instantaneous water‐use efficiency (WUEi) of plants at Castor, but not at Vegreville. Leaf carbon isotope discrimination (CID, Δ¹³C) increased with the rate of P application but was not affected by fungal inoculations. Phosphorus concentrations of stem and seed increased with both fungal inoculation and P application irrespective of location, with AMF inoculation showing the largest effects. The interaction between P addition and fungal inoculation was significant for stem P concentration in Vegreville. Both fungal inoculation and P application increased the leaf area index (LAI), biomass production and grain yield at both locations. Under the same P level, AMF inoculation had a greater positive effect on LAI, biomass production and grain yields than Penicillium inoculation. Morphological characters such as spike length and kernels/spike were also improved by fungal inoculation and P application at both locations. We conclude that the studied sites were deficient in P availability, and both fungal inoculation and P application improved P uptake and crop productivity, while the effect of fungal inoculation on water‐use efficiency was site specific.     

Three-way fungal interactions affect the potential biological control of Himalayan balsam,Impatiens glandulifera

Himalayan balsam (Impatiens glandulifera) is one of the most invasive weeds across Europe. The rust fungus, Puccinia komarovii var. glanduliferae has been introduced as a biological control agent, but success has been patchy. Here, we investigated whether mycorrhizal and endophytic fungi can affect rust efficacy and plant growth. Over three experiments, we found that AM fungi and the rust alone or together consistently reduced plant growth, but this depended on the identity of species in the AM inoculum. Meanwhile, AM fungi increased infection frequency of the endophyte Colletotrichum acutatum. Rust inoculation had no detrimental effects on mycorrhizal colonisation or C. acutatum infection, but the latter two fungi reduced rust sporulation. However, plant size was reduced when all three fungal types were present, suggesting that a combined fungal inoculum offers a promising approach for the control of this weed.     

Effect of inoculation with ecto- and arbuscular mycorrhizae and Rhizobium on the growth and nitrogen fixation by black locust,Robinia pseudoacacia

Experiments were made to determine the effect of inoculation withRhizobium, the ectomycorrhizal fungus Hebelomamesophasem and the arbuscular mycorrhizal fungus Glomuscaledonium on the growth and nitrogen fixation of black locust(Robinia pseudoacacia Linn.) seedlings grown invitro and in pot culture. The results showed that both mycorrhizalfungi and Rhizobium stimulated the growth and nitrogenfixing ability of inoculated seedlings. Inoculation with all three microbestogether produced the most beneficial effects on nitrogen fixation, mycorrhizaldevelopment and seedling growth.     

The potential of mycorrhizal inoculation and organic amendment to increase yields of Galega orientalis and Helianthus tuberosus in a spoil‐bank substrate

An agricultural use of reclaimed coal‐mine spoil banks is limited to nonfood crop uses and provides potential for biofuel crops. Two high‐biomass crops—Galega orientalis and Helianthus tuberosus—were cultivated in a greenhouse pot experiment conducted in sterilized and nonsterile spoil bank clay. We aimed (1) to determine the possibility of reducing the applied rate of organic amendments (thus decreasing the costs of spoil‐bank reclamation) and (2) to assess whether the inoculation with arbuscular mycorrhizal fungi (AMF) can improve plant growth and biomass accumulation of bioenergy crops even in nonsterile soil containing naturally occurring AMF. The spoil substrate was either unamended or treated with a mixture of composted urban waste and ligno‐cellulose at a rate corresponding to 40 t ha^–1. Three native AMF isolates or three isolates from the International Bank of Glomeromycota (BEG) originating from man‐made ecosystems were used for inoculation. Generally, both plant species positively responded to both mycorrhizal inoculation and organic amendment. While G. orientalis did not show any preferences towards the AMF inoculum origin in the nonsterile soil, for H. tuberosus the specific combination of organic amendment and BEG isolates resulted in highest yields of shoot biomass. The study shows that the successful planting of both tested crops requires the organic amendment. However, its dosage can be substantially reduced. The effectiveness of mycorrhizal inoculation can vary for the combination of plant species and the origin of the applied AMF.