Many papers have been published in the field of mycorrhizal research because of the development of scientific technology and the widespread use of mycorrhizal technology.In this paper,the progress of mycorrhizal studies and their applications in China are reviewed.On the basis of the 1 166papers published from 2006to 2010,we analyzed the progress made by Chinese scientists during this period.The main results,including mycorrhizal nutrition,mycorrhizal ecology,use of molecular technology in mycorrhizal studies and the effects of mycorrhizal infection on plant resistance are discussed.The applications of mycorrhiza at the plant nursery stage and in edible fungus production are also discussed.The prospects for mycorrhizal studies and their applications in agricultural and forestry fields in the future are addressed.

To establish a propagation system for arbuscular mycorrhizal(AM)fungi,four different plants: maize(Zea mays),sorghum(Sorghum bicolor),white clover(Trifolium repens)and green onion(Allium fistulosum)were selected for this study.Two different cultivation densities were used to test the influence of plant densities on the propagation of an AM fungus(Glomus versiforme).Different plant species and different densities had a significant influence on the colonization and spore production of G.versiforme and on the biomass of host plants(P0.05).The extent of AM colonization and spore densities at 10plants per pot were much higher than at 5plants per pot(P0.05).Our studies suggest that maize,which has the highest biomass with high density,was suitable for propagation of G.versiforme.

紫花苜蓿(Medicago sativa L.)适应性强、生物质产量高,茎可用于生产酒精,叶片可用于家畜饲料,是最具开发潜力的能源植物之一.本文从紫花苜蓿生物能源利用角度出发,系统回顾了近年来紫花苜蓿作为能源植物在种质资源评价、细胞壁主要成分(纤维素、半纤维素、木质素)合成途径及其遗传调控以及栽培管理对酒精生产效率的影响等方面的研究进展,重点讨论了苜蓿细胞壁发育和木质素生物合成基因及其调控效应,并 对紫花苜蓿作为能源植物的研发前景进行了展望.

Arbuscular mycorrhizal(AM) fungi are one of the widely spread micro-organisms,which could form symbionts with more than 80% of the vascular plants in natural ecosystems. It has been showed that AM symbionts could improve plant nutrients and water absorption; increase the resistance ability to stress conditions,thus AM fungi could enhance the host plant growth. The plant soil-borne diseases caused by soil-borne pathogens,including fungi,nematodes and bacteria,are considered as one of the most difficult controlling diseases in agriculture ecosystem. Previous studies have been demonstrated that AM symbionts could increase plant resistance to diseases,and to antagonize soil-borne pathogens. Thus,using AM fungi as a biological control method to antagonize soil-borne pathogens has received increasing interests by phytopathologists and ecologists. On the basis of this,the mechanisms of resistance to diseases induced by AM fungi were summarized in this paper. Mechanisms covered in this review include root morphology alteration,regulation of secondary metabolite production,improvement of rhizosphere environments,competition with pathogenic microorganisms on invasive sites and on nutrition distribution in host plants,and formation of defense systems in plants. Firstly,the characteristics of root morphology alterations were explained,including how AM fungi influence their structures and functions. Secondly,the regulation of AM fungi to secondary metabolites was illustrated. Several types of products,including phytoalexin,callose,alkaloid and phenols were reviewed. Thirdly,AM fungi could improve the rhizosphere environments by influence soil physical and chemical proprieties,and enhance the growth of other beneficial microorganism in rhizosphere soil. Fourth,AM fungi could compete with pathogenic microorganisms. The two kinds of microorganisms maybe compete for the same invasive sites in root systems,and thus they could regulate the nutrition distribution. Fifth,AM fungi could induced the host plant to form the defense systems in plants,including improvement the concentrations of phytohormone,induced the production of signal substrates,regulation of genes expression and enhanced the proteins production,thus AM fungi could enhance the resistance ability of host plant to pathogenic microorganisms. The aim of this paper was to enhance the potential use of AM fungi as a biological control method for preventing plant diseases in future.

土壤重金属污染威胁人类健康和整个生态系统,而高效、低耗、安全的生物修复技术显示出了极大的应用潜力,特别是利用植物-微生物共生体增强生物修复效应的应用。丛枝菌根（Arbuscular Mycorrhizae,AM）真菌是一类广泛分布于土壤生态系统中的有益微生物,能与90%以上的陆生高等植物形成共生体。研究发现,AM真菌能够增强宿主植物对土壤中重金属胁迫的耐受性。当前,利用AM真菌开展重金属污染土壤的生物修复已经引起环境学家和生态学家的广泛关注。基于此,围绕AM真菌在重金属污染土壤生物修复作用中的最新研究进展,从物理性防御体系的形成、对植物生理代谢的调控、生化拮抗物质的产生、基因表达的调控等角度探究AM真菌在重金属污染土壤生物修复中的作用机理,以期为利用AM真菌开展重金属污染的生物修复提供理论依据,并对本领域未来的发展和应用前景进行了展望。

Arbuscular mycorrhizae(AM) are the symbionts between AM fungi and plant roots in natural and artificial ecosystems.AM symbionts could decrease the harmful stress from heavy metals and regulate the heavy metals uptake and translocate to their host plants.In order to discover the physiological and molecular mechanism of heavy metals tolerance induced by AM fungi,the function and strategies of AM symbionts were discussed in this paper: 1) the fungal hyphae could immobilize heavy metals and restrict the translocation of heavy metals from roots to shoots;2) chelating substances could immobilize heavy metals;3) AM fungi could promote the nutrient acquisition to host plants;4) AM fungi could regulate the distribution of heavy metals in host plants;5) AM fungi could influence the anti-oxidative enzymes system activity and hormones in host plants;6) the molecular mechanisms that AM fungi regulate heavy metal uptake and translocation.On the basis,this study focused on the possibility of using the system of AM-soil microbiology-host plant for remediation of heavy metals polluted soil in future.

Arbuscular mycorrhiza(AM) is an important symbiont between plant roots and AM fungi in natural grassland.In ecosystem,the important ecological function of the natural grassland is to support the grazing animals.Recently,the relationship between AM fungi,host plants and the grazing animals has been paid more attention in ecology research,especially the relationship between AM fungi and host plants,and the relationship between grazing animals and host plants.However,the inter-relationships among AM fungi,host plants and grazing animals have not been discovered yet.On the basis of this,this study focused on the influence of AM fungi on the inter-relationship of host plants and grazing animals.Three mechanisms were provided to explain the inter-relationship of AM fungi,host plant and grazing animals.Firstly,AM fungi could regulate the compensatory growth of host plants on different grazing pressure.Secondly,the response of morphological plasticity of the host plant varied with AM fungi or without AM fungi.Thirdly,the plant community structure and plant diversity could be changed with AM fungi.Thus,AM fungi could regulate the plant and the grazing behavior in grassland.This theory could be used for the reclamation and conservation in the over-grazing grassland and it will benefits for the grassland management and grassland healthy.

In order to investigate the function of arbuscular mycorrhizae in Tibetan Plateau Alpine meadow ecosystems, experiments were carried out to evaluate the influence of arbuscular mycorrhizal (AM) fungi on inter-specific competition between the poisonous plant, Ligularia virgaurea , and the grazing grass, Elymus nutans , at different relative densities. Our results showed that the biomass of L. virgaurea significantly declined in AM treatments while the biomass of E. nutans increased in our inter-specific competition system. Relative yields and root/shoot ratios of these two species indicated that AM fungi had a significant influence on the growth of L. virgaurea and E. nutans. This implies that arbuscular mycorrhiza do not benefit both plant species equally but rather contribute to the growth of E. nutans more than L. virgaurea. We thus provide evidence that AM fungi could regulate plant interactions and influence the plant community structure in the Tibetan Plateau Alpine meadow ecosystem.