AMF接种与根系分隔对红壤上间作玉米生长及磷素吸收的影响

通过盆栽模拟试验研究比较以Glomus mosseae(GM)和Glomus etunicatum(GE)为接种剂,设置不同根系分隔方式(不分隔,隔尼龙网,隔塑料膜)对间作玉米植株生长及磷素吸收累积的影响。结果表明,两种菌根真菌GM和GE对玉米根系的侵染效果相近,GM为玉米优势丛枝菌根真菌(AMF),接种GM使玉米根长、地上部和根系生物量、地上部和根系磷含量、磷吸收量均显著提高;接种GE显著降低了玉米根冠比、株高和根系磷吸收效率。间作体系不同根系分隔方式对玉米的影响也不同,根系隔尼龙网处理显著降低了玉米根长和根系生物量,显著提高了根系的磷含量;根系隔塑料膜处理对玉米的地上部和根系磷含量、磷吸收量以及根系磷吸收效率均起显著降低作用。所有复合处理中,以GM不分隔处理组合对间作玉米的生长及磷素累积的促进作用最好。     

AMF复合菌剂对寒地水稻光合作用和生长效应的影响

研究AMF复合菌剂对水稻生长及产量的促进效果,旨在为绿色高产水稻的种植提供技术基础。本试验以水稻(Oryza sativa L.)为研究对象,测定大田条件下水稻植株的光合作用参数、总生物量和水稻产量及其构成因素。AMF复合菌剂能显著提高内生真菌在水稻根部的侵染率,AMF+PI+AR处理的侵染率高达86.7%,能与水稻根系建立良好的共生关系。施加AMF复合菌剂能提高水稻叶片的光合作用强度和水稻总生物量,与PI、AR、AMF、FP、CK相比水稻的总生物量分别提高了25.9%、31.7%、24.4%、17.2%、38.1%。AMF复合菌剂种植与常规农作物施肥种植相比产量提高了6.9%。AMF复合菌剂能够有效促进水稻生长并提高产量,相比较常规农作物施肥有着零施肥、低成本、高产量的优势,可实现水稻清洁生产并解决稻田面源污染问题。     

Influence of an Arbuscular Mycorrhizal Fungus on Competition for Phosphorus Between Sweet Orange and a Leguminous Herb

Grass or herb intercropping with trees is widely practiced as an orchard-floor management strategy, but nutrient competition from grass species can inhibit the growth of intercropped fruit trees. Two experiments were conducted to investigate whether inoculation with the arbuscular mycorrhizal (AM) fungus Glomus versiforme can alleviate such competition and thus promote the growth of intercropped fruit trees by increasing soil nutrient exploitation. In the first experiment, intercropping was established in rhizoboxes containing sweet orange (Citrus sinensis) and the leguminous herb Stylosanthes gracilis inoculated with the AM fungus. Mycorrhizal inoculation did not appear to decrease competition, but increased the biomass of the herb much more than that of sweet orange. Inoculation had little effect on phosphorus (P) content of sweet orange, but significantly increased that of the legume roots. The AM fungal contribution to P uptake of the herb was twice that of sweet orange. Lateral roots of the herb tended to branch horizontally, with a large proportion entering the soil volume occupied by sweet orange; AM inoculation enhanced this effect. In Experiment 2, growth of the plants in monoculture revealed that the mycorrhizal dependency of the legume was much higher than that of sweet orange. It is suggested that mycorrhizal dependency can have a large influence on the role of the AM fungus in mediating competition in an intercropping system, and that fruit trees with high mycorrhizal dependency, together with a grass or herb with low mycorrhizal dependency, may be the optimum intercrop combination in orchards.     

Effect of indigenous arbuscular mycorrhizal fungi combined with manure on the change in concentration some mineral elements in cotton (Gossypium hirsutum L.)

A pot experiment was conducted to evaluate the effect of indigenous arbuscular mycorrhizal fungi (AMF) and the synergy of indigenous AMF and sheep manure (SM) on potassium (K), calcium (Ca) and some micronutrient concentrations in cotton plant. Indigenous AMF were a mixture of Glomus viscosum, Glomus mosseae and Glomus intraradices initially isolated from a cotton field. Cotton was grown for 12 weeks and the elements of shoot were determined at three stages of plant growth. Inoculated cotton plants with AMF had higher concentrations of K, Ca, manganese (Mn), iron (Fe), copper (Cu) and zinc (Zn) than non-mycorrhizal plants. Shoot concentrations of these elements increased significantly when SM was added to mycorrhizal plants. Maximum plant micronutrient uptake was found in the treatment of AMF inoculation with SM. Mn, Fe, Cu and Zn uptake increased significantly by 457%, 282%, 272% and 295%, respectively, over control. Indigenous AMF combined with SM resulted in better plant growth and micronutrient uptake.     

丛枝菌根真菌促进植物摄取土壤磷的作用机制

磷在土壤中易被固定沉淀,在植物磷利用率低的情况下,过度施肥会造成磷肥浪费,可能通过地表径流、地下水溶解等方式,造成水体富营养化产生面源污染,对人类生产生活造成较大影响。丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)和植物结合所形成的共生菌根可以显著增强植株对磷的吸收利用。通过AMF可以提高宿主植株对磷的吸收转运的特性,从AMF促进植株对磷元素的摄取机制、AMF促进植物磷摄取分子机理、AMF作用下根系分泌物对植株磷利用的影响与根际微生物对AMF磷元素利用的影响4个方面的研究进展进行分析总结。AMF可以通过改变宿主植株的根系形态和菌丝网络的形成,扩大植株对养分吸收范围;释放有机酸、磷酸酶和质子等根系分泌物改变土壤结构和理化性质,与根际微生物共同作用降解土壤中难溶性磷酸盐;诱导相关磷转运蛋白基因的特异性表达,提高植株对磷的转运能力而促进其吸收。     

栌菊木共生丛枝菌根真菌的分离鉴定

为了解栌菊木(Nouelia insignis Franch)共生丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)的物种多样性,探明其形成乔木与丛枝菌根真菌多样性的关系,野外采集栌菊木根系及根际土壤,利用土壤湿晒法和根系透明染色镜检法,研究丛枝菌根真菌在土壤中的孢子密度及丛枝菌根真菌的侵染率,并采用形态学和分子生物学方法对分离的AMF孢子优势菌株进行鉴定。结果表明:传统形态学方法初步鉴定出栌菊木土壤中存在摩西球囊霉(Glomus mosseae)和幼套球囊霉(Claroideoglomus etunicatum)2种AM真菌;应用nested-PCR技术扩增18SrRNA中的NS31-AM1区,通过序列比对构建系统发育树A-1真菌与Glomus mosseae(DQ273793)亲缘性为97%,A-2真菌与Claroideoglomus etunicatum(AJ510231)亲缘性为99%。根据形态学与分子生物学的双重鉴定,确定侵染栌菊木根系的AM真菌是摩西球囊霉和幼套球囊霉。     

丛枝菌根真菌对淮安红椒连作土壤养分和酶活的影响

在分析淮安红椒(Capsicum annuum L.)连作10年大棚土壤养分含量和土壤酶活性的基础上,研究了根际施用不同量丛枝菌根真菌对土壤有机质、有效养分和酶活的影响,探讨了丛枝菌根真菌修复淮安红椒连作障碍的可能性及其机理。结果表明,连作土壤中有机质、碱解氮、速效磷和速效钾含量显著升高,脲酶、蔗糖酶、蛋白酶、过氧化物酶、脱氢酶活性显著降低,而过氧化氢酶活性显著升高;每株施用3、5g丛枝菌根真菌能够促进红椒对土壤有机质和有效养分的吸收,使土壤中有机质、碱解氮、速效磷和速效钾含量显著降低,能够改善根际土壤微生态,显著提高土壤脲酶、蔗糖酶、蛋白酶、过氧化物酶和脱氢酶活性,从而降低过氧化氢酶活性;丛枝菌根真菌能够显著缓解淮安红椒连作障碍。     

几种有机肥对玉米光合特性及土壤酶活性的影响

为了比较研究有机肥、化肥对玉米生产能力的影响,为北方黑土地区有机肥与化肥的施用提供科学依据.大田条件下对玉米施用4种有机肥和传统化肥,测定玉米产量、叶片光合特性、土壤酶活性以及丛枝菌根真菌(AMF)侵染情况等指标.结果表明:超效有机肥(T4)处理下的玉米产量为9800kg/hm2,相比于传统化肥(CK)增产11.53％...     

丛枝菌根真菌、根瘤菌和解磷细菌之间相互作用的研究进展

在生物圈中,合作是普遍存在的,对于不同物种之间合作的研究,人们也做出了许多努力。研究发现,丛枝菌根真菌(Arbuscular mycorrhizal fungi, AMF)、根瘤菌和解磷细菌对植物和土壤发挥着积极的作用。本文主要研究了AMF、根瘤菌和解磷细菌之间的合作共生关系及其相互作用,并归纳了接种AMF、解磷细菌和根瘤菌对植物生长、土壤修复和微生物生长的影响。总结了该三种微生物双接种的优势,进一步分析了AMF、解磷细菌和根瘤菌三者之间的相互作用,以及接种后对植物生长和周围土壤状况的影响。最后,提出了对AMF、解磷细菌和根瘤菌之间相互作用的主要研究方向。     

Molecular characterization and glomalin production of arbuscular mycorrhizal fungi colonizing a heavy metal polluted ash disposal island, downtown Venice

In this work the arbuscular mycorrhizal (AM) fungal communities colonizing a polluted ash dump island, downtown Venice, were studied by using a multimodal approach. The island, Sacca San Biagio, was covered with a thick layer of municipal solid waste residues produced by an incinerator operating from 1973, to 1984. Such residues contained high levels of heavy metals (Cu, Pb and Zn). We characterized the AMF communities present in soils on Sacca San Biagio island by using molecular methods. Nine AM fungal sequence types were detected in the roots of three plant species, representative of the dominant flora, by using partial SSU ribosomal RNA genes. The most abundant sequence types corresponded to Glomus intraradices/Glomus fasciculatum, and to Glo18, a sequence detected so far only in planta. Two sequences were new to science. Glomalin-related soil protein (GRSP), extracted from rhizosphere soil of dominant plant species, ranged from 1.6 to 2.3 mg g⁻¹. The occurrence of an active AM fungal community able to live in such harsh environment was evinced by the correlation between mycorrhizal colonization and GRSP content.