丛枝菌根真菌对牡丹根系构型的影响

本试验以分别接种AM真菌Glomus mosseae和G.versiforme的两年生盆栽‘凤丹’幼苗为材料,以不接种为对照,研究不同AM真菌对牡丹幼苗根系构型和生长的影响。结果表明:不同AM真菌的侵染率不同,G.mosseae的侵染率高于G.versiforme;接种G.mosseae的植株干重、根冠比和根系活力显著高于对照。接种不同AM真菌的牡丹幼苗的根系参数均比对照有不同程度的增加,其中对水平延伸根系所占比例和根系总体积的影响最为显著。相关性分析表明,水分饱和亏缺与植株干重、根冠比、根系活力等呈显著负相关;根系参数与牡丹生长呈显著正相关。不同AM真菌可通过影响牡丹幼苗的根系构型而影响其生长。G.mosseae是促进牡丹生长的高效菌种。     

Seed source and vesicular-arbuscular mycorrhizal symbiont affects growth of Juglans nigra seedlings

Seedlings of Juglans nigra from three seed sources were grown in fumigated soil without vesicular-arbuscular mycorrhizal (VAM) fungi or inoculated with Gigaspora margarita, Glomus deserticola or Glomus etunicatum. Vesicular-arbuscular mycorrhizal development varied significantly between fungal symbionts within a black walnut source. Glomus deserticola and G. etunicatum produced the highest levels of root colonization in all sources. Significant differences in seedling shoot and root growth were attributed to root colonization by specific VAM fungi in each black walnut source. Glomus deserticola stimulated seedling leaf area and root weight 26 and 52%, respectively, in one seed source. Seedling leaf N, P and K concentrations were significantly improved by VAM in two seed sources. Juglans nigra seedlings respond favorably to VAM colonization. However, differences between seed sources suggest a strong host-symbiont interaction.     

Growth response, phosphorus content and root colonization of Polylepis australis Bitt. seedlings inoculated with different soil types

Polylepis forests are one of the most endangered high mountain ecosystems of South America and reforestation with native Polylepis species has been highly recommended. Greenhouse bioassays were set up to determine the influence of three different soils on growth and phosphorous nutrition of Polylepis australis seedlings. Soils were collected from a grassland, a rare mature forest and a forest degraded due to repeated fires. We identified the arbuscular mycorrhizal fungi (AMF) present in the three soils and after 12 months we harvested the seedlings to evaluate root and shoot biomass, plant P content and root colonization by native AMF and dark septate endophytes (DSE). The soil inocula contained 26 AMF morphospecies. Grassland inoculum showed the highest AMF richness, and mature forest showed a different AMF community assembly from grassland and degraded forest inocula. Root biomass and root colonization were highest in seedlings inoculated with mature forest soil, meanwhile shoot biomass and plant P content were similar between all treatments. AMF colonization correlated negatively with DSE and root biomass was negatively correlated with DSE colonization, thus these fungal symbionts could be competing for resources. Our results indicate that AMF inoculum from the mature forest stand has the potential to improve P. australis performance, probably due to the dominance of Glomeraceae and Acaulosporaceae families. However, other soil microorganisms could be together with AMF in the natural inocula, affecting the growth response of P. australis seedlings. Future studies evaluating the effect of these inocula under field conditions should be carried out.     

Growth of Nursery-grown Bamboo Inoculated with Arbuscular Mycorrhizal Fungi and Plant Growth Promoting Rhizobacteria in two Tropical Soil Typeswith and without Fertilizer Application

A nursery experiment was conducted to assess the effect of bioinoculants (Glomus aggregatum, Bacillus polymixa, Azospirillum brasilense) on seedling growth promotion of bamboo (Dendrocalamus strictus (Roxb.) Nees.) in two soil types (alfisol, vertisol) with or without fertilizer application. Bamboo seedlings were grown in the presence or absence of bioinoculants either individually or in all combinations for 180 days in field soil under tropical nursery conditions. Shoot, rhizome and root length, dry masses, nutrient concentrations and arbuscular mycorrhizal (AM) colonized root lengths were determined at harvest. Under the experimental condition tested combined inoculation of AM fungi, PSB and A. brasilense resulted in maximum growth response both under fertilized and unfertilized conditions in both soil types. Fertilizer application enhanced the efficiencies of N, P and K uptake, whereas reduced their usage efficiencies. Though soil type did not affect microbial inoculation response, fertilizer application significantly affected plant response to microbial inoculation.     

喜树育苗和接种菌根菌试验

用苏格兰球囊菌 [Glomuscaledonium (Nicol&Gerd .)Trappe&Gerd .]和地表球囊 [Glomusversiforme (Karsten)Berch]菌种接种喜树幼苗。试验结果表明 :喜树幼苗根均可与两种菌种菌形成菌根 ,接种前者的苗木菌根感染率为 5 3% ,接种后者的苗木菌根感染率为 4 0 % ,非接种苗木 (对照 )的感染率 6 .7%。接种菌根菌后的苗木总生物量、根茎比及根系长度和地径有所提高 ,反映了 2个菌种均促进了喜树幼苗的生长 ,但对幼苗高生长的促进作用不大。     

Selection of efficient VA mycorrhizal fungi for Casuarina equisetifolia—second screening

An investigation was carried out to screen and select efficient vesicular arbuscular mycorrhizal (VAM) fungi for inoculating the forest tree species, Casuarina equisetifolia. The seedlings were inoculated with 10 different VAM fungi, obtained from various sources. Inoculated seedlings generally had greater plant height, stem girth, biomass and P content than uninoculated plants. They also had more mycorrhizal root colonization and spore numbers in root zone soil. C. equisetifolia seedlings responded best (in biomass) to inoculation with Glomus mosseae (Nicolson and Gerdemann) Gerdemann and Trappe, closely followed by Acaulospora laevis Gerdemann and Trappe and G. fasciculatum (Thaxter Sensu Gerdemann) Gerdemann and Trappe; all the three being statistically on par with each other.     

丛枝菌根对喜树幼苗的生长效应

2005年2月精选喜树种子培养无菌根幼苗,生长90天以后分别接种3种丛枝菌根真菌,即蜜色无梗囊霉(Acaulospora mellea)、透光球囊霉(Glomus diaphanum)和弯丝硬囊霉(Sclerocystis sinuosa),探讨了菌根真菌对喜树幼苗株高、生物量以及氮、磷吸收的影响。结果表明,丛枝菌根的形成显著促进了菌根幼苗的高生长和生物量的积累,对喜树幼苗氮素营养的吸收影响不大,但却有利于喜树幼苗对磷素营养的吸收。从植株高度和生物量来看,菌根幼苗优于无菌根幼苗,蜜色无梗囊霉菌根幼苗尤为突出,分别达到无菌根幼苗(CK)的1.2和1.6倍,差异显著。丛枝菌根的形成对喜树幼苗氮素营养的吸收影响不大。从全株的氮含量来看,菌根幼苗与无菌根幼苗相近,只有在根、茎和叶片中Am菌根幼苗的氮含量才有明显变化,而透光球囊霉和弯丝硬囊霉菌根幼苗与无菌根幼苗之间则没有显著差异。丛枝菌根的形成总体上促进了喜树幼苗对磷素营养的吸收,并且主要体现在根的磷含量上。与无菌根幼苗比,所有菌根幼苗根的氮、磷分配比例增加,而茎和叶片的氮、磷分配比例减少。图2表2参13。     

Source of mycorrhizal inoculum influences growth of Faidherbia albida seedlings

Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on different land uses.We quantified the growth and nutrient uptake of F.albida seedlings inoculated with AM from different sources.These efforts were based on soil and fine root samples from the rhizosphere soils of F.albida trees.AM root colonization was determined using the gridline intersect method.Spores were extracted by the wet sieving and decanting method and identified to genus level.The seedling experiment had a completely randomized onefactorial design with four treatments and five replications.Faidherbida albida seedlings were grown in a greenhouse.All in situ F.albida trees were colonized by AM fungi.AM root colonization of F.albida trees was significantly higher(P<0.0086)in area exclosures than on lands used for grazing or cultivation.Spore abundance was significantly higher(P<0.0014)in area exclosures followed by cultivated land and grazing land.Glomus was the dominant genus in all land-uses.AM-inoculated F.albida seedlings grew better(P<0.05)than non-inoculated controls.Seedlings inoculated with AM from area exclosure had significantly(P<0.05)higher growth and nutrient uptake than those inoculated with AM from grazing and cultivated land.This emphasizes the importance of the native soil AM potential for better establishment of seedlings to achieve optimum plant growth improvement and assist in rehabilitation of degraded arid lands.     

Effect of the arbuscular mycorrhizae <Emphasis Type="Italic">Glomus fasciculatum</Emphasis> and <Emphasis Type="Italic">G. macrocarpum</Emphasis> on the growth and nutrient content of <Emphasis Type="Italic">Cassia siamea</Emphasis> in a semi-arid Indian wasteland soil

The effect of two arbuscular mycorrhizal (AM) fungi, Glomus fasciculatum and G. macrocarpum on shoot and root dry weights and nutrient content of Cassia siamea in a semi-arid wasteland soil was evaluated. Under nursery conditions, mycorrhizal inoculation improved growth of seedlings. Root and shoot dry weights were higher in mycorrhizal than non-mycorrhizal plants. The concentration of P, K, Cu, Zn and Na was significantly higher in AM inoculated seedlings than in non-inoculated seedlings. Mycorrhization led to decrease in alkalinity of the rhizosphere soil from pH 8.5 to 7.4. Under nursery conditions, the degree of mycorrhizal dependency increased with age of C. siamea seedling. On transplantation to the field, the survival rate of mycorrhizal seedlings (75%–90%) was higher than that of non-mycorrhizal seedlings (40%). Besides better survival rate, AM inoculation improved the growth performance of seedlings in terms of height and stem diameter. Among the two AM fungi used, the efficiency of Glomus macrocarpum was higher than that of G. fasciculatum under both nursery and field conditions.This revised version was published online in May 2005 with corrected page numbers.     

马褂木菌根真菌筛选和菌根化育苗效果研究

通过对马褂木菌根真菌种类调查,发现其为典型的内生菌根树种,分离和鉴定出地表球囊霉菌、苏格兰球囊霉菌和摩西球囊霉菌3种优势的共生菌根.利用马褂木福建武夷山种源苗木,通过接种效果比较,摩西球囊霉菌的促生效果最好,为马褂木的优良菌根菌种.利用摩西球囊霉菌进一步的菌根化育苗试验表明,马褂木菌根化育苗的促生效应明显,显著促进了苗木对N、P素的吸收利用,其苗高、地径、根长、侧根数和干物质积累量分别较未接种试验对照提高了42.41%、38.30%、12.90%、21.13%和137.78%.此外,菌根化育苗还能有效地改善基质的理化性质,其速效N和有效P含量分别较育苗前原始基质提高了158.48%和48.09%.     

Management of ectomycorrhizal symbionts associated to useful exotic tree species to improve reforestation performances in tropical Africa

? The objective of this review was to summarize scientific data on the symbiotic status of exotic tree species useful in tropical Africa, and to update reports about their growth improvement through microbial inoculations, especially ectomycorrhizal symbionts.

? The studies reviewed microbial symbionts associated to exotic tree species belonging to Myrtaceae, Pinaceae, Casuarinaceae and Leguminosae. In their native areas, these trees are associated either with ectomycorrhizal (ECM) fungi (e.g. Pinaceae) or both ECM and arbuscular mycorrhizal (AM) fungi (e.g. Eucalyptus), or sometimes as in Casuarina and Acacia with three coexisting symbionts (nitrogen fixing bacteria, ECM and AM fungi). In their new habitats, using highly efficient mycorrhizal fungi, controlled mycorrhization experiments have pointed out the importance of root symbionts in establishment and growth of exotic tree species such exotic pines or Australian acacias.

? Since the challenge in sylviculture and reforestation was to determine the best compromise between symbiotic compatibility and efficiency of both partners under local soil constraints, further researches have to be encouraged to elucidate the complexity of these tree symbioses in terms of diversity, interaction and effectiveness of their symbiotic partners for their better exploitation in reforestation programmes.

     

我国南方桉树人工林菌根合成及其多样性研究(英文)

对我国南方部分地区桉树人工林菌根真菌资源和菌根类型进行了调查 .对采自广东、云南 15个桉树林地的根系样品进行了显微观察 ,结果证实了在自然土壤中桉树能形成不同类型的菌根 ,检查的根样在不同程度上均有菌根菌的感染 .其中 ,有 4个人工林的根系样品AM感染率在 50 %以上 ,另有 4个根样ECM感染根段长超过 50m .调查发现林分年龄大小对菌根形成及菌根类型有一定的影响 ,表现在幼林及过熟林菌根感染率均较低 ,而 4～ 7年生按树林菌根感染率相对较高 ,在同一根系上AM与ECM菌间存在一定的竞争性 .在菌根菌资源方面 ,从总体上来说 ,我国南方菌根菌资源较少 ,尤其是ECM菌 .调查结果表明 ,我国南方桉树人工林根际土壤中有AM菌 2 8种 ,隶属于 4个属 ,其中以球囊霉属真菌最多 ,占 6 4 % ;地球囊霉在所采集的土样中出现的频度最高 .南方 15个桉树人工林中发现有 17种ECM菌 ,隶属 10个属 ,其中彩色豆马勃、多根硬皮马勃、光硬皮马勃等菌种在两广地区许多桉林中较常见 ,云南地区则多以黄须腹菌、硬皮马勃等菌较多 .这些ECM菌通常生长于松树林中 ,能否与引进的桉属树种形成较好的菌根还有待于进一步研究 .本文对自然条件下混合菌根的形成及真菌间的竞争关系进行了讨论     

广东清远石灰岩3个植物群落菌根及土壤AMF孢子多样性

以广东省清远市清新县石灰岩山区风水林、次生草坡和旱作耕地的退化植被群落为主要研究对象,比较研究了3个植物群落常见植物的菌根感染率和根际土丛枝型菌根真菌(AMF)孢子的密度和丰富度。结果如下:在所检测的29种常见植物中,除凹头苋(Amaranthus blitum)外,其余植物均具有典型的丛枝型菌根结构;次生草坡植物的菌根感染强度和频度均较高,风水林次之,旱作耕地杂草的菌根感染强度和频度相对较低;在3个植物群落土样中共分离出70种AMF孢子,以球囊霉属(Glomus)最为丰富,无梗囊霉属(Acaulospora)次之;林相保护较完整、植物较丰富的风水林拥有最丰富的AMF孢子类型和最高的密度,而结构退化、物种贫乏的次生草坡和旱作耕地中的AMF孢子类型少,密度也明显降低。研究表明植物群落的物种多样性与其根际土AMF孢子丰富度和多样性具有密切的联系。     

Application of mycorrhizal roots improves growth of tropical tree seedlings in the nursery: a step towards reforestation with native species in the Andes of Ecuador

Most tree species in tropical mountain rain forests are naturally associated with arbuscular mycorrhizal fungi. Previous studies in southern Ecuador of 115 tree species revealed that only three species were not associated with arbuscular mycorrhizal fungi. Seedlings of tropical tree species raised in the nursery may need to be associated with arbuscular mycorrhizal fungi to survive transplantation shock in higher numbers. Methods for establishing plantations with native tree species are not yet established for Ecuador. Thus, we investigated the feasibility of using mycorrhizal roots of seedlings of Inga acreana, Tabebuia chrysantha, Cedrela montana and Heliocarpus americanus that had trapped mycorrhizal fungi from forest humus in the nursery to inoculate C. montana and H. americanus with native arbuscular mycorrhizal fungi. Inoculation with either a mixture of mycorrhizal roots from the four species or only with mycorrhizal roots from the same tree species were compared with effects of moderate fertilization. Assessment of plant growth and mycorrhizal status of 6-months-old Cedrela montana and Heliocarpus americanus revealed an improvement in growth and diverse associated fungi through mycorrhizal root inoculation in comparison with moderate fertilization. Moderate fertilization did not suppress mycorrhization.     

Influence of arbuscular mycorrhizae and phosphate fertilization on shoot apical growth of micropropagated apple and plum rootstocks

We studied the effects of phosphate fertilization and inoculation with the arbuscular mycorrhizal fungi Glomus mosseae (Nicol. and Gerd.) Gerdmann and Trappe, Glomus intraradices Schenck and Smith or Glomus viscosum Nicolson on shoot apical growth of plantlets that had been micropropagated from MM 106 apple (Malus pumila L.) and Mr.S. 2/5 plum (Prunus cerasifera Ehrh.) rootstocks. Unfertilized and non-mycorrhizal plantlets showed no apical growth during the post in vitro acclimation phase, whereas P fertilization induced early resumption of shoot apical growth. Growth enhancement and percentage of actively growing apices of mycorrhizal-inoculated plantlets were comparable to those obtained in plantlets fertilized with P. Furthermore, tissue P concentrations of mycorrhizal plantlets were similar to those of plantlets fertilized with P. We conclude that mycorrhizal inoculation can be used as a biotechnological tool to overcome blocked apical growth and to reduce chemical inputs, especially P inputs, to micropropagated fruit trees.     

山地木麻黄菌根菌的筛选和接种效应的研究

利用3个内生菌根菌(AMF)和6个外生菌根菌(ECMF)接种山地木麻黄苗,测定小苗的树高、根长、地径、地上干质量、地下干质量和总生物量,并在干旱胁迫下测定小苗的保存率.结果表明:接种内、外生菌根菌后都能极显著地促进山地木麻黄苗期的生长;山地木麻黄对供试的AMF和ECMF菌根都属于中等强度或较弱的依赖性;山地木麻黄接种菌根菌后对地上部分(苗高、地径和地上干质量)生长的促进作用比地下部分(根长和地下干质量)要大;在供试的9个菌根菌种和菌株中,AMF比ECMF更能提高山地木麻黄的抗旱力;筛选出菌根效应较好的菌根菌有:苏格兰球囊霉90068、苏格兰球囊霉90036、地表球囊霉9004、黄硬皮马勃0207、蜡蘑E439,可在山地木麻黄苗期接种应用.     

Growth response of three native timber species to soils with different arbuscular mycorrhizal inoculum potentials in South Cameroon: Indigenous inoculum and effect of addition of grass inoculum

After tropical forest disturbance, mycorrhizal inoculum could be insufficient. Increasing mycorrhizal density through inoculum addition is then crucial for successful regeneration of deforested lands. Greenhouse bioassays were set up to determine the effectiveness of native arbuscular mycorrhizal fungi in soils from different disturbance stages on the growth of three important timber species, Terminalia superba, Distemonanthus benthamianus, and Entandrophragma utile. Soils were collected from late and early successional forest stands, fields of food crops, fallow of Chromolaena odorata, skid trails, bare soil landings, and landings with the pioneer tree Musanga cecropioides. These soils were used to grow seedlings without or with addition of an inoculum collected under the grass Paspalum conjugatum. The extent to which seedlings responded to indigenous inoculum and inoculum addition varied with tree species and with mycorrhizal inoculum potential. After inoculum addition, Terminalia strongly increased root colonization with a small increase in shoot dry weight and Distemonanthus hardly increased root colonization but showed a strong increase in shoot dry weight. Entandrophragma increased both root colonization and shoot dry weight. Plant biomass was lower in soils with low inoculum potential such as late successional stands, skid trails, and both kinds of landings; the mycorrhizal inoculation effect was then large. Plant biomass was high in agricultural fields and fallow; mycorrhizal inoculation effect was sometimes even negative. These data indicate that low inoculum might limit plant re-establishment after disturbance and that mycorrhizal inoculation has a potential for improving seedling establishment on deforested land.     

杉木林地土壤微生物研究进展

杉木是我国主要造林树种之一,具有生长快、产量高、材质好的优点。土壤微生物与杉木林地土壤理化性质、土壤肥力以及植物根系之间有密切的关联。文中概述了不同林分条件下杉木林地土壤微生物的群落特征及其与土壤质量之间的响应机制,尤其是与植物根系共生关系方面的研究进展,以期为实现杉木林质量的精准提升提供理论参考。天然林和阔叶林较杉木人工林有更丰富的微生物群落,在杉木林生长发育过程中,中龄阶段各微生物指标最低。杉木林土壤微生物群落组成、生物量和活性等均与土壤酸碱性、通气状况、养分含量等存在密切的响应关系。杉木林菌根真菌主要属于球囊霉属,国内对杉木林下菌根真菌的研究仍处于初级阶段。未来土壤微生物的研究热点包括土壤微生物的时空演变规律、土壤微生物在提升土壤肥力上的机理和途径、菌根真菌在土壤养分高效利用中的机制等。     

陕西省咸阳地区林木VA菌根真菌资源调查

通过对陕西省咸阳地区16种林木VA菌根研究,从根际土壤中分离鉴定出VA菌根真菌17种。其中无梗囊霉属1种,球囊霉属16种,球囊霉属为广谱性菌根真菌,摩西球囊霉、地表球囊霉,地球囊霉为常见种,本文还分析了VA菌根真菌与宿主植物的选择性及其分布规律。     

Cytokinins in the root pressure exudate of Citrus jambhiri Lush. colonized by vesicular-arbuscular mycorrhizae

The influence of vesicular-arbuscular mycorrhizal (VAM) symbiosis on the transport of cytokinins from the root to the shoot of Citrus jambhiri Lush. seedlings inoculated with cultures of Glomus etunicatum (Becker and Gerd.), G. fusciculatum (Thaxt.) Gerd. and Trappe, or G. mosseae (Nichol. and Gerd.) was investigated. Cytokinins collected from root exudates over a 90-day period were analyzed by high-performance liquid chromatography, mass spectrometry and a bioassay. The flux of cytokinins was independent of root exudate flux. Seedlings inoculated with G. fasciculatum or G. mosseae yielded a greater flux of zeatin, dihydrozeatin and zeatin riboside than non-inoculated seedlings. The flux of zeatin riboside was significantly greater than the flux of zeatin in seedlings inoculated with VAM symbionts. Vesicular-arbuscular mycorrhizal relationships apparently contributed to, or influenced, the export of cytokinins from the root. The elevated cytokinin flux of inoculated seedlings was associated with improved tissue phosphorus nutrition and a significant increase in seedling biomass.