蓝桉和尾叶桉混合菌根研究 Ⅰ.菌根合成及真菌间的相互作用

采用蜡磨菌与ＶＡ 菌根真菌分别对蓝桉和尾叶桉进行单接种或混合接种,研究结果表明,两种菌根类型的真菌均能在桉树苗木根系上成功地定殖,分别合成了外生菌根、ＶＡ 菌根和混合菌根,证实了桉树不仅是菌根营养型树种,而且能形成多种菌根类型。ＶＡ 菌根感染率在接种初期较高,但随时间的推移有降低的趋势;而外生菌根菌初期合成菌根的速度较慢,但单位长度根段内菌根根尖数目有明显增加的趋势。与单接种ＶＡ菌根真菌苗木相比,外生菌根真菌抑制了ＶＡ 菌根菌在根系上的进一步侵染,体现在较低的ＶＡ 菌根感染率;而外生菌根菌显示出了较强的竞争能力,并能在接种后９ 周时开始形成子实体。在混合菌根中,外生菌根有逐步替代ＶＡ 菌根的发展趋势,两种类型的菌根真菌间存在一定的竞争性作用关系。基质磷（Ｐ）素水平对菌根的形成也有一定的影响     

蓝桉的尾叶桉混合菌根研究：Ⅰ.菌根合成及真菌间的相互作用

采用蜡磨菌与ＶＡ菌根真菌分别对蓝桉和叶桉进行单接种或混合接种，研究结果表明，两种菌根类型的真菌均能在桉树苗木根系上成功地定殖，分别合成了外生菌根、ＶＡ菌根和混合菌根，证实了桉树不仅是菌根营养型树种，而且能形成多种菌根类型。ＶＡ菌根感染率在接种初期较高，但随时间的推移有降低的趋势；而外生菌根菌初期合成菌根的速度较慢，但单位长度根段内菌根根尖数目有明显增加趋势。与单接种ＶＡ根真菌苗木相比，外生菌根真菌     

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     

外生菌根真菌促进油松人工幼林生长试验

应用从不同林型下分离获得的外生菌根真菌纯培养菌株中的优良菌种,对油松人工林进行菌剂混合接种试验。结果表明:采用外生菌根真菌对油松林接菌,能使土壤微生物种群数量发生变化;接菌后的土壤中的细菌、真菌、放线菌总数比对照有明显的增加,其中真菌增加558.7%。接菌后的油松菌根侵染率为75%,对照为20%;采用外生菌根真菌对油松林接菌,能够提高其抗病力,增强抗旱性,促进林木的生长。对连续2年接种菌剂的油松幼林调查表明,施用菌剂的油松与对照相比,其地径、树高均有显著增加,树高增长46.1%,地径增长41.3%。所以说外生菌根真菌作为一项生物接种技术,对提高油松林的抗病力,增强抗旱性,促进林木的生长具有重要的作用。     

蓝桉和尾叶桉混合菌根研究Ⅱ.混合菌根的接种效应

接种苗木在生长量和生物量上均表现出极其显著的生长优势,ECM真菌蜡蘑菌单接种及其与4种VA菌根菌剂混合接种,对苗木生长的促进作用尤为显著。在接种后16周时,与对照苗相比,蓝桉和尾叶桉接种苗木的高生长量最大增幅分别为28.86%(LS)和86.65%(LG);两种桉树地上部分平均干质量最大增幅分别为129.93%(LS)和133.34%(L),地下部分分别为119.93%(LF)和174.83%(LG)。桉树对不同菌根菌及其组合的菌根依赖性表现出很大的差异,对混合接种的真菌组合有相对高的菌根依赖性,而对土壤菌剂依赖性很小。菌根感染与苗木生物量间有显著的相关性。试验结果还证实了P素对桉苗生长的促进作用,P素水平对菌根的接种效应有一定的影响。     

毛白杨苗期VA菌根菌与外生菌根菌接种的研究

1998～1999年在田间条件下布置了毛白杨VA菌根(包括根内球囊霉菌和单孢球囊霉菌)与外生菌根硬皮马勃混合接种试验.结果表明接种菌根菌对毛白杨苗高生长量有促进作用,且以根内球囊霉菌作用最明显,单孢球囊霉菌处理次之,硬皮马勃处理最差.水涝大大降低人工接种菌根菌的效果,严重影响VA菌根和外生菌根菌单独接种及混合接种的效应,根内球囊霉菌甚至会抑制毛白杨苗木的高生长,VA菌根和外生菌根间的负交互作用也不对苗高生长产生影响.菌根真菌的感染率随时间变化出现较大的波动和变化.     

马占相思菌根调查及利用

马占相思菌根调查及人工接种结果表明：马占相思在自然界能形成外生菌根及VA菌根。在贫瘠的立地条件下，外生菌根的子实体多；在较肥沃的立地条件下，外生菌根的子实体少，优势外生菌根菌是多根硬皮马勃菌（Sclerioerma polyrhium)。马占相思对VA菌有较强的选择性和其特定的优势VA菌根菌，即从马占思根部分离的VA菌。用优势外生菌根菌 及优势VA菌根菌对马占相思苗木进行接种，都能形成菌根，且都能显著地提高马占思的生长。马占思优势VA菌接种效果优于多种硬皮马勃菌。     

菌根菌接种对白皮松生长影响试验初报

通过对白皮松小树和古树的共生菌根菌的分离鉴定,并采用彩色豆马勃菌剂进行接种试验.结果表明,与白皮松共生的菌根菌均为外生菌根菌,不同生长地点的白皮松的共生菌根菌数量和种类不完全相同,但多数种类相同;接种彩色豆马勃菌剂能显著地促进白皮松小树树高的生长,但对地围的促进作用不显著;对白皮松古树接种彩色豆马勃菌剂,能显著地促进新发枝条和针束的生长,从而促进古树复壮.     

马占相思菌根调查及利用

马占相思菌根调查及人工接种结果表明 :马占相思在自然界能形成外生菌根及VA菌根。在贫瘠的立地条件下 ,外生菌根的子实体多 ;在较肥沃的立地条件下 ,外生菌根的子实体少 ,优势外生菌根菌是多根硬皮马勃菌 (Sclerioermapolyrhium)。马占相思对VA菌有较强的选择性和其特定的优势VA菌根菌 ,即从马占相思根部分离的VA菌。用优势外生菌根菌及优势VA菌根菌对马占相思苗木进行接种 ,都能形成菌根 ,且都能显著地提高马占相思的生长。马占相思优势VA菌接种效果优于多根硬皮马勃菌     

桉树菌根的研究

室外调查结果表明,华南地区的桉树菌根虽然较贫乏,但仍发现有9种外生菌根真菌。在平均气温20℃以上,相对湿度80%以上及有相当降雨量的条件下,菌根菌子实体可大量产生;不同立地条件对外生菌根的分布有密切关系。使用5种不同的接种方法对桉树幼苗进行接种,均有较好的接种效果,其中,VA 菌根土接种,孢子菌剂接种,罐栽菌木接种及 Mycobeads 接种均有较好的效果,而且方法简单,使用方便。一年生桉树接种苗比对照株高生长平均增加14.3%;胸径平均增加13.67%;处理区一年生幼树蓄积比对照区每公顷增加5.12m~3,增加39.9%,投入与产出比为1∶15。     

Analysis of Norway spruce dieback phenomenon in Latvia – a belowground perspective

In 2010, dieback of Norway spruce (Picea abies) was observed in Latvia. As mostly stands on seasonally or permanently water-saturated soils were damaged, we hypothesized that the recorded foliar damage might be associated with belowground factors. We established 48 sample plots in stands with damage symptoms for soil parameter evaluation and fine root sampling to determine the number of fine roots in different growth stages and to describe the associated fungal community. Among sample plots on organic soils, there were fewer viable older fine roots and greater number of dead fine roots in more damaged sites than in less damaged. These root parameters were significantly correlated with higher groundwater level and soil pH. The fungal community was dominated by ectomycorrhizal (ECM) species (the most common was Tylospora asterophora), the endophyte Oidiodendron maius and saprotrophic species Cryptococcus magnus. Saprotrophic species had higher abundance in more damaged sites, suggesting a shift in fungal communities from ECM fungi. In conclusion, the results of this work suggest Norway spruce root system response to short-term climatic stress, which should be considered when planning spruce forest management, especially on organic soils with a high groundwater level.     

Ectomycorrhizal fungal communities of Dipterocarpus alatus seedlings introduced by soil inocula from a natural forest and a plantation

We attempted to introduce ectomycorrhizal (ECM) fungi onto seedlings of Dipterocarpus alatus (Dipterocarpaceae) by soil inocula collected from tree stands of D. alatus. Top soils collected from beneath the trees of D. alatus in a dry evergreen forest and a 15-year-old plantation were inoculated onto germinating seeds of D. alatus. After 7 months of seedling cultivation, ECM fungal communities in the seedlings were investigated based on the sequences of ITS rDNA. The ECM fungi detected were divided into 19 phylotypes by molecular analysis. Most of the phylotypes were identified as ECM fungal taxa, i.e., Clavulina, Laccaria, Lactarius, Tomentella, Pyronemataceae, and Tricholomataceae. Accordingly, we can confirm that soil inoculation is a simple method to induce ECM formation with diverse fungi in pot cultured seedlings, which would be useful for introducing diverse ECM fungi to dipterocarp plantations.     

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.     

High diversity of ectomycorrhizal fungi associated with Arctostaphylos uva-ursi in subalpine and alpine zones: Potential inoculum for afforestation

Arctostaphylos uva-ursi plant associations have long been suggested to be a suitable location for afforestations, but systematic studies on the observed beneficial effect are still missing in Alpine areas. In this study we address the question which ectomycorrhizal (ECM) fungal communities exist in Austrian alpine and subalpine Arctostaphylos habitats, and if they persist in A. uva-ursi stands even hundred of years after disappearance of trees in these areas. The diversity of fungal communities associated with A. uva-ursi was assessed in four study sites (1800–2450 m a.s.l.) in the Central European Alps of Tyrol (Austria). Three approaches were applied: (i) collecting and identifying fungal fruit bodies; (ii) studying the arbutoid mycorrhiza morphotypes of A. uva-ursi; (iii) molecular identification of the most common arbutoid morphotypes. The detected diversity of ECM fungal species was very high (99 taxa), and the occurrence of e.g. Boletus, Cantharellus, Suillus, Tricholoma, Russula spp. in sites that have been treeless for centuries is especially remarkable. Fruit bodies of 82 fungal species were found in association with A. uva-ursi, 63 of them were ECM. Seventy arbutoid morphotypes were detected on 2072 mycorrhized root tips, and 39 taxa of basidiomycete mycobionts were identified with molecular methods. Twelve Cortinarius spp. clearly dominated the mycobiont species richness, followed by nine spp. of Thelephoraceae and four spp. of Boletaceae. Most mycobionts of A. uva-ursi were generalists, but fungal taxa (e.g. Lactarius deterrimus and Suillus spp.) known to be specifically associated with other host plants were also detected. We therefore consider A. uva-ursi as a “non-selective” host, providing mycorrhizal inoculum of highly specialized and effective mycorrhizal fungi for afforestation. This explains why A. uva-ursi plant associations represent suitable locations for forest regeneration and afforestation, especially in the harsh environmental conditions of subalpine and alpine sites.     

Mycorrhizal formation of nine ectomycorrhizal fungi on poplar cuttings

In order to discover which ectomycorrhizal-(ECM) fungi have better growth-promoting effects on poplars, cuttings from four poplar species were inoculated with nine species of ECM fungi by three methods. We investigated the status of mycorrhizal formation and the effects of these fungi on the growth of the poplars. The results show that Xrocomus chrysentero (Xc), Boletus edulis (Be), Pisolithus tinctorius (Pt) and Laccaria amethystea (La) formed clear ectomycorrhizal symbiosis with the poplar seedlings. Among these four ECM fungi, Xc had the greatest ability to develop mycorrhizae with all four poplar species. Be shows a greater ability to form mycorrhizae with Populus deltoides Bartr cv. ‘Lux’ (Poplar I-69). Pt and La had relatively weaker abilities of colonization. The other five ECM fungal species, i.e., Scleroderma luteus (Sl), Leccinum scabrum (Ls), Boletus speciosus (Bs), Calvatia craniiformis (Cc) and Rhizopogen luteous (Rl) could not easily form mycorrhizae with poplar seedlings grown in sterilized substrates, but could do so in non-sterilized soil. With the method of drilling and injecting liquid inoculum, a simple operation, the mycorrhizal infection rates were higher than with the other two methods, applying solid inoculum as fertilizer at the bottom of the pots and dipping roots in the inoculum slurry. P. simonii Carr. formed mycorrhizae with most of the nine ECM fungi. P. x euramericana (Dode) Guinier cv. ’san Martino’ (Poplar I-72) and P. deltoids Harvard x P. deltoids Lux (Poplar NL-351) had the highest compatibility with Pt. Poplar I-69 shows the highest compatibility with Xc. The study indicates that the optimal ECM fungi for poplars I-69, I-72 and NL-351 were Be, Xc and Pt, respectively. The optimal fungi for P. simonii Carr. were Xc and Be. These ECM fungi promoted the growth of the poplar seedlings significantly. __________ Translated from Journal of Nanjing Forestry University (Natural Sciences Edition), 2007, 31(6): 29–33 [译自: 南京林业大学学报(自然科学版)]     

Nursery inoculation of Eucalyptus seedlings in Western Australia and Southern China using spores and mycelial inoculum of diverse ectomycorrhizal fungi from different climatic regions

A large-scale ectomycorrhizal (ECM) fungus inoculation program was conducted in plantation forest tree nurseries in Australia and China over a period of 2 years. These experiments used a wide diversity of fungi (90 isolates belonging to 23 genera), most of which were obtained from Australian eucalyptus plantations or forests. These trials compared the effectiveness of mycelial slurries (homogenised liquid fungal cultures) and spore suspensions (ground dried fruit bodies) as inoculum forms in nurseries with widely differing management regimes. The success rate of inoculation was moderate, regardless of nursery management regime (38% overall). However, there were substantial differences in overall performance between fungal genera, with agaricoid genera, such as Descolea and Laccaria, and hypogeous (truffle-like) fungi performing better than sequestrate genera, such as Pisolithus and Scleroderma. Comparison of congeneric fungal isolates from different climatic regions did not show significant differences in the performance of fungi from regions where climatic conditions were most similar to nursery conditions relative to those from disparate climatic regions (tropical, temperate, or mediterranean). There was a higher overall success rate for inoculation with spore suspensions (49%) than for mycelial slurries obtained from liquid cultures (35%). Spore-based inoculum was also easier to use and much less expensive to produce than mycelial slurries. It is recommended that future studies investigate the use of mixtures of fungi and attempt to optimise spore germination to increase the reliability of eucalypt seedling nursery inoculation.     

Changes and effects of a natural fire on ectomycorrhizal inoculum potential of soil in a Pinus halepensis forest

A typically mediterranean forest of Pinus halepensis wass tudied. During two years following fruiting fungal species, the number of sclerotia in soil, and the percentages and types of mycorrhizas present were determined. In burned stands ascomycetes were typical carbonicolous while basidiomycetes were strongly reduced. The sclerotia extracted from soils were mainly Cenococcum. The number of sclerotia in burned stands was greater than in unburned stands. Seven types of mycorrhizas were recognized in Pinus halepensis root systems from bioassays: Cenococcum, E-strain, Rhizopogon, Suillus, Tuber, Xerocomus, and one non-identified. Nearly 100% of the roots were colonized by mycorrhizal fungi. Ectendomycorrhizas represented 50–90% of the total number. The predominant type is ectendomycorrhizas formed by ascomycetes included in the E-strain group.