茶树品种、叶片生育期和茶叶化学成份对内生真菌的影响

通过茶树品种、叶片龄期及叶片化学成份对茶树内生真菌分布影响的研究,发现:(1)在供试的4个茶树品种中,黄旦的内生真菌分离频率达100%,而福云六号只有7.5%,表明茶树品种不同或遗传背景不同,其叶片中内生真菌的发生存在明显差异。(2)随着茶树叶片的成熟,叶片中内生真菌的种类与数量逐渐增多,与叶片龄期呈正相关,叶片龄期影响茶树内生真菌的种群结构。(3)不同龄期叶片水浸提液对Colletotrichum、Pestalotiopsis、Guignardia三种茶树上的主要内生真菌的生长产生不同的影响;在PDA培养基中添加15%的茶多酚,对此3种内生真菌均有一定的抑制作用,但抑制程度有所不同,表明茶树叶片的化学成份是影响内生真菌分布的重要因素之一。     

量天尺根部内生真菌的多样性

为了解不同量天尺（火龙果）品种根部内生真菌菌群组成及多样性,采集GHL-1、GHL-2、GHL-3、ML-1和DL 5个量天尺品种健康根部样品,进行内生真菌分离,采用形态观察和ITS序列分析相结合的方法进行鉴定、归类。共分离得到内生真菌菌株117株,总体分离率为25.71%,分别隶属于13个属,其中Trichoderma、Fusarium、Chaetomium和Phoma为量天尺内生真菌的优势种群,分别占总菌株数的24.79%、35.04%、10.26%和10.26%;不同量天尺品种内生真菌的结构和组成存在一定差异,GHL-2、GHL-3和DL 3个品种中分离频率最高的内生真菌类群为Fusarium,GHL-1和ML-1分离频率最高的类群为Trichoderma;多样性分析结果反映出不同量天尺品种内生真菌菌群的多样性指数、丰富度指数和均匀度指数水平存在差异,其中GHL-2的3项指数均为最高。表明品种差异对内生真菌的组成和多样性均有影响。     

The foliar endophytic fungal community composition in Cirsium arvense is affected by mycorrhizal colonization and soil nutrient content

Foliar fungal endophytes are ubiquitous, but understudied symbionts of most plant species; relatively little is known about the factors affecting their occurrence, diversity and abundance. We tested the effects of soil nutrient content and arbuscular mycorrhizal (AM) colonization on the occurrence of foliar endophytic fungi in Cirsium arvense in two field studies. In the first study, we assessed relationships between soil moisture, organic matter, carbon and nitrogen content and plant water, nitrogen and carbon content and AM colonization and the occurrence of foliar endophytic fungal species. In the second study, we manipulated soil nutrient content and AM colonization of potted seedlings and identified differences in endophytic fungal species composition of the leaves and stems. The results reveal that endophytes can occur either more or less frequently, depending on soil nutrient and plant water content and AM colonization. We propose that these patterns were the result of differences in fungal growth responses to nutrient availability in the leaves, which can be affected by resources obtained from the soil or symbiotic fungi in the roots.     

Contrasting preferences of arbuscular mycorrhizal and dark septate fungi colonizing boreal and subarctic Avenella flexuosa

Arbuscular mycorrhizal (AM) and dark septate endophytic (DSE) fungi are ubiquitous in grass roots, but their colonizations may vary according to latitudinal gradient and site conditions. We investigated how vegetation zone (boreal vs. subarctic), humus thickness, and site openness affect root fungal colonizations of the grass Avenella flexuosa. More precisely, we hypothesized that AM and DSE fungal colonizations would have different responses to environmental conditions such that AM fungi could be more common in boreal zone, whereas we expected DSE fungi to be more affected by the amount of humus. We found site openness to affect AM and DSE fungi in a contrasting manner, in interaction with the vegetation zone. AM colonization was high at open coastal dunes, whereas DSE fungi were more common at forested sites, in the boreal zone. Humus thickness affected AM fungi negatively and DSE fungi positively. To conclude, the observed AM and DSE fungal colonization patterns were largely contrasting. AM fungi were favored in seashore conditions characterized by thin humus layer, whereas DSE fungi were favored in conditions of higher humus availability.     

贵州栽培笃斯越橘DSE真菌、AM真菌与ERM真菌空间分布研究

为探明贵州省栽培笃斯越橘根系深色有隔内生真菌（dark septate endophytes,DSE）、丛枝菌根（arbuscular mycorrhiza,AM）真菌与欧石南菌根（ericoid mycorrhiza,ERM）真菌的定殖及地理分布情况,揭示共生真菌在栽培笃斯越橘生长中的地位,本研究在贵州省笃斯越橘主栽区麻江县、凤岗县和高坡乡分别选取主栽品种圆蓝、粉蓝、奥尼尔和莱格西的根样及根围土样,观测不同地区不同品种根样DSE真菌、AM真菌和ERM真菌的定殖结构和定殖率,并测定土样土壤理化性质,分析不同真菌与土壤因子相关性。结果表明,3个地区的4个笃斯越橘品种均有DSE真菌、AM真菌和ERM真菌定殖,栽培笃斯越橘能与3类真菌形成共生关系,平均定殖率分别为61.11%、25.55%和22.50%。DSE真菌定殖率：高坡（62.50%）>麻江（61.66%）>凤岗（59.16%）;AM真菌定殖率：凤岗（34.14%）>麻江（25.83%）>高坡（16.66%）;ERM真菌定殖率：高坡（35.00%）>凤岗（20.00%）>麻江（12.5%）。相关性分析表明,DSE真菌中的菌丝与微菌核的定殖率呈负相关,AM真菌的总定殖率及定殖强度与微菌核的定殖率呈极显著正相关,与DSE真菌菌丝的定殖率呈负相关。ERM真菌总定殖率与DSE真菌菌丝的定殖率及AM真菌定殖强度呈极显著正相关,与DSE真菌总定殖率呈显著正相关。土壤有效磷与DSE真菌和ERM真菌总定殖率呈显著正相关,与AM真菌定殖率呈显著负相关。土壤铵态氮与DSE真菌中微菌核结构定殖率及AM真菌定殖率呈极显著正相关,与ERM真菌定殖率呈极显著负相关。土壤pH值与DSE定殖强度呈显著负相关,与ERM定殖强度呈极显著正相关。本研究分析比较贵州省3个笃斯越橘种植基地不同品种栽培笃斯越橘DSE真菌、AM真菌和ERM真菌的定殖及其与土壤理化性质之间的相关性,为贵州省栽培笃斯越橘的管理和发展提供技术基础和理论依据。     

Genetic diversity for mycorrhizal symbiosis and phosphate transporters in rice

Phosphorus(P) is a major plant nutrient and developing crops with higher P-use efficiency is an important breeding goal.In this context we have conducted a comparative study of irrigated and rainfed rice varieties to assess genotypic differences in colonization with arbuscular mycorrhizal(AM) fungi and expression of different P transporter genes.Plants were grown in three different soil samples from a rice farm in the Philippines.The data show that AM symbiosis in all varieties was established after 4 weeks of growth under aerobic conditions and that,in soil derived from a rice paddy,natural AM populations recovered within6 weeks.The analysis of AM marker genes(AM1,AM3,AM14) and P transporter genes for the direct Pi uptake(PT2,PT6) and AM-mediated pathway(PT11,PT13) were largely in agreement with the observed root AM colonization providing a useful tool for diversity studies.Interestingly,delayed AM colonization was observed in the aus-type rice varieties which might be due to their different root structure and might confer an advantage for weed competition in the field.The data further showed that P-starvation induced root growth and expression of the high-affinity P transporter PT6 was highest in the irrigated variety IR66 which also maintained grain yield under P-deficient field conditions.     

Functional compatibility in cucumber mycorrhizas in terms of plant growth performance and foliar nutrient composition

Functional compatibility in cucumber mycorrhizas in terms of plant and fungal growth, and foliar nutrient composition from all possible combinations of six cucumber varieties and three species of arbuscular mycorrhizal (AM) fungi was evaluated. Measurements of foliar nutrient composition included N, P, K, Mg, Ca, Na, Fe, Zn, Mn and Cu. Growth of AM fungi was measured in terms of root colonisation, as examined with microscopy and the AM fungus biomarker fatty acid 16:1ω5 from both phospholipids and neutral lipids. Different responses of plant growth and foliar nutrient profiles were observed for the different AM symbioses examined. The AM fungus Claroideoglomus claroideum caused growth depression in association with four out of six cucumber varieties; Rhizophagus irregularis caused growth promotion in one of six cucumber varieties; whereas Funneliformis mosseae had no effect on the growth performance of any of the cucumber varieties examined. All three AM fungi markedly altered host plant shoot nutrient composition, with the strongest contrast observed between cucumber–R. irregularis symbioses and non‐mycorrhizal cucumber plants, independent of cucumber variety. On the other hand, AM fungal growth in roots differed between the three AM fungi, but was unaffected by host genotype. Strong build‐up of storage lipids was observed for R. irregularis, which was more moderate in the two other AM fungi. In conclusion, strong differential responses of cucumber varieties to inoculation with different AM fungi in terms of growth and shoot nutrient composition revealed high functional diversity in AM symbioses in cucumber plants.     

烟草根部内生真菌群落结构和功能特征

烟草内生真菌是烟田生态系统的重要组成,根系是烟草内生真菌重要来源途径。本研究通过高通量测序技术分析了5个品种的烟草根部内生真菌群落结构及功能特征。结果表明,烟草根部内生真菌群落多样性较低;粪壳菌纲Sordariomycetes、座囊菌纲Dothideomycetes、散囊菌纲Eurotiomycetes、伞菌纲Agaricomycetes及锤舌菌纲Leotiomycetes为主要菌群,肉座菌目Hypocreales、煤炱目Capnodiales和散囊菌目Eurotiales为优势真菌目,丛赤壳科Nectriaceae、小戴维霉科Davidiellaceae和发菌科Trichocomaceae为优势真菌科,未定义腐生菌和动物病原菌是主要的生态功能群,但不同品种之间的真菌群落组成和生态功能分布差异显著。本研究为进一步挖掘利用烟草内生真菌资源,阐明烟草内生真菌的生态功能提供了参考。     

Interactive effects of root endophytes and arbuscular mycorrhizal fungi on an experimental plant community

Plant-soil microbial interactions have moved into focus as an important mechanism for understanding plant coexistence and composition of communities. Both arbuscular mycorrhizal (AM) as well as other root endophytic fungi co-occur in plant roots, and therefore have the potential to influence relative abundances of plant species in local assemblages. However, no study has experimentally examined how these key root endosymbiont groups might interact and affect plant community composition. Here, using an assemblage of five plant species in mesocosms in a fully factorial experiment, we added an assemblage of AM fungi and/or a mixture of root endophytic fungal isolates, all obtained from the same grassland field site. The results demonstrate that the AM fungi and root endophytes interact to affect plant community composition by changing relative species abundance, and consequently aboveground productivity. Our study highlights the need to explicitly consider interactions of root-inhabiting fungal groups in studies of plant assemblages.     

Effects of Different Arbuscular Mycorrhizal Fungi on Physiology of <i>Viola prionantha</i> under Salt Stress

Arbuscular mycorrhizal (AM) fungi distribute widely in natural habits and play a variety of ecological functions. In order to test the physiological response to salt stress mediated by different AM fungi, Viola prionantha was selected as the host, the dominant AM fungus in the rhizosphere of V. philippica growing in Songnen saline-alkali grassland, Rhizophagus irregularis, and their mixtures were used as inoculants, and NaCl stress was applied after the roots were colonized. The results showed that V. philippica could be colonized by AM fungi in the field and the colonization rate ranged from 73.33% to 96.67%, and Claroideoglomus etunicatum was identified as the dominant AM fungi species in the rhizosphere of V. philippica by morphology combined with sequencing for AM fungal AML1/AML2 target. Inoculation with both the species resulted in the formation of mycorrhizal symbiosis (the colonization rate was more than 70%) and AM fungi significantly enhanced plants’ tolerance to salt stress of varying magnitude. Higher activity of antioxidant enzymes and augmented levels of proline and other osmoregulators were observed in AM plants. The content of MDA in CK was higher than that in the inoculations with the stress of 100, 200, and 250 mM. All indices except soluble protein content and MDA content were significantly correlated with AM fungal colonization indices. The analysis for different AM fungal effects showed that the mixtures and R. irregularis worked even better than C. etunicatum. These results will provide theoretical support for the exploration and screening of salt-tolerant AM fungi species and also for the application of AM-ornamental plants in saline-alkali urban greening.     

“Mini-community” simulation revealed the differences of endophytic fungal communities between the above- and below-ground tissues of Ephedra sinica Stapf

The microecology of endophytic fungi in special habitats, such as the interior of different tissues from a medicinal plant, and its effects on the formation of metabolites with different biological activities are of great importance. However, the factors affecting fungal community formation are unclear. This study is the first to utilize “mini-community” remodeling to understand the above phenomena. First, high-throughput sequencing technology was applied to explore the community composition and diversity of endophytic fungi in the above-ground tissues (Ea) and below-ground tissues (Eb) of Ephedra sinica. Second, fungi were obtained through culture-dependent technology and used for “mini-community” remodeling in vitro. Then, the effects of environmental factors, partner fungi, and plant tissue fluid (internal environment) on endophytic fungal community formation were discussed. Results showed that environmental factors played a decisive role in the selection of endophytic fungi, that is, in Ea and Eb, 93.8% and 25.3% of endophytic fungi were halophilic, respectively, and 10.6% and 60.2% fungi were sensitive to high temperature (33 °C), respectively. Meanwhile, pH had little effect on fungal communities. The internal environment of the plant host further promoted the formation of endophytic fungal communities.     

Seasonal and temporal dynamics of arbuscular mycorrhizal and dark septate endophytic fungi in a tallgrass prairie ecosystem are minimally affected by nitrogen enrichment

Root colonization by arbuscular mycorrhizae (AM) and dark septate endophytic (DSE) fungi in nitrogen amended and unamended mixed tallgrass prairie communities were analyzed monthly over two growing seasons. Roots were stained with Trypan blue and Sudan IV and fungal structures quantified using the modified magnified intersections method. Root length colonized (RLC) by DSE exceeded AM colonization during early part of the growing season. Fungal colonization varied among the years and was greater in 2003 than in 2002. Seasonal variation among the months within a growing season was observed in 2002 but not in 2003 for both AM and DSE. AM fungi were most abundant during the peak growing season of dominant C₄ vegetation while DSE were most abundant during the early part of the growing season. Hyperparasitism of AM hyphal coils by melanized septate fungi was frequently observed and increased with AM coil frequency. Although nitrogen amendment had altered the plant community composition, it had no impact on the colonization by AM or DSE fungi.     

广藿香内生真菌多样性及其对青枯菌的拮抗活性

【目的】对广藿香各部位内生真菌的类群结构及多样性进行系统分析,筛选出对青枯菌具拮抗活性的菌株。【方法】采用组织块分离法从广藿香健康植株的根、茎、叶中分离内生真菌,结合形态学和基于ITS-r DNA序列分析鉴定方法分析广藿香内生真菌的类群结构及多样性,并利用双层平板拮抗法筛选对青枯菌具有抑制活性的菌株。【结果】从广藿香中共分离获得313株内生真菌,隶属于30个属,其中链格孢属(占28.75%)、拟茎点霉属(占23.00%)和炭疽菌属(11.82%)为优势类群,此外还分离到炭皮菌属、弯孢聚壳属、Gibellulopsis、新萨托菌属、葡萄座腔菌属、篮状菌属等较为少见的类群。茎、叶内生真菌的定殖率和分离率明显高于根,而根部多样性指数为2.64,要高于茎(2.00)和叶(1.97);广藿香茎与叶、根与茎、根与叶之间的内生真菌相似性指数分别为0.35、0.20、0.19,均小于0.5,显示各部位之间的内生真菌组成不相似程度高。从313株广藿香内生真菌中通过拮抗实验筛选到16株对青枯菌有拮抗活性的菌株,其中GHXR07、GHXR27和GHXR29的拮抗活性尤为显著,分别被鉴定为Talaromyces sp.、Myrothecium roridum Tode和Talaromyces wortmannii(Kl?cker)Benjamin。【结论】广藿香内生真菌具有丰富的物种多样性且其类群分布具有一定的组织特异性,其中部分菌株对青枯菌具有明显的拮抗活性。     

Testing Potential Effects of Maize Expressing the Bacillus thuringiensis Cry1Ab Endotoxin (Bt Maize) on Mycorrhizal Fungal Communities via DNA- and RNA-Based Pyrosequencing and Molecular Fingerprinting

The cultivation of genetically modified (GM) crops has increased significantly over the last decades. However, concerns have been raised that some GM traits may negatively affect beneficial soil biota, such as arbuscular mycorrhizal fungi (AMF), potentially leading to alterations in soil functioning. Here, we test two maize varieties expressing the Bacillus thuringiensis Cry1Ab endotoxin (Bt maize) for their effects on soil AM fungal communities. We target both fungal DNA and RNA, which is new for AM fungi, and we use two strategies as an inclusive and robust way of detecting community differences: (i) 454 pyrosequencing using general fungal rRNA gene-directed primers and (ii) terminal restriction fragment length polymorphism (T-RFLP) profiling using AM fungus-specific markers. Potential GM-induced effects were compared to the normal natural variation of AM fungal communities across 15 different agricultural fields. AM fungi were found to be abundant in the experiment, accounting for 8% and 21% of total recovered DNA- and RNA-derived fungal sequences, respectively, after 104 days of plant growth. RNA- and DNA-based sequence analyses yielded most of the same AM fungal lineages. Our research yielded three major conclusions. First, no consistent differences were detected between AM fungal communities associated with GM plants and non-GM plants. Second, temporal variation in AMF community composition (between two measured time points) was bigger than GM trait-induced variation. Third, natural variation of AMF communities across 15 agricultural fields in The Netherlands, as well as within-field temporal variation, was much higher than GM-induced variation. In conclusion, we found no indication that Bt maize cultivation poses a risk for AMF.     

Fungal colonization of shrub willow roots at the forefront of a receding glacier

Shrub willows (Salix spp.) form associations with arbuscular mycorrhizal (AM), ectomycorrhizal (EM) and dark septate endophytic (DSE) fungi. Willow root colonization by these three types of fungi was studied on a deglaciated forefront of Lyman Glacier, Washington, USA. Root colonization was low; less than 1% of the root length was colonized by AM and 25.6% by DSE. EM colonized 25% of the root tips and 19.4% of the root length. AM and DSE colonization were not related to distance from the present glacier terminus or to canopy cover. EM colonization increased with distance from the glacier terminus based on gridline intercept data but not on root tip frequency data. Availability of propagules in the substrate was low, but numbers of propagules increased with distance from the glacier terminus. The EM communities were dominated by three ascomycetes showing affinity to Sordariaceae in BLAST analyses. Other frequent taxa on the glacier forefront included species of Cortinariaceae, Pezizaceae, Russulaceae, Thelephoraceae and Tricholomataceae. When occurrence of individual taxa was used as a response variable to canopy cover, distance from the glacier terminus, and their interaction, four different fungal guilds were identified: 1) fungi that did not respond to these environmental variables; 2) fungi that occurred mainly in intercanopy areas and decreased with distance from the glacier terminus; 3) fungi that were insensitive to canopy cover but increased with distance from the glacier terminus; 4) fungi that occurred mainly under willow canopies and increased with distance from the glacier terminus. We suggest that fungal colonization is mainly limited by fungal propagule availability. Environmental conditions may also limit successful establishment of plant-fungus associations. We propose that the four EM guilds partly explain successional dynamics. The initial EM community comprises fungi that tolerate low organic matter and nitrogen environment (first and second guilds above). During later community development, these fungi are replaced by those that benefit from an increased organic matter and nitrogen environment (third and fourth guilds above).     

Arbuscular mycorrhizal fungi associated with the Meliaceae on Hainan island, China

Species richness, spore density, frequency of occurrence, and relative abundance of AM fungi were determined in rhizosphere soil samples from nine tropical rainforest sites on Hainan island, south China, and the arbuscular mycorrhizal (AM) status of members of the Meliaceae was examined. All 28 plant taxa investigated (25 species including two varieties of 1 species and three varieties of another) were colonized by AM fungi. The mean proportion of root length colonized was 56% (range 10–95%). Vesicles were observed in 27 and hyphal coils in 26 of the 28 plant taxa. Mycorrhizas were of the Paris-type or intermediate-type, with no Arum-type mycorrhizas observed. Species richness of AM fungi varied from 3 to 15 and spore density from 46 to 1,499 per 100 g rhizosphere soil. Of 33 AM fungal taxa in five genera isolated and identified, 18 belonged to Glomus, 9 to Acaulospora, 1 to Entrophospora, 2 to Gigaspora, and 3 to Scutellospora. Acaulospora and Glomus were the dominant genera identified. Glomus claroideum was the taxon most commonly isolated, with a frequency of occurrence of 56.5% and relative abundance of 10.4%. A positive correlation was found between percentage of root length colonization and species richness. However, there was no correlation between spore density and percentage of root length colonized by AM fungi.     

Effects of simultaneous infections of endophytic fungi and arbuscular mycorrhizal fungi on the growth of their shared host grass Achnatherum sibiricum under varying N and P supply

Grasses can be infected by endophytic fungi and arbuscular mycorrhizal (AM) fungi simultaneously. Here, we investigated the interactions of a native grass, Achnatherum sibiricum, with both endophytic and AM fungi (Glomus mosseae, GM and Glomus etunicatum, GE) at different nitrogen (N) and phosphorus (P) levels. The results showed that endophyte infection significantly suppressed the colonization rates and spore density of GE, but had no effect on those of GM. Endophyte infection increased shoot biomass regardless of the nutrient conditions. The effects of AM fungi on host growth were dependent on mycorrhizal species. There was no significant interaction between endophytic fungi and GE on host growth; however, a significant interaction between endophytic fungi and GE occurred in total phenolic concentrations and P uptake. As for GM, a significant interaction among endophytic fungi, AM fungi and nutrient availability occurred in shoot growth. Under sufficient N and P conditions, endophyte infection alleviated the detrimental effects of GM colonization on host growth.     

Study on the communities of endophytic fungi and endophytic actinomycetes from rice and their antipathogenic activities in vitro

The populations of endophytic fungi and actinomycetes from four rice cultivars in the Panyu district (Site 1) and Wushan district (Site 2) in Guangdong province, South China, were studied. The preponderant endophytic fungi and actinomycetes isolated belonged to Fusarium and Streptomyces respectively. The incidence of Streptomycetes griseofuscus ranged from 36.1 to 69% out of all the different rice cultivars from the two sites. It is the commonest population of endophytic actinomycetes, and constituted the greatest part of all the antagonistic communities. The distributions of endophytic fungi and actinomycetes in roots and leaves were different, endophytic fungi from leaves were diverse, some were organ-specific. More diverse endophytic actinomycetes were isolated from roots than from leaves. The endophytic fungi isolated from rice in Site 2 were more diverse than that in Site 1. The diversity of the endophytic actinomycetes, however, was less than that in Site 1. Acid soil in Site 2 is ideal for the growth and colonization of fungi while the alkaline soil in Site 1 is better for the growth and colonization of actinomycetes. The results suggested that differences in the chemical composition of soil could influence the endophytic microbial communities of rice plants. The endophytic fungi and actinomycetes isolated from poor-growing seedlings and susceptible rice cultivars were more abundant than that the disease-resistant counterparts. In the dual culture and activity detection of the metabolites, 41.2% of all the isolated endophytic fungi showed antagonism to rice pathogens. Fifty percent of all the isolated endophytic actinomycetes were antagonistic to those pathogens. The percentage of Streptomyces griseofuscus and hygroscopicus reached 55.4 and 21.4% of all the active actinomycetes. This revised version was published online in August 2006 with corrections to the Cover Date.     

抗感白粉病青稞的内生真菌群落差异分析

种子内生微生物组与种子的健康发育有着密切的关系。本研究收集对白粉病抗病和易感共11个品种的青稞种子,利用扩增子测序技术对内生真菌的群落、丰度和多样性进行研究。从不同品种的青稞种子中共鉴定4个门、17个纲、35个目、66个科、107个属的内生真菌,其中子囊菌门Ascomycota、担子菌门Basidiomycota和被孢菌门Mortierellomycota是优势菌门;链格孢属Alternaria、微座孢属Microdochium、亚隔孢壳属Didymella、镰刀菌属Fusarium和球腔菌属Mycosphaerella为优势菌属。根据生物信息学注释结果,在鉴定到的107个属中,抗病品种的青稞种子中特有的属有20个,感病品种的青稞种子中特有的属有50个;通过对两组样本的分析,发现感病品种中真菌物种多样性高于抗病品种。本研究通过扩增子测序技术初步确定了青稞抗、感白粉病两组样品中的真菌群落结构和优势菌群,为进一步研究青稞内携真菌与抗/感病的关系提供了基础,从内生菌的角度为青稞白粉病的防控提供新的策略。     

黑老虎内生真菌及根际土壤真菌的群落结构与生态功能分析

为探讨黑老虎(Kadsura coccinea)根际土壤和组织内生真菌菌群的组成及其生态功能，该研究采用ITS高通量测序技术对成熟黑老虎(根、茎、叶)内生真菌及根际土壤真菌群落结构、多样性和生态功能进行了分析。结果表明：(1)从12个样品中共获得2 241个可操作分类单元(OTU),涉及10门、41纲、95目、212科、367属，内生真菌(根、茎、叶)和根际土壤真菌OTU数分别为386、536、258、1 435个，其中共有的OTU为18个。在门水平上，黑老虎内生真菌及根际土壤真菌优势群落均为子囊菌门和担子菌门，其中子囊菌门在叶和茎中占比分别高达96.99%和95.37%;在属水平上，黑老虎根际土壤真菌中腐生真菌被孢霉属占比较高(为13.5%),叶和茎等生长旺盛的组织中子囊菌门未分类属和痂囊腔菌属占比较高。(2)α多样性分析结果显示，黑老虎根际土壤真菌群落的丰度和多样性明显高于内生真菌，茎中内生真菌丰度显著高于根和叶，而根、茎和叶组织间内生真菌多样性差异不显著；PCoA分析结果显示，叶和茎的真菌群落结构相似性更高。(3)利用FUNGuild数据库进行的功能预测分析结果显示，黑老虎根际土...