共查询到20条相似文献,搜索用时 31 毫秒
1.
《Fungal Ecology》2019
Ash dieback disease (caused by Hymenoscyphus fraxineus) has affected European ash species (Fraxinus spp.) in recent decades. However, some Asian and American species of Fraxinus and certain genotypes of Fraxinus excelsior are less affected by the disease. We used ITS1-metabacoding to explore the drivers influencing diversity and composition of the twig fungal communities of Fraxinus species and F. excelsior genotypes. Our results revealed that fungi in the classes Eurotiomycetes and Dothideomycetes were among the most prevalent taxa in both Fraxinus species and F. excelsior genotypes. The diversity of the fungal communities differed significantly among Fraxinus species and could be explained by seed origin. Neither host genotype nor season had a significant effect on the community diversity of F. excelsior genotypes. On the other hand, the composition of twig fungal communities differed significantly among host species and among F. excelsior genotypes, and in F. excelsior there was also a significant effect of season on the composition of the fungal community. We did not find a clear effect of ash dieback susceptibility on either diversity or composition of fungal communities in twigs of Fraxinus species, although the effect was significant on the composition of fungal communities among F. excelsior genotypes. Our results demonstrated differences in fungal communities among species of Fraxinus and of F. excelsior genotypes, suggesting specific relationship between individual host genotypes and endophytic fungi. 相似文献
2.
Nimali I. De Silva Siraprapa Brooks Saisamorn Lumyong Kevin D. Hyde 《Fungal Biology Reviews》2019,33(2):133-148
Plant diseases, caused by various microorganisms, including viruses, bacteria, fungi, protozoa and nematodes, affect agricultural practices and result in significant crop losses. Fungal pathogens are the major cause of plant diseases and infect most plants. Agrochemicals play a significant role in plant disease management to ensure a sustainable and productive agricultural system. However, the intensive use of chemicals has adverse effects on humans and ecosystem functioning and also reduces agricultural sustainability. A sustainable agriculture is achieved through reduction or elimination of fertilizers and agrochemicals, resulting in minimal impact to the environment. Recently, the use of antagonistic endophytes as biocontrol agents is drawing special attention as an attractive option for management of some plant diseases, resulting in minimal impact to the environment. Endophytes that resides asymptomatically within a plant, have the potential to provide a source of candidate strains for potential biocontrol applications. This review addresses biocontrol methods using endophytic fungi such as Colletotrichum, Cladosporium, Fusarium, Pestalotiopsis and Trichoderma species as an attractive option for management of some plant diseases. Potential endophytes are screened in vitro and in vivo to test their antagonistic actions by different mechanisms, including mycoparasitism, production of lytic enzymes and/or antibiotics and induction of plant defenses. Currently, efforts are being made to commercialize these biocontrol agents. A continued research pipeline consisting of screening, in vitro and in vivo testing, biomass production and commercialization of endophytes as biocontrol agents may contribute to sustainable agriculture. 相似文献
3.
《Fungal Ecology》2017
Communities of endophytic fungi in leaves of Manna ash (Fraxinus ornus) were examined to both the north and south of the Alps, i.e. within and beyond the native range of this tree species. Almost all leaves examined had been colonized by endophytic fungi. One hundred and two morphotypes were found, and 62 of them were identified to genus or species level using ITS sequencing and micromorphology. Venturia orni was most frequent and occurred in almost one third (32%) of the 1536 examined leaf segments. It was five times more abundant than Colletotrichum acutatum, the second most frequent endophyte. Other frequently isolated endophytes include Paraconiothyrium sp. 1, Mycosphaerella aurantia, Septoria cretae, Botryosphaeria dothidea and Boeremia exigua. The ash dieback pathogen was not isolated. The endophyte communities differed between the north and south of the Alps and the individual tree types had a distinct influence within sites. 相似文献
4.
Moths that Vector a Plant Pathogen also Transport Endophytic Fungi and Mycoparasitic Antagonists 总被引:1,自引:0,他引:1
Claviceps paspali, a common fungal pathogen of Paspalum grasses, attracts moth vectors by producing sugary exudates in the grass florets it infects. These exudates also support
mycoparasitic Fusarium species that may negatively influence C. paspali fitness. We examined the potential for moths on which C. paspali depends to also transmit mycoparasitic Fusarium and fungal endophytes, which inhabit asymptomatic plant tissue and may influence host susceptibility to pathogens. We quantified
infections by C. paspali, Fusarium spp., and endophytic fungi associated with Paspalum spp. at focal sites in the southeastern USA and used data from the nuclear internal transcribed spacer (ITS rDNA) to compare
communities of plant-associated and moth-borne fungi. ITS sequences of moth-borne fungi were identical to reference sequences
of mycoparasitic Fusarium heterosporum and to three distinct endophytic fungi isolated from Paspalum species. Our results demonstrate an unexpected overlap of fungal communities between disparate locations and among plant
species and plant tissues, and suggest an unexpected role of moths, which vector a plant pathogen, to transmit other guilds
of fungi. In turn, the potential for insects to transmit plant pathogens as well as mycoparasites and endophytic fungi suggests
complex interactions underlying a commonly observed grass–pathogen system.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
Takahiro Inoue Izumi Okane Yasuhiro Ishiga Yosuke Degawa Tsuyoshi Hosoya Yuichi Yamaoka 《Mycoscience》2019,60(2):89-94
Hymenoscyphus fraxineus causes a lethal disease known as “ash dieback” in the common ash, Fraxinus excelsior, in Europe. It is hypothesized that the fungus originated from East Asia. This fungus is found on the leaf litter of the Manchurian ash, Fraxinus mandshurica, in Japan and is reported to produce apothecia on pseudosclerotial plates formed mainly on decomposing rachises. However, dieback disease has not been reported in Japan, and little is known about the life cycle of H. fraxineus. This study was conducted to explore the behavior and life cycle of this fungus. It was revealed that, after infection by ascospores, H. fraxineus endophytically inhabits the living leaves of F. mandshurica. On fallen leaves, the fungus behaves saprophytically, producing apothecia on pseudosclerotial plates formed mainly on the decomposing rachises. Analysis by real-time quantitative polymerase chain reaction (qPCR) revealed that the amount of H. fraxineus DNA sharply increased in rachises, while such sharp increase of DNA was not found in leaflets. 相似文献
6.
Martin Unterseher Romina Gazis Priscila Chaverri Carlos Fernando García Guarniz Diógenes Humberto Zavaleta Tenorio 《Biodiversity and Conservation》2013,22(4):999-1016
Biodiversity and biogeography of leaf-inhabiting endophytic fungi have not been resolved yet. This is because host specificity, life cycles and species concepts, in this heterogeneous ecological guild of plant-associated microfungi, are far from being understood. Even though it is known that culture-based collection techniques are often biased, this has been the method of choice for studying fungal endophytes. Isolation of fungal endophytes only through culture-based methods could potentially mask slow growing species as well as species with low prevalence, preventing the capture of the communities’ real diversity and composition. This bias can be partially resolved by the use of cultivation-independent approaches such as direct sequencing of plant tissue by next generation techniques. Irrespective of the chosen sampling method, an efficient analysis of community ecology is urgently needed in order to evaluate the driving forces acting on fungal endophytic communities. In the present study, endophytic ascomyceteous fungi from three different plant genera (Vasconcellea microcarpa, Tillandsia spp., and Hevea brasiliensis) distributed in Peru, were isolated through culture-based sampling techniques and sequenced for their ITS rDNA region. These data sets were used to assess host preferences and biogeographic patterns of endophytic assemblages. This study showed that the effect of the host’s genetic background (identity) has a significant effect on the composition of the fungal endophytic community. In other words, the composition of the fungal endophytic community was significantly related to their host’s taxonomic identity. However, this was not true for all endophytic groups, since we found some endophytic groups (e.g. Xylariales and Pleosporales) occurring in more than one host genus. Findings from this study promote the formulation of hypotheses related to the effect of altitudinal changes on the endophytic communities along the Eastern Andean slopes. These hypotheses and perspectives for fungal biodiversity research and conservation in Peru are addressed and discussed. 相似文献
7.
Silma L. Rocha Vanessa L. Jorge Terezinha M. C. Della Lucia Robert W. Barreto Harry C. Evans Simon L. Elliot 《Arthropod-Plant Interactions》2014,8(5):485-493
Leaf-cutting ants of the genera Acromyrmex and Atta forage vegetation for incorporation into their mutualistic fungal gardens. However, the presence of certain endophytic fungi in this predominantly leaf-based material could affect the fungal garden and thus the choice of material by the ants. The present study was conducted to document the endophytic fungal communities occurring in the vegetation being transported by workers of Atta laevigata into their nests and to compare this community structure with that of the vegetative material subsequently rejected from the nests. We found considerable diversity in the fungi isolated. Acremonium, Cylindrocladium, Drechslera, Epicoccum, Fusarium, Trichoderma, Ulocladium and two unidentified morphospecies were significantly more common in rejected compared with foraged material, and some of these genera include mycoparasites, which could represent a threat to the fungal gardens. Conversely, Colletotrichum, Pestalotiopsis, Phomopsis, Xylaria and an unidentified morphospecies were more common in carried compared with rejected material. The possibility that ants have a ‘quality-control’ mechanism based on the presence of antagonistic fungal endophytes is discussed, as is the potential use of these fungi as biocontrol agents against Attini pests. 相似文献
8.
Betelvine is prone to several fungal diseases including leaf spots, foot and root rot caused by Fusarium spp. due to humid conditions prevailing in fields. In the present study, a potent antagonistic bacterial endophyte and a virulent fungal pathogen were selected after rigorous screening of isolates from different betelvine varieties to provide an efficient biocontrol strategy in cultivation of betelvine. Wild varieties of crops are a rich source of untapped endophytes. Of the four betelvine varieties used for isolations and screening, the wild variety was richest in endophytic populations. Using 16S rRNA sequencing, the selected antagonist was identified as Bacillus sp. (NBRI-W9). The pathogen, virulent against cultivated varieties, was identified as Fusarium sp. (NBRI-PMSF12) using ITS 1 and 2 region sequencing. Under in vitro and field conditions, NBRI-W9 was able to induce early rooting, provide plant growth promotion, increase leaf size and yield (leaf number) and provide biocontrol against the Fusarium sp. infection. NBRI-W9 treatments showed bacterial colonization on the leaf surface preferably in the vicinity of pearl glands and the collenchyma region in scanning electron microscope (SEM) studies. NBRI-W9 was observed to directly enter the leaf by degrading cell walls and colonize the subcellular layers. SEM analysis showed direct confrontation of NBRI-W9 with Fusarium on the leaf surface and in the collenchyma region as one of the probable modes of biocontrol. 相似文献
9.
《Fungal Ecology》2018
To explore the biogeographical patterns of endophytic fungal communities on a large scale, we surveyed fungal endophytes in roots of Stipa krylovii from six vegetation types in grassland along a 3200 km west–east transect in northern China. Pyrosequencing of samples collected from 18 sites (three sites per vegetation type) revealed that Pleosporales, Hypocreales, Agaricales, and Xylariales were the dominant fungal orders in roots of S. krylovii. The dominant genera were Marasmius, Fusarium, Acremonium, Sarcinomyces, and Monosporascus, and these genera were distributed differently among the six vegetation types. In a variation partitioning analysis, vegetation type, geographical distance, and environmental parameters (mean annual precipitation and air temperature, soil organic carbon, soil total nitrogen, pH, elevation) explained 98.2% of variation in the endophyte fungal community, and environmental parameters explained more variation than did vegetation type or geographical distance. Mean annual precipitation was the major significant factor influencing endophytic fungal communities. 相似文献
10.
《Systematic and applied microbiology》2022,45(4):126333
A group of isolates of the genus Luteimonas was characterised, which represented a specific component of the healthy core microbiome of Fraxinus excelsior in forest districts with a high infection rate of H. fraxineus, the causal agent of ash dieback. Based on phylogenomic and phenotypic analyses, a clear differentiation from related Luteimonas species was shown. Comparisons of the overall genome relatedness indices with the closest phylogenetic neighbours resulted in values below the recommended species cut-off levels. In addition, differences in several physiological and chemotaxonomic traits allowed a clear demarcation from the type strains of closely related species. Conclusively, the strain group was considered to represent a novel species in the genus Luteimonas, for which the name Luteimonas fraxinea sp. nov. is proposed, with strain D4P002T (=DSM 113273T = LMG 32455T) as the type strain. A functional analysis of the genome revealed features particularly associated with attachment, biofilm production and motility, indicating the ability of D4P002T to effectively colonise ash leaves. In nursery trials, ash seedlings inoculated with this strain showed suppression of the pathogen over a period of three years. This effect was accompanied by a significant shift in the bacterial microbiome of the plants. Altogether, the exclusive occurrence in the microbiome of tolerant ash trees, the genetic background and the results of the inoculation experiment suggest that strain D4P002T may suppress the penetration and spreading of H. fraxineus in or on ash leaves via colonisation resistance or trigger a priming effect of plant defences against the pathogen. 相似文献
11.
Ravindra N. Kharwar Surendra K. Gond Anuj Kumar Ashish Mishra 《World journal of microbiology & biotechnology》2010,26(11):1941-1948
Eucalyptus citriodora Hook, is frequently cultivated tree in India for its wood and medicinal usages. The endophytic and epiphytic fungi were estimated
from healthy leaves of E. citriodora growing in the premise of Banaras Hindu University, Varanasi, India. A total of 33 fungal species were isolated from leaf
segments. Of 33 taxa, 20 were recorded as endophytes, while 22 as epiphytes. Nine, out of 33 species were found to be common
in leaf tissues and surfaces (Alternaria alternata, Aspergillus fumigatus, A. terreus, Cladosporium cladosporioides, Drechslera rostrata, Humicola grisea, Nigrospora oryzae, Penicillium
cristata, and Pestalotia sp.). Out of 478 fungal isolates, 279 were epiphytic while only 199 were endophytic. Most isolates were anamorphic filamentous
fungi which often don’t produce sexual spores. The Sorensen’s index of similarity between endophytes and epiphytes (leaf surface
colonizers) was found to be at 0.300. Diversity index of fungal species was higher in endophytes than epiphytes. The frequency
of colonization differs greatly in both myco-populations. Cladosporium cladosporioides (26%) was dominant species on leaf surfaces while Botrytis cinerea (10.5%) was dominant in leaf tissues. Out of 16 endophytic isolates evaluated for antagonistic test, 8 (50%) gave the antagonistic
activity against variety of fungi representing pathogens to both humans and plants. 相似文献
12.
To clarify the effects of forest fragmentation and a change in tree species composition following urbanization on endophytic fungal communities, we isolated fungal endophytes from the foliage of nine tree species in suburban (Kashiwa City, Chiba) and rural (Mt. Wagakuni, Ibaraki; Mt. Takao, Tokyo) forests and compared the fungal communities between sites and host tree species. Host specificity was evaluated using the index of host specificity (Si), and the number of isolated species, total isolation frequency, and the diversity index were calculated. From just one to several host-specific species were recognized in all host tree species at all sites. The total isolation frequency of all fungal species on Quercus myrsinaefolia, Quercus serrata, and Chamaecyparis obtusa and the total isolation frequency of host-specific species on Q. myrsinaefolia, Q. serrata, and Eurya japonica were significantly lower in Kashiwa than in the rural forests. The similarity indices (nonmetric multidimensional scaling (NMS) and CMH) of endophytic communities among different tree species were higher in Kashiwa, as many tree species shared the same fungal species in the suburban forest. Endophytic fungi with a broad host range were grouped into four clusters suggesting their preference for conifer/broadleaves and evergreen/deciduous trees. Forest fragmentation and isolation by urbanization have been shown to cause the decline of host-specific fungal species and a decrease in β diversity of endophytic communities, i.e., endophytic communities associated with tree leaves in suburban forests were found to be depauperate. 相似文献
13.
Paola Angelini Andrea Rubini Daniela Gigante Lara Reale Rita Pagiotti Roberto Venanzoni 《Fungal Ecology》2012,5(6):683-693
We surveyed the fungal endophytes in the leaves and roots of Phragmites australis plants along a gradient of reed decline at Lake Trasimeno (central Italy) in Oct. 2010. An integrated approach consisting of cultivation and molecular identification was used. Endophytes were recovered from 61.59 % of the samples, with a total of 1 541 isolates. On the basis of a molecular analysis of the rDNA Internal Transcribed Spacer (ITS) region, 25 operational taxonomic units (OTUs) were identified. Fusarium sp. (OTU 21) and Gibberella moniliformis (OTU 1) were the most frequently isolated fungi. Comparisons of the leaf and root samples demonstrated spatial heterogeneity in the endophyte assemblages among the plant parts and sites. In this study, we have shown that reed plants in different states of decline harbour different endophytic communities. This finding may help to understand the very complex scenario of reed die-back. 相似文献
14.
广藿香内生真菌多样性及其对青枯菌的拮抗活性 总被引:2,自引:0,他引:2
【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。 相似文献
15.
Ajay Kumar Gautam 《Archives Of Phytopathology And Plant Protection》2013,46(5):537-544
Fungal endophytes were isolated from surface sterilised leaf segments of five medicinal plants collected from Mandi district, Himachal Pradesh, India. A total of 373 fungal strains belonging to 15 fungal genera and 18 species, Aspergillus niger, A. flavus, A. clavatus, A. variecolor, Penicillium chrsogenum, Alternaria alternata, Curvularia lunata, Haplosporium sp., Phoma sp., Nigrospora sp., Colletotrichum sp., Cladosporium sp., Stemphylium sp., Fusarium sp., Geotrichum sp., Phomopsis sp., Trichoderma sp., Rhizopus sp. and some sterile mycelium were isolated from all the plants. The relative frequency, isolation rate and colonisation rates of endophytes were used to study the endophytic diversity. The results showed that the highest colonisation rate (93.05%) was observed in Adhathoda vasica, while it was 91.66% in Ocimum sanctum, 85% in Viola odorata, 82.81% Cannabis sativa and lowest (61.11%) in Withania somnifera. Moreover, reading the richness and diversity of the endophytic fungi, the highest was obtained for O. sanctum, W. somnifera and C. sativa having eight species each, while lowest (6 and 4) was obtained from A. vasica and V. odorata, respectively. As the role of endophytic organisms in defensive mechanisms of plants is now well established, the present study is an important step to find new and interesting endophytes among the medicinal plants. 相似文献
16.
Promputtha I Lumyong S Dhanasekaran V McKenzie EH Hyde KD Jeewon R 《Microbial ecology》2007,53(4):579-590
Fungal endophytes and saprotrophs generally play an important ecological role within plant tissues and dead plant material.
Several reports based solely on morphological observations have postulated that there is an intimate link between endophytes
and saprotrophs. This study aims to provide valuable insight as to whether some endophytic fungi manifest themselves as saprotrophs
upon host decay. Ribosomal DNA-based sequence comparison and phylogenetic relationships from 99 fungal isolates (endophytes,
mycelia sterilia, and saprotrophs) recovered from leaves and twigs of Magnolia liliifera were investigated in this study. Molecular data suggest there are fungal taxa that possibly exist as endophytes and saprotrophs.
Isolates of Colletotrichum, Fusarium, Guignardia, and Phomopsis, which are common plant endophytes, have high sequence similarity and are phylogenetically related to their saprotrophic
counterparts. This provides evidence to suggest that some endophytic species change their ecological strategies and adopt
a saprotrophic lifestyle. The implication of these findings on fungal biodiversity and host specificity is also discussed. 相似文献
17.
This study assessed the diversity and distribution of endophytic fungal communities associated with the leaves and stems of four vascular plant species in the High Arctic using 454 pyrosequencing with fungal-specific primers targeting the ITS region. Endophytic fungal communities showed high diversity. The 76,691 sequences obtained belonged to 250 operational taxonomic units (OTUs). Of these OTUs, 190 belonged to Ascomycota, 50 to Basidiomycota, 1 to Chytridiomycota, and 9 to unknown fungi. The dominant orders were Helotiales, Pleosporales, Capnodiales, and Tremellales, whereas the common known fungal genera were Cryptococcus, Rhizosphaera, Mycopappus, Melampsora, Tetracladium, Phaeosphaeria, Mrakia, Venturia, and Leptosphaeria. Both the climate and host-related factors might shape the fungal communities associated with the four Arctic plant species in this region. These results suggested the presence of an interesting endophytic fungal community and could improve our understanding of fungal evolution and ecology in the Arctic terrestrial ecosystems. 相似文献
18.
This study investigated the taxonomic identities and diversity of fungal endophytes isolated from four Rhizophoraceae mangrove
plant species, Ceriops tagal, Rhizophora
apiculata, R. stylosa and Bruguiera sexangula var. rhynchopetala, using a combination of morphological and molecular approaches. Two hundred ninety-five isolates were classified into 38
taxa by morphological characteristics. The representative 38 isolates from each taxa were selected for further molecular identification
using nuclear ribosomal DNA sequences, including both the internal transcribed spacers (ITS1 and ITS2) and the 5.8S gene region.
The 38 representative endophytes were identified to various taxonomic levels. These results suggest that Pestalotiopsis and Phomopsis were the most frequent endophytes in the four host species. Some of the endophytes exhibit host and tissue specificity. The
colonization frequencies of endophytic fungi in the stems of the four host plants are evidently higher than in the roots.
The four Rhizophoraceae mangrove species have low similarities of endophyte communities. 相似文献
19.
Zhou Sheng-Liang Yan Shu-Zhen Wu Zhen-Ying Chen Shuang-Lin 《World journal of microbiology & biotechnology》2014,30(6):1775-1784
Endophytic fungi play an important role in terrestrial ecosystem, while little is known about those in hemi-parasitic plants, a group of special plants which absorb nutrients from its hosts by haustoria. The relationship of the endophytes in the two parts of the bipartite systems (hemiparasites together with their hosts) is also poorly understood. Endophytic fungi of a hemi-parasitic plant Macrosolen tricolor, and its host plant Camellia oleifera were investigated and compared in this study. M. tricolor contained rich and diversified endophytic fungi (H′ = 2.829), which consisted mainly of ascomycetes, distributed in more than ten orders of four classes (Sordariomycetes, Dothideomycetes, Leotiomycetes and Eurotiomycetes) besides Incertae sedis strains (23.2 % of total). In addition, 2.2 % of isolates were identified to be Basidiomycota, all of which belonged to Agaricomycetes. Obvious differences were observed between the endophytic fungal assembles in the leaves and those in the branches of M. tricolor. The endophytic fungi isolated from C. oleifera distributed in nearly same orders of the four classes of Ascomycota and one class (Agaricomycetes) of Basidiomycota as those from M. tricolor with similar proportion. For both M. tricolor and C. oleifera, Valsa sp. was the dominant endophyte species in the leaves, Torula sp. 1 and Fusarium sp. 1 were the dominant endophytic fungi in the branches. The similarity coefficient of the endophyte assembles in the two host was 64.4 %. Canonical correspondence analysis showed that the endophyte assembles of M. tricolor and C. oleifera were significantly different (p < 0.01). 相似文献
20.
湖北烟草内生真菌生物多样性和种群结构分析 总被引:1,自引:0,他引:1
【目的】研究传统药用植物烟草(Nicotiana tabacum L.)内生真菌的丰富度,揭示其种群多样性和群落结构,为烟草内生真菌资源的有效利用奠定基础。【方法】采用组织分离法进行烟草内生真菌的分离,通过形态学和分子生物学相结合的方法进行菌株分类鉴定,以香农多样性指数及相对分离频率反映内生真菌物种多样性及分布规律。【结果】从不同组织部位、不同生长时期、不同海拔样地的健康烟草中共分离获得539株内生真菌,根据r DNA-ITS系统发育分析鉴定为31属73种,香农多样性指数为2.78,曲霉属Aspergillus和镰孢属Fusarium为优势菌群,其相对分离频率分别为22.63%和12.99%。其分布规律表现为茎部内生真菌的多样性高于叶部和根部;随着生育期的延长,内生真菌多样性逐步增多;随着海拔高度升高,内生真菌的种类和数量呈现降低的趋势。【结论】烟草内生真菌具有丰富的生物多样性,其分布表现出组织、生长时期、海拔高度专化性。阐明内生真菌在烟草中的分布规律,可以为烟草内生真菌在农业生产领域的开发应用提供科学依据。 相似文献