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1.
Zhang Y  Guo LD  Liu RJ 《Mycorrhiza》2004,14(1):25-30
The colonization and diversity of arbuscular mycorrhizal (AM) fungi associated with common pteridophytes were investigated in Dujiangyan, southwest China. Of the 34 species of ferns from 16 families collected, 31 were colonized by AM fungi. The mean percentage root length colonized was 15%, ranging from 0 to 47%. Nineteen species formed Paris-type and 10 intermediate-type AM. In two ferns, only rare intercellular non-septate hyphae or vesicles were observed in the roots and AM type could not be determined. Of the 40 AM fungal taxa belonging to five genera isolated from rooting-zone soils, 32 belonged to Glomus, five to Acaulospora, one to Archaeospora, one to Entrophospora, and one to Gigaspora. Acaulospora and Glomus were the dominant genera and Glomus versiforme was the most common species. The average AM spore density was 213 per 100 g air-dried soil and the average species richness was 3.7 AM species per soil sample. There was no correlation between spore density and percentage root length colonized by AM fungi.  相似文献   

2.
Arbuscular mycorrhizal fungi associated with sedges on the Tibetan plateau   总被引:1,自引:0,他引:1  
Gai JP  Cai XB  Feng G  Christie P  Li XL 《Mycorrhiza》2006,16(3):151-157
The arbuscular mycorrhizal (AM) status of nine dominant sedge species and the diversity of AM fungi in Tibetan grassland were surveyed in the autumn of 2003 and 2004. Most of the sedge species and ecotypes examined were mycorrhizal, but Carex moorcroftii and Kobresia pusilla were of doubtful AM status, and Kobresia humilis was facultatively mycorrhizal. This is the first report of the mycorrhizal status of eight of the nine sedge species examined. Intraradical vesicles and aseptate hyphae were the structures most frequently observed. Appressoria, coils, and arbuscules were found in the roots of a few sedge species. A strong negative correlation was found between soil organic matter content and the extent of mycorrhizal colonization. Using trap cultures, 26 species of AM fungi belonging to six genera, Glomus, Acaulospora, Paraglomus, Archaeospora, Pacispora, and Scutellospora, were isolated from the soil samples collected. The frequency of occurrence of different taxa of AM fungi varied greatly. Glomus and Acaulospora were the dominant genera, and Acaulospora scrobiculata was the most frequent and abundant species. The species richness of AM fungi was 2.73 in the study area. Species richness and diversity index differed among the sedge species but were not correlated with soil factors such as pH, available P, or organic matter content.  相似文献   

3.
We examined arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal association in 50 south Indian grasses from four different sites. AM fungal diversity was also compared among the different sites. Forty-four of the 50 grasses examined had AM association and dual association with DSE fungi occurred in 25 grasses. We report for the first time AM and DSE fungal status in 23 and 27 grasses respectively. Arum-type AM morphology was the dominant occurring in 21 grasses with typical Paris-type colonization occurring in 6 grasses. AM morphology is reported for the first time in 35 grasses. Over the different sites, spore density in the soil ranged from 5–22 per 100 g air-dried soil. Spores of 11 AM fungal taxa were isolated from the soil samples of grasses of which nine belonged to Glomus, one to Acaulospora and one to Scutellospora. No significant relationship existed between AM fungal colonization and spore numbers. Species richness was high in site II and Glomus aggregatum, Glomus viscosum and Glomus mosseae were most frequent species at different sites. Overall species diversity indices (Simpson index, Shannon-Weaver index, species equitability index) differed significantly between sites.  相似文献   

4.
Gai JP  Feng G  Cai XB  Christie P  Li XL 《Mycorrhiza》2006,16(3):191-196
We report for the first time the arbuscular mycorrhizal (AM) status of native plant species and AM fungal diversity in the grasslands of southern Tibet. A total of 51 soil samples were collected from the rhizospheres of the dominant plant species, and AM fungal structures were observed in 18 (82%) of 22 plant species examined. Vesicles and aseptate hyphae were the structures most frequently observed in the plant roots. After trap culture for 5 months, 25 AM fungal taxa were identified in the soil samples collected, of which nine belonged to Glomus, ten to Acaulospora, one to Entrophospora and five to Scutellospora. The frequency of occurrence of different genera and species varied greatly. Glomus was the dominant genus, and the most frequent and abundant species was Glomus mosseae. Over the whole sampling area, spore density in the rhizosphere soil of different host plant species ranged from 2 to 66 per 20 g air-dried soil. Overall AM fungal species richness was 2.10 and species diversity was 2.35. AM fungal diversity was also compared among the four different land use types (farmland and normal, disturbed and highly disturbed montane scrub grassland). Spore densities in the farmland and normal grassland were much higher than in the grasslands that had been degraded to varying degrees. The species richness in normal grassland was the highest of the four land use types examined. Species diversity varied from 1.99 to 0.94 and was highest in normal grassland, intermediate in degraded grassland and farmland, and lowest in the highly disturbed grassland.  相似文献   

5.
Shi ZY  Feng G  Christie P  Li XL 《Mycorrhiza》2006,16(4):269-275
A survey was made of the arbuscular mycorrhizal (AM) status of 73 spring ephemeral plant species that grow in the desert ecosystem of Junggar Basin, northwest China. The proportion of AM colonization ranged from 7 to 73% with a mean value of 30%. A total of 65 plant species studied were AM with coils/arbuscules or vesicles and the remaining eight species were possibly AM with no coils/arbuscules or vesicles but with fungal mycelia in the root cortex. AM fungal spores were isolated from rhizosphere samples of all 73 plant species and identified. The mean spore density was 22 per 20 ml of air-dried soil, ranging from 0 to 120. Colonization and spore density of perennials were slightly higher than of annuals and varied among different plant families. A total of 603 AM fungal spore (or sporocarp) specimens were isolated belonging to six genera, Acaulospora, Archaeopora, Entrophospora, Glomus, Paraglomus, and Scutellospora; Glomus was the dominant genus. We conclude that spring ephemerals may be highly dependent on AM associations for survival in the very infertile and arid soils of this desert ecosystem.Electronic supplementary material Supplementary material is available for this article at  相似文献   

6.
The world heritage of Huangshan is located in the east-central China. In order to obtain a better overview of biodiversity in Huangshan, we investigated the diversity of arbuscular mycorrhizal fungi in the soil of Huangshan. Forty-two rhizosphere soil samples were collected and 989 arbuscular mycorrhizal fungal spore samples were obtained using the wet-sieving method. Twenty-five species of arbuscular mycorrhizal fungi were identified from the collections. The species were of the genera Acaulospora (6 species), Entrophospora (1 species), Glomus (16 species) and Scutellospora (2 species). Acaulospora and Glomus were dominant at the study site. The arbuscular mycorrhizal fungi spore density ranged from 45 to 3,250 per 100 g soil (average 839), and the species richness of arbuscular mycorrhizal fungi ranged from 1 to 9 (average 4.2) per soil sample. Shannon–Wiener index and Simpson’s index were calculated to evaluate the arbuscular mycorrhizal fungal diversity. The diversity of arbuscular mycorrhizal fungal community in the subtropical forest of Huangshan may be the result of mutual selection between arbuscular mycorrhizal fungi and the ecological environment.  相似文献   

7.
Y. Zhang  L.-D. Guo  R.-J. Liu 《Plant and Soil》2004,261(1-2):257-263
The diversity of arbuscular mycorrhizal (AM) fungi in deforested (Mantoushan) and natural forest (Banruosi) land in the subtropical region of Dujiangyan was surveyed and compared. A total of 44 taxa of AM fungi were isolated, and the same number of AM fungus taxa (34 taxa) was found in both deforested and natural forest land. Acaulospora and Glomus were the dominant genera in the two sites. Glomus convolutum and G. versiforme were the dominant species in the natural forest land, while only G. versiforme was dominant in the deforested land. There was no significant difference in total spore density of AM fungi between the two sites, but the total species richness of AM fungi was significantly higher in the deforested land than in the natural forest land. The Shannon-Weiner index of AM fungus diversity was a higher in the natural forest land (2.67) than in the deforested land (2.15). There was high AM fungus composition similarity (Sorenson's coefficient C S=0.71) between the two sites. We suggest that there was little effect of deforestation on the diversity of AM fungi, and that annual herbaceous plants play a major role in maintaining and increasing AM fungus spore density and species richness in deforested land.  相似文献   

8.
Su YY  Guo LD 《Mycorrhiza》2007,17(8):689-693
Arbuscular mycorrhizal (AM) fungal diversity was investigated in non-grazed, restored and over-grazed (fenced) plots of a grassland in the Inner Mongolia steppe. Plant cover and variety differ between the plots, being highest in the non-grazed to lowest in the over-grazed plots. A total of 19 AM fungal taxa belonging to six genera were found based on spores isolated from field samples and trap cultures. One belonged to Acaulospora, one to Archaeospora, one to Entrophospora, one to Gigaspora, 12 to Glomus and three to Scutellospora. Glomus was the dominant genus in all plots, and Glomus geosporum was the dominant species, whilst G. albidum and G. etunicatum were dominant in the restored plot. Scutellospora was the second dominant genus in the non-grazed plot with Scutellospora calospora being the dominant species. The mean spore density and mean species richness of AM fungi were significantly decreased by long-term over-grazing. The Sorenson’s similarity coefficients of AM fungal community composition ranged from 0.5 to 0.64 among the three types of plot management. The results suggest that the AM fungal diversity is greatly affected by long-term over-grazing and that fencing of degraded areas partly restores plant cover and AM fungal diversity in grassland ecosystems.  相似文献   

9.
The arbuscular mycorrhizal (AM) status and root phosphatase activities were studied in four vegetative Carica papaya L. varieties viz., CO-1, CO-2, Honey Dew and Washington. Standard techniques were used to ascertain information on spore density and species diversity of AM fungi. Although in case of estimation of root colonization and root phosphatase activities, the existing methods were slightly modified. Root colonization and spore density of AM fungi along with root phosphatase (acid and alkaline) activities varied significantly in four papaya varieties. The present study recorded higher acid root phosphatase activity when compared with alkaline root phosphatase activity under P-deficient, acidic soil conditions. The present study revealed that the root colonization of AM fungi influenced acid root phosphatase activity positively and significantly under P-deficient, acidic soil conditions. A total of 11 species of AM fungi belonging to five genera viz., Acaulospora, Dentiscutata, Gigaspora, Glomus and Racocetra were recovered from the rhizosphere of four papaya varieties.  相似文献   

10.
Arbuscular mycorrhizas in a valley-type savanna in southwest China   总被引:6,自引:1,他引:5  
Tao L  Jianping L  Zhiwei Z 《Mycorrhiza》2004,14(5):323-327
The arbuscular mycorrhizal (AM) status of 67 plant species in a savanna community in the hot, dry valley of Jinsha River, southwest China was surveyed. It was found that about 95% of the plant species formed AM and 5% possibly formed AM. The composition of AM fungi (AMF) in the rhizosphere soils was also investigated. The AMF spore density ranged from 5 to 6,400 per 100 g soil, with an average of 1,530, and these spores/sporocarps were identified as belonging to six genera. Fungi belonging to the genera Glomus and Acaulospora were the dominant AMF. High densities of AMF spores in the rhizosphere soils, and the intensive colonization of the plant roots, indicated that plants grown in this valley-type savanna may be highly dependent on AM.  相似文献   

11.
Experiments were conducted to study the arbuscular mycorrhizal (AM) status and its role in P-uptake through assay of root phosphatases activities in four varieties of male Carica papaya L. viz. CO-1, CO-2, Honey Dew and Washington during flowering stages. In the present study, mean total root colonization of AM fungi recorded peak increase in flowering stage-II while mean root phosphatase (acid and alkaline) activities recorded peak increase in flowering stage-I. Unlike root colonization and root phosphatase activities, spore density did not exhibit any definite patterns and recorded a narrow range of fluctuation during different flowering stages of male C. papaya. The study brought out the fact that root colonization and spore density of AM fungi along with root phosphatase activities varied significantly within the four varieties of male C. papaya plants during each flowering stage. The study also recorded consistently higher acid root phosphatase activity than alkaline root phosphatase activity under P-deficient, acidic soil conditions during all flowering stages of male C. papaya plants. Studies revealed that the root colonization of AM fungi influenced root phosphatase activities (acid and alkaline) positively and significantly during all flowering stages of male C. papaya plants. A total of twelve species of AM fungi belonging to five genera viz. Acaulospora, Dentiscutata, Gigaspora, Glomus, and Racocetra were recovered from the rhizosphere of male C. papaya plants.  相似文献   

12.
采用高通量(Illumina Miseq)测序技术对栽培和野生2种生境下川麦冬根围的丛枝菌根(AM)真菌多样性和群落结构进行测定,并结合土壤理化因子进行相关性分析,以明确两种生境下川麦冬根围土壤AM真菌多样性和优势群落的分布特点,探讨AM真菌群落分布差异的驱动因子,为AM真菌应用于麦冬生产提供理论依据和技术支持。结果表明:(1)不同生境下川麦冬根围土壤中共鉴定出AM真菌3属10种,其中野生川麦冬根围土壤鉴定出的AM真菌3属7种,分别隶属于无梗囊霉属(Acaulospora)、多孢囊霉属(Diversispora)和球囊霉属(Glomus),而栽培环境下鉴定出AM真菌1属6种,隶属于球囊霉属。2个生境优势属均为球囊霉属。(2)不同生境下川麦冬根围AM真菌之间存在显著差异,野生生境下川麦冬根围土壤AM真菌多样性指数ACE和Shannon均显著高于人工栽培生境,而Simpson指数则相反。(3)相关性分析表明,AM真菌多样性指数及群落组成结构均与土壤理化因子存在相关性,其中全钾(TK)、全磷(TP)、全氮(TN)对AM真菌多样性指数和群落结构组成均存在显著影响。研究认为,不同生境下川麦冬根围AM真菌群落存在显著差异,球囊霉属为川麦冬互利共生的关键属,TK、TP、TN是不同生境川麦冬根围AM真菌群落差异的主要驱动因子。  相似文献   

13.
The influences of different fertilizer treatments on spore community structure and diversity of arbuscular mycorrhizal (AM) fungi (AMF) were investigated in a long-term fertilization experiment with seven treatments: organic manure (OM), half organic manure N plus half fertilizer N (1/2 OMN), fertilizer NPK, fertilizer NP, fertilizer NK, fertilizer PK, and the control (without fertilization). Fertilization generally increased the nutrient contained in the fertilizer and treatments with NPK and 1/2 OMN produced the highest crop yields. Thirty-five species of AMF within 6 genera, including 8 previously undescribed species, were recovered. Similarly in all seven treatments, the most abundant genus was Glomus, and followed by Acaulospora. All the fertilization treatments changed AM species composition, and NK treatment had the slightest influence. Fertilization with fertilizers NP, PK and NPK markedly increased AM fungal spore density, while 1/2 OMN, OM and NK treatments showed no significant influences. All the fertilizer treatments, especially OM, significantly decreased species richness and species diversity (Shannon-Weiner index). There were no significant correlations between AM fungal parameters (spore density, species richness and species diversity) and soil properties. The findings indicate that long-term fertilization all can change AM fungal community structure and decrease species diversity, while balanced fertilization with NPK or 1/2 OMN is the most suitable fertilization regime if taking both crop yields and AM species diversity into account.  相似文献   

14.
To understand arbuscular mycorrhizal (AM) fungi resources and develop AM fungal species in ornamental plants with saline-alkaline tolerances, Iris lactea, which grows in the Songnen saline-alkaline grassland with a high ornamental value, was selected as the experimental material, and the colonization characteristics of its roots and the AM fungal diversity in its rhizosphere were explored. The results of the observations and calculations of mycorrhizae from ten different samples showed that AM fungi colonized the roots of I. lactea and formed Arum-type mycorrhizal structures. There was a significant correlation between soil spore density and pH value, while the colonization rate showed a fluctuating trend with increasing pH values. The observed colonization intensities were of Levels II (1%–10%) or III (11%–50%), and the vesicle abundances were of grades A2 or A3 among different sites. AM fungi produced a large number of mycelia and vesicles in the roots of I. lactea after colonization. Thirty-seven species belonging to 15 genera of AM fungi were isolated from the rhizosphere of I. lactea and identified by morphological identification. Funneliformis and Glomus were the dominant genera, accounting for 21.79% and 20.85% of the total number, respectively. F. mosseae and Rhizophagus intraradices were isolated in all samples with importance values of 58.62 and 51.19, respectively. These results are expected to provide a theoretical basis for the analysis of the salt tolerance mechanism of I. lactea and for the discovery, exploration and further screening of AM fungal resources with salinity tolerances in saline-alkaline soils.  相似文献   

15.
Li LF  Li T  Zhao ZW 《Mycorrhiza》2007,17(8):655-665
We investigated the spore density, species composition, and diversity of arbuscular mycorrhizal fungi (AMF) in a cultivated land (CL), an old field (OF), and a never-cultivated field (NCF), which are located adjacently in a slope in the hot and arid ecosystem of southwest China. AMF spores in the rhizosphere soils of representative plants in the three habitats were extracted by wet-sieving and decanting. A total of 47 taxa of AMF including 31 taxa from the genus Glomus, 8 from Acaulospora, 6 from Scutellospora, 1 from Entrophospora, and 1 from Gigaspora were extracted and identified morphologically. The highest spore density occurred in NCF, slightly lower in OF and lowest in CL, and the Shannon–Wiener index of species diversity was reversed. The dominant species of AMF were different in the three habitats. OF resembled NCF more than CL in AMF spore density, species richness, and community composition, which means that AMF community in the OF has been developing from cultivated land to natural habitat. Cluster analysis based on the similarity in AMF community composition indicated that the distribution of AMF was not random over space and that AMF community composition associated with a given plant species was greatly habitat-convergence. Following the cluster analysis, we hypothesized that the effect of habitats on AMF communities were greater than that of the host preference to AMF. L-F. Li and T. Li contributed equally to this work.  相似文献   

16.
No previous studies have been conducted on the diversity and population of arbuscular mycorrhizal fungi (AMF) in relation to organically grown chili (Capsicum frutescens L.) in Thailand. This study was carried out to investigate the diversity and status of AMF populations at four organically managed farms in Ubon Ratchathani and Sisaket provinces. The effects of each AMF species on the growth and nutrient uptake of chili grown in sterile, organically managed soil were determined. Fourteen AM fungal taxa belonging to the genera Acaulospora (4 spp.), Entrophospora (1 sp.), Glomus (7 spp.) and Scutellospora (2 spp.) were found. Among these, Glomus was the dominant genus found at all sites, followed by Acaulospora. The spore density and root colonization of AMF on chili did not vary significantly among the sites. The effects of ten selected AMF species on the growth of chili showed that Gl. clarum RA0305 increased the growth, flowering, and fruit production of chili, and also increased the P uptake significantly, compared to non-mycorrhizal plants. This fungus showed the highest potential as a promoter of growth, flowering and yield in organically managed chili production.  相似文献   

17.
Chen YL  Liu S  Dell B 《Mycorrhiza》2007,17(6):527-535
The aim of this study is to assess the mycorrhizal status of Eucalyptus plantations in south China and to determine the need for inoculation. In four provinces in south China, 155 plantations were sampled for sporocarps of ectomycorrhizal (ECM) fungi, spores of arbuscular mycorrhizal (AM) fungi, and mycorrhizas over 2 years. This study revealed a low above-ground diversity of ECM fungi consisting of 15 taxa fruiting beneath Eucalyptus plantations. The most common ECM genera were Scleroderma and Pisolithus, but they were infrequent. A total of 21 AM fungi, mostly Glomus species, were recognized from spores collected from eucalypt plantations. Four Glomus species were frequently present in soils, but spore density and relative abundance of AM fungi were generally low. Eucalypt roots from all plantation sites were poorly colonized by either ECM fungi or AM fungi. A bioassay with E. urophylla as a bait host, using soils collected from 11 eucalypt plantations, confirmed low levels of inoculum of both ECM and AM fungi in field soil. This is the first integrated study on the mycorrhizal status of eucalypt plantations in China. Findings from this research can be used to encourage adoption of mycorrhizal technology by eucalypt nurseries in the region. The potential of using spores of compatible ECM fungi or collections for forest nurseries is discussed.  相似文献   

18.
Arbuscular mycorrhizal (AM) fungal spore communities and distribution patterns were surveyed in montane scrub grassland, alpine steppe, and alpine meadow sites at altitudes ranging from 3,500 to 5,200 m a.s.l. on the Tibetan Plateau. Thirty-two representative soil samples were collected from the root zone of the dominant and common plant species in late May 2004. Twenty-three AM fungal species representing six genera (Acaulospora, Entrophospora, Glomus, Pacispora, Paraglomus, and Scutellospora) were detected and species richness varied from 5.3 ± 0.8 to 10.5 ± 2.5 per site. Some AM fungal species were restricted to one vegetation type and Glomus mosseae, Glomus intraradices, and Scutellospora calospora were detected in all three vegetation types. Glomus species were found to be the most frequent and abundant in all three vegetation types. Acaulospora occurred mostly in the alpine steppe and alpine meadow. Scutellospora occurred mostly in montane scrub grassland. At the species level, Glomus mosseae was dominant in the montane scrub, Acaulospora laevis and Pacispora scintillans were dominant in the alpine steppe, and Acaulospora laevis, Pacispora scintillans, and Glomus claroideum dominated the alpine meadow. It was evident from the distribution pattern of AM fungi in the different vegetation types that the abundance and diversity of AM fungal species were lowest in the montane scrub grassland than the other two plant communities. Climatic conditions, especially temperatures, and intensity of land use may be the most important factors influencing the AM fungal community.  相似文献   

19.
The controlled disposal of tannery sludge in agricultural soils is a viable alternative for recycling such waste; however, the impact of this practice on the arbuscular mycorrhizal fungi (AMF) communities is not well understood. We studied the effects of low-chromium tannery sludge amendment in soils on AMF spore density, species richness and diversity, and root colonization levels. Sludge was applied at four doses to an agricultural field in Rolandia, Paraná state, Brazil. The sludge was left undisturbed on the soil surface and then the area was harrowed and planted with corn. The soil was sampled at four intervals and corn roots once within a year (2007/2008). AMF spore density was low (1 to 49 spores per 50 cm3 of soil) and decreased as doses of tannery sludge increased. AMF root colonization was high (64%) and unaffected by tannery sludge. Eighteen AMF species belonging to six genera (Acaulospora, Glomus, Gigaspora, Scutellospora, Paraglomus, and Ambispora) were recorded. At the sludge doses of 9.0 and 22.6 Mg ha−1, we observed a decrease in AMF species richness and diversity, and changes in their relative frequencies. Hierarchical grouping analysis showed that adding tannery waste to the soil altered AMF spore community in relation to the control, modifying the mycorrhizal status of soil and selectively favoring the sporulation of certain species.  相似文献   

20.
We studied extent and type of arbuscular mycorrhizal (AM) and septate endophytic (SE) fungal associations in five lycophytes and 50 ferns collected from Eastern and Western Ghats regions. Of the 54 species and one variety (belonging to 31 genera) examined; 54 taxa had AM association and AM fungal structures were absent in Marsilea quadrifolia. This is the first report of AM and SE fungal status for 26 species each. Of the 55 taxa examined, AM morphology has been evaluated for the first time in 51 species. The hydrophytic fern Salvinia molesta was mycorrhizal and non-mycorrhizal at different sites. All the epiphytic and saxicolous species examined were mycorrhizal. The percentage of AM colonization ranged from 22.23 (Christella parasitica) to 82.20 (Adiantum lunulatum) in ferns and 53.46 (Selaginella bryopteris) to 84.34 (Selaginella sp.) in lycophytes. Epiphytic life-forms had the maximum average AM colonization levels, whereas aquatic life-forms had the minimum colonization levels. The percentage root length colonized by septate fungi ranged between 0.59 in Ophioglossum reticulatum and 16.36 in Pteris pellucida. The root length with AM and SE fungal structures as well as their total colonization significantly varied among the taxa examined. Most of the lycophytes and ferns had intermediate-type of AM morphology with a few exhibiting Paris-type. AM fungal spore numbers ranged from 1.0 (Angiopteris evecta, Pteridium aquilinum) to (Nephrolepis exaltata) 9.3 spores per 25 g soil and varied significantly among taxa. AM fungal spore morphotypes belonging to Claroideoglomus, Funneliformis, Glomus and Rhizophagus were recorded.  相似文献   

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