Arbuscular mycorrhizal development,glomalin‐related soil protein (GRSP) content,and rhizospheric phosphatase activitiy in citrus orchards under different types of soil management

The arbuscular mycorrhizal (AM) status with respect to colonization of different AM structures in the citrus roots, spore density and hyphal length density, GRSP content, and phosphatase activity in the citrus rhizosphere were investigated in the orchards at Zigui county of the Three Gorges Region, S China. Four soil managements, no‐tillage and natural grass (NN), no‐tillage and sod culture (NS), half‐tillage and film mulching (HT), and clean‐tillage (CT) were employed in those citrus orchards. Our survey showed heavy AM colonization (36%–89%), indicating a high AM dependency of citrus in our experimental orchards. The colonization of different AM structures, spore density, hyphal length density, GRSP content, and phosphatase activity varied greatly between the no‐tillage and tillage citrus orchards. The highest colonization of different AM structures except the ratio of root length with vesicles (RLV), spore density, hyphal length density, GRSP content, and phosphatase activity was observed in the no‐tillage orchards, and the lowest was found in the tillage orchards. A cluster analysis based on the similarity in AM status, GRSP content, and phosphatase activity showed similarities between the NS citrus orchards and the NN citrus orchards. The data presented here demonstrate that tillage reduced the total AM colonization (RLT), spore density, hyphal length density, GRSP content, and phosphatase activity, while those were recovered in the no‐tillage citrus orchards. So, we propose that no‐tillage and planting grass is an effective way for citrus production and improvement of soil quality in orchards of the study area.     

Effects of avocado (Persea americana Mill.) scion on arbuscular mycorrhizal and root hair development in rootstock

Grafting is an important process to propagate horticulture plants; however, the mechanism through which the scion affects the absorption of rootstock remains poorly understood. The effects of the scion on AM fungi types in the rhizosphere soil of rootstock and the absorption of mycorrhizal root were determined in this study. Composition of arbuscular mycorrhizal (AM) fungi, soil assessment, spore density, hyphal length density, glomalin-related soil protein (GRSP) content in rhizosphere soil, root hair morphology and AM colonisation rate were measured among ‘Kampong’ avocado rootstocks grafted with five scions and ‘Kampong’ seedling trees. Results showed the main types of AM fungi in avocado seedling trees and trees grafted with five scions were nearly identical. However, the proportion of main genera exhibited differences. In addition, alkali-hydrolysable N, alkali-hydrolysable P and available K in rhizosphere soil, root hair density, AM colonization, spore density, hyphal length and GRSP content suggested the absorption of ‘Kampong’ rootstocks grafted with ‘Monroe’, ‘Wilson seedless’, ‘Hass’ and ‘Tonnage’ possessed stronger absorption than ‘Kampong’ seedling trees because of high AM colonisation and root hair density. This study suggested scions regulated both the AM and root hair development systematically and laid the foundation for future research of AM-enhancing avocado production.     

Karlheinz richter zum 65. geburtstag

Studies were carried out on spatio-temporal variations of arbuscular mycorrhizal (AM) fungi associated with Carica papaya L. growing in two different geographic localities in Goa, India – Western Ghats and coastal area, differing in soil characteristics and plantation status. The study recorded considerable variation in root colonization, spore density and distribution of AM fungi in the selected sites. The mean total root colonization was at a maximum in the month of July, while spore density was highest in April. The study recorded a total 33 species of AM fungi. Western Ghats recorded a relatively higher diversity of AM fungi compared to coastal area. Species richness of AM fungi was at a maximum in April and coincided with maximum mean spore density. Edaphic as well as climatic factors influenced the AM fungal parameters. The study recorded the existence of seasonality in AM fungi.     

Patterns of endorhizal fungal associations in fruit crops of southern India

A survey on the endorhizal status of 39 fruit crops of 25 families, indicated that 22 fruit crops had arbuscular mycorrhizal (AM)–, four had dark septate endophyte (DSE)–fungal association, and 13 had dual colonization of AM and DSE fungi. Fruit crops were capable of forming Arum‐, Paris‐, or intermediate‐types of AM morphologies of which intermediate‐type was common. To our knowledge, we report for the first time AM in 10 fruit crops and DSE‐fungal association in 17 fruit crops. The extent of AM‐ and DSE‐fungal colonization ranged from 41% to 98% and < 1% to 89.9%, respectively, in different fruit crops. Arbuscular mycorrhizal–fungal spore numbers in the rhizosphere ranged from 6 to 61 spores per 25 g of soil. Arbuscular mycorrhizal–fungal spores belonging to Acaulospora, Glomus, and Scutellospora were isolated from the rhizosphere soil.     

Distribution of roots and arbuscular mycorrhizal associations in tropical forest types of Xishuangbanna,southwest China

Root distribution and mycorrhizal associations were compared in primary, secondary and limestone forests in Xishuangbanna, southwest China. Soil cores to a depth of 20 cm were collected at random points from four 50 m² quadrats in each forest type. Arbuscular mycorrhizal (AM) associations were the only form of mycorrhiza found in all forest types. The primary forest was characterized by high root mass, root lengths and AM colonization levels higher than other forest types. In contrast, secondary forests had greater AM fungal spore numbers and specific root length, indicating that plant species in secondary forests achieved a greater degree of soil exploration with less biomass allocation to roots. Root density, AM colonization and AM fungal spore numbers decreased with soil depth in all forest types. Although the correlation between AM colonization levels and spore numbers was insignificant when all forest types were considered together, significant relationships emerged when each forest type was considered individually. AM colonization and spore numbers were correlated with several root variables.     

FALLOW VERSUS WHEAT CROPPING OF UNAMENDEDAND MANURE-AMENDED SOILS RELATED TO MYCORRHIZAL COLONIZATION,YIELD, AND PLANT NUTRITION OF DRY BEAN AND SWEET CORN

Previous studies reported manure application to eroded Portneuf silt loam soil (Coarse-silty, mixed, superactive, Durinodic Xeric Haplocalcid) improved dry bean (Phaseolus vulgaris L., cv. Viva) yield to levels of topsoil. These yield increases only correlated with whole-plant zinc (Zn) concentration and soil organic matter. This might be related to enhanced arbuscular mycorrhizal (AM) colonization stimulated by manure application. A greenhouse study with dry bean suggested a relationship between manure application, increased AM colonization, and whole-plant Zn uptake, while field studies with wheat (Triticum aestivum L.) and sweet corn (Zea mays L.) did not. To clarify the apparent contradiction of manure application on AM relationships, the present field study with dry bean and sweet corn was conducted in subsoils on the same experimental site established in 1991 and used in previous studies. The existing rotation also allowed the study of the effects of previously fallowed versus wheat cropped subsoils on yield, AM colonization and nutrition of dry bean and sweet corn. Average mycorrhizal root colonization in dry bean was greater on unamended than on manure-amended soils but was not related to increases in yield, Zn concentration, or Zn uptake. Average colonization of sweet corn roots was generally greater in unamended than manure-amended soils, but yields were greater in manure-amended soils. Colonization of sweet corn roots measured over time was consistently greater in subsoils previously cropped to wheat than fallowed, but yields were similar. Previous wheat-cropping resulted in leveling off of colonization beginning 7 July (second sampling) in dry bean, while previous fallow resulted in continuously increasing colonization throughout the five sampling periods. Bean yields were greater on subsoils previously cropped than fallowed; thus yields were generally not related to AM colonization. Results of our study confirm other field results where AM colonization was greater in unamended than manure-amended soils and in cropped than in fallowed soils. Any yield increases observed were not closely related to AM colonization.     

Diversity of arbuscular mycorrhizal fungi in red tangerine (Citrus reticulata Blanco) rootstock rhizospheric soils from hillside citrus orchards

Root colonization, abundance of spores and hyphae, as well as species diversity of arbuscular mycorrhizal (AM) fungi were analyzed in citrus orchards along an altitudinal gradient. The citrus trees were heavily colonized (50.87–77.45%) by native AM fungi. In citrus orchards located at <600 m above sea level (asl), we recorded more extensive hyphal and arbuscular colonization, and higher spore and hyphal length density. AM fungal colonization, spore density, and hyphal length density were closely correlated with edaphic factors such as available phosphorus, pH, and organic matter. A total of 18 AM fungal species belonging to 3 different orders, Archaeosporales (1 species), Diversisporales (7 species) and Glomerales (10 species), were identified on the basis of spore morphological characteristics. In orchards located at higher altitudes (≥700 m asl), we observed a significant decrease in species richness and Shannon–Wiener index values. However, in all of the surveyed orchards, Glomus aggregatum, Funneliformis mosseae and Rhizophagus intraradices were the dominant species. Isolate frequency and relative abundance of AM fungi exhibited clearly distinct distribution patterns among taxonomic families. Canonical correspondence analysis revealed that the AM fungal community structure was significantly influenced by environmental factors, especially altitude, pH, soil moisture, and available nitrogen. Our data indicated that environmental factors are important in determining AM fungal root colonization, propagule numbers, and species diversity in citrus orchards.     

Influence of organic manures on arbuscular mycorrhizal fungi associated with Vigna unguiculata (L.) Walp. in relation to tissue nutrients and soluble carbohydrate in roots under field conditions

 The interaction of plant nutrients, root-soluble carbohydrate availability and arbuscular mycorrhizal (AM) fungi was examined in field grown cowpea [Vigna unguiculata (L.) Walp.]. Plant nutrients were altered through application of farmyard (cow dung, sheep manure) and green (sunnhemp, pongamia) manures. Organic amendments increased plant growth, AM fungal colonization, soluble carbohydrate concentration in roots, and spore numbers. Percent total colonization, root length with vesicles and spore numbers in soil were negatively correlated with the concentration of soluble carbohydrates within roots, which in turn were related to tissue nutrient levels. However, a positive correlation existed between soluble carbohydrate concentrations within root and root length with arbuscules. But the mycorrhizal parameters were related more to plant nutrient level and their ratios, indicating that tissue nutrients have another level of control in addition to their effect on soluble carbohydrate concentration in roots. Increased AM colonization due to organic amendment significantly reduced nutrient imbalances. The strong relationship between colonization and root-soluble carbohydrate concentration levels validates the basic assumption that mycorrhizal fungi act as a 'strong sink' for photosynthates. This study indicates that the host influences AM colonization by regulating the formation of AM fungal structures and spore formation via availability of root carbohydrates. Received: 15 January 1999     

Arbuscular mycorrhizal fungal diversity along a Tibetan elevation gradient

Rhizosphere samples were taken from herbaceous plants along an altitudinal gradient on Segrila Mountain slope. Root colonization and spore biodiversity of arbuscular mycorrhizal fungi (AMF) from different altitudes were analyzed. Of the 146 plant species representing 45 families investigated, 72.2% of plant species were colonized by AMF and formed typical AM structures. A broad range of AM fungal taxa, 62 taxa representing all 4 orders of AMF were isolated from the soil. The composition of the AMF spore community was quite different at different positions along the elevation gradient. Some AM fungi, such as Scutellospora, preferred some specific elevations, or a range of elevation. Intensity of root colonization (M%) and spore density were negatively correlated with the altitude of the study sites. Species richness showed a decreasing trend with increasing elevation but the Shannon–Weiner index was unaffected by elevation. Isolate frequency and relative abundance of AMF also showed quite different distribution patterns among taxonomic families. The drivers of these changes in the AM fungal assemblages is not known and cannot be determined conclusively using such a comparative study along an environmental gradient.     

Reintroduction of a native Glomus to a tropical Ultisol promoted grain yield in maize after fallow and restored the density of arbuscular mycorrhizal fungal spores

Maize (Zea mays L.) is an important crop in central Thailand where fallow is widely practiced and farmers are interested in crop rotation and beneficial soil biota. A pot experiment using a Typic Paleustult (topsoil + subsoil) from the National Corn and Sorghum Research Centre, Nakhonratchasima Province, Thailand was undertaken over three successive crops to evaluate effects of agronomic practices on populations of arbuscular mycorrhizal (AM) fungi and to determine whether reintroduction of a local Glomus was beneficial to maintain maize yield. The three crops and their treatments were: (1) preceding crop: maize grown in all pots; (2) subexperiment 1: agronomic practices [maize, fallow ± soil disturbance, fallow with solarization, non–AM host (cabbage)]; and (3) subexperiment 2: maize ± Glomus sp. 3 at three rates of P fertilization (0, 33, 92 kg P ha^–1). The AM‐fungal community was established under the preceding crop. In subexperiment 1, the three fallow treatments decreased (30%–40%) the total AM spore number in the topsoil whereas there was no change under maize or cabbage. Glomus, the dominant genus, showed sensitivity to fallow. In subexperiment 2, inoculation with Glomus sp. 3 enhanced total AM spore number and root colonization when applied following the three fallow treatments. Furthermore, inoculation promoted grain yield; at nil P following fallow ± soil disturbance, at 33 kg P ha^–1 following fallow without soil disturbance, and following solarization. Two treatments, maize following maize and maize following cabbage, did not respond to inoculation with Glomus sp. 3. Overall, the results suggest that reintroduction of Glomus sp. 3, a local AM fungus in this soil, may overcome negative effects of fallow and promote effectiveness of P fertilizer. Further work is needed to evaluate the benefits of other indigenous AM species that persist under modern fertilization practices.     

Comparison of arbuscular mycorrhizal and dark septate endophyte fungal associations in soils irrigated with pulp and paper mill effluent and well-water

We compared arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal associations in 2 crops and 31 weeds commonly occurring in pulp and paper mill effluent irrigated and well-water irrigated soils. Soil pH, organic C, N, P and K, were higher in pulp and paper mill effluent irrigated than in well-water irrigated soils. In contrast, the average AM fungal colonization, root length with AM fungal hyphae/hyphal coils, spore numbers and diversity were lower in pulp and paper mill effluent irrigated soils compared to well-water irrigated soils. However, no significant variation was found in DSE fungal colonization nor root length with AM fungal arbuscules/arbusculate coils and vesicles between pulp and paper mill effluent irrigated and well-water irrigated soils. A significant negative correlation existed between AM and DSE fungal colonization in both effluent and well-water irrigated soils. Twelve AM fungal spore morphotypes belonging to Acaulospora, Dentiscutata, Glomus, Racocetra and Scutellospora were isolated from the well-water irrigated soils, whereas spores of six morphotypes were isolated from effluent irrigated soils. AM fungal spore numbers were correlated significantly and positively to AM fungal colonization in effluent and well-water irrigated soils.     

Influence of arbuscular mycorrhizal fungi and salinity on growth,biomass, and mineral nutrition of<Emphasis Type="Italic"> Acacia auriculiformis</Emphasis>

The effect of salinity on the efficacy of two arbuscular mycorrhizal fungi, Glomus fasciculatum and G. macrocarpum, alone and in combination was investigated on growth, development and nutrition of Acacia auriculiformis. Plants were grown under different salinity levels imposed by 0.3, 0.5 and 1.0 S m^-1 solutions of 1 M NaCl. Both mycorrhizal fungi protected the host plant against the detrimental effect of salinity. The extent of AM response on growth as well as root colonization varied with fungal species, and with the level of salinity. Maximum root colonization and spore production was observed with combined inoculation, which resulted in greater plant growth at all salinity levels. AM fungal inoculated plants showed significantly higher root and shoot weights. Greater nutrient acquisition, changes in root morphology, and electrical conductivity of soil in response to AM colonization was observed, and may be possible mechanisms to protect plants from salt stress.     

Interactive effect between Cu‐adapted arbuscular mycorrhizal fungi and biotreated agrowaste residue to improve the nutritional status of Oenothera picensis growing in Cu‐polluted soils

The interactive effect of sugar beet (SB) agrowaste and arbuscular mycorrhizal (AM) fungi inoculation in response to increasing Cu levels was evaluated in the metallophyte Oenothera picensis. Plants were grown in a Cu‐added soil (0, 100, or 500 mg Cu kg^?1), in presence or absence of SB, and inoculated with: (1) indigenous Cu adapted mycorrhiza (IM) isolated from Cu‐polluted soils; (2) Claroideoglomus claroideum (CC); or (3) maintained uninoculated (control). Sugar beet application produced an increase in shoot biomass of 2 to 7 times, improving plant nutritional status and allowing their survival at the highest Cu concentrations. Moreover, AM fungi utilization had a positive effect promoting the plant establishment; nevertheless, Cu plant concentration as well as the mycorrhizal development in terms of AM colonization, AM spore density, and glomalin production were strictly dependent of the AM fungi strains used. Remarkable differences between AM fungi strains were observed at the highest soil Cu level where only plants colonized by IM were able to survive and grow when no SB residue was added. An interactive effect between AM fungi and SB produced a higher plant growth than plants without the amendment application, improving the plant establishment and allowing their survival at highest copper concentrations, suggesting that this combination could be used as a biotechnological tool for the phytoremediation of Cu‐polluted soils.     

钼污染对丛枝菌根和球囊霉素的影响

丛枝菌根作为地球上最广泛的共生体,在各种逆境环境中发挥着重要作用.基于不同钼污染程度的钼矿区,分析了钼污染对丛枝菌根真菌侵染、繁殖及其分泌球囊霉素能力的影响.结果 表明,在4个不同钼污染级别的土壤中,丛枝菌根真菌与植物共生关系的形成未受到钼污染的影响,平均菌根侵染频度为50.64％.洛阳钼矿区土壤的平均孢子密度为19....     

沿海拔梯度分布的柑橘园中土壤肥力因子与丛枝菌根共生体的关系

Arbuscular mycorrhizal(AM) symbionts are able to greatly affect soil fertility. However, the relationships between AM symbiosis development levels and citrus mycorrhizosphere soil fertility remain weakly known in field. In our study, AM colonization, spore density, hyphal length density, and glomalin-related soil protein(GRSP) content in citrus(Robertson naval orange grafted on Citrus reticulata Blanco) orchards along an altitudinal gradient were investigated seasonally in southern China. The results showed that AM colonization and abundances of spore and hyphae fluctuated significantly in different seasons and altitudes. The highest AM colonization(83.03%) was observed in orchards at 200 m above sea level in summer, spore density(16.8 spores g-1soil) in orchards at 400 m in autumn, and hyphal length density(2.36 m g-1soil) in orchards at 600 m orchards in summer; while the lowest values(43.60%, 2.7 spores g-1soil and 0.52 m g-1soil of AM colonization, spore density, and hyphal length density, respectively) were all observed in orchards at 800 m in winter. Correlation analyses demonstrated that the soil properties such as soil organic matter,alkali-hydrolyzable N, available P, and p H were significantly(P < 0.05) positively correlated with either citrus total AM colonization or the abundances of spore and hyphae. GRSP was significantly(P < 0.05) positively correlated with soil organic matter and p H.Redundancy analysis supported that soil environmental factors such as altitude, GRSP, soil organic matter, and alkali-hydrolyzable N severely(Monte Carlo permutation tests, P = 0.002) influenced AM colonization and abundances of spore and hyphae in citrus orchards. Our data demonstrated that soil environmental factors are vital in determining AM symbiosis development in citrus orchards.     

Arbuscular mycorrhizal fungi respond to rhizobial inoculation and cropping systems in farmers' fields in the Guinea savanna

 It has been difficult to explain the rotation effect based solely on N availability in maize-soybean cropping systems in the moist savanna zone of sub-Saharan Africa. Although arbuscular mycorrhizal fungi (AMF) can contribute to plant growth by reducing stresses resulting from other nutrient deficiencies (mainly P) and drought, their role in the maize/soybean rotation cropping systems in the Guinea savanna has not yet been determined. Pot and field experiments were conducted for 2 years using 13 farmers' fields with different cropping histories in two agroecological zones (Zaria, northern Guinea savanna and Zonkwa, southern Guinea savanna) in Nigeria. We quantified the influence of cropping systems and rhizobial inoculation on plant growth, mycorrhizal colonization and diversity of promiscuous soybean and maize grown in rotation. The relationships between these variables and selected soil characteristics in farmers' fields were also examined. Percentage mycorrhizal colonization in promiscuous soybean roots ranged from 7% to 36%, while in maize it varied between 17% and 33%, depending on fields and the previous cropping history. A large variation was also observed for mycorrhizal spores, but these were not correlated with mycorrhizal colonization and did not appear to be influenced by rotation systems. Soybean mycorrhizal colonization was higher (13% increase) in Zonkwa, but not in Zaria, if the preceding crop was maize and not soybean. These differences were related to the soil P concentration, which was positively related to mycorrhizal colonization in Zonkwa but negatively to this parameter in Zaria. The previous crop did not affect mycorrhizal colonization of maize in both locations. Soybean cultivars inoculated with rhizobia had a higher mycorrhizal colonization rate (25%) and more AMF species than maize or uninoculated soybean (19%). Maize grown in plots previously under inoculated soybean also had higher percentage mycorrhizal colonization than when grown after uninoculated soybean and maize. Four AMF genera comprising 29 species were observed at Zaria and Zonkwa. Glomus was the dominant genus (56%) followed by Gigaspora (26%) and Acaulospora (14%). The genus Sclerocystis was the least represented (4%). Received: 28 October 1998     

西北地区赤霞珠葡萄根际土壤中AM真菌的多样性

对西北地区5个酿酒葡萄赤霞珠（Vitis vinifera L. cv. Cabernet Sauvignon）葡萄园根际土壤060 cm土层的AM真菌空间分布进行了研究。结果表明,葡萄根系可形成丛枝菌根,且侵染率较高,最高达79%; 在西北地区的5个样地中共分离出AM真菌4属22种,其中球囊霉属（Glomus）15种,无梗囊霉属（Acaulospora）4种,盾巨孢囊霉属（Scutellospora）2种,巨孢囊霉属（Gigaspora）1种。5个样地孢子密度大小顺序为: 陕西泾阳（JY）＞山西永济（YJ）＞陕西杨凌（YL）＞宁夏银川（YC）＞甘肃莫高（MG）。各样地葡萄根际土壤中AM真菌种的丰富度不同,陕西泾阳地区最高; 分布于葡萄根际的AM真菌按种类多少排序的属依次是: 球囊霉属无梗囊霉属盾巨孢囊霉属巨孢囊霉属,球囊霉属占据的比例保持着绝对优势; 根内球囊霉、摩西球囊霉、地表球囊霉在不同样地中均为优势菌株,副冠球囊霉,集球囊霉,细凹无梗囊霉是多数样地中的稀有种类。研究表明,葡萄与AM真菌具有良好的共生关系,二者协同进化产生了具有生态环境特异性的菌根真菌多样性; 葡萄根际存在较为丰富的丛枝菌根真菌资源,可供进一步开发利用。     

Long‐term effects of cropped vs. fallow and fertilizer amendments on soil organic matter I. Organic carbon

A long‐term field experiment, conducted since 1962 in Gumpenstein (Austria) on a Dystric Cambisol, was used for the present investigation. We combined a physical fractionation procedure with the determination of natural abundance of ¹³C and FT‐IR spectroscopy to study the influence of fertilizer amendments (organic manure and mineral fertilizers) and management practices (fallow vs. cropped) on changes in organic carbon (OC) associated with different particle‐size fractions. The OC content in bulk soil decreased or was not affected by slurry+straw, PK, and NPK treatments in both fallow and cropped plots after 28 and 38 yr of treatment. However, OC in plots receiving organic manures increased depending on the quality of the organic manures applied. The ranking among the different treatments under both fallow and cropped plots was: animal manure (liquid) > animal manure (solid) > cattle slurry = slurry+straw = PK = NPK. Results showed that the two types of management practices, fallow (non‐tilled) vs. cropped (tilled) had effects on OC concentrations. Comparing the OC contribution of particle‐size fractions to the total OC amount revealed the following ranking: silt > clay > fine sand > coarse sand except in the plots receiving solid or liquid animal manure. Size fractions within treatments showed larger variations of ¹³C abundances than bulk samples between treatments. The natural abundances of ¹³C increased especially in cropped (and tilled) plots. It was shown by cluster analysis that FT‐IR spectra differentiated between the different treatments originating from different land management practices. The present study revealed that below‐ground C deposition by agricultural plants can hardly compensate the C losses due to tillage.     

Arbuscular mycorrhizal associations in sesame under low-input cropping systems

The abundance and composition of arbuscular mycorrhizal fungi (AMF) are generally low under managed agroecosystems in comparison to natural ecosystems. The objective of the study was to determine the composition and species richness of AMF associated with sesame under traditional low-input cropping system in Kerala, India. Wide variability in root colonization by AMF as well as spore density in the rhizosphere existed in sesame. Correlation between frequency of colonization (F%) and spore density as well as between these variables and soil characteristics showed a negative relationship. The fungal variables were influenced by soil factors such as pH, soil organic carbon (OC) and available nutrients. Frequency of colonization was positively correlated (P < 0.01) with soil pH and potassium (K) and negatively correlated with OC, nitrogen (N) and phosphorus (P). AM spore density was positively correlated with OC, N and P and negatively correlated with pH and K. Ten taxa of AMF belonging to the genera Acaulospora, Diversispora, Funneliformis, Gigaspora, Glomus and Scutellospora were associated with sesame, with the predominance of Funneliformis and Acaulospora in both frequency and relative abundance over a wider soil nutrient range. Soil characteristics appear to have a profound influence on the composition and species richness of AMF under traditional low-input cropping systems.     

不同地点和复垦方式煤矸石山土壤中丛枝菌根真菌群落变化

以山西省大同市晋华宫人工复垦和自然恢复煤矸石山以及忻州窑自然恢复煤矸石山为研究对象,采用IlluminaMiSeq高通量测序技术对三座煤矸石山土壤AM真菌群落组成进行分析,并测定其土壤理化性质,以探究不同地点煤矸石山不同复垦方式下土壤中丛枝菌根真菌（Arbuscular mycorrhizal fungi, AM真菌）群落组成的差异及其土壤影响因子。结果表明：晋华宫人工复垦煤矸石山和忻州窑自然恢复煤矸石山AM真菌多样性指数（Chao指数和香农-威纳指数）存在显著差异,但晋华宫人工复垦和自然恢复煤矸石山AM真菌群落的多样性指数差异不显著。试验共检测到67个AM真菌OTUs,可鉴定到3个AM真菌属级分类单元,其中球囊霉属（Glomus）在晋华宫人工复垦煤矸石山、晋华宫自然恢复煤矸石山和忻州窑自然恢复煤矸石山中均为最优势菌,多样孢囊霉属（Diversispora）、类球囊霉属（Paraglomus）仅出现在晋华宫自然恢复煤矸石山。多元置换方差分析和多维尺度分析结果表明,晋华宫两种恢复方式的煤矸石山之间AM真菌群落组成差异不显著,而晋华宫与忻州窑两个地点的煤矸石山AM真菌群落组成差异显著。AM...