不同套种模式云南核桃丛枝菌根与土壤因子的相关性研究

为探明不同套种模式核桃根际丛枝菌根(AM)与土壤因子之间的相关关系,采用菌根形态学的研究方法,研究了核桃根系中丛枝菌根真菌(AMF)定殖状况和根际土壤中AMF的孢子密度,运用相关分析、主成分分析和通径分析方法,研究了核桃AMF与土壤因子的相关性.结果表明:核桃根系能与AMF形成良好的共生关系,不同套种模式之间核桃根系中...     

云南不同栽培区油橄榄的丛枝菌根研究

为探索云南不同栽培区油橄榄的丛枝菌根状况,在云南省3个主要的油橄榄引种栽培区即永仁、丽江和昆明的油橄榄种植园,选择4年生油橄榄幼树为研究对象,采用形态学的研究方法,对该树种的丛枝菌根(AM)状况和土壤中丛枝菌根真菌(AMF)的孢子数量和群落组成进行了研究。结果发现,3地种植园的油橄榄植株根系均有AMF的定殖,根系中AMF的总定殖率分别为47.11%、71.79%和87.15%,孢子密度依次为300.22个/20g土、702.56个/20g土和489.75个/20g土。统计分析表明,根系AMF总定殖率昆明显著高于丽江,丽江显著高于永仁(p0.05),3地根际土壤中AMF孢子密度差异显著。从永仁、丽江和昆明油橄榄的根际土壤中分离到的AMF孢子种类分别为6种、4种和4种,大果球囊霉是3地共有AMF优势种;永仁样地AMF类群显著不同于昆明和丽江两个样地,与两地的AMF群落相似性Sorenson’s系数均为0.2;昆明和丽江两地的共有种除大果球囊霉以外,还有缩球囊霉和根内球囊霉,两地的Sorenson’s系数达0.75。     

广东清远石灰岩3个植物群落菌根及土壤AMF孢子多样性

以广东省清远市清新县石灰岩山区风水林、次生草坡和旱作耕地的退化植被群落为主要研究对象,比较研究了3个植物群落常见植物的菌根感染率和根际土丛枝型菌根真菌(AMF)孢子的密度和丰富度。结果如下:在所检测的29种常见植物中,除凹头苋(Amaranthus blitum)外,其余植物均具有典型的丛枝型菌根结构;次生草坡植物的菌根感染强度和频度均较高,风水林次之,旱作耕地杂草的菌根感染强度和频度相对较低;在3个植物群落土样中共分离出70种AMF孢子,以球囊霉属(Glomus)最为丰富,无梗囊霉属(Acaulospora)次之;林相保护较完整、植物较丰富的风水林拥有最丰富的AMF孢子类型和最高的密度,而结构退化、物种贫乏的次生草坡和旱作耕地中的AMF孢子类型少,密度也明显降低。研究表明植物群落的物种多样性与其根际土AMF孢子丰富度和多样性具有密切的联系。     

枫香根际丛枝菌根真菌多样性

【目的】为探明湖北、安徽两省20个典型采样地枫香根际丛枝菌根真菌(AMF)多样性,对枫香根际土壤中AMF种类、分布、菌根侵染等状况进行调查,初步了解该地区枫香林区AMF资源情况,为进一步探究当地枫香林地AMF群落结构及其生理生态功能提供参考。【方法】以10、20、50和100年生枫香为对象,采集枫香根际5～25 cm土壤样品,测定土壤理化性质。试验基于形态特征对分离的AMF孢子进行分类鉴定,利用KOH脱色锥虫蓝染色法观察20个采样地枫香根系的AMF侵染状况。冗余分析(RDA)探讨枫香根际丛枝菌根真菌与土壤因子的关系。【结果】1) 20个样本中97.65%的枫香根样均检测到了AMF侵染,侵染率为49.43%～73.84%,平均侵染率为62.07%,安徽稽灵山枫香根样侵染率最高(73.84%),湖北九峰山森林公园枫香根样侵染率最低(49.43%)。根内真菌丛枝和泡囊较多,呈均匀分布,表明枫香容易被AMF侵染,但不同采样点之间无显著差异(P0.05)。2)取样地土壤中分离出AMF孢子数为[86～275个·(50 g)~(-1)]土,平均孢子密度为166个·(50 g)~(-1)土,表现为安徽稽灵山最高[275个·(50 g)~(-1)土],安徽黄山最低[86个·(50 g)~(-1)土]。3)通过形态学鉴定,共分离AM真菌11属46种,其中球囊霉属12种、无梗囊霉属13种、盾巨孢囊霉属5种,为取样地区枫香根际土壤AM真菌的优势属。4)土壤总球囊霉素和易提取球囊霉素含量分别在1.01～2.01 mg·g~(-1)和0.62～0.84 mg·g~(-1)之间。5)不同取样点枫香根际土壤AM真菌的属数、Shannon(香农)和Simpson多样性指数呈显著性差异(P0.05),并发现黄山林科院AMF的均匀度指数(1.04±0.03)和香农指数(3.55±0.04)最高。6) RDA分析可知枫香根际土壤过氧化氢酶活性、土壤有机质、土壤pH值和土壤蔗糖酶活性与AMF多样性呈显著相关(P0.05)。其中土壤pH和土壤过氧化氢酶活性对AMF多样性影响最大,土壤蔗糖酶活性和总球囊霉素含量呈显著正相关(R=0.705,P0.05)。【结论】湖北、安徽两省的20个样地人工林和天然林枫香根际均可形成丛枝菌根,根际土壤中的AMF孢子多样性丰富,球囊霉属为优势菌群。本研究结合AMF在生态系统中的分布特点,为开发枫香专用AMF肥料提供了丰富的菌种资源。     

油桐人工林AMF多样性及接种试验研究

为了研究油桐根系丛枝菌根(AM)共生状况和丛枝菌根真菌(AMF)多样性,并通过油桐苗木AMF接种试验以探索与油桐高效种植相配套的菌根接种技术。在云南丘北,对4 a生和10 a生油桐人工林的根系丛枝菌根真菌定殖及根际丛枝菌根真菌多样性进行了研究,采用油桐林的土著AMF和商品AMF菌剂"Endo"开展了接种试验研究。结果显示:10 a生的油桐具有更高的AMF定殖程度,而4 a生的油桐根际孢子密度相对比较大;油桐育苗期对土著菌种接种具有较好的响应,接种后苗木生长状况基本优于对照;在幼树初期,"Endo"菌剂对油桐植株的促进生长效应较为显著,接种处理也基本优于对照;菌剂在育苗基质中浓度越大,促进生长效果越好。     

土庄绣线菊AMF多样性及季节变化分析

为探讨内蒙古大青山土庄绣线菊根围丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)多样性及季节变化规律,分别于2014年春、夏、秋3个季节采集土庄绣线菊根际土壤,采用湿筛倾析-蔗糖离心法分离AMF孢子,运用形态学方法进行种类鉴定。结果表明,AMF侵染强度、丛枝丰富度、孢子密度、种的丰富度的季节变化存在显著的差异,4个指标均显示夏季最高,秋季次之,春季最低。3个季节共分离出AMF10属44种,包括2个未知种,其中Rhizophagus、Funneliformis和Glomus为3个季节的共有优势属,Rhizophagus intraradices和Funneliformis mosseae为3个季节的共有优势种。丰富度、Shannon指数和Simpson指数与全N和速效P呈显著负相关,与速效K呈显著正相关。丰富度与p H值呈显著负相关,与碱解N呈显著正相关。土庄绣线菊根际AMF季节变化与植物物候一致,并与土壤因子密切相关。     

紫背天葵丛枝菌根真菌多样性研究

紫背天葵（Begonia fimbristipula）是集营养保健和特殊风味为一身的野生高档蔬菜之一,也是 南方传统中药材,但人工栽培尚存在较大的技术障碍。以紫背天葵为研究对象,对分布于广西壮族自治 区贺州市姑婆山国家森林公园的野生植株根际土丛枝菌根真菌（Arbuscular Mycorrhiza Fungi,AMF）孢 子、菌根侵染率和土壤营养元素等开展研究,以期对后期的菌根化栽培提供技术支撑。结果表明：紫背 天葵根际土中AMF 种类丰富,孢子密度大,菌根侵染率较高,共统计真菌孢子26 种,主要属为球囊霉 属（Glomus）、无梗囊霉属（Acaulospora）、盾孢囊霉（Scutellospora）和巨孢囊霉属（Gigaspora）;根际 土孢子密度和菌根侵染率在不同采样点间存在显著性差异,而且均与土壤的全K 含量呈负相关,与交换 性Ca 含量呈正相关,另外,AMF 孢子丰富度与速效K 呈负相关,菌根侵染率与有机质含量呈正相关。 可见紫背天葵野生根际土的真菌孢子在K 含量较低时,多样性较高,主要为球囊霉属和无梗囊霉属的种 类。     

横断山脉亚高山带几种高山栎林下丛枝菌根菌（AMF）调查

[目的]明确横断山脉亚高山带高山栎林下AMF孢子分类地位。[方法]自横断山脉亚高山带不同地段选择6个高山栎根围土壤和根系样本，对其土壤中AMF孢子利用湿筛沉淀法进行选取。利用AMF特异引物对其ITS区段18S rRNA基因进行扩增，结合形态学与分子生物学手段对其进行鉴定，构建系统发育演化树并推测其亲缘关系。[结果]四川、西藏高山栎林下土壤AMF孢子与根系克隆为类球囊霉属（Paraglomus），云南香格里拉高山栎林下土壤AMF孢子与根系克隆为球囊霉属（Glomus）。克隆结果表明：AMF能够广泛存在于高山栎组植物根系。根系苯胺蓝染色结果可见明显类似丛枝和泡囊的结构。综合高山栎土壤AMF孢子与根际AMF鉴定结果认为，高山栎林下存在大量AMF，且目前不同采样地高山栎林下根围土和根系分别仅发现一种AMF存在，提示各高山栎同时仅能与一种AMF发生共生关系。此外，高山栎林下AMF孢子在演化过程中发生分化并介于Paraglomus与Glomus的分类地位之间，且西藏、四川地区AMF与云南香格里拉地区AMF存在差异。[结论]本研究发现，自然条件下横断山脉亚高山地区高山栎林下菌塘普遍存在AMF，且云南...     

孟加拉国Dinajpur农林复合区内不同树种和作物种中丛枝菌根分布和孢子群落多样性的研究

从孟加拉国Dinajpur地区采集了不同农林复合区内树种和作物种,对采集植物的丛枝菌根多样性进行了研究.在3个取样地采集了18种植物的根和根际土,取样地和被采取植物分别为：取样地Dashmail为黄豆树 （Albizia procera Benth.）、小指椒 （Capsicum frutescens L）、姜黄（Curcuma domestica Vahl）、印度黄檀 （Dalbergia sissoo Roxb.） 和大叶桃花心木（Swietenia macrophylla）5种植物; 取样地Kantaji为姜黄（C.Domestica）、印度檀 （D.Sissoo）、赤桉 （Eucalyptus camaldulensis Dehnn.）、石梓（Gmelina arborea （Roxb） DC） 和水稻 （Oryza sativa L.） 5种植物; 取样地Ramsagar为姜黄（C.Domestica）, 印度檀 （D.Sissoo）, Litchi chinensis Sonn.和水稻.在取样地Dashmail,植物丛枝的分布范围在36%-79%,其中分布最高的是小指椒,达到79%,而C.Domestica仅占36%.取样地 Kantaji丛枝的分布范围在33%-70%之间,其中分布最高的是石梓,达到79%,而O.Sativa分布最低,仅36%.取样地 Ramsagar丛枝的分布范围在35%-70%之间,印度檀丛枝分布在该地最高, 达70%,而水稻丛枝在该地的分布最小,仅35%.在采样地Dashmail,每100克干土中所含采样植物丛枝菌根孢子群落54-140个;孢子群落最多的是印度檀（140/100g dry soil）,最低的是姜黄（C.Domestica） （40/100g dry soil）.在采样地Kantaji,孢子群落在63-221/100g dry soil,石梓具有的群落最高,为221/100g dry soil;印度檀为63/100g dry soil.在采样地Ramsagar, 所具有的最高和最低群落分别是 160/100g dry soil （D.Sissoo）和69/100g dry soil（L.Chinensis）.土壤Ph值与土壤中丛枝分布和菌根孢子群落无显著相关性.Simpson多样性指数和Shannon多样性指数在取样地Kantaji 的印度檀土壤中最高;而在取样地Ramsagar的水稻土壤中最低.研究表明孟加拉国Dinajpur地区丛枝菌根的存在、树种和作物种中的营养性质、丛枝菌根的必要性和贡献以及复合农林植物生长与丛枝?     

丛枝菌根真菌及其在石灰岩地区植物恢复中的应用

丛枝菌根真菌(AMF)是一类能与绝大部分植物根系形成互利共生体的微生物,为生态系统中重要的土壤微生物之一。石灰岩加速环境恶化,生态系统退化。AMF具有独特的生理功能,在石灰岩地区植被恢复中具有重要的价值。该文总结了AMF结构特点、生理功能及其在石灰岩山地植物恢复中应用,并探讨了AMF在石灰岩地区的发展与应用前景,对石灰岩退化生态系统恢复具有重要的理论和实践意义。     

Arbuscular mycorrhizas and performance of Polylepis australis trees in relation to livestock density

Polylepis australis trees endemic to Argentina dominate the canopy of subtropical high altitude forests. Here, livestock rearing is the main economic activity and is suspect of the low performance of P. australis trees through direct and indirect effects which could include the reduction in arbuscular mycorrhizal fungi (AMF) and their benefit to trees. To elucidate the role of AMF, we compare plant performance indicators, arbuscular mycorrhizal (AM) colonization and AMF communities in 20 trees distributed in two areas of central Argentina which differed in livestock grazing intensity. The area with high livestock density presented more soil degradation and trees with a lower overall plant performance than the area with reduced livestock density. The AM colonization values of P. australis were considerably higher than reported for other tree species and the area with high livestock density had a lower proportion of arbuscules and higher proportion of hyphae, while vesicles and AM colonization – all structure considered together – did not differ between areas. Overall AMF spore number and of most species when considered separately was significantly higher in the area with high livestock density, suggesting a high tolerance and adaptation of AMF to livestock. We conclude that a reduction in livestock improves the performance of P. australis, that this improvement could be mediated by an increase in the proportion of arbuscules, but there does not appear to be any limitation in AM colonization or AMF spore number which could otherwise be limiting forest restoration.     

Growth response, phosphorus content and root colonization of Polylepis australis Bitt. seedlings inoculated with different soil types

Polylepis forests are one of the most endangered high mountain ecosystems of South America and reforestation with native Polylepis species has been highly recommended. Greenhouse bioassays were set up to determine the influence of three different soils on growth and phosphorous nutrition of Polylepis australis seedlings. Soils were collected from a grassland, a rare mature forest and a forest degraded due to repeated fires. We identified the arbuscular mycorrhizal fungi (AMF) present in the three soils and after 12 months we harvested the seedlings to evaluate root and shoot biomass, plant P content and root colonization by native AMF and dark septate endophytes (DSE). The soil inocula contained 26 AMF morphospecies. Grassland inoculum showed the highest AMF richness, and mature forest showed a different AMF community assembly from grassland and degraded forest inocula. Root biomass and root colonization were highest in seedlings inoculated with mature forest soil, meanwhile shoot biomass and plant P content were similar between all treatments. AMF colonization correlated negatively with DSE and root biomass was negatively correlated with DSE colonization, thus these fungal symbionts could be competing for resources. Our results indicate that AMF inoculum from the mature forest stand has the potential to improve P. australis performance, probably due to the dominance of Glomeraceae and Acaulosporaceae families. However, other soil microorganisms could be together with AMF in the natural inocula, affecting the growth response of P. australis seedlings. Future studies evaluating the effect of these inocula under field conditions should be carried out.     

Vegetation cover density and disturbance affected arbuscular mycorrhiza fungi spore density and root colonization in a dry Afromontane forest,northern Ethiopia

Arbuscular mycorrhiza fungi(AMF) are vital in the regeneration of vegetation in disturbed ecosystems due to their numerous ecological advantages and therefore are good indicators of soil and ecosystem health at large. This study was aimed at determining how the seasonal, vegetation cover density, edaphic and anthropogenic factors affect AMF root colonization(RC) and spore density(SD)in Desa'a dry Afromontane forest. AMF RC and SD in the rhizosphere of five dominant woody species, Juniperus procera, Olea europaea, Maytenus arbutifolia, Carissa spinarum and Dodonaea angustifolia growing in Desa'a forest were studied during the rainy and the dry seasons in three permanent study vegetation cover density plots(dense, medium, and poor). Each plot(160 x40 m~2) has two management practices(fenced and unfenced plots) of area. A 100 g sample of rhizosphere soil from moisturefree composite soil was used to determine spore density.Spore density ranged from 50 to 4467 spores/100 g soil,and all species were colonized by AMF within a range of 4–95%. Glomus was the dominant genus in the rhizosphere of all species. Vegetation cover density strongly affected SD and RC. The SD was significantly higher(p 0.05) in the poor vegetation cover density than in the other two and lowest in the dense cover; root colonization showed the reverse trend. Management practices significantly(p 0.05) influenced AMF SD and RC, with the fenced plots being more favoured. Seasons significantly(p 0.05) affected RC and SD. More RC and SD were observed in the wet period than the dry period. Correlating AMF SD and RC with soil physical and chemical properties showed no significant difference(p 0.05) except for total nitrogen. Disturbance, vegetation cover density, season and total nitrogen are significant factors that control the dynamics and management interventions to maintain the forest health of dry Afromontane forests.     

Disturbance changes arbuscular mycorrhizal fungal phenology and soil glomalin concentrations but not fungal spore composition in montane rainforests in Veracruz and Chiapas,Mexico

Mexican montane rainforests and adjacent disturbed areas were studied for disturbance-related spatio-temporal changes to the arbuscular mycorrhizal fungal (AMF) community and soil glomalin concentration. The AMF community functions to both improve plant growth and soil conditions and is thus an important component to the restoration of this forest type to disturbed areas. The study areas included mature rainforests that were converted to pine forests, milpas, pastures and shrub/herbaceous plant communities via burning and logging. Seasonal patterns in AMF spore species richness and sporulation significantly differed across disturbance types at two of the three sites surveyed. Contrasting patterns of sporulation among AMF families across different disturbance types helped to explain how species richness and composition were maintained despite dramatic changes to the host plant community. Meaning, in most cases, disturbance induced changes in when different AMF taxa sporulated but not what taxa sporulated. Only conversion from mature pine–oak–Liquidambar–Persea forests to pine-dominated stands severely reduced AMF spore richness and total sporulation. Surprisingly, in pine-dominant stands no concomitant negative impacts on soil glomalin (MAb32B11 immunoreactive soil protein) concentrations were detected. However, soils of mature forests containing no pines had the highest concentration of glomalin. Conversion to pasture and milpa (diverse cornfield) had a strong negative impact on the concentration of soil glomalin concentrations. In sharp contrast, the same disturbance types improved AMF sporulation and AMF spore richness. It appears that disturbance type, and not AMF community measures used herein, best predicts changes in soil glomalin concentration.     

Arbuscular mycorrhizal fungi communities associated with wild plants in a coastal ecosystem

Arbuscular mycorrhizal fungi(AMF) form a near-ubiquitous mutualistic association with roots to help plants withstand harsh environments,and play a key role in the establishment of coastal beach plant communities.Yet little is known about the structure and composition of AMF communities on coastal beaches of eastern China.In this study,we investigated the occurrence,community composition and diversity of AMF associated with common wild plants on a coastal beach of North Jiangsu,China.Almost all of the local wild species were colonized by AMF except for Chenopodium album L.Thirty-seven AMF species were isolated from the rhizosphere belonging to 12 genera in seven families.Glomus was the dominant genus and Funneliformis mosseae the dominant species.The colonization,spore composition and diversity of AMF were strongly related to edaphic factors.Sodium(Na~+) ions in the soil significantly and negatively affected the colonization rate by AMF and both soil Na~+ levels and pH had a significant negative effect on AMF spore density and evenness.However,there was a significant positive correlation between species richness and total organic carbon.The results provide insights into soil factors affecting native AMF communities in coastal beach habitats which could benefit vegetation recovery and soil reclamation efforts.     

Arbuscular mycorrhizae and ectomycorrhizae in native tree legumes in Uruguay

The level of colonization by ectomycorrhizae (ECM) and arbuscular endomycorrhizae (AM) of 23 species of native trees and shrub legumes was studied. Root samples were obtained from different regions of Uruguay. Colonization level was determined by observing AM fungal structures (hyphae, arbuscules, vesicules) in stained root segments. The number and morphological type of spores were determined in 100 g of rhizosphere soil. Ectomycorrhizal colonization was evaluated by direct and microscopic observation of root tips. All species had a high level of AM colonization. In Papilionoideae colonization varied between 62% and 78%, in the Mimosoideae between 18% and 69% and in the Caesalpinioideae the variation was larger (6–74%). These results show a significant presence of fungi that form arbuscular mycorrhizae in our soils. The number of spores forming AM in rhizosphere soil (280–l.620 spores/100 g of dry soil) was also highly relative to references for other leguminous trees. Spores were grouped in three principal morphological types Acaulospora, Glomus and Sclerocystis. Presence of ECM fungi was evident only when observed under the microscope. 26% of the plant species exhibited this type of mycorrhizae, reaching a maximal value of 36% in Mimosoideae. Only six plant species exhibited both types of mycorrhizae. Dual colonization could help in the colonization of poor soils and for their use in agroforestry systems.     

Biodiversity of arbuscular mycorrhizal fungi in Amygdalus scoparia Spach plantations and a natural stand

The biodiversity of arbuscular mycorrhizal fungi(AMF) was surveyed in the Kolm region of Iran in three adjacent sites, a natural stand, a 10-year-old and a 15-yearold plantation of Amygdalus scoparia. To date, there have been few studies of AMF biodiversity in Iran, especially in the western forests of the country. For this study, soil and root samples were taken from A. scoparia rhizosphere soil in spring and autumn. Almost half of the root length was colonized by AMF. We identified 13 AMF species belonging to Glomeraceae, Claroideoglomeraceae or Diversisporaceae. The three plantations differed in terms of soil electrical conductivity, organic C and P. Spore density was significant correlated with P concentration. Root length colonization was correlated only with soil Ca.Species diversity and richness were significantly correlated with soil N, P, organic C and spore density. AMF diversity in 15-year-old plantations was more similar to that in the natural stand than in the 10-year-old plantation. We confirmed that a 15-year-old plantation is not similar in terms of AMF colonization to natural stands. We conclude that more than 15 years are required for AMF colonization of plantations to resemble that of natural stands.     

Specific Variations of Arbuscular Mycorrhizal (AM) Fungi in Potential Timber Yielding Tree Species From the Western Ghat Region of Goa,India

Studies were carried out on the arbuscular mycorrhizal (AM) fungal association in four potential timber yielding tree species from four forest areas of the Western Ghat region of Goa, India. The edaphic factors selected for the study varied within the four study sites. Significant positive and negative correlations were exhibited between spore density and root colonization of AM fungi at two sites, Collem and Dharbandoda. The study recorded the presence of 21 AM fungal species belonging to three genera—viz., Acaulospora, Gigaspora, and Glomus. The present study suggests that there is a site specific variation in root colonization (except at Mollem) and spore density as well as edapho-specific variation in association, composition, and distribution of AM fungi associated with potential timber yielding trees from four forest areas in the Western Ghat region of Goa. Further investigations of AM fungal dynamics if carried out can help elucidate the ecological significance of AM fungal associations in the Western Ghat region of Goa. To add, learning more about the ecology and intricacies of the AM association is crucial for attaining a good understanding of its life cycle and functions in edapho-climatic conditions of the Western Ghat region of Goa to further use it in the management of reforestation practices.