商洛地区8种药用植物VA菌根真菌的资源调查

通过对陕南商洛地区8种药用植物VA菌根真菌资源进行了调查,共鉴定出3科3属6种VA菌根真菌:缩球囊霉(Glomus constrictum Trappe)、集球囊霉(Glomus fasciculatu Gerd.&Trappe emend.Walker&Koske)、白色球囊霉(Glomus albidum Walker&Rhodes)、多梗球囊霉(Glomus multicaule Gerd.&Bakshi)、细凹无梗囊霉(Acaulospora scrobiculata Trappe)、大巨孢囊霉(Gigaspora gigantean Gerd.&Trappe)。本文对这六种VA菌根真菌的主要形态学特征进行了描述,并分析了其侵染率。     

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。     

矿区排土场土壤中丛枝菌根真菌对刺槐接种效应

土壤中丛枝菌根真菌促进植物对矿质营养和水分的吸收,可以增强宿主植物在逆境条件下的生存能力。利用丛枝菌根真菌与宿主植物共生关系,在以矿区排土场土壤为基质的盆栽试验条件下,向刺槐幼苗接种供试丛枝菌根真菌(摩西球囊霉Glomus mosseae、象牙白多孢囊霉Diversispora eburnea、隐类球囊霉Paraglomus occultum及3种真菌的混合菌剂),验证丛枝菌根真菌对刺槐生长的影响。结果表明,接种供试丛枝菌根真菌能显著提高刺槐幼苗生物量和叶绿素含量,其中以接种摩西球囊霉组植株菌根侵染率、株高、地径、生物量和SPAD值最高,说明供试菌剂中摩西球囊霉与刺槐幼苗根系的亲和力最高,接种效应最显著。研究结果为菌根技术在矿区土地复垦中的应用提供参考。     

四川主要农用土壤中丛枝菌根真菌数量和种类的初步研究

用形态学分类法测土壤样品中丛枝菌根真菌的数量和种类分布特点,结果表明,丛枝菌根真菌广泛分布于四川农业土壤中,但其数量和种类较少,种群结构单一。共计分离鉴定出3个属18种丛枝菌根真菌,球囊霉属(Glomus)13种,无梗囊霉属(Acaulospora)2种,盾巨孢囊霉属(Scutellospora)3种,其中只有Gl.mosseae,Gl.cale-donium,Gl.constrictum的出现频率大于10%,是主要四川省农用土壤中的优势种。研究还发现,地域因素、土壤类型和土壤的理化性质以及人为因素对丛枝菌根真菌的数量和种类有显著影响(P<0.05)。     

黄芪幼苗丛枝菌根形成过程研究

盆栽灭菌条件下,研究了黄芪Astragalus membranaceus与摩西球囊霉Glomus mosseae形成丛枝菌根的过程及细胞结构变化情况。结果发现,黄芪接种34 d时,真菌菌丝开始侵染根表皮;44 d时菌丝在皮层细胞内逐渐增多,并且细胞间有极少量泡囊产生,形状为椭圆形;54 d时细胞内大量菌丝扩展;63 d时有大量真菌孢子萌发;84 d时细胞间有大量泡囊形成,呈圆形、近圆形或椭圆形,部分泡囊开始收缩衰老,同时皮层细胞内有少量丛枝并存。生长期间,菌根侵染率和孢子密度的变化与丛枝菌根的发育状况密切相关。     

重庆植烟区丛枝菌根真菌资源调查及初选分析

对重庆市主要植烟区连作烟田丛枝菌根真菌资源进行了调查,鉴定分析了烟草丛枝菌根真菌共7属32种,包括球囊霉属(Glomus)18种(包括新种1个),无梗囊霉属(Acaulospora)7种,内养囊霉属)1种,盾巨孢囊霉属(Scutellospora)1种,巨孢囊霉属(Gigaspora)1种,原囊霉属(Archaespora)2种,近球囊霉属(Paraglomus)2种。其中,球囊霉属(Glomus)的根内球囊(G.intraradices)和摩西球囊霉(G.mosseae)为烟草丛枝菌根真菌的优势菌种。     

印度西高止山药用植物丛枝菌根真菌多样性

调查了印度西高止山脉南北Goal区内25个科的36种药用植物的丛枝菌根真菌多样性。30个物种带有丛枝菌根真菌,其余6个物种没有丛枝菌根真菌定植。在根际士壤中,共发现了来自5个菌属（球囊霉属、无梗囊霉、盾巨孢囊霉、巨孢囊霉属和Ambispora）的42种丛枝菌根真菌。本研究区内,球囊霉属是优势属,聚线绣球菌是优势种。定植百分比和孢子密度间存在显著负相关。南、北Goa区内,Simpson和ShannonWeiner多样性指数差异不显著,说明该区具有稳定、多样的植物群落。     

3种丛枝菌根真菌对沙冬青的接种效应

为了研究丛枝菌根真菌对沙冬青幼苗的接种效应,对盆栽沙冬青幼苗分别接种摩西球囊霉、幼套球囊霉、根内球囊霉3种丛枝菌根真菌,测定样苗成活率、侵染率、生长量及养分含量等指标。结果表明：3种丛枝菌根真菌均不影响样苗移栽成活率,均能与沙冬青幼苗形成菌根,侵染率40～50%;摩西球囊霉接种对样苗高、径、干物质生长和N、P、K吸收积累均有促进作用;幼套球囊霉接种样苗含水率最小,根冠比最大。总之,摩西球囊霉可以有效促进沙冬青幼苗生长,具有开发促进生长菌肥的潜力;幼套球囊霉可以提高幼苗耐旱性能,具有开发增强苗木抗逆性能的菌肥的前景。     

油茶根际AM真菌群落对不同季节、土层和品种的响应

【目的】探究油茶根际丛枝菌根(Arbuscular mycorrhizas, AM)真菌群落对不同季节、土层和品种的响应,为油茶菌根生物技术的研发和集约化可持续发展提供理论依据。【方法】以5年生的油茶为研究对象,采集3个季节2个土层5个品种的油茶根际土,采用Illumina Miseq高通量测序技术探究油茶根际AM真菌多样性与群落组成。【结果】在集约化经营模式下,油茶能与AM真菌形成共生关系,AM真菌对油茶的侵染率受季节和油茶品种的影响。油茶根际土壤中共检测到4目8科9属AM真菌,相对丰度最高的为球囊霉属Glomus(58.50%),其次是类球囊霉属Paraglomus(19.43%)和近明球囊霉属Claroideoglomus(3.28%)。秋季油茶根际AM真菌丰富度和多样性显著高于春季和夏季,且春季最低;0～20 cm土层油茶根际AM真菌丰富度高于20～40 cm土层,而其多样性低于20～40 cm土层。品种对油茶根际AM真菌的丰富度没有显著影响,对AM真菌的多样性指数Shannon有显著影响。相似性分析(Anosim)表明,季节对AM真菌群落结构没有显著影响,土层和品种显著影响A...     

文冠果VA菌根真菌的分离、扩繁及幼苗菌根化效果的研究

本文以我国北方唯一的木本油料树种——文冠果为目标,对与其共生的VA菌根真菌进行了采集、分离和扩繁,并进行了文冠果幼苗的菌根化试验。在采集到的文冠果根系中发现了VA菌根真菌共生结构,其自然侵染率约为20.5%左右;从根际土中分离出典型孢子,经初步检索鉴定其为球孢囊霉属的某个种(Glomus sp.);利用高丹草作为载体进行该菌种的扩大繁殖培养,培养60d后采集根样进行镜检,可明显观察到菌根孢子在根表的侵染点、菌丝及在根皮层细胞内形成的丛枝结构,表明VA菌根真菌的孢子已经与高丹草根系发生了有效侵染。利用继代培养后的接种体进行文冠果幼苗的菌根化回接试验,1年生菌根化幼苗苗高、地径、地上、地下部鲜重与对照相比分别提高了5.9%、7.2%、8.8%和7.4%,差异显著,表明文冠果幼苗期菌根化效果显著。     

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.     

Tree species as hosts for arbuscular mycorrhizal and dark septate endophyte fungi

A survey of 35 tree species(belonging to 28 genera in 19 families) in Aliyar,South India was carried out to ascertain their arbuscular mycorrhizal(AM) and dark septate endophyte(DSE) fungal status.All the tree species examined had AM association.AM and DSE colonization is reported for the first time in 20 and 14 species respectively.Cooccurrence of AM and DSE was observed in 14(40%) tree species.The extent of DSE colonization was inversely related to the extent of AM fungal colonization.Six tree species had Arum-type,18 had intermediatetype and 11 had typical Paris-type AM morphology.AM fungal spore morphotypes belonging to 11 species in two genera were isolated from the rhizosphere soil.AM fungal spore numbers were not related to the extent of AM colonization and Glomus dominated spore diversity.AM association individually and along with DSE were found respectively in the 63% and 44% of the economically important tree species.The occurrence of AM and DSE fungal association in economically important indigenous tree species indicates the possibility of exploiting this association in future conservation programmes of these species.     

钦州湾红树植物根部内生真菌初步研究

通过多年对钦州湾区域不同位点的红树林根际取样研究，发现暗色有隔内生真菌和丛枝菌根真菌在红树植物的根系中普遍存在。报道这两类真菌在红树植物根部侵染情况的初步观察结果，并分析讨论红树林根部真菌存在的可能性和可能作用。     

Biodiversity of arbuscular mycorrhizal fungi in <Emphasis Type="Italic">Amygdalus scoparia</Emphasis> 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-year-old 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.     

大兴安岭4种杜鹃花科植物的DSE真菌分布

深色有隔内生真菌在寒温带地区的研究在国内还属空白。本研究首次对内蒙古大兴安岭兴安落叶松林下笃斯越橘、越橘、杜鹃和杜香的DSE真菌进行了研究。结果表明,这4种杜鹃花科植物都有DSE真菌定殖,但DSE定殖率都小于10%。DSE菌根定殖率与全氮呈极显著负相关。依据菌落形态特征和菌丝体的显微结构特征将这4种植物的根样中分离得到的187个DSE菌株分为15个菌株类型,并对这4种植物进行回接实验,其中有8种DSE菌株类型可以定殖这4种植物,8个菌株类型属于子囊菌门的Phialocephala属,分属4个种。     

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.     

Response of <Emphasis Type="Italic">Theobroma cacao</Emphasis> and <Emphasis Type="Italic">Inga edulis</Emphasis> seedlings to cross-inoculated populations of arbuscular mycorrhizal fungi

Response of Theobroma cacao L. (cacao) and the shade tree Inga edulis Mart. (inga) seedlings from an organically-grown cacao plantation to inoculation with native arbuscular mycorrhizae forming fungi (AMF) was studied in a cross-inoculation assay under greenhouse conditions. Seedlings of inga and cacao were grown in pots filled with heat-treated soil from the plantation. Control was heat-treated soil without inoculum and roots of cacao and inga from the plantation were applied as AMF inocula. Undisturbed soil blocks were used as a “positive control” of the inoculation potential of untreated soil and roots combined. No AMF structures were observed in the roots of either species in the heat-treated control. All inocula were infective in both hosts and the differences in the total AMF colonization percentage between the hosts were not significant but inga had significantly higher colonization by hyphal coils and arbuscules. Cacao roots but neither inga roots nor soil block inocula stimulated cacao growth. All inocula significantly increased growth of inga, which had higher relative mycorrhizal responsiveness than cacao. Thus, in spite of the strong infectivity of the inocula in both hosts, cacao and inga responded differently to the same AMF populations. The strong conspecific preference of cacao suggests that attention must be paid to the AMF inoculum used for this species. However, the strong response of inga to cacao root inoculum indicates that the two species may share same AMF symbionts, thus enabling positive interactions between them, including formation of common mycelial networks.     

氮和生物炭添加对毛竹林AMF侵染率和孢子密度的影响

目的 探讨氮沉降和生物炭添加对毛竹林丛枝菌根真菌特征的影响,为全球变化背景下毛竹林的可持续经营提供科学参考。 方法 以毛竹林为研究对象,探讨了不同梯度的氮沉降（0、30、60和90 kg·hm−2·yr−1）和生物炭添加（0、20和40 t ·hm−2）及其复合作用对毛竹林AMF侵染率和孢子密度以及土壤理化性质的影响。 结果 与对照（0 kg·hm−2·yr−1 N + 0 t·hm−2 BC）相比,氮添加显著降低了AMF侵染率（16.1%～51.7%）。高生物炭添加（40 t·hm−2）显著降低了AMF侵染率（46.0%）,但提高了孢子密度（162.5%）。在氮添加处理下,生物炭添加提高了AMF侵染率,对孢子密度无显著影响。AMF侵染率与土壤pH呈显著正相关关系,与有效氮和有效磷呈显著负相关关系。AMF孢子密度与有效磷呈显著正相关关系。 结论 在氮添加处理下,生物炭添加提高了AMF侵染率,增强了毛竹与AMF的共生关系,表明在氮沉降背景下生物炭添加是实现毛竹林可持续经营的有效措施之一。     

Occurrence of dark septate endophytes in Nothofagus seedlings from Patagonia,Argentina

Temperate forests of southern Argentina and Chile cover a wide latitudinal and altitudinal range on both sides of the Andes, with Nothofagus species being one of the main tree species. Most of the larger remnants are protected within the limits of national parks and forest reserves. However, some of these are invaded by exotic conifers such as Pseudotsuga menziesii. In order to better understand the mycorrhizal condition within the Nothofagus–P. menziesii interaction, transects were established at six study sites along the effective recruitment area. Three treatments were established: Nothofagus forest without P. menziesii invasion (Forest), Nothofagus–P. menziesii matrix (Interface) and P. menziesii plantation lacking Nothofagus specimens (Plantation). A 2 kg mixed soil sample was taken at each treatment site and kept in brand-new plastic bags. A soil bioassay with Nothofagus seedlings acting as baits was set to evaluate the mycorrhizal inoculum potential and soil-fungi composition at each sampling treatment. Forty percent of the evaluated seedlings were found to be colonised by dark septate endophytes (DSE) fungi. Ectomycorrhizal colonisation percentage was significantly higher in plants growing in Forest soils (mean = 57.77%) when compared with Interface (mean = 42.53%) and Plantation (mean = 44.65%). The high incidence of DSE in young roots of Nothofagus seedlings in this study supports the hypothesis that DSE might be pioneering colonisers of young tree seedlings in secondary successional environments. For future interventions in the forest, either with productive or protective intentions, it should be taken into account the incidence of these fungi, which may have an important positive role in Nothofagus forest post-invasion recovery.     

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.