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[目的 ]通过分析种植方式对两种菌根类型树种吸收根性状的影响,揭示物种共存的适应条件。[方法 ]本研究选择8个树种（5个AM树种和3个EM树种）的单种和所有树种混种的样地,分析不同种植方式（单种vs混种）下两类型菌根（AM vs EM）树种吸收根（1～2级根）的主要形态性状（根直径、比根长、根组织密度、单根长）和构型性状（根分支强度、根分支比）及菌根侵染率的差异。[结果 ]菌根类型极显著影响吸收根的形态和构型性状（p<0.001）,显著影响菌根侵染率（p<0.05）;种植方式仅显著影响吸收根的组织密度和根构型性状（p<0.05）;菌根类型和种植方式对所有性状均无交互影响（p>0.05）。AM树种根性状间的相关程度高于EM树种,混种大幅度降低AM树种根性状间的相关性。混种降低AM树种根形态性状的可塑性（比根长除外）,增大其构型性状的可塑性;混种降低EM树种根组织密度的可塑性,增大根直径、构型性状及侵染率的可塑性。[结论 ]AM和EM树种的根形态和构型性状均有显著差异。混种对AM和EM树种根性状的可塑性有不同程度的影响,主要增大AM树种的分支强度,降低EM树种的根组... 相似文献
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磷（P）是林木生长的主要限制性养分之一，而土壤中大部分的P难以被植物所直接利用。菌根共生是林木提高P利用效率的重要途径。菌根真菌可以与陆地上大部分植物形成菌根共生关系，促进植物P吸收和生长发育。不同类型的菌根共生对P养分具有偏好性。菌根真菌通过外延菌丝增加P吸收表面积、释放分泌物、调控磷酸盐转运蛋白与相关基因机制协同作用，促进林木对土壤P养分的高效利用。菌根共生体形成及其养分获取受到土壤p H值和养分状况、林龄、气候等多种因素的影响。文中从不同菌根共生体的养分偏好性、利用机制及影响因素等方面，评述有关林木菌根共生影响P养分利用及作用机制的研究进展，并提出未来研究方向，对于促进菌根共生在林业中的应用具有重要的理论和现实意义。 相似文献
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森林细根分解是陆地生态系统养分循环的关键环节和重要过程，腐生真菌通过其特性广泛参与有机质分解、养分循环，连接植物与土壤2大碳库。环境和生物因素共同影响着腐生真菌生态功能的实现。文中综述了森林细根分解的腐生真菌功能特性、胞外酶特性、腐生真菌群落多样性变化、演替过程及影响因素，指出在后期研究中可利用高通量测序技术，深入开展腐生真菌胞外酶功能特性、营养策略、功能多样性组间协作研究，探索真菌主导的凋落物分解机制，并应用网络关系分析生境和底物异质性对腐生真菌群落结构和多样性、生态位划分、竞争或合作频率关系的影响，揭示细根分解的腐生真菌群落演替、聚集和驱动机制。 相似文献
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菌根是土壤真菌与植物根系形成的一种共生体，是森林生态系统中的重要组成部分，由于其特殊的结构和与林木共生的生态关系，在林业中被广泛研究与应用。该文分别从提高育种率、促进林木生长、增强林木抗逆性和生态环境修复4个方面总结了菌根真菌在林业中的作用及研究进展，旨在为菌根技术在林业中的应用提供理论支持。 相似文献
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本文综述了细根在凋落物层的觅食行为与策略,细根生长与凋落物数量、质量及分解过程的关系,细根生长与凋落物分解的相互作用机制及影响因素等以期为理解森林生态系统中细根对凋落物分解的作用机制以及凋落物分解对细根生长的影响提供依据。一方面,凋落物的数量和质量影响细根生长,地上凋落物的数量影响细根的觅食行为,并驱动细根在凋落物层的生长动态,凋落物质量的差异也对细根的生长产生影响,不同性质的地上凋落物对细根的生长是促进还是阻碍主要取决于分解过程中所产生的养分以及多酚含量的正平衡或负平衡;另一方面,生长进入凋落物层的细根通过根际激发效应、养分吸收以及共生真菌等作用综合影响凋落物的分解过程,生活的细根对凋落物分解的激发效应主要表现在根系分泌物控制微生物群落的活力及组成,进而加速或抑制凋落物分解;N的有效性是影响凋落物分解的重要因素,处于分解后期的凋落物层中生长的细根,通过吸收凋落物表面矿化形成的大量无机N,避免过量的N对微生物群落及其生境的不利影响;根系的共生伙伴——菌根真菌也对凋落物的分解产生重要影响,这与真菌类型及其分泌的酶和有机酸有关。未来该领域应注重全球变化背景下细根生长对凋落物分解作用机制以及细根的分支结构与其获取凋落物层养分功能的联系等方面的研究。 相似文献
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丛枝菌根真菌提高林木抗逆性机制研究进展 总被引：1，自引：0，他引：1
丛枝菌根（AM）真菌是存在于土壤中的重要真菌之一,它能够与宿主林木根系产生互利共生体,从而对林木的生长发育有着多种促进作用。文中综述了近10年来国内外关于AM真菌对林木影响的研究进展,包括AM真菌对林木的抗旱性、抗病性、抗盐性、耐热性、耐虫性及对有害重金属抗性的影响等,通过促进林木光合作用、营养吸收、新陈代谢等来增加林木生长量、生物量的积累,从而提高林木的抗逆性;对在AM真菌研究中存在的难题进行了分析,并对其在林木中的应用研究进行了展望,旨在为林木抗逆性机制研究、森林经营等提供科学参考。 相似文献
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外生菌根真菌能与某些树木形成稳定的菌植共生体——外生菌根。外生菌根能吸收土壤中植物难以吸收的无机或有机形式营养物质,并传递至宿主植物为其所利用。由于这种养分传递的生态重要性,外生菌根真菌介导的“菌植”N传递关系受到研究人员的广泛关注。文中综述了外生菌根真菌的可利用N形式及其促进宿主植物N营养吸收的机理,主要归纳为:1）菌根增加了养分吸收面积,促进N吸收;2）外生菌根真菌编码利用N源所必需的一套酶和转运体,协助宿主对难吸收的硝酸盐和有机N的利用。在全球N沉降日益加剧的背景下,本综述将有助于了解外生菌根在当前和未来气候情景下的生态作用。 相似文献
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橡胶是四大工业原料之一 ,在交通、军用工业中尤为重要。其中天然橡胶的主要来源是巴西橡胶树 (H evea brasiliensis Muell. Arg.) ,它在我国南方热带地区广为栽培 ,是重要的经济树种和用材树种 ,因而是工业与民用的重要资源。已有研究证实 :橡胶树根系可以形成 AM菌根 (arbuscular mycorrhiza)。AM菌根是广泛分布的一类内生菌根 ,能够促进宿主植物吸收土壤中的养分 ,增强宿主的抗逆性 ,有利于植物生长。近 30 a来 ,国外一些学者对橡胶树菌根真菌的资源与分布 ,菌根真菌对苗木营养和生长效应以及提高苗木抗逆性方面进行了研究。而国内尚… 相似文献
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菌根是真菌与高等植物的根的共生体,这类生物演化的现象普遍存在,它不仅包括显花植物的裸子植物（如松、柏）,也包括许多被子植物（如壳斗科和桦木科）,而且还包括少数苔藓和菌类。菌根真菌可分为三大类。一类称为外生菌根,它的主要特征是那些真菌仅仅侵入了寄主根部表面,在细胞间交互织成一个菌丝网络,为哈迪什网。这些真菌多属担子菌的牛肝 相似文献
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Arbuscular mycorrhiza （AM） formed between plant roots and fungi is one of the most widespread symbiotic associations in nature. To understand the molecular mechanisms of AM formation, we profiled 30 symbiosis-related genes expressed in Amorpha fruticosa roots colonized by Glomus mosseae and in non-mycorrhizal roots at different stages using differential-display RT-PCR （DDRT-PCR）. The expressed genes were confirmed by reverse Northern blotting. Eleven fragments were sequenced and putatively identified by homologous alignment. Of the eleven AM-related genes, five were obtained at the early-stage of plant-fungus interaction and six at the later stage. Three expressed se-quence tag （ESTs） sequences were found to originate from the fungi and eight from the host plant by use of PCR evaluation of gDNA of both plant and fungi. The target genes included an ATP-binding cassette sub-family transporter gene, a transposon-insertion display band, and a photosynthesis-related gene. The results provided information on the molecular mechanisms underlying the development of mycorrhizal sym-biosis between woody plants and AM fungi. 相似文献
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Arbuscular mycorrhizal (AM) symbioses may alter the competitive abilities of plant species and facilitate positive interactions such as nutrient transfer between plants. They are therefore particularly interesting components in agroforestry systems. We studied spatial variation of AM colonisation on a cut-and-carry fodder production site (agroforestry plot) of the legume tree Gliricidia sepium and the fodder grass Dichanthium aristatum. Roots of the two plant species were sampled under the tree canopies and on the adjacent grass plot at 1 and 3.5 m from the first tree row where G. sepium roots also occur. Roots of D. aristatum were also sampled on a nearby grass monocrop. Colonisation of arbuscules, vesicles and hyphae in root samples was visually determined, and AM fungal species were identified by DNA sequencing. Colonisation and frequency of types of AM formations varied statistically significantly between the species and sampling points. Arbuscular colonisation in G. sepium roots was higher under the tree canopies than on the adjacent grass plot. Soil nutrient content, particularly P and N, and interspecies competition are the most probable explanations for the observed variation in AM colonisation. Both arbuscular colonisation and arbuscule:vesicle ratio in D. aristatum roots was lower on the D. aristatum monocrop than on the agroforestry plot under or near the tree canopies. Intercropping could stimulate AM symbiosis in D. aristatum. Both plant species formed symbiosis with Rhizophagus intraradices, indicating potential for interplant N transfer via common mycelial networks of AM-forming fungi. 相似文献
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Ectomycorrhizal fungal diversity, tree diversity and root nutrient relations in a mixed Central European forest 总被引：1，自引：0，他引：1
Knowledge is limited about whether root nutrient concentrations are affected by mixtures of tree species and interspecific root competition. The goal of this field study was to investigate root nutrient element concentrations in relation to root and ectomycorrhizal (EM) diversity in six different mixtures of beech (Fagus sylvatica), ash (Fraxinus excelsior) and lime (Tilia sp.) in an old-growth, undisturbed forest ecosystem. Root biomass and nutrient concentrations per tree taxon as well as the abundance and identity of all EM fungi were determined in soil cores of a volume of 1 L (r=40 mm, depth=200 mm). Stand-level nutrient concentrations in overall root biomass and H' (Shannon-Wiener diversity) were obtained by pooling the data per stand. At stand level, Shannon H' for roots and aboveground tree species abundance were correlated. H' for roots and EM fungi were not correlated because of the contribution of ash roots that form only arbuscular mycorrhizal but no EM associations. Nutrient element concentrations in roots showed taxon-related differences and increased in the following order: beech?≤?lime?相似文献
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The relative diversity and abundance of different functional groups of macrofungi were investigated in the northern jarrah forest, a mediterranean climate sclerophyllous forest dominated by eucalyptus trees in Western Australia. We sampled paired sites that were either severely affected by dieback, a disease caused by Phytophthora cinnamomi which causes selective plant mortality, or unaffected by this type of forest decline. Macrofungi were sampled 3 times during the growing season along six 100 m × 2 m transects in these sites. Dieback-unaffected sites were found to have significantly different macrofungal floras than unaffected sites. Macrofungal abundance and diversity were approximately 1.5 times and 1.8 times greater respectively in dieback-unaffected sites than in severely affected sites. Dieback-affected sites had a similar diversity of saprotrophic and ectomycorrhizal fungi, whereas more fungal taxa on dieback-unaffected sites were mycorrhizal (>60%). Dung fungi were the most common saprophytes, especially in dieback-affected sites, but abundance data greatly overestimated the importance of these relatively small fungi. We concluded that vegetation changes linked to dieback had a negative effect on fungal community structure and biodiversity in the northern jarrah forest, in a similar manner to other forms of severe disturbance. Conversely, high tree mortality increased the abundance of wood decay fungi, at least in the short term. We expect that reductions in macrofungal species richness were indirectly linked to impacts on mycorrhizal host plants and saprotrophic substrates. Our data show that changes in vegetation composition had the greatest effect on ectomycorrhizal fungi, presumably due to their obligate symbiotic associations. 相似文献
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We conducted a study to find out if arbuscular mycorrhizal (AM) fungi (Acaulospora scrobiculata, Scutellospora calospora) and phosphate solubilizing bacteria (PSB, Paenibacillus polymyxa) inoculation either individually or in combinations can improve Acacia auriculiformis seedling growth, uptake of nutrients and quality in a phosphorus deficient tropical Alfisol. The seedlings were assessed for various growth and nutrient uptake parameters after 60 days of treatment. Inoculation with P. polymyxa stimulated mycorrhizal formation. Seedling height, stem girth, taproot length, number of leaves and leaf area, plant dry matter production, nodulation, and nodular dry weight were significantly higher for seedlings that were either dual inoculated or triple inoculated compared to individual inoculation of AM fungi or PSB, and uninoculated seedlings. Dual and triple application of AM fungi and PSB also significantly improved the nutrient contents of shoots and roots and nutrient uptake efficiencies. The calculated seedling quality indexes of the AM fungi and PSB inoculated seedling were 25–208% higher than uninoculated seedlings. These findings show that A. auriculiformis seedlings when dual inoculated or triple inoculated performed better than seedlings inoculated with the microbes individually and compared with uninoculated control seedlings. We conclude that bioinoculation is important for the production of high-quality A. auriculiformis seedlings in tree nurseries for planting in nutrient deficient soils. 相似文献
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Amornrat Chaiyasen David D. Douds Paiboolya Gavinlertvatana Saisamorn Lumyong 《New Forests》2017,48(4):547-562
Regeneration of stands of valuable tropical hardwood tree species for sustainable harvest requires production of seedlings with high probabilities of survival. One way to enhance the vigor of plants for outplanting is pre-colonization of roots by arbuscular mycorrhizal (AM) fungi. We pursued the strategy that the most promising AM fungus candidates for inoculation would be those associated with the tree of interest in the field. AM fungus communities were assessed in five plantations of Tectona grandis Linn.f. A total of 18 AM fungal morphotypes were found, representing four families: Glomeraceae (49.6%), Acaulosporaceae (24.9%), Claroideoglomeraceae (20.8%), and Gigasporaceae (4.8%). AM fungus spore density was negatively correlated with soil organic carbon. Some of these AM fungi, plus Rhizophagus irregularis, were established in pot culture and in vitro with transformed carrot roots, and subsequently used to inoculate micropropagated plantlets of T. grandis. Tectona grandis plantlets inoculated in vitro were successfully colonized by all AM fungi studied. Plants inoculated with Funneliformis mosseae were taller than uninoculated plants. Tectona grandis plantlets inoculated with the AM fungus Claroideoglomus etunicatum PBT03 were taller than uninoculated controls in ex vitro experiments. This study provides early insight for the targeted use of the AM symbiosis in production of important tree species in future greenhouse studies and reforestation. 相似文献
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Pablo Vásquez Gassibe Raul Fraile Fabero María Hernández-Rodríguez Pablo Martín-Pinto 《Forest Ecology and Management》2011,262(4):655-662
This study examined the succession of fungal communities following fire in a Mediterranean ecosystem dominated by Pinus pinaster Ait. in northwestern Spain. A large wildfire occurred in August 2002. During the autumn seasons from 2003 to 2006, fruiting bodies were collected and identified, production in burned (early stage) and unburned (late stage) areas was measured. For statistical analysis, data were grouped into the following four categories: saprotrophic, mycorrhizal; edible and inedible. A total of 115 fungal taxa were collected during the four sampling periods (85 in the late and 60 in the early stage). The number of mycorrhizal species increased from early to late succession and there were shifts in community composition. After fire, pyrophytic species such as Pholiota carbonaria, Peziza violacea, Rhizopogon luteolus and Rhizopogon sp. appeared. Fire strongly affected the production of fungal species in the studied area. Thus, yields in the early stage treatment were significantly lower than those observed in the late stage. Total fungal fresh weight decreased from 209.95 kg fw ha−1 in the late stage to 162.45 kg fw ha−1in the early stage when richness and production of mycorrhizal species and production of edible fungi were significantly lower. Fresh weight for saprotrophic and inedible species was higher than for mycorrhizal fungi in the early stage treatment. The results obtained can be useful to forest managers for optimization of management and harvesting of these increasingly appreciated non-timber resources. 相似文献
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我国南方桉树人工林菌根合成及其多样性研究(英文) 总被引：2，自引：0，他引：2
对我国南方部分地区桉树人工林菌根真菌资源和菌根类型进行了调查 .对采自广东、云南 15个桉树林地的根系样品进行了显微观察 ,结果证实了在自然土壤中桉树能形成不同类型的菌根 ,检查的根样在不同程度上均有菌根菌的感染 .其中 ,有 4个人工林的根系样品AM感染率在 50 %以上 ,另有 4个根样ECM感染根段长超过 50m .调查发现林分年龄大小对菌根形成及菌根类型有一定的影响 ,表现在幼林及过熟林菌根感染率均较低 ,而 4～ 7年生按树林菌根感染率相对较高 ,在同一根系上AM与ECM菌间存在一定的竞争性 .在菌根菌资源方面 ,从总体上来说 ,我国南方菌根菌资源较少 ,尤其是ECM菌 .调查结果表明 ,我国南方桉树人工林根际土壤中有AM菌 2 8种 ,隶属于 4个属 ,其中以球囊霉属真菌最多 ,占 6 4 % ;地球囊霉在所采集的土样中出现的频度最高 .南方 15个桉树人工林中发现有 17种ECM菌 ,隶属 10个属 ,其中彩色豆马勃、多根硬皮马勃、光硬皮马勃等菌种在两广地区许多桉林中较常见 ,云南地区则多以黄须腹菌、硬皮马勃等菌较多 .这些ECM菌通常生长于松树林中 ,能否与引进的桉属树种形成较好的菌根还有待于进一步研究 .本文对自然条件下混合菌根的形成及真菌间的竞争关系进行了讨论 相似文献
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Amadou M. Bâ Abdala G. Diédhiou Yves Prin Antoine Galiana Robin Duponnois 《Annals of Forest Science》2010,67(3):301-301