941 resultados para Hoya fungi


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外生菌根是重要的菌根类群,在自然界中分布广泛。外生菌根真菌参与了生物地球化学循环,是森林生态系统中的重要组分。由于外生菌根真菌的宿主植物通常是一些生态系统的优势种和建群种,并且这些真菌还参与了许多森林生态系统的有机和无机元素循环、物种的竞争和共存、生物多样性的维持、生态系统的演替等过程,因而对外生菌根真菌的研究有助于对这些生态系统维持和演替机制的深入理解。作者在中国四川都江堰地区选择了两个不同林龄的森林,应用分子生物学方法,研究了它们的外生菌根真菌群落组成。比较分析了两种年龄亚热带森林下真菌群落的物种组成、密度和多样性的差异,并分析了外生菌根真菌群落与宿主植物群落之间的相互关系,主要研究结果如下: (1) 用分子方法(巢式PCR, RFLP和DNA测序)鉴定了87个土样中的ECM真菌。共检测到70种真菌,属于13目21科30属,其中,子囊菌门5目6科6属8种,担子菌门8目15科24属62种。在担子菌门中,革菌目、红菇目和伞菌目三个目的真菌为常见种。 (2) 成熟林的ECM真菌物种数、密度和物种多样性都显著高于幼林。 (3) 少数几种ECM真菌在群落中占绝对优势,而大多数种类的相对多度和相对频度都较低。重要值(IV)至少在一个样地中大于4.0%的真菌共有12种。成熟林中,IV大于4.0%的ECM真菌有8种,分别是:Russula sp.01,Tomentella sp.01,Tomentella sp.04,Tomentella sp.05,Boletales-01,Lactarius sp.01,Tricholomataceae-01,Leptodontidium sp.01;幼林中IV大于4.0%的真菌有6种,分别是:Lactarius quietus,Russula sp.01,Tomentella sp.01,Tomentella sp.02,Tomentella sp.03, Trechisporales-01。 (4) 成熟林与幼林中的优势属有所不同,成熟林以绵菌属和红菇属最丰富,幼林以乳菇属最丰富,其次是绵菌属和红菇属; (5) ECM真菌群落与乔木群落关系密切,ECM真菌群落物种多样性随着菌根乔木群落物种多样性的增加而增加;ECM群落密度随着非菌根乔木群落密度的增加而降低;ECM群落物种数随着非菌根乔木群落物种数的增加而降低。 (6) ECM真菌群落间的相似性与菌根乔木群落间相似性之间呈显著正相关,即,菌根乔木群落之间越相似,则菌根群落之间也越相似;ECM群落间的相似性与非菌根乔木群落间的相似性之间无相关性。

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Three species of bacteria, 8 species of fungi and 3 species of VAM-fungi were isolated from the soil substrata supporting Avicennia marina which comprises the majority of mangrove vegetation along the Karachi coast. The species abundances for fungi and bacteria were greater at one site (Sandspit) supporting healthy mangrove growth with soil pH 7.8, EC 16.2mmhos/cm², TSS 2.57% and available phosphorus 0.008% than at the other site (Korangi creek) with stunted growth of mangrove where the soil samples showed pH 7.9, EC 18.8mmhos/cm², TSS 1.45% and available phosphorus 0.001%. Symbiotic association by vasicular-arbuscular mycorrhizal (VAM) fungi in the roots of mangrove plants was also observed on a small scale at Korangi creek where the substratum was undergoing microbial degradation.

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克隆植物同一基株的相连克隆分株或克隆片段常常生长在资源条件不同的斑块中,分株间形成克隆整合和克隆可塑性以及克隆分工等有效地获取必需资源的生态适应对策,提高在异质性斑块生境中的适合度,适应环境的异质性变化。但在以往的克隆植物生态学的理论研究中,为了研究的简化和方便,往往忽略了土壤中微生物的作用。丛枝菌根(Arbuscular mycorrhiza, AM)真菌是自然界中广泛存在的土壤微生物之一,可与大多数的高等植物形成共生菌根,影响植物的生长、发育及其在生态系统中的作用。 本文应用实验生态学方法,以蛇莓、狗牙根和白三叶为研究对象,在温室受控条件下,对异质养分斑块中的分株对接种AM真菌,探讨AM真菌对资源斑块中克隆植物的影响。 第一个实验设计单一磷养分斑块,以蛇莓(Duchesnea indica)和摩西球囊霉(Glomus mosseae)为研究对象,探讨丛枝AM真菌对克隆整合的影响。将蛇莓相连的两个分株,即分株对,分别种植在两个隔离的花盆中,各施以高磷和低磷营养液,保持或切断分株间匍匐茎连接,即间隔子,再将菌剂接种到低磷斑块中分株。结果发现间隔子状态和接菌处理都显著影响低磷斑块中蛇莓分株的根系生物量分配。对照处理中保持间隔子连接显著减少低磷斑块中分株生物量向根系的分配,接菌后这一差异显著减小。保持间隔子连接或接菌对高磷斑块中分株的根系生物量分配不显著。保持间隔子连接和接菌都显著增加低磷斑块分株的生物量在分株对生物量中所占比例,二者无显著交互作用。 第二个实验设计光照和养分斑块,以狗牙根(Cynodon dactylon)和摩西球囊霉为研究对象,探讨AM真菌对克隆植物非局域反应的影响。将狗牙根分株对的两个分株分别种植在两个花盆中,各施以光照强度与土壤养分交互斑块性环境条件,形成高养低光和高光低养斑块,保持或切断间隔子,再将菌剂接种到目标分株。结果发现对照处理中,间隔子状态显著影响分株的局域反应。高养斑块中保持间隔子连接的分株的根长显著大于间隔子断裂的分株的根长,高光斑块中保持间隔子连接的分株的根长显著小于间隔子断裂的分株的根长。高光斑块中保持间隔子连接的分株的叶面积显著大于间隔子断裂的分株的叶面积,间隔子状态对低光高养斑块分株的叶面积无显著影响。在低光高养斑块中,相对于间隔子断裂的分株,间隔子连接的分株将更多的生物量分配到根系,而在高光斑块中的分株则相反。这些都说明,无AM真菌侵染的情况下,狗牙根分株对的两个分株在实验中各自形成的克隆部分的分株形态反应都受到了克隆整合的作用,表现为非局域反应。接种AM真菌后,高光斑块中分株的根长和高养斑块中分株的叶面积在间隔子连接和断裂处理之间的差异显著减小。生物量分配的差异不受接菌的影响。对照处理中,高养斑块中间隔子连接的分株生物量和分株数显著高于间隔子断裂的分株,但高光斑块中分株之间无显著差异。接种AM真菌显著降低高养斑块中分株的生物量和分株数,对高光斑块中分株无显著影响。 第三个实验设计光照和养分交互斑块,以白三叶(Trifolium repens)和多种AM真菌为研究对象,探讨AM真菌及其多样性对克隆分工的影响。将间隔子连接(整合)或断裂(无整合)的白三叶分株对种植于光照强度和土壤养分交互斑块性资源条件下(即,高光低养和低光高养),向分株对接种灭菌处理、单种或五种AM真菌的菌剂。结果发现,对照处理中,间隔子连接的分株对在光养交互斑块中与间隔子断裂的分株对相比较表现出克隆分工,即高光低养斑块中的分株的根系生物量分配增加,低光高养斑块中的分株的根系生物量分配减少。单菌处理没有影响对照处理中间隔子状态对分株对生物量分配的改变;多菌处理显著减小对照中生物量分配的改变;与单菌处理比较,多菌处理能显著减小生物量分配的改变。在高光低养斑块中,多菌处理显著抑制间隔子断裂分株的根生物量分配的增加。在低光高养斑块中,多菌处理完全抑制在对照处理中间隔子连接的分株的根生物量分配的增加。在对照处理中,间隔子连接分株的单叶面积、总叶面积、叶柄长、根长都与生物量分配趋势一致,表现出对丰富资源的特化。接菌处理能显著抑制这些形态指标的改变。多菌处理显著抑制这些指标的特化,并且抑制效果显著强于单菌处理。间隔子状态和AM真菌处理显著增加高光低养、低光高养斑块中分株及整个克隆片段的生物量和分株数。多菌处理抑制间隔子连接的克隆片段生物量和分株数增加。克隆片段的生物量和分株数在对照和单菌处理间无显著差异,在多菌处理中显著高于在单菌处理中。 以上三个实验说明,(1)AM真菌对克隆植物生长的影响与非克隆植物一样,受到植物种类和环境资源水平的影响;(2)AM真菌对异质性资源环境中克隆植物的影响由于植物不同而产生不同的效应;(3)提高AM真菌的多样性可能增强菌根对克隆植物的作用。 这些研究结果揭示出AM真菌与异质性环境中克隆植物整合作用、非局域反应和克隆分工作用的交互影响,表明克隆生长在生态系统中的重要性可由生物和非生物因素共同决定。

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In India the chief marine timber boring organisms are 2 species of Martesia, 28 species of shipworms, 4 species and a variety of Sphaeroma and 9 species of Limnoria besides bacteria and fungi. The occurrence, abundance and activity of the various species of borers show remarkable variations and fluctuations in the different harbours of India, each harbour or area having its own dominant set of species and an assemblage of less important forms. These species have their own characteristic preferences, life history and seasons of attachment and a scheme evolved for one locality may prove ineffective for another. Through a delicate and complex ecological adjustment the borers occurring in a locality have reached an interrelationship reducing interspecific and intraspecific competition. The seasons of settlement of the dominant borers in the different harbours of India are indicated. The need for a detailed biological enquiry is stressed.

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杜鹃花属(Rhododendron L.)植物分布广泛,研究发现所有的杜鹃花科植物都能形成一种特殊的菌根——杜鹃花类菌根(Ericoid Mycorrhiza)。杜鹃花类菌根对杜鹃花科植物在营养胁迫的环境下生长起到重要的作用。近几年,对杜鹃花类菌根的生物学和生态功能的研究越来越重视。我国是杜鹃花属植物资源最为丰富的国家,因此研究杜鹃花属植物菌根真菌多样性,充分利用杜鹃花特有的菌根资源,促进杜鹃花迁地保护成功具有重大的意义。 本研究以分布较广并且是中国特有的杜鹃花属植物——大白花杜鹃(Rhododendron decorum Franch.)的野生植株为研究对象,应用直接扩增根中真菌ITS区的分子鉴定方法和T-RFLP(末端限制性片段长度多态性)的分析方法,来研究其菌根真菌的多样性;并结合生态化学计量学特征分析、宿主遗传相似性及其群落组成分析等内容,探讨大白花杜鹃的菌根真菌-宿主植物-根际土壤三者之间的关系。主要结果如下: (1)通过用直接扩增真菌ITS区序列,揭示了大白花杜鹃根部真菌的多样性,本研究发现,野生大白杜鹃根部的真菌种类比较丰富,至少有26个ITS-taxa,包括子囊菌和担子菌共5个真菌目:Helotiales、Lecanorales(≡Agyriales)、Onygenales、Sebacinales和Thelephorales,其中包括典型的ERM真菌——树粉孢属Oidiodendron sp.(Myxotrichaceae)真菌。另外还发现了黑色有隔内生菌(Dark septate endophyte,DSE)以及一些未命名的子囊菌。担子菌在本研究中占有较大比例,尤其是蜡壳耳菌目真菌;此外还有较典型的外生菌根真菌——革菌目真菌。 (2)大白花杜鹃野生植株与栽培植株在菌根真菌种类组成上,有一定的相似性;在忽略种源差异等条件下相较而言,前者的物种丰富度远高于后者。 (3)大白花杜鹃菌根真菌多样性和丰富度同它的根际土壤与叶片的C、N、P含量以及C/N、N/P、土壤pH值、宿主的海拔高度等都没有显著的相关关系。 (4)在大白花杜鹃的菌根真菌群落组成方面,整体上保持了相当程度的相似性,同时还保持了一定水平的差异;大白杜鹃菌根真菌的种类是丰富的,优势度指数表明其多样性水平很高。 (5)大白花杜鹃的遗传距离与其菌根真菌群落组成结构有极显著的相关关系,宿主的种内遗传差异可能对菌根真菌群落物种组成产生选择偏好。 (6)大白花杜鹃的群落组成与其菌根真菌群落组成有极为显著的关联性,伴生种的菌根类型可能会影响宿主植物菌根真菌的物种组成结构。

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A quality of survey was conducted at the fish curing yards in a northwest coast and the southern coast in Sri Lanka. A total of 40 samples different varieties of fishes were collected from the market and jaadi curing yards and all were evaluated for the quality, fungal and insect infestation. Samples were analyzed for proximate composition chemical, microbiological and sensory quality. Thirty percent of the total analyzed samples of fish were found to be unfit for consumption. Samples collected from Negombo were found to the infected with maggots. Only 42% samples had dry matter above 50%. All the samples showed a protein content above 20%. The highest protein content was 27.92% in hurulla. Over 90% of the samples had TVN at acceptable quality limits (>40). The TBC for 33% of the samples were in the range 104-105/g range, while 48% were in the range of 107-108/g due to contamination of maggots and fungi. The Survey showed jaadi had a high level of protein in its composition. But defects of curing process such on imperfect cleaning inadequate salting resulted in low (Chemical and microbiological) quality of the product.

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In the present study, EA-CATH1 and EA-CATH2 were identified from a constructed lung cDNA library of donkey (Equus asinus) as members of cathelicidin-derived antimicrobial peptides, using a nested PCR-based cloning strategy. Composed of 25 and 26 residues, respectively, EA-CATH1 and EA-CATH2 are smaller than most other cathelicidins and have no sequence homology to other cathelicidins identified to date. Chemically synthesized EA-CATH1 exerted potent antimicrobial activity against most of the 32 strains of bacteria and fungi tested, especially the clinically isolated drug-resistant strains, and minimal inhibitory concentration values against Gram-positive bacteria were mostly in the range of 0.3-2.4 mu g center dot mL-1. EA-CATH1 showed an extraordinary serum stability and no haemolytic activity against human erythrocytes in a dose up to 20 mu g center dot mL-1. CD spectra showed that EA-CATH1 mainly adopts an alpha-helical conformation in a 50% trifluoroethanol/water solution, but a random coil in aqueous solution. Scanning electron microscope observations of Staphylococcus aureus (ATCC2592) treated with EA-CATH1 demonstrated that EA-CATH could cause rapid disruption of the bacterial membrane, and in turn lead to cell lysis. This might explain the much faster killing kinetics of EA-CATH1 than conventional antibiotics revealed by killing kinetics data. In the presence of CaCl2, EA-CATH1 exerted haemagglutination activity, which might potentiate an inhibition against the bacterial polyprotein interaction with the host erythrocyte surface, thereby possibly restricting bacterial colonization and spread.

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The mud crab Scylla serrata is an important commercial species found in many brackish areas in the Philippines. During spawning and hatching, the berried females migrate to the sea. Seeds for pond stocking are obtained from the wild. Because of the unpredictability of seed supply, there is a need to propagate the species artificially. Thus, spawning, larval rearing, maturation, and rematuration of the species are being studied. The first attempts at hatching S. serrata were successful with rates varying between 75% and 90%. Two out of three trials on larval rearing yielded a few megalops. The first zoeal stages were fed diatoms, rotifers, Artemia salina, and bread yeast. Overfeeding programs were implemented during the critical premolting periods to prevent weakening of the larvae and lessen cannibalism. Larval weakening during the premolt makes them susceptible to attacks by fungi like Lagenidium and ciliates like Vorticella. S. serrata larvae survived salinity levels as low as 15 ppt until the 14th day of rearing. Other larvae were able to survive in salinities of 30-32 ppt for 8 to 13 days. Zoeal molting was hastened by lowering the salinity to 25-27 ppt. Artificial broodstocking of juveniles and adult crabs has been made possible using a simple refuge system made of three-compartmented hollow blocks. This system has been helpful in minimizing fighting among crabs. Remarkable growth rates have been observed with feeds like mussel meat and trash fish. Average growth increments of 11 mm carapace length and 20 . 35 g body weight have been observed every fortnight. A newly spent spawner could gain additional weight of 22 . 5 g in only 6 days. Feeding rates of juveniles and adult crabs have been established based on the average body weight from an experiment using mussel meat. Crabs feed more at night. In another experiment, eyestalk ablation was found to be effective in inducing growth and mating. Aside from hastening the molting process, copulation is induced even among the small crabs (average carapace length = 55 mm). Natural mating lasts about 26 hr. A copulation which lasted for seven days with a break in between was observed.

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Fermented vegetable and kitchen wastes are available as feeds for not only zoea but also mysis and up to certain points in the postlarval stages of sugpo, Penaeus monodon. It is recommended that the hatchery use fermented wastes as larval feed for P.monodon when diatoms or brine shrimp nauplii are lacking or in short supply. Among three stages namely, zoea, mysis and postlarva, the survival rate during postlarva particularly after P SUB-4 was quite low. The problems encountered are as follows: (a) how to prevent fermented particles from lumping, (b) how to prevent them from easily sinking to the bottom, and, (c) how to prevent bacteria and fungi, particularly Lagenidium sp blooming.

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Non-symbiotic, free living, nitrogen fixing bacteria, Azotobacter sp. was estimated in sediments of estuarine, marine, backwater and mangrove environments of Portonovo. Number of colony forming units (CFU) of Azotobacter sp. was less (5 to 27 cells/g of dry sediment). CFU of total heterotrophic bacteria (THB), actinomycetes and fungi were between 4.1x10 super(6) and 4.5x10 super (7), 0.8x10 super(5) and 4.9x10 super(5), 1.1x10 super(5) and 3.8x10 super(5)/g respectively. Mangrove sediments contained more CFU of the above microbial groups.

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Biodegradable protein-based film was developed by incorporating cinnamon essential oil (CEO) into whey protein concentrate (WPC) at level of 0.8% and 1.5% v/v. Then physical and mechanical properties of the films were evaluated. Adding CEO to the WPC matrix decreased the water vapour permeability of the films and water solubility. Films containing CEO showed significant antibacterial activity both gram-positive and gram-negative strains and exhibited significant inhibitory effect on the studied fungi. In continue, the effect of whey coating and whey coating incorporated with 1.5% CEO on quality and shelf life of Huso huso fillet during refregrated (4±1°C) storage period were also investigated. The control and treated fish samples were analyzed for microbiological (total viable count, psychrophilic counts), chemical (PV, TBA, FFA, pH, TVB-N), and sensory characteristics in 4-day intervals up of microbial, chmical and sensoy analyses indicated lower levels of PV, TBA, FFA, pH, TVB-N in coasted sampels and specially, those with CEO while were kept in refrigerator. Based on results, whey protein edible coating contain 1.5% cinnamon essential oil could enhance preserving ability Huso huso during storage cold.

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Fish protein concentrate (FPC) is a healthy, sustainable and high nutritive product which sanitized produced from fishes in which, protein and other nutrients are more concentrated than in fresh fishes. The aim of this research is to study on the sustainability of FPC produced from Kilka (Clupeonella engrauliformis , C. grimmi and C. cultriventris) in two Vaccum Packaging and Modified Atmosphere Packaging at different environmental factors during six months. In our study the analysis of FPC protein showed 91.2%, lipid: 0.5%, ash: 3.6%, moisture: 2.3%, Total Volatile Nitrogen: 10 ml/100gr and peroxide: 5meq/kg. Amino acids and fatty acids were also determined. Bacteria and Fungi were lower than 1000 colony. Samples are kept in different condition of temperature (5, 20 and 35 degree centigrade), humidity (25, 40 and 90 percent) and light and dark environment in six month. Lipid rate in FPC after 6 months in VP and MAP (60% C02, 30 % N2 and 10% O2), packages was decreased but was not significant (P>0.05). It was also detected that increase temperature lead to more decrease in lipid content. Protein rate of FPC was decreased from 91.2% to 73.6% during six months at 35°C in VP Package and from 91.2% to 69.4% in MAP package. These changes were significant (P<0.05). TVN and PV rate in FPC after 6 months in VP and MAP packages was increased but was significant (P<0.05). Amino acids and fatty acids were also determined. But more changes in MAP packages was detected.

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Mangroves play an important role in creating habitats for a diverse community of organisms ranging from bacteria and fungi to fishes and mammals. They grow in intertidal flats, estuaries and offshore islands. In the Philippines, mangrove forests have dramatically decreased in area since the start of the century, and therefore there is a need to reforest. However, first mangrove nurseries must be established since they serve as sources of planting materials for different mangrove species. Furthermore, nurseries would mean a sustainable source of livelihood for coastal communities because of continuous demand for propagules. A brief account is given of procedures as to the establishment of a mangrove nursery, describing the construction of a nursery, preparation of potting materials, seed collection, seed sowing, and maintenance and protection. Details are provided of the most common true mangrove species in the Philippines. The mangrove nursery is a place for raising and tending seedlings until they are ready for permanent planting. The establishment of mangrove nurseries is in line with government s efforts to rehabilitate the coastal and mangrove ecosystems.

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The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene, GlTop 2 was identified. It is a single copy gene with a 4476 by long ORF without intron. The deduced amino acid sequence shows strong homology to eukaryotic DNA Top 2. However, some distortions were found, such as six insertions in the ATPase domain and the central domain, a similar to 100 as longer central domain; a similar to 200 as shorter C-terminal domain containing rich charged residues. These features revealed by comparing with Top 2 of the host, human, might be helpful in exploiting drug selectivity for antigiardial therapy. Phylogenetic analysis of eukaryotic enzymes showed that kinetoplastids, plants, fungi, and animals were monophyletic groups, and the animal and fungi lineages shared a more recent common ancestor than either did with the plant lineage; microsporidia grouped with fungi. However, unlike many previous phylogenetic analyses, the "amitochondriate" G. lamblia was not the earliest branch but diverged after mitochondriate kinetoplastids in our trees. Both the finding of typical eukaryotic type IIA topoisomerase and the phylogenetic analysis suggest G. lamblia is not possibly as primitive as was regarded before and might diverge after the acquisition of mitochondria. This is consistent with the recent discovery of mitochondrial remnant organelles in G. lamblia.

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:从云南西双版纳不同生境下的14 株热带兰菌根中分离到19 株真菌,分别鉴定为9 个属,其中优势 菌为镰孢霉属( Fusarium) 9 株占47. 37 %;组丝核菌属( Phacodium) 3 株占15. 79 %.