亚热带森林外生菌根真菌的生态学研究

菌根是一种植物营养根与土壤真菌形成的共生体，在自然界中分布广泛。外生菌根真菌是菌根真菌的重要类群，其宿主植物约占陆地植物总数的3%左右。由于外生菌根真菌的宿主植物常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。本文通过外生菌根真菌的种类鉴定和多样性，外生菌根真菌种群的遗传结构，外生菌根真菌群落的结构、空间格局及植物-菌根真菌空间关系，外生菌根真菌接种对植物生长和竞争的影响等四个方面的研究，使我们对这一地区的外生菌根真菌的种类组成、空间分布和传播规律、年度变化、以及对植物群落组成和多样性的影响等方面，有一个初步了解。 外生菌根真菌的鉴定和种类组成是进行菌根真菌研究的前提之一。在第一章中，主要通过子实体形态分类和分子方法，对大型真菌的种类进行了鉴定。在对东灵山和都江堰森林的调查中分别发现的大型真菌106种和98种，菌根真菌比例分别为44.3%和69.4%，木生真菌比例分别为16%和10.2%。按Fellner的评价标准，两个森林群落均属于健康的生态系统。我们应用ITS-RFLP和ITS序列比较的方法对地上子实体、地下菌根及分离培养的菌种进行了种类鉴定和分析。结果表明，ITS-RFLP可以用来进行外生菌根真菌的种类鉴定，而序列分析能够提供更为可靠的信息。二者的结合，可以使我们建立菌根真菌分子数据库成为可能。 种群遗传结构的研究包括种群中个体的空间分布和亲缘关系等方面，有助于加深我们对种群的生殖和传播方式，菌根真菌与风、雨、动物等生态因子的关系等方面的理解。第二章主要以两个外生菌根真菌种群为例，对种群遗传结构中空间距离与遗传相似性的关系、种群结构的年度变化等方面进行了探讨。正红菇（Russula vinosa）种群具有较高的遗传多样性，每个子实体来自不同的克隆。空间距离-遗传相似性关系和空间格局分析的结果均表明，这一正红菇的种群结构可能是由短距离孢子传播产生的，而不可能是无性生长或长距离孢子传播形成的。在对隐花青鹅膏菌（Amanita manginiana）连续两年的种群结构进行了研究中，种群的每一个子实体也均来自不同的克隆。遗传相似性分析、AMOVA、遗传相似性-空间距离关系的结果均显示，这两年的种群在遗传相似性和种群结构上均具有显著差异。对此的一个合理的解释就是，这一外生菌根真菌种群来说，其个体由有性孢子发育为子实体的时间可能超过一年，因而2001和2002年的个体并非同一种群的连续世代。 外生菌根真菌群落可以定义为在一定地理范围和时间尺度内不同外生菌根真菌种群的组合。对外生菌根真菌群落的研究有助于揭示森林生态系统中菌根真菌与植物、菌根真菌与环境因子、以及菌根真菌之间的相互关系。在第三章中，我们应用点格局的分析方法和二元逻辑回归分析对外生菌根真菌的主要类群，即鹅膏菌科，牛肝菌科和红菇科，的空间格局及其与周围（5×5米样方）树种组成的关系进行研究。结果表明，某些树种与特定类群菌根真菌的子实体出现有负相关，而三个类群的外生菌根真菌在克隆生长上的差异并不是子实体空间分布的决定因素。而在较小尺度上（450平方米样方）研究也表明，三个主要外生菌根真菌类群的空间分布为聚集半径不等的集群分布，并且其空间分布不依赖于木本植物的分布。外生菌根真菌主要类群在空间分布上具有相互抑制的特点，而抑制能力的大小可能与菌根真菌地下菌丝体的分布范围及连续性有关。 外生菌根真菌的盆栽接种实验通常用来验证菌根真菌-宿主植物的相互关系，不但有理论意义，也是大田实验和大规模生产应用的基础。第四章中进行了两个实验，对外生菌根真菌多样性与宿主植物生长的关系以及菌根真菌与植物之间竞争平衡的关系进行了初步研究。在外生菌根真菌多样性对马尾松生长影响实验中，菌根真菌接种并未显著促进马尾松幼苗的生长和生物量积累，不同的菌种与地上、地下生物量的积累存在不同（正或负）的相关关系。外生菌根真菌的多样性水平与马尾松幼苗的针叶数量存在显著的正相关，并且随接种时间的延长相关关系更为显著。外生菌根真菌多样性水平还与马尾松幼苗地下生物量的累积呈显著的正相关关系。在外生菌根真菌对三种植物的竞争平衡和共存的影响实验中，外生菌根真菌接种没有显著促进马尾松幼苗的生长，但对漆树和枹栎幼苗的生长有显著影响。外生菌根真菌接种能够在两个外生菌根真菌宿主植物竞争中降低枹栎对马尾松的优势，在马尾松和漆树的竞争中降低马尾松的优势，并促使枹栎与漆树（一个外生菌根真菌宿主和一个非宿主植物）的竞争处于不稳定状态。 本文首次通过生态学的角度对外生菌根真菌的物种多样性、种群结构、群落中的空间格局、以及外生菌根真菌与植物生长的关系进行了较为全面的研究。在大型真菌的多样性方面，菌根和木生真菌比例的引入可以完善森林生态系统的健康评价体系，而分子数据库的建立使对大型真菌尤其是外生菌根真菌多样性的长期监测成为可能;在种群遗传结构方面，本文验证了红菇属和鹅膏菌属克隆较小的特点，以及红菇属菌根真菌以短距离孢子传播为主的繁殖特性，并首次从生活史特点的角度解释菌根真菌的种群结构的年度差异;在菌根真菌群落的空间格局方面，本文首次应用二元逻辑回归和点格局分析的方法研究外生菌根真菌的空间分布及菌根真菌－植物关系，并发现三个类群的外生菌根真菌在子实体分布上具有相互排斥的特点;在控制实验中，本文首次研究了菌根真菌接种的多样性水平对宿主植物的影响，首次研究了外生菌根真菌接种对三个物种之间竞争与共存的影响。虽然这些研究在很多方面都仅得到初步的结果，但我们希望这些探索可以为今后对外生菌根真菌的生态学研究提供有益的启示。

Diseases and parasites of penaeid prawns of India: a short review

The diseases caused by bacteria, fungi, protozoa and metazoa as well as by other biotic and abiotic agents reported in the penaeid prawns of India are reviewed.

中国都江堰地区两种林龄森林中外生菌根真菌的多样性

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。

Some observations on the problem of marine timber destroying organisms of Indian coasts

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.

Survey on the quality of Jaadi available [in] Sri Lankan market

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.

Novel cathelicidin-derived antimicrobial peptides from Equus asinus

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.

The propagation of the mud crab Scylla serrata (F.) de Haan

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.

Use of fermented kitchen waste in rearing Penaeus monodon larvae

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.

Nitrogen fixing bacteria, Azotobacter sp. in aquatic sediment

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.

Application of whey protein incorporation with Cinnamon oil as a preservative in Huse huso fillet under chilled storage condition

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.

Study on the sustainability of FPC produced from Kilka (Clupeonella engrauliformis, C. grimmi and C. cultriventris) in two vacuum packaging and modified atmosphere packaging at different environmental factors

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.

Establishing a mangrove nursery

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.

Identification, characteristic and phylogenetic analysis of type II DNA topoisomerase gene in Giardia lamblia

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.

NK-lysin of channel catfish: Gene triplication, sequence variation, and expression analysis

Antimicrobial peptides (AMPs) are important components of the host innate immune response against microbial invasion. In addition to the previously known four classes of antimicrobial peptides, a fifth class of antimicrobial peptides has been recently identified to include NK-lysins that have a globular three-dimensional structure and are larger with 74-78 amino acid residues. NK-lysin has been shown to harbor antimicrobial activities against a wide spectrum of microorganisms including bacteria, fungi, protozoa, and parasites. To date, NK-lysin genes have been reported from only a limited number of organisms. We previously identified a NK-lysin cDNA in channel catfish. Here we report the identification of two noveltypes of NK-lysin transcripts in channel catfish. Altogether, three distinct NK-lysin transcripts exist in channel catfish. In this work, their encoding genes were identified, sequenced, and characterized. We provide strong evidence that the catfish NK-lysin gene is tripled in the same genomic neighborhood. All three catfish NK-lysin genes are present in the same genomic region and are tightly linked on the same chromosome, as the same BAC clones harbor all three copies of the NK-lysin genes. All three NK-lysin genes are expressed, but exhibit distinct expression profiles in various tissues. In spite of the existence of a single copy of NK-lysin gene in the human genome, and only a single hit from the pufferfish,genome, there are two tripled clusters of NK-lysin genes on chromosome 17 of zebrafish in addition to one more copy on its chromosome 5. The similarity in the genomic arrangement of the tripled NK-lysin genes in channel catfish and zebrafish suggest similar evolution of NK-lysin genes. (c) 2005 Elsevier Ltd. All rights reserved.

Root zone microbial populations, urease activities, and purification efficiency for a constructed wetland

In order to investigate the effects of microorganisms and their urease activities in macrophytic root zones on pollutant removal, four small-scale plots (SSPs) of vertical/reverse-vertical flow wetlands were set up to determine: a) the relationship between the abundance of microorganisms in the root zones and water purification efficiency; and b) the relationship between urease activities in the root zones and pollutant removal in a constructed wetland system. Total numbers of the microbial population (bacteria, fungi, and actinomyces) along with urease activities in the macrophytic root zones were determined. In addition, the relationships between microbial populations and urease activities as well as the wastewater purification efficiencies of total phosphorus (TP), total Kjeldahl nitrogen (TKN), biochemical oxygen demand in 5 days (BOD5), and chemical oxygen demand (COD) were also analyzed. The results showed that there was a highly significant positive correlation (r = 0.9772, P < 0.01) between the number of bacteria in the root zones and BOD5 removal efficiency and a significant negative correlation (r = -0.9092, P < 0.05) between the number of fungi and the removal efficiency of TKN. Meanwhile, there was a significant positive correlation (r = 0.8830, P < 0.05) between urease activities in the root zones and the removal efficiency of TKN. Thus, during wastewater treatment in a constructed wetland system, microorganism and urease activities in the root zones were very important factors.