1000 resultados para ITS-RFLP


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Mycobacterium kansasii is a pulmonary pathogen that has been grown readily from municipal water, but rarely isolated from natural waters. A definitive link between water exposure and disease has not been demonstrated and the environmental niche for this organism is poorly understood. Strain typing of clinical isolates has revealed seven subtypes with Type 1 being highly clonal and responsible for most infections worldwide. The prevalence of other subtypes varies geographically. In this study 49 water isolates are compared with 72 patient isolates from the same geographical area (Brisbane, Australia), using automated repetitive unit PCR (Diversilab) and ITS RFLP. The clonality of the dominant clinical strain type is again demonstrated but with rep-PCR, strain variation within this group is evident comparable with other reported methods. There is significant heterogeneity of water isolates and very few are similar or related to the clinical isolates. This suggests that if water or aerosol transmission is the mode of infection, then point source contamination likely occurs from an alternative environmental source.

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冷杉属是松科中的第二大属,在北半球有着广泛的分布区,从温带的高纬度地带到亚热带(偶达热带地区)的山地,呈间断不连续的分布。虽然一些学者曾对冷杉属进行过大量的分类学和系统学研究,但该属复杂的变异式样至今仍困扰着植物系统学家们。本论文是在腊叶标本和野外实地调查的基础上,从形态学、解剖学、分子系统学和植物地理学等方面进行分类学和系统发育的分析研究。现得到以下初步结果。1.对冷杉属叶角质层内表面胞间凸缘的研究结果表明,可以分为4种类型: 1. 弯曲且发达的单凸缘;2直且发达的单凸缘;3不发达的单凸缘;4双桥型凸缘。分布于欧洲和亚洲的绝大部分种类都是弯曲且发达的单凸缘类型(日本一种除外),而分布于北美的种类则具有四种不同的类型。 2. 叶横切面的研究结果表明皮下层细胞的发育状况和树脂道的位置与大小在Sect. Balsamea中稳定,皮下层细胞的缺失和不发育、树脂道大且中生在该属中可能反映原始状态。 3. 本研究首次发现nrDNA ITS的长度在属下有较大的变异,变异幅度1700 bp-2500 bp,分析得出引起这一变异的主要原因是由于ITS1中有以GGCCACCCTAGTC为核心数目不等的重复序列的存在,并讨论了ITS长度的变异在冷杉属和松科系统演化中的意义。 4. nrDNA ITS的RFLP分析结果和5种冷杉的ITS序列分析结果(以Keteleeria davidiana为外类群)表明A. bracteata与Sect. Balsamea总是聚在一起,亲缘最近;A. kawakamii应属于Sect. Momi。 5. 地理分布和系统发育分析的研究结果表明,冷杉属的多样性中心在北美西南部、而种类分布最大多的地区为东亚、种群分化最强烈的地区为我国的横断山脉。根据冷杉属的系统发育、化石资料和现代冷杉属的地理分布格局,冷杉属可能起源于白垩纪的高纬度地带。 6. 结合ITS RFLP和ITS序列的分支分析结果以及某些形态特征和地理分布资料,重建属下分类系统,将冷杉属分为8组2亚组。探讨了各组间的亲缘关系,认为Sect. Balsamea是冷杉属中的原始类群,Sect. Balsamea是与Sect. Balsamea亲缘最近,形态上十分特化的类群。来自ITS的分析结果为摒属下亚属的划分和将A. kawakamii自Sect. Balsamea中移出,放入Sect. Momi中提供了强有力的证据。经过标本和文献考证,综合各方面的资料,本文对冷杉属进行了全面系统的分类学修订,包括44种17变种1亚种,系统排列如下: 组1. 树脂冷杉组Sect. 1. Balsamea Engelmann。该组包括8种4变种:Abies balsamea, A. lasiocarpa, A. sibirica, A. sachalinensis, A. fraseri, A. koreana, A. nephrolepis, A. veitchii, A. bracteata。 组3. 日本冷杉组Sect. 3. Momi Franco。 亚组1.日本冷杉亚组Subsect. 1. Firmae (Franco) Farjon et Rushforth。该亚组包括6种3变种:A.holophylla, A. homolepis, A. firma, A. beshanzuensis, A. chensiensis, A. pindrow, A. beshanzuensis var. ziyuanensis, A. chensiensis var. ernestii, A. chensiensis var. salouenensis。 亚组2. 鳞皮冷杉亚组Subsect. 2. Squamatae E. Murray。该亚组包括12种6变种:A squamata, A. delavayi, A. nukiangensis, A. recurvata, A. spectabilis, A. mariesii, A. kawakamii, A. forrestii, A. fargesii, A. fansipanensis, A. fanjingshanensis, A. yuanbaoshanensis, A. delavayi var. fabri, A. delavayi var. motuoensis, A. spectabilis var. densa, A. forrestii var. georgei, A. forrestii var. ferreana, A. fargesii var. faxoniana。 组4. 冷杉组Sect. 4. Abies。该组包括7种1变种1亚种:A. alba, A. cephalonica, A. nordmanniana, A. nebrodensis, A. cilicica, A. pinsapo, A. numidica, A. nordamanniana ssp. equitrojani, A. pinsapo var. marocana。 组5. 太平洋冷杉组成Sect. 5. Amabiles (Matzenko) Farjon et Rushforth。该组仅一种:A. amabilis。 组6. 高贵冷杉组Sect. 6. Nobilis Engelmann。该组有2种1变种:A. procera, A. magnifica, A. magnifica var. shastensis。 组7. 大冷杉组成Sect. 7. Grandes Engelmann, emend. Farjon et Rushforth。该组包括4种2变种:A. concolor, A. grandis, A. durangensis, A. guatemalensis, A. concolor var. lowiana, A. durangensis var. coahuilensis。 组8. 墨西哥冷杉组Sect. 8. Oiamel Franco, emend. Farjon et Rushforth。该组包括A. religiosa, A. vejarii, A. vejari var. mexicana, A. hickelii

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稻属(Oryza L.)隶属于禾本科(Gramineae)Ehrhartoideae亚科的稻族(Oryzeae),包括两个栽培种(亚洲栽培稻O. sativa和非洲栽培稻O. glaberrima)和大约20多个野生种,广布于热带亚洲、非洲、大洋洲、中美洲和南美洲。药用野生稻复合体(O. officinalis complex)是稻属中最大、也是最复杂的一个复合体,共包括9个种,含有5种染色体组类型(B、C、BC、CD 和E)。作为栽培稻品质改良的重要基因库,药用野生稻复合体在稻属中具有重要的地位。但是,相似的形态和重叠的地理分布使部分物种的分类和鉴定一直较为困难;种内染色体组构成和倍性的不同更增加了分类鉴定的复杂性。这种情况阻碍了对这些野生稻遗传优势的有效利用。另外,由于物种间断分布和缺乏明确的二倍体亲本等原因,药用野生稻复合体内的异源多倍体起源一直存在争议。本文通过细胞核乙醇脱氢酶基因(Adh)和nrDNA的内转录间隔区(ITS)限制性片段长度多态性(RFLP)分析;叶绿体matK 基因、trnL 内含子和trnL-trnF 基因间隔区、核基因Adh和GPA1以及核糖体DNA ITS片段等序列比较的方法,对药用野生稻复合体中染色体组和物种的鉴定、种间系统发育关系,以及异源多倍体CCDD物种的起源和多倍体ITS的分子进化等进行了研究。主要研究结果如下: 1. 利用核Adh 基因限制性片段长度多态性,检测了来自国际水稻研究所基因库的64份药用野生稻复合体的样品。结果证明,所有O. rhizomatis样品都是含C染色体组的二倍体,所有O. minuta样品都是含BC 染色体组的四倍体。但是,种子库中鉴定为O. officinalis、O. punctata和O. eichingeri的样品中,同时都发现了含C染色体组的二倍体和含BC染色体组的四倍体。四倍体的O. officinalis只在印度分布,而且曾被描述为另一个种O. malampuzhaensis。 四倍体的O. punctata,也被一些学者称为O. schweinfurthiana,被发现和其二倍体一样分布广泛。值得注意的是,有两个曾被作为O. officinalis 四倍体的样品实际上是含有CD染色体组的物种O. latifolia。我们的结果增进了对国际水稻研究所种子库中部分野生稻样品染色体组构成的理解, 纠正了以往对药用野生稻复合体样品的错误鉴定,为今后进一步研究和利用这部分资源提供了种质编目的重要基础。 2. 对稻属中代表不同地理分布区的、含CD染色体组的11个样品(包括77个克隆)的ITS片段进行了测序。基于这些ITS序列的限制性片段长度多态性,提出一个快速而可靠的区分稻属CD 染色体组物种的方法。这个方法的具体步骤是:(1)利用通用引物扩增ITS 片段;(2)利用限制性内切酶FokI和/或DraⅢ消化PCR扩增产物;(3)用1%的琼脂糖胶电泳并根据消化产物的片段长度多态性来区分不同物种。 3. 利用包括两个叶绿体片段(matK和 trnL-trnF)、nrDNA内转录间隔区(ITS)和三个核基因(Adh1、Adh2和GPA1)的同源序列分析,探讨了药用野生稻复合体中二倍体物种和它们所代表的染色体组之间的系统发育关系。独立和合并的基因系统发育树都显示了一致的结果,即C染色体组和B染色体组的亲缘关系要比它们和E染色体组的近。三个含C染色体组的二倍体中,O. officinalis 和O. rhizomatis表现出较近的亲缘关系。值得注意的是,在O. eichingeri种内,尽管基于多基因的数据支持来自斯里兰卡的样品和来自非洲的样品聚成一个分支,但是较低的支持率表明, 两个地区的样品之间存在着较高的遗传分化。 4. 稻属中含CD染色体组的物种特产于拉丁美洲,包括O. alta、 O. grandiglumis 和O. latifolia。由于具有相同的染色体组类型、相似的形态特征和重叠的地理分布,这3个物种间的系统发育关系一直存在争论。另外,因为美洲大陆上没有含C和D染色体组的二倍体物种存在,对这些含CD染色体组物种的可能起源也有不同的假设被提出。使这个问题更具挑战性的是,尽管开展了世界范围的收集,至今仍没有找到含D 染色体组的二倍体物种。在本研究中,代表含C、CD和E染色体组以及含G染色体组的外类群共7个物种,共15份样品的2个叶绿体片段(matK和trnL-trnF)和3个核基因(Adh1,Adh2 和 GPA1)部分片段被测序。基于简约法、距离法和最大似然法的系统发育分析都充分支持含CD染色体组的物种起源于一次杂交事件的推论,并且显示,在物种形成时,含C染色体组的物种(O. officinalis 或O. rhizomatis 而非O. eichingeri)可能承担了母本,而含E染色体组的物种(O. australiensis)则可能承担了父本。另外,CCDD物种间非常一致的系统发育关系表明,非常大的分歧存在于 O. latifolia 和其它两个种(O. alta和O. grandiglumis)之间,这个结果倾向于将后两个种处理为同种或同种下不同分类群。 5. 基于178个克隆序列比较,探讨了ITS在稻属多倍体中的致同进化及其系统学意义。研究发现稻属异源四倍体的ITS存在不同形式的进化方式:首先,非洲BBCC四倍体O. eichingeri和O. punctata 的ITS片段同时保留了双亲拷贝,而且系统发育研究表明,二倍体的O. eichingeri和O. punctata 可能是这两个四倍体的直接祖先;其次,亚洲四倍体O. malampuzhaensis和O. minuta 的ITS仅定向保留母本ITS拷贝;另外,美洲CCDD四倍体的ITS序列发生了双向致同进化,即O. alta和O. grandiglumis的ITS位点一致化成C染色体组类型,而O. latifolia一致化成 D/E 染色体组类型。我们的研究进一步表明在利用ITS片段进行系统发育分析时,特别是涉及异源多倍体时必须慎重。 6. 利用栽培稻的微卫星引物,对含B/C染色体组的6个物种,157个体的SSR位点进行扩增。结果在这些亲缘关系稍远的野生稻中得到7个SSR位点,其中5个位点表现出多态性。比较BB、CC和BBCC物种SSR位点的每位点平均等位基因数A、多态位点百分率P和期望杂合度He ,3项指标发现,四倍体物种的遗传多样性,总体上要高于二倍体物种;二倍体物种内部,O. officnalis的遗传变异最大。另外,以遗传相关性为标准,讨论了B/C染色体组物种间的系统发育关系,同时推测了现存二倍体物种和4个BBCC四倍体物种的遗传关系。

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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。

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A total of 107 putative ericoid mycorrhizal endophytes were isolated from hair roots of Calluna vulgaris from two abandoned arsenic/copper mine sites and a natural heathland site in southwest England. The endophytes were initially grouped as 14 RFLP types, based on the results of ITS-RFLP analysis using the restriction endonucleases Hinf I, Rsa I and Hae III. ITS sequences were obtained for representative isolates from each RFLP type and compared phylogenetically with sequences for known ericoid mycorrhizal endophytes and selected ascomycetes. The majority of endophyte isolates (62-92%) from each site were identified as Hymenoscyphus ericae, but a number of other less common mycorrhizal RFLP types were also identified, all of which appear to have strong affinities with the order Leotiales. None of the less common RFLP types was isolated from C. vulgaris at more than one field site. Neighbour-joining analysis indicated similarities between the endophytes from C. vulgaris and mycorrhizal endophytes isolated from other Ericaceae and Epacridaceae hosts in North America and Australia.

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Bursaphelenchus antoniae sp. n. is described and illustrated. Dauer juveniles were isolated from the body of the large pine weevil, Hylobius sp., collected from maritime pine (Pinus pinaster) stumps, in Portugal. Bursaphelenchus antoniae sp. n. was reared and maintained in P. pinaster wood segments and on Petri dish cultures of the fungi Botrytis cinerea and Monilinia fructicola. The new species is characterised by a relatively small body length of ca 583 μm (females) and 578 μm (males), a lateral field with two incisures, presence of a small vulval flap and a conoid female tail with a rounded or pointed terminus. Males have stout spicules with a disc-like cucullus and seven caudal papillae arranged as a single midventral precloacal papilla, one precloacal pair and two postcloacal pairs. In the character of the lateral field, B. antoniae sp. n. comes close to B. abietinus, B. rainulfi and B. hylobianum, whilst spicule characters place it within the piniperdae-group sensu Ryss et al. Morphologically, B. antoniae sp. n. is closest to B. hylobianum; the spicules of these two species having flattened, wing-like, alae on the distal third of the lamina. Bursaphelenchus antoniae sp. n. is distinguished from B. hylobianum on the arrangement of the caudal papillae (two vs three pairs). ITS-RFLP profiles and the failure to hybridise support the separation of the two species. Phylogenetic analysis of the new species, based on the 18S rDNA sequence, supports the inclusion of this new species in the B. hylobianum-group sensu Braasch. Sequence analysis of the 28S rDNA D2/D3 domain did not place the new species in a definite group.

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A survey for Bursaphelenchus nematodes, associated with different conifer trees, was conducted in several forest areas in the northern regions of Turkey. Only pine trees (Pinus nigra, P. pinaster and P. sylvestris) yielded Bursaphelenchus specimens. Nematodes were identified using several morphological diagnostic characters of the genus (male spicule structure, number of lateral incisures, number and distribution of the male papillae, presence of female vulval flap), and confirmed by using RFLP analysis of the internal transcriber spacer (ITS) regions of ribosomal DNA. Three different species were identified from several sampled areas, namely B. mucronatus, B. pinophilus and B. sexdentati, representing a first report of the last two species for Turkey. The association of B. pinophilus with black pine (P. nigra) is herein reported for the first time.

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The occurrence of Bursaphelenchus species in the Czech Republic is poorly known, the first report of the genus being made by Kubátová et al. (2000) who reported the association of B. eremus with the hyphomycetous microfungus, Esteya vermicola, and the bark beetle, Scolytus intricatus, collected from Quercus robur, in central Bohemia. To date, four other species have been reported from the country, namely B. fungivorus (Braasch et al., 2002), B. hofmanni (see Braasch, 2001), B. mucronatus (see Braasch, 2001) and B. vallesianus (Gaar et al., 2006). More recently, a survey for Bursaphelenchus species associated with bark- and wood-boring insects in the Czech Republic identified B. pinophilus Brzeski & Baujard, 1997 from the Moravia region. Although this represents a new country record, it was also associated with nematangia on the hind wings of a new insect vector. A total of 404 bark- and wood-boring insects were collected from declining or symptomatic trees and screened for the presence of Bursaphelenchus. Bark and longhorn beetles were captured manually after debarking parts of the trunk displaying symptoms of insect attacks. Longhorn beetle larvae were also collected together with logs cut from the trunk. Logs were kept at room temperature in the laboratory until insect emergence. Each adult insect was individually dissected in water and examined for nematodes. All nematodes resembling dauer juveniles of Bursaphelenchus were collected and identified by molecular characterisation using a region of ribosomal DNA (rDNA) containing the internal transcribed spacer regions ITS1 and ITS2. ITS-RFLP analyses using five restriction enzymes (AluI, HaeIII, HinfI, MspI, RsaI) were performed to generate the species-specific profile according to Burgermeister et al. (2009). Species identification was also confirmed by morphological data after culture of the dauers on Botrytis cinerea Pers. ex Ft., growing in 5% malt extract agar. During this survey, only species belonging to the Curculionidae, subfamily Scolytinae, revealed the presence of nematodes belonging to Bursaphelenchus. Dauers of this genus were found aggregated under the elytra in nematangia formed at the root of the hind wings (Fig. 1). The dauers were identified from 12 individuals of Pityogenes bidentatus (Herbst, 1783) (Coleoptera: Scolytinae) collected under the bark of Pinus sylvestris trunks. Each insect carried ca 10-100 dauers. The ITS-RFLP patterns of the dauers so obtained confirmed the identification of B. pinophilus associated with this insect species. Bursaphelenchus pinophilus has been found mainly in Europe and has been reported from various countries such as Poland (Brzeski & Baujard, 1997), Germany (Braasch, 2001), and Portugal (Penas et al., 2007). The recent detection of this species associated with dead P. koraiensis in Korea (Han et al., 2009) expands its geographical distribution and potential importance. It has been found associated only with Pinus species, but very little is known about the insect vector. The bark beetle, Hylurgus ligniperda, was initially suggested as the insect vector by Pe-nas et al. (2006), although the nematode associated with this insect was later reclassified as B. sexdentati by morphological and molecular analysis (Penas et al., 2007). According to the literature, P. bidentatus has been cited as a vector of Ektaphelenchus sp. (Kakuliya, 1966) in Georgia, and an unidentified nematode species in Spain (Roberston et al., 2008). Interestingly, B. pinophilus was found in the nematangia formed at the root of the hind wings of P. bidentatus. Although this phenomenon is not so common in other Bursaphelenchus species, B. rufipennis has been found recently in such a structure on the hind wings of the insect Dendroctonus rufipennis (Kanzaki et al., 2008). Although other nematode species (e.g., Ektaphelenchus spp.) are frequently found associated within the same nematangia (see Kanzaki et al., 2008), in this particular case, only dauers of B. pinophilus were identified. The association between B. pinophilus and P. bidentatus represents the first report of this biological association and the association with the Scolytinae strengthens the tight and specific links between this group of Bursaphelenchus species and members of the Scolytinae (Ryss et al., 2005).

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Abstract - The genus Bursaphelenchus comprises almost 100 species mainly from the northern hemisphere, with conifers as the most important hosts. Among the various nematode species, the pine wood nematode (PWN), Bursaphelenchus xylophilus, is the casual agent of pine wilt disease (PWD), and the most important forest pest for pines worldwide, classified as an A1 quarantine organism within the European Union. In 1999 this nematode was detected for the first time in Portugal and Europa associated with maritime pine, Pinus pinaster. Following detection, a national program denominated "Programa Nacional de Luta contra o Nemátodo da Madeira do Pinheiro" (PROLUNP) was created to, among other objectives, determine the distribution of the PWN and its associated vector(s) and host(s), and therefore intensive surveys covering the entire country were conducted with thousands of wood samples and suspected insects being analyzed. This thesis presents the listing, distribution, frequency and the insects associated with Bursaphelenchus species found associated with maritime pine in Portugal, identifying and characterizing the various species by morphological, biometrical and molecular biology (ITS-RFLP and rDNA sequencing analysis) techniques. To achieve the objectives, a total of 4813 maritime pine wood samples and 3294 insects from 22 species and six families were individually analyzed. A total of nine Bursaphelenchus species were found, namely: B. antoniae, B. hellenicus, B. leoni, B. mucronatus, B. pinasteri, B. sexdentati, B. teratospicularis, B. tusciae and B. xylophilus, all of them (with the exception of B. xylophilus) being new records for Portugal. Some of the species appear to have a widespread distribution, such as B. leoni, B. teratospicularis and B. tusciae while others were very rarely found and apparently have a localized distribution range within the country, namely B. antoniae and B. mucronatus. The majority of the species is characteristic of the Mediterranean region and can also be found in countries such as Spain, Italy and Greece, reflecting the affinity of our fauna with those locations. The association of B. hellenicus and B. tusciae with maritime pine is here reported for the first time. Six of the Bursaphelenchus species were also found associated with insects, mainly from the family Scolytidae (Coleoptera). Some of these interactions were described for the first time, namely: B. hellenicus with both Ips sexdentatus and Hylurgus ligniperda, B. sexdentati with both H. ligniperda and Orthotomicus erosus and B. tusciae with H. ligniperda. The exclusive association of B. xylophilus with the cerambycid Monochamus galloprovincialis was also confirmed. The nematode's dauer juveniles were usually found in low numbers in the insect vectors (ca 10-100 per insect), although for B. xylophilus a few thousand specimens per insect were sometimes found. The location of the dauer juveniles differed according to the species, although they were more common under the elytra and wings of the adult insects. A species new to science was detected and formally described as B. antoniae, associated with Hylobius sp. (Coleoptera; Curculionidae) beetles. Morphologically, this new species is very similar to B. hylobianum, although it's distinct ITS-RFLP molecular pattern (with only the enzyme Haelll producing comparable restriction bands) and the failure of hybridization supported the two species as distinct entities. Additional phylogenetic analysis of the 18S rDNA sequence further supported the taxonomical proximity of B. antoniae with B. hylobianum. Concerning the PWN, detailed studies on the development and morphology of B. xylophilus were conducted, and comparative measurements of field-collected and laboratory-maintained populations demonstrated that nematodes from the second group displayed larger size in all morphometric parameters, which could derive from more adequate conditions of nourishment and/or temperature. Taxonomical studies on the development stages of B. xylophilus confirmed the existence of four propagative juvenile stages (J1,J2,J3 and J4), an adult stage with both sexes and two dispersal stages (jIII e jIV), with the measurements of the gonad length allowing the separation of the propagative stages. It is hoped that the acquired knowledge will be useful on future surveys of nematodes of the Bursaphelenchus genus collected from either wood material or insect vectors, and facilitate the correct distinction and identification of the various species which are now known to occur. ### Resumo - 0 género Bursaphelenchus compreende quase 100 espécies, distribuídas sobretudo nos países do hemisfério norte do globo terrestre. Embora algumas espécies já tenham sido detectadas em plantas herbáceas, os hospedeiros vegetais mais comuns deste género são as coníferas, particularmente pinheiros. 0 nemátode da madeira do pinheiro (NMP), Bursaphelenchus xylophilus, é considerado a espécie mais importante deste género uma vez que é o agente causal da doença da murchidão dos pinheiros ("pine wilt disease"). Originário dos Estados Unidos, onde não causa grande impacte, o NMP foi introduzido em alguns países da Ásia (China, Japão, Coreia e Taiwan) e mais recentemente na Europa (Portugal). Nestas regiões é responsável pela destruição de milhares de hectares de coníferas, assumindo uma elevada importância económica. Em Portugal, depois da sua detecção em 1999, associado a Pinus pinaster, foi implementado um programa nacional "Programa Nacional de Luta contra o Nemátodo da Madeira do Pinheiro" (PROLUNP) que permitiu determinar a área afectada pela praga (a sul do rio Tejo, península de Setúbal) bem como definir e implementar estratégias de controlo e prevenção da disseminação do NMP a outras zonas de Portugal. Recentemente, em Junho de 2008, foi confirmada a presença de B. xylophilus em outras regiões de Portugal levando as autoridades oficiais a definir todo o território continental como zona afectada e de restrição. As prospecções intensivas realizadas nos últimos anos incluíram a recolha e análise de milhares de amostras de madeira de pinheiro bem como de insectos associados ao pinheiro bravo conduzindo à identificação de várias espécies de Bursaphelenchus. Assim, os estudos conduzidos neste trabalho tiveram como objectivos efectuar uma caracterização morfológica, biométrica e molecular das espécies associadas a P. pinaster em Portugal bem como a sua distribuição geográfica e abundância. Os estudos biométricos foram realizados com populações extraídas directamente do meio natural. Foi ainda realizada uma pesquisa que permitiu identificar os insectos a que estão associadas essas espécies, os seus possíveis vectores. Foram analisadas no total 4813 amostras de P. pinaster e 3294 insectos (22 espécies pertencentes a seis famílias diferentes). Foram identificadas um total de nove espécies: B. antoniae n. sp., B. hellenicus, B. leoni, B. mucronatus, B. pinasteri, B. sexdentati, B. teratospicularis, B. tusciae e B. xylophilus. Foram realizados estudos morfológicos e biométricos de todas as espécies com excepção de B. mucronatus; o reduzido número de exemplares encontrados em apenas uma amostra foram utilizados para efectuar o diagnóstico molecular desta espécie (ITS-RFLP). Apesar de ter havido, sempre que possível, a confirmação molecular, na maioria dos casos a caracterização morfológica e biométrica permitiu a correcta identificação das espécies. Contudo, foi imprescindível a análise molecular em algumas amostras, nomeadamente para a identificação de B. xylophilus e B. sexdentati; dada a grande semelhança entre B. xylophilus e B. mucronatus e tendo sido encontradas algumas populações de B. xylophilus que possuíam fêmeas com cauda mucronada, foi necessária a realização da confirmação molecular. Com excepção de B. xylophilus, todas as outras espécies foram reportadas pela primeira vez em Portugal. Juntamente com B. xylophilus, B. pinasteri foi a espécie encontrada nas amostras de madeira de pinheiro com maior frequência. Algumas destas espécies como B. leoni, B. teratospicularis e B. tusciae foram reportadas em diferentes localidades do norte, centro e sul de Portugal, apresentando uma vasta distribuição geográfica; este resultado está em consonância com a forte associação destas espécies a climas mediterrânicos tal como acontece em Espanha, França, Itália e Grécia. Em oposição, espécies como B. antoniae e B. mucronatus foram encontradas apenas numa ocasião na região centro (Leiria) e norte (Figueira da Foz) do país, respectivamente. Bursaphelenchus mucronatus é igualmente pouco frequente em Espanha onde ocorre sobretudo na região norte, na Galiza. Esta espécie preferirá climas mais frios, ocorrendo com uma maior frequência nas regiões de latitude norte; esta análise é corroborada pela presença constante em países como Alemanha, Finlândia, França, Noruega, Rússia e Suécia. A nível mundial são descritas neste trabalho pela primeira vez as associações das espécies B. hellenicus e B. tusciae ao hospedeiro vegetal P. pinaster.

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Mitochondrial DNA ND5/6 region was studied by PCR-RFLP analysis among ten representative strains belonging to three subspecies (Cyprinus carpio carpio, Cyprinus carpio haematopterus and Cyprinus carpio rubrofuscus) of common carp (Cyprinus carpio L.). A total of 2.4 kb fragment was amplified and subjected to restriction endonuclease analysis with nine restriction endonucleases subsequently. The results indicated that each subspecies owned one hyplotype and four restriction enzymes (Dde I, HaeIII, Taq I and Mbo I) produced diagnostic restriction sites which could be used for discriminating the three subspecies and as molecular genetic markers for assistant selective breeding of common carp.

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Cobia is a native fish species in Iranian waters in the Persian Gulf and Sea of Oman and has a good internal and foreign market. This fish is a fast growing species and for this reason Iranian Fisheries is considering to go for it culture practices. To go for any utilization such as fishing from wild stocks or culture activities, needs a better understanding of its peculiarities and genetic characteristics of its natural resources. Therefore, this project was discribed and conducted. In this investigation, cuts 2 or 3 cm of fin tissue of  specimen of Cobia obtained from Sistan and Bluchestan, Hormozgan, Bushehr and Khuzestan water provinces, were collected. DNA was extracted by Phenol-chlorophorm method and produced PCR product in length of 1060 and 1450 base pair of two mitochondrial genes COI and NADH2. Using 13 cutting enzymes (4 enzymes were subscriber for both of genes), 205 base pair (from 2510 base pair, equal with %3.8 from gene regains) were directly investigated. But binding patterns of enzymatic digestion of PCR products of both COI and ND genes from electrophoresis were monomorph in all samples and no polymorphism was observed. This may be attributed to the unsuitable choice of COI and ND2 genes for showing of intra specific divergence. But in general non-existence of genetic diversity or noticeable decrease of that among individuals has been reported in regions were fish migration exist and they can freely move between two regions. Therefore, non-observation of polymorphism in the study area might be the case and indicates represents the area. On the other hand, some scientists believe that the distributions of populations in different regions are greatly affected by environmental and physical and ecological factors. Althoug Cobia is a migratory fish, but with regard to the fact that the environmental conditions are different (specially temperature and salinity) between east and west of Persian Gulf and Oman sea, there is a possibility that different genetic groups of this species exist in the regions. Of course It is clear that using more samples and enzymes from other genetically regions could produce better results. Since none of the two investigated genes didn’t show genetic divergence or polymorphism amongst the individuals of one region or between different regions, therefore, statistic analysis for estimating of haplotype diversity or nucleotide diversity and drawing of relationship tree among individuals using available softwares was not possible.

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Lysozyme functions as a crucial biodefence effector against the infection of bacterial pathogens in innate immunity. The nucleotide sequence polymorphisms in promoter region of a nuclear goose type lysozyme gene from Zhikong scallop Chlamys farreri (designated as CFLysG) were investigated to explore their association with susceptibility/resistance to Listonella anguillarum infection. Eight sites of single nucleotide polymorphisms (SNPs) and two sites of insert-deletion (ins-del) polymorphisms were identified in the promoter region of CFLysG. Two of them, -753 TATCTCGATCAGG ins-del polymorphism and -391 A-G SNP were selected to analyze their distribution in the susceptible and resistant stocks, which were identified according to the survival time after L. anguillarum challenge. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), two genotypes were found at each site, which were ins/del and ins/ins at locus -753, and A/A and A/G at locus -391, respectively. The -753 ins/del genotype was more prevalent in the resistant stock than that in the susceptible stock, 30% vs 16.67% in frequency, but there was no significant difference in the frequency distribution between these two stocks (P=0.15). In contrast, the frequency of -391A/G genotype in the resistant stock was significantly higher (30%) than that in the susceptible stock (7.14%) (P=0.007), indicating a significant association with the resistance of Zhikong scallop to L anguillarum. To confirm the presumption, another independent challenge experiment was performed, in which the cumulative mortality of scallops with -391 A/A genotype (96.8%) was significantly higher than those with -391 A/G genotype (64.5%) (P=0.001), which further validate the association between -391 A/G genotype and the resistance of Zhikong scallop to L anguillarum. These results suggested that the -391 A/G could be a potential marker applied in future selection of Zhikong scallop with enhanced resistance to L anguillarum. (C) 2008 Elsevier Ltd. All rights reserved.

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Five Mbo I (Mbo-A, Mbo-M, Mbo-C(1), Mbo-C(2) and Mbo-C(3)) and Hinf I (Hinf-1 to Hinf-5) patterns were observed in Apis mellifera samples after restriction of a 485 bp fragment of the mitochondrial cytochrome-b (cyt-b) gene. Associating the cyt-b Restriction fragment length polymorphism (RFLP) pattern of each sample to its respective previously established COI-COII (Dra I sites) pattern, five restriction patterns (Mbo-C(1), Mbo-C(2), Mbo-C(3), Hinf-1 and Hinf-4) were observed in samples of maternal origin associated to the evolutionary branch C. No deletions or insertions were observed and the nucleotide substitution rate was estimated at 5.4%. Higher nucleotide diversity was observed among the branch C-haplotypes when compared with A and M lineages. Further studies are needed to confirm if the cyt-b + COI-COII haplotypes help to assign certain phylogeographic patterns to the branch C and to clarify phylogenetic relationships among A. mellifera subspecies.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The length polymorphism of ribosomal DNA ITS-1 intergenic spacer was analyzed in eight species of triatomines belonging to Triatoma, Rhodnius, and Panstrongylus genera. The analyzed species were Rhodnius domesticus, R. neivai, R. robustus, Triatoma brasiliensis, T. infestans, T. vitticeps, Panstrongylus megistus, and P. herreri. These insects are vectors of Chagas' disease, one of the most prominent public health problems among South American countries. This work allowed the differentiation between species of the Triatomini and Rhodniini tribes through the analysis of ITS-1 length polymorphism by PCR and RFLP techniques. The species of the Triatoma and Panstrongylus genera presented an amplified ITS-1 fragment between 600 and 1000 bp, whereas Rhodnius presented a less variable ITS-1 length fragment, around 300 bp, which could reflect the monophyletic origin of the Rhodniini tribe. Species belonging to this genus were further differentiated by RFLP with HaeIII and AluI endonucleases. Our results corroborate the hypothesis of polyphyletic origin in this group of insects and contribute to knowledge about evolutionary relationships in triatomines.