中国葱属系统发育的PCR-RFLP分析

在综合形态分类和细胞分类的基础上, 从国产葱属的全部9个组中, 选择18个代表种(含外类群), 运用PCR方法, 分别扩增出trnK和rpL16两个叶绿体基因片段. 用26种限制性内切酶对其进行酶切分析, 共获得303个酶切变异位点, 其中163个为信息位点. 运用PAUP(Version 3.1.1)等软件对所得数据分析表明: 葱属可以分为6个亚属级的分类阶元, 宽叶组的划分是合理的; 根茎组、单生组和洋葱组均是不自然的分类群, 属下组的划分应作相应调整. 对葱属属下分类系统进行了讨论.     

松科系统发育的分子生物学证据

运用PCR方法分别从松科8属、9种植物中扩增出一长约2550bp的cpDNA片段,这一片段包括rbcL、trnR、部分accD及基因间的非编码区(相对于黑松cpDNA中的同源片段而言)。运用18种限制性内切酶对这一cpDNA片段进行酶切分析,共获得86个酶切位点,其中54个为变异位点。运用PAUP(version 3．1．1)和Mega(version 1．01)软件对数据进行分析,结果Wagner简约树和Neighbor-Joining树反映出的松科系统发育关系基本一致：银杉属、松属、黄杉属和落叶松属形成一个单系群,且银杉属与松属的亲缘关系更近于与另外二属的关系,但这一结果未得到Bootstrap分析的较强支持;落叶松属近缘于黄杉属;冷杉属近缘于油杉属。此外,松科中的冷杉亚科和落叶松亚科均不是单系类群,将松科划分为冷杉亚科、落叶松亚科和松亚科三个亚科的系统(郑万钧,傅立国,1978)是不自然的。     

基于nrDNA ITS 序列数据的兰属系统发育关系的初步分析

现存的兰属分类系统是基于宏观形态学性状、尤其是花粉块的数目以及唇瓣与蕊柱的愈合程度而建立的.兰属因此而划分为3个亚属:兰亚属 (subgenus Cymbidium),大花亚属(subgenus Cyperorchis) 和建兰亚属 (subgenus Jensoa).本文运用PCR扩增和直接测序的方法分析兰属 (Cymbidium) 27种、3个栽培品种以及3个外类群的核DNA ITS 区段序列.通过最简约性分析产生的ITS系统发育树表明,兰属的3个亚属均可能为不自然的类群.大花亚属表现为一复系群,兰亚属的冬凤兰 (C.dayanum) 隐藏于其中;建兰亚属为一并系群,它的成员之一兔耳兰 (C.lancifolium) 偏离出去而成为兰属一最基部的分支;兰亚属为一复系群,它分为几支而分别与另两个亚属组合在一起.由于兰属ITS序列位点变异率较低,最简约性分析产生的几支主要分支均得不到Bootstrap分析的高度支持,各亚属内组之间的关系也不明确.研究兰属的系统发育关系还需要新的数据.     

福建省放线菌结瘤植物共生菌Frankia遗传多样性研究

[目的]了解福建省放线菌结瘤植物共生固氮菌Frankia的遗传多样性.[方法]利用16S-23SrDNA间隔区(rrn)和nifD-K基因间隔区的PCR扩增和RFLP技术,分析了福建省木麻黄、杨梅、桤木、胡颓子等共生Frankia纯培养菌株的遗传差异.[结果]17个菌株获得rrn扩增片段,2个杨梅菌株和1个胡颓子菌株扩增未成功,酶切图谱经聚类分析表明6个地点的细枝木麻黄、短枝木麻黄、粗枝木麻黄12个共生Frankia菌株同源性高,属于一个类群,2个地点的4个杨梅菌株和1个四川桤木菌株亲缘关系近,为另一类群.25个Frankia菌株的,nifD-K基因间隔区PCR-RFLP分析结果显示,7个地点的3种木麻黄14个菌株聚类为一个类群,4个地点的7个杨梅菌株、2个地点的2个四川桤木菌株以及1个台湾桤木菌株聚类为另一个类群,胡颓子菌株则为独立的类群.[结论]研究结果表明福建省共生Frankia遗传多样性丰富.     

幽门螺杆菌hpaA基因RFLP研究

用限制性片段长度多态性(RFLP)的方法评价幽门螺杆菌不同菌株鞭毛粘附素基因(hpaA)的变异性。PCR扩增9株幽门螺杆菌710bp的hpaA基因,用Hha Ⅰ、HaeⅢ限制性内切酶对该基因片段进行酶切分析。hpaA基因HaeⅢ单酶切可见4种带型,HhaⅠ单酶切出现5种带型。从临床分离的H.pylori菌株hpaA RFLP互有差异,且不同于国际标准菌株;临床分离株感染动物后分离得到的动物适应株其hpaA基因也发生了变异。不同H.pylori菌株间hpaA基因表现出明显的多态性,为开展H.pylori的分子流行病学调查提供了一种有效的方法。     

入侵中国大陆的红火蚁的鉴定及发生为害调查

根据形态特征鉴定结果首次证实红火蚁SolenopsisinvictaBuren入侵中国大陆 ,并调查了广东省吴川市红火蚁发生为害情况。调查结果表明 ,发生区内部分地点红火蚁发生密度较高 ,主要发生于较稳定的生态环境中 ,如荒坡、草地、长满杂草的田埂等。红火蚁已对当地农业生产、人们的身体健康、日常生活等造成了不利影响。此外 ,Cytb基因序列分析结果表明 ,采自美国佛罗里达和广东吴川的红火蚁与采自广东 4个地方的热带火蚁S .geminata (Fabr.)两物种间有 61个变异位点 ,种内变异为 0。限制性酶切多态实验 (RFLP)的结果显示 ,BamHI酶在红火蚁的特异扩增片段中有一个识别位点 ,而在热带火蚁中无酶切位点 ;MspI酶在热带火蚁的扩增片段中也有一个识别位点 ,而在红火蚁中无识别位点。有酶切位点的扩增产物在酶切后分别获得近 2 0 0bp与 2 5 0bp的片段各一带。因此 ,用PCR RFLP的方法可以简单快速地鉴别红火蚁和热带火蚁。     

基于nrDNAITS序列数据的兰属系统发育关系的初步分析(英)

现存的兰属分类系统是基于宏观形态学性状、尤其是花粉块的数目以及唇瓣与蕊柱的愈合程度而建立的。兰属因此而划分为 3个亚属 :兰亚属 (subgenusCymbidium) ,大花亚属 (subgenusCyperorchis)和建兰亚属 (subgenusJensoa)。本文运用PCR扩增和直接测序的方法分析兰属 (Cymbidium) 2 7种、3个栽培品种以及 3个外类群的核DNAITS区段序列。通过最简约性分析产生的ITS系统发育树表明 ,兰属的 3个亚属均可能为不自然的类群。大花亚属表现为一复系群 ,兰亚属的冬凤兰 (C .dayanum )隐藏于其中 ;建兰亚属为一并系群 ,它的成员之一兔耳兰(C .lancifolium)偏离出去而成为兰属一最基部的分支 ;兰亚属为一复系群 ,它分为几支而分别与另两个亚属组合在一起。由于兰属ITS序列位点变异率较低 ,最简约性分析产生的几支主要分支均得不到Bootstrap分析的高度支持 ,各亚属内组之间的关系也不明确。研究兰属的系统发育关系还需要新的数据。     

动物遗传工程

951070利用PCR扩增的ZFX/ZFY位点的限制性片段多形性鉴别牛胚胎性别[英]/Pollevick,G.D.…,Bio/Technology.一1992,10(7).-805~'807[译自DBA,1992,11(17),92-09812] 克隆了雄z~ZFX和ZFY位点的PCR扩增片段并进行了测序。447bp扩增片段的检测显示若千多形性。检测出31个点突变,其中部分包括限僚5性内切酶位点。证实存在已介绍过的多形性Pstl位点(用于鉴别雌雄性),检测出2个更替性限制性片段长度多形性(RFLP)。FokI位点存在于ZFX位点中,而不存在于ZFY中,NsiI位点只存在于ZFY中。用牛ZFX和ZFY位点序列设计一套寡核苷酸,以提…     

三色书虱体内共生微生物Wolbachia的wsp基因的分子检测

采用常规PCR和巢式PCR方法对三色书虱Liposcelis tricolor体内的共生微生物Wolbachia的wsp基因进行分子检测;通过Wolbachia的通用引物以及A、B亚群引物分别比较了常规PCR和巢式PCR对wsp基因扩增的灵敏性。从三色书虱体内扩增出了610bp的Wolbachia的wsp基因片段,500bp的WolbachiaA亚群的wsp基因片段和450bp的Wolbachia B亚群的wsp基因片段。扩增结果说明三色书虱被A和B两个亚群的Wolbachia混合感染;巢式PCR比常规PCR更为灵敏。     

(鱼兆)科鱼类细胞色素b基因片段的序列测定及其系统发育的初步研究

从9种(鱼兆)科鱼类的福尔马林标本中获得了333 bp的细胞色素b基因片段的序列.这9个种分别代表(鱼兆)科鱼类的8个属.333 bp的DNA序列经MUST软件排序后,有101个变异位点,其中有39个信息位点.序列在成对物种间的距离为8～48.平均遗传距离为2.4%～14.4%.简约分析产生了最大简约系统树,其步长是162(CI=0.735,RI=0.494).在该系统树上,Bagarius是最原始的属,并与所有其他的物种形成姊妹群.其余8个属形成一个单系类群并分为二个姊妹群.尽管在形态上具有13个离征,但在分子系统树上,(鱼宴)(鱼兆)鱼类并未形成一个单系类群.可能的原因是333 bp序列中的星系信息位点太少;另外单从福尔马林浸制标本获得的DNA序列的可靠性尚有待进一步验证.     

Phylogeny of Chinese Allium (Liliaceae) using PCR-RFLP analysis

Eighteen representative species were selected from all the nine sections of Chinese Allium on the basis of the classification of morphology and cytotaxonomy. The trnK and rpL16 gene fragments of chloroplast DNA were amplified from 18 species by PCR method. The two cpDNA fragments were digested by 26 restriction enzymes, and 303 polymorphic restriction sites were found, of which 163 were informative. The restriction site data were analyzed with PAUP (version 3.1.1) and MEGA (version 1.01) as well as PHYLIP. As a result, the genus Allium could be classified into six subgenera. The recognition of Sect. Anguinum in the Flora of China is reasonable, Sect. Rhizirideum, Sect. Haplostemon and Sect. Cepa are not monophyletic. The infrageneric system of this genus was also discussed.     

Phylogeny of Chinese Allium (Liliaceae) using PCR-RFLP analysis

Eighteen representative species were selected from all the nine sections of Chinese Allium on the basis of the classification of morphology and cytotaxonomy. The trnK and rpL16 gene fragments of chloroplast DNA were amplified from 18 species by PCR method. The two cpDNA fragments were digested by 26 restriction enzymes, and 303 polymorphic restriction sites were found, of which 163 were informative. The restriction site data were analyzed with PAUP (version 3.1.1) and MEGA (version 1.01) as well as PHYLIP. As a result, the genus Allium could be classified into six subgenera. The recognition of Sect. Anguinum in the Flora of China is reasonable, Sect. Rhizirideum, Sect. Haplostemon and Sect. Cepa are not monophyletic. The infrageneric system of this genus was also discussed.     

葱属系统发育的PCR—RFLP分析初报

葱属（Ａｌｉｕｍ）为广义百合科（Ｌｉｌｉａｃｅａｅ）葱族（Ａｌｉｅａｅ）的一个重要类群。该属种类丰富、分布极广，关于它的系统发育和进化问题，目前尚存在不少分歧［１］。我国有葱属１１０种（含变种和引进外来种），主要分布于东北、华北、西北和西南地区。我们...     

PCR-RFLP Analysis on Phylogeny of Allium

The molecular phylogeny of the genus Allium which includes eighteen species selected from nine sections was investigated through PCR-RFLP analysis of two chloroplast DNA fragments, including trak gene (approximately 2 520 bp) and rpL16 gene (approximately 1 230 bp). Digestion of these two fragments by 26 restriction endonucleases yielded 303 polymorphic recognition sites, of which 163 were informative sites. The restriction site data matrix were analyzed following the parsimonious Wagner and parsimonious Dollo principle of PAUP ( version 3.1.1 ). Topologically, the most parsimonious Wagner tree constructed by branch-and-bound and heuristic search was similar to the most parsimonious Dollo tree. All the taxa of Allium form a monophyletic group, and five sections based on morphological characters were supported strongly by this result. Sect. Augninum is closely related to Sect. Bromatorrhiza, Sect. Molium is closely related to Sect. Caloscordum. Their reliability was farther confirmed by the bootstrap test very well. In morphology, A. pallasii is closely related to A. caeruleum and belongs to Sect. Haplostemen, A. cepa is closely related to A. galanthum and belongs to Sect. Cepa. But evidence from cladistics of parsimonious tree based on 163 informative sites of PCR-RFLPs showed that they are neither confined to a monophyletic group nor to a natural taxon.     

Phylogeny of Iris based on chloroplast matK gene and trnK intron sequence data

Phylogenetic analyses of 46 species of Iris, representing all subgenera and all sections except Regelia, Brevituba, and Monolepis, utilized matK gene and trnK intron sequence data. Sequence data show that Iris is paraphyletic because Belamcanda chinensis is resolved within the genus. The two largest subgenera, Iris and Limniris, are both resolved as polyphyletic. With the removal of section Hexapogon, subgenus Iris is weakly supported as monophyletic. Relationships within subgenus Limniris are more complex with the subgenus as currently circumscribed representing eight independent origins among the species included in this study. Several potential monophyletic groups are identified including subgenus Scorpiris, series Spuria (subgenus Limniris section Limniris), and a clade of section Limniris species from North America and Asia.     

中国栎属(壳斗科)基于叶表皮及叶结构特征的分支分析

以三棱栎为外类群,基于叶表皮及叶结构特征对中国栎属进行初步的分支分析,结果显示了栎属内稳定的“支”结构及其种间关系。栎亚属可划分为5个组,分别为巴东栎组,高山栎组,Jiang子栎组,麻栎组和槲栎组,Jiang子栎组是栎亚属常绿栎类与落叶栎类之间的过渡类群;高山栎组应为栎亚属常绿栎类中的特化类群,而非最原始类群,5个组中,仅巴东栎组不是单系类群,而是一个多系类群,青冈亚属较栎亚属早分支,可划分为3大类;无毛类,简单被毛类和复杂被毛类;无毛类最原始,复杂被毛类与栎亚属关系最近,因此,叶表皮及叶结构特征对解决栎亚属组间亲缘关系有重要的分类学意义。     

13种21居群葱属植物的细胞分类学研究

采用常规压片法,对13种（含1变种）21居群葱属（Allium L.）植物进行了细胞分类学研究。结果表明：所研究类群的染色体基数为7、8和11,核型的类型为2A、2B和3A型,并且存在2倍体、3倍体和4倍体。主要讨论了葱属根茎组（Sect.Rhizirdium G.Don）部分类群的核型分化和进化机制,高山韭（A.sikkimense Baker）和多星韭（A.wallichii Kunth）的细胞地理学,以及B染色体的多态性及其在生境上的适应意义。最后在本研究的基础上,结合前人的细胞分类学研究结果,对葱属植物的核型进化形成了如下认识：（1）该属植物的原始染色体基数为8,其他基数的类群是由基数为8的类群进化而来的;（2）葱属植物在核型类型的进化上存在两条路线：基数为7的类群核型进化趋势为2A→2B→2C,而基数为8的类群的核型进化趋势为1A→2A→2B→2C;（3）多倍化是葱属植物进化的重要机制之一。     

基于形态性状的葱属粗根组植物系统发育关系

以环地中海地区和北美葱属Allium的Amerallium亚属种类为外类群,基于36个形态学性状对葱属粗根组sect. Bromatorrhiza进行系统发育分析。简约分析获得的分支拓扑结构与分子系统学的研究结果相吻合,粗根组与环地中海地区的Amerallium亚属种类形成姐妹群关系,表明它们具有密切的亲缘关系。粗根组明显分为两支,粗根韭A. fasciculatum (x = 10,2胚珠)与染色体基数为11的种类(单胚珠)形成一支,另一支由染色体基数为7的大花韭A. macranthum与多星韭A. wallichii (2胚珠)组成,从而否定了粗根亚组subsect. Bromatorrhiza(粗根韭+大花韭+多星韭)的成立。综合已有研究结果,本研究认为粗根组内存在4个相对独立的演化支系,即多星韭及其变种、大花韭、粗根韭,以及染色体基数为11的种类(5种1变种),尽管前人建议的单胚珠亚组subsect. Uniovulatum是合理的,但没有必要在物种数量相对较少的粗根组下进一步细分。     

红豆杉科及相关类群rbcL基因PCR—RFLP分析

运用RFLP方法对红豆杉科及相关类群14种植物叶绿体rbcL基因PCR产物进行限制酶酶切分析,共获29个酶切变异位点。采用PHYLIP软件包对限制位点变异数据进行极大简约法分析得到18个步长为6的最简约树并求得一致树,结果显示：⑴红豆杉科和三尖杉科属单系群;⑵穗花杉属Amentotaxus以置于红豆杉科内为宜,不支持将穗花杉属独立成科的处理方式;⑶白豆杉应为红豆杉科内一个属Pseudotaxus;⑷三尖杉属内篦子三尖杉地位特殊,可设篦子三尖杉组;⑸不赞同将竹柏类从罗汉松属中分离出去成立新科;⑹红豆杉科、三尖杉科和罗汉松科三者间,前两者的关系更为接近。     

Evolution of genome size across some cultivated Allium species.

Allium L. (Alliaceae), a genus of major economic importance, exhibits a great diversity in various morphological characters and particularly in life form, with bulbs and rhizomes. Allium species show variation in several cytogenetic characters such as basic chromosome number, ploidy level, and genome size. The purpose of the present investigation was to study the evolution of nuclear DNA amount, GC content, and life form. A phylogenetic approach was used on a sample of 30 Allium species, including major vegetable crops and their wild allies, belonging to the 3 major subgenera Allium, Amerallium, and Rhizirideum and 14 sections. A phylogeny was constructed using internal transcribed spacer (ITS) sequences of 43 accessions representing 30 species, and the nuclear DNA amount and the GC content of 24 Allium species were investigated by flow cytometry. For the first time, the nuclear DNA content of Allium cyaneum and Allium vavilovii was measured, and the GC content of 16 species was measured. We addressed the following questions: (i) Is the variation in nuclear DNA amount and GC content linked to the evolutionary history of these edible Allium species and their wild relatives? (ii) How did life form (rhizome or bulb) evolve in edible Allium? Our results revealed significant interspecific variation in the nuclear DNA amount as well as in the GC content. No correlation was found between the GC content and the nuclear DNA amount. The reconstruction of nuclear DNA amount on the phylogeny showed a tendency towards a decrease in genome size within the genus. The reconstruction of life form history showed that rhizomes evolved in the subgenus Rhizirideum from an ancestral bulbous life form and were subsequently lost at least twice independently in this subgenus.