948 resultados para molecular systematics, mosses, evolution
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萤火虫因具有生物荧光现象而众所周知。狭义的萤火虫仅指萤科昆虫,而广义的萤火虫则包括萤科和雌光萤科昆虫。萤科和雌光萤科在分类上隶属于节肢动物门、昆虫纲、鞘翅目、多食亚目、软鞘类昆虫。萤火虫主要生活在热带和亚热带地区,广布于除南极洲以外的各大洲。中国地跨热带、亚热带地区,具有潜在的物种多样性,但在中国,尤其在大陆地区,对萤火虫的研究相对较少。为了更好的保护和应用中国的萤火虫,本文对中国萤火虫的系统分类和进化进行了初步研究。 本文先简单概述了自然界的发光生物类群、生物发光的原理、生物荧光的生物学意义及应用,之后,从以下几个方面对萤火虫的研究概况作了概述:首先,介绍了萤科的分类地位、形态特征、分类历史与现状,并根据文献初步总结了当前萤科分类中使用的属名、各属的物种数及地理分布概况;其次,介绍了雌光萤科的分类地位、形态特征及分类概况;第三,从宏观和微观两方面介绍了萤火虫的系统发育与进化研究概况。 根据对标本检视及对文献归纳整理的初步结果,中国萤科昆虫隶属于5亚科(Lampyrinae, Amydetinae, Luciolinae, Ototretinae, Psilocladinae)、13属(Lampyris, Diaphanes, Pyrocoelia, Lucidotopsis, Lucidina, Pristolycus, Lamprigera, Vesta, Luciola, Curtos, Drilaster, Stenocladius, Cyphonocerus)、116种,其中包括1个新种、10个中国新记录种。Lampyrinae 亚科包括7个属:Lampyris仅包括1种;Diaphanes包括18种,其中1个新种,3个中国新记录种;Pyrocoelia包括23种,其中2个中国新记录种;Lucidotopsis包括2种;Lucidina包括5种;Pristolycus包括6种,其中3个中国新记录种;Lamprigera包括3种。Amydetinae 亚科包括1个属即Vesta,该属在中国分布5种,其中1个中国新记录种。Luciolinae亚科包括2个属:Luciola包括28种,其中1个中国新记录种;Curtos包括9种。Ototretinae亚科包括2个属:Drilaster包括10种;Stenocladius包括2种。Psilocladinae亚科在中国仅分布1个属即Cyphonocerus,该属在中国仅分布3种。新种Diaphanes pectinealis的发现对Pyrocoelia和Diaphanes两个相似属的界定提出了新的挑战,因此,当前萤科昆虫分类学研究中,对这两个属的系统修订是急需的,这也表明中国萤科分类的研究对完善萤科的分类系统具有重要意义。 中国雌光萤科仅包括1个属即雌光萤属,该属主要分布于东洋区,已知种类32种,中国分布16种。为了更好了解这类特殊的发光甲虫,根据文献和对标本的检视,对雌光萤属的32种作了简要介绍,并根据文献编制了种检索表。 为了更好的探讨萤火虫的系统发育关系,本文对采自云南的18种萤科昆虫进行线粒体16S基因的部分测序,加上来自GenBank的已知同源序列,采用贝叶斯法、邻接法和最大简约法构建了包括日本、韩国和中国萤科的5个亚科、12个属共45个种50个种群及近缘科雌光萤科的1个种的系统发育树。根据所构建的系统发育树得出如下结论:萤科不是单系;Amydetinae亚科是萤科中相对原始的亚科,推测Lamprigera属(其亚科分类地位有争议,当前放在Lampyrinae)与Amydetinae有近缘关系;由于Pristolycus sagulatus (当前放在Lampyrinae,但其亚科分类地位也有争议)出现在Luciolinae中,Luciolinae的单系概念仍是一个有争议的课题;在Luciolinae中,Curtos 和Hotaria均为单系,但形态学和分子数据依然表明萤科最大的属Luciola不是单系,对这个属的再分是必需的;由于一些在亚科分类上有争议的属如Lamprigera和Pristolycus目前均放在Lampyrinae,因此,Lampyrinae是否是单系有待于这些属的分类工作的进一步完善;在Lampyrinae中,Lucidina 是单系;Pyrocoelia 和 Diaphanes均不是单系,但Pyrocoelia+Diaphanes是很好的单系。 本文首次讨论了Diaphanes属在萤科中的系统发育地位。结合形态学和行为学的观察,确立了采自云南高黎贡山的1个具有Pyrocoelia 和Diaphanes两个属的某些镶嵌特征但具有特殊的触角结构的1个特殊种即Diaphanes pectinealis的分属及新种地位。这一新种的发现对Pyrocoelia 和 Diaphanes两个属的界定提出了挑战。结合形态学、行为学和交配体系的概念,在萤科分类中应该对受性选择的特征如触角予以更多的关注。
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柳叶鲜科植物是侧茹蓟类中的一个大科,其系统位置介于羽醉科和青醉科之间,在全世界分布很广。柳叶蓟科植物全世界先后报道有39属,约300余种,中国己记载26属。该科的种类众多,配子体和抱子体形态、生活习性呈多样化,根据不同形状研究其系统发育往往差异较大。目前柳汗卜蓟科科内属间和属内种间的系统位置存有许多争议。本研究对中国柳叶鲜科植物的RJ气PD分析,从DNA水平上对它们的亲缘关系和分类问题加以研究,为它们的分类学研究和亲缘关系提供分子证据。研究的主要结果有:1.苔醉植物中酚类化合物含量高,DNA提取和纯化非常困难,本研究采用改良CTAB法提取基因组DNA。从试验结果看出:改良CTAB法提取的基因组DNA的纯度较大,浓度较高,且稳定性、完整性都比较好。2.采取正交设计方法,建立了柳叶鲜科植物RAPD扩增的优化体系,反应体系主要成分为:模板DNA100ng、dNTPo.lmmol/L·Taq酶0.75U、引物0.20μmol/L、Mg2+浓度2.00mmol/1:反应体系总体积为25林L。反应程序为:94℃预变性5min,94℃lmin,36.5℃min,72℃90see,进行35个循环,最后一次延伸72℃10min,冷却至4℃保存。3.利用RAPD技术分析柳叶鲜科植物12个属26个种,用14个随机引物进行扩增,共得到171条清晰稳定的多态片段,Nei遗传相似系数分析结果表明:柳仆卜鲜属和薄网蓟属明显聚合在一起,可以合并为柳叶蓟属。传统上定义很广的细湿醉属(包括狭义的细湿蓟属、嗜湿龄属和偏叶鲜属)和水灰鲜属在聚类图中不聚合在一起,说明广义细湿鲜属和水灰鲜属不是一个很自然的分类类群,而应分为更细的属。且三洋蓟属、范氏辞属和湿原蓟属的关系较近。4-采用RAPD技术构建了9份牛角蓟标本的指纹图谱,结果表明:9份牛角鲜标本的形态特征差异虽然非常大,但通过RAPD分析表明其为同一种。通过RAPD分析不同意Ochyra(1989)将牛角鲜属单独成牛角鲜科,仍将牛角鲜属归于柳叶鲜科,包括1种1变种。
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对隆肛蛙属的物种构成进行了订正,建立新属肛刺蛙属Yerana gen. nov.;订正后的隆肛蛙属现仅隶2种, 即隆肛蛙F. quadrana和太行隆肛蛙F. taihangnicus。运用形态学分析探讨了隆肛蛙属物种及种群的形态差异和分类关系,通过分子系统学研究探讨了隆肛蛙属物种及种群的分类和系统发育关系,运用动物地理学方法结合系统发育关系探讨了隆肛蛙属种群的地理分布格局成因与历史过程。主要结果和推论如下: 1.隆肛蛙属物种构成的订正及一新属建立 建立新属肛刺蛙属,将隆肛蛙属中的原叶氏隆肛蛙F. yei归隶新属肛刺蛙属并更名为叶氏肛刺蛙Y. yei,,新属建立的主要依据为:(1)雄性肛部隆起,肛孔下方有两个布满黑刺的大的白色球形隆起,具单咽下内声囊, 第一指具婚刺;(2)形态量度分析表明叶氏肛刺蛙与隆肛蛙和太行隆肛蛙的形态差异远大于后两者之间的差异;(3)叶氏肛刺蛙的分布区与隆肛蛙和太行隆肛蛙的分布区距离较远且呈隔离状态;(4)分子系统学研究资料(Jiang et al.,2005)证明叶氏肛刺蛙与隆肛蛙和太行隆肛蛙非单系发生;叶氏肛刺蛙在第二支中位于基部。因此,隆肛蛙属现仅隶2种,即隆肛蛙和太行隆肛蛙。 2.隆肛蛙属种群形态学研究 对隆肛蛙属中隆肛蛙和太行隆肛蛙的15个地理种群565只标本的28项形态性状进行了测量,运用典型判别分析法对其分析的结果表明:(1)太行隆肛蛙与隆肛蛙形态差异明显,支持其为不同的物种;(2)原隆肛蛙河南伏牛山种群和山西中条山种群应为太行隆肛蛙的地理种群;(3)隆肛蛙不同地理种群之间形态差异明显,其中四川安县种群、陕西周至种群和湖北利川种群与模式产地重庆巫山种群的差异可能达到了亚种或亚种以上分化水平。对隆肛蛙属量度分析的15个种群进行定性形态分析表明其分为三种形态型,对应隆肛蛙、过渡型和太行隆肛蛙,其变异特征主要为内跗褶、雄性肛部隆起及疣粒分布、第五趾外侧缘膜等,这与量度分析结果相似。 3.隆肛蛙属种群分子系统学研究 测定隆肛蛙属Feirana的2种19种群的线粒体12S rRNA和16S rRNA基因片段、ND2基因的DNA序列,比对后共计1953bps。(1)遗传多样性与距离分析:结果表明,隆肛蛙属种群具很高的遗传多样性,19个种群样品表现出19种单倍型(遗传多样性指数Hd=1.0); ND2基因的进化信息含量远高于12SrRNA和16SrRNA。隆肛蛙属2种群组内的种群间的遗传距离远小于两种群组间的距离,种群在不同基因上的遗传距离表现的关系与对应的系统树一致。(2)系统发育关系分析:结果表明,不同基因片断基于不同方法构建的隆肛蛙属种群系统发育树结构基本一致,基本表明隆肛蛙属种群为单系发生;它们在系统树中分为两大支,分别对应于隆肛蛙和太行隆肛蛙;支持中条山种群(沁水、历山和济源种群)和伏牛山种群(栾川和内乡种群)为太行隆肛蛙的地理种群,而原隆肛蛙秦岭中东段的部分种群(柞水、宁陕、长安大坝沟种群)也应为太行隆肛蛙的地理种群。(3)亚种分化分析:根据遗传距离分析和系统发育关系分析结果,并考虑形态上的差异情况以及地理分布信息,隆肛蛙所隶种群组可分为2亚种,即隆肛蛙指名亚种F. quadrana quadrana包括四川盆地东缘大巴山东段-巫山-武陵山北麓种群和秦岭中段(周至板房子和长安广货街)种群,他们在系统关系树上聚为一支;安县亚种F. quadrana anxianensis包括四川盆地西缘岷山东麓-龙门山-大巴山和秦岭西段的种群(安县、青川、文县、南江和凤县种群),他们在系统关系树上聚为一支。太行隆肛蛙所隶种群组也可分为2亚种,即太行隆肛蛙指名亚种F. taihangnicus taihangnicus包括中条山的种群(沁水、历山和济源种群)和中东秦岭的部分种群(柞水、长安大坝沟和宁陕种群),他们在系统关系树上聚为一支;太行隆肛蛙伏牛亚种F. taihangnicus funiuensis,为伏牛山地区的种群(栾川和内乡种群),他们在系统关系树上聚为一支。 4.隆肛蛙属种群动物地理学研究 隆肛蛙属19种群的分歧年代分析: 以长江巫山段和黄河三门峡段的形成历史时期为参考点,根据已测隆肛蛙属19种群及其外群包括N. pleski、P. yunnanesis、P. robertingeri、F. limnocharis的1953bps DNA序列构建分子钟,获得各支系的分歧年代。结果表明:①棘蛙族在70Ma左右开始其独立演化历程,这与Roelants et al.(2004)的分析结果~60±15Ma左右开始分化基本一致,后者印证了本文的分子钟。②隆肛蛙属的起始分化年代较早,隆肛蛙和太行隆肛蛙两种群组的最近祖先种群大概在46Ma~50Ma左右;隆肛蛙和太行隆肛蛙种群组内的种群分化年代相对两种群组间晚得多, 隆肛蛙种群组内两亚种分化起始年代约为10Ma左右,而太行隆肛蛙种群组内两亚种分化起始年代约为6Ma。 隆肛蛙属种群分布格局形成过程分析: ①隆肛蛙属的系统关系与地理分布格局密切相关,大部分系统分支分级与地理距离成正比;②隆肛蛙属最近祖先种群的分化中心可能位于秦岭中部地区, 隆肛蛙属的种群分布格局的形成表现为隔离分化与扩散相结合的机制,由隔离分化产生的隆肛蛙祖先种群主要从秦岭中部向西南方向扩散,后隔离分化为两亚种;太行隆肛蛙祖先种群向东北方向扩散也分化为两亚种。 隆肛蛙属种群分布区域地质历史的探讨:本文所建分子钟和种群分化方式印证了该区域的几次主要地质事件,包括岷山-龙门山-西秦岭等地区的快速差异隆起、第四纪冰期等。 The specific composition of the genus Feirana should be revised. A new genus Yerana gen. nov.(Ranidae:Dicroglossinae)was established based on morphological data-set and molecular phylogeny, as a result, only two species F. quadrana and F. taihangnicus are classified into Feirana now. Morphological differences and taxonomy of populations of Feirana were investigated based on morphological and morphometric data; phylogenetic relationships and taxonomy of populations of Feirana were elucidated using molecular data, and then the proceeding of the distribution pattern of populations of Feirana were discussed. The main results and conclusions and proposals were presented as following: 1. Revising of the specific composition of the genus Feirana and establishment of a new genus The new genus Yerana, only containing the type species Y. yei, was established based on the following evidences: (1) In adult male, distinct up-heaved circular vesicle presents around the anal, and under anal there are two white balls on which black spines exist, black horny spines scatter on the upper side of first finger, and internal single subgular vocal sac presents; (2) there is obvious morphometric differences between Yerana and Feirana; (3) Yerana is distributed far from Feirana; (4) evidences of molecular phylogeny(Jiang et al.,2005)suggested that Yerana take a special phylogenetic clade which is different from other genus included in the tribe Paini. As a result, there are only two species in Feirana, i.e., F. quadrana and F. taihangnicus. 2. Morphological research of populations of Feirana Twenty-eight characters of 565 individuals of 15 populations of the genus Feirana were measured, the results of Canonical Discriminant analysis of the morphometric data-set indicated that: (1) there are very prominent differences between the two species F. quadrana and F. taihangnicus. The validity of species F. taihangnicus was approved here; (2) Mt. Funiu population and Mt. Zhongtiao population should belong to the species F. taihangnicus; (3) Obvious differences exist among 12 populations of F. quadrana, the differentiation among Zhouzhi population, Anxian population, Lichuan population, and Wushan population together with the others probably reach sub-specific or specific level. Result of morphological comparison between 15 different populations show that 3 morphological types are recogenized in according with F. quadrana, F. taihangnicus and intergradation, this result conform to the result of morphometric analysis. 3. Molecular phylogenetic study on populaions of Feirana Fragment of 12SrRNA and 16SrRNA genes, and ND2 gene of 19 populations of two species of Feirana were sequenced and aligned, from which 1953 bps were received. (1) analyses of genetic distance and hereditary diversity indicated that: genetic distance between populations in each group were less than distance between two groups of Feirana, 19 haplotypes were recognized from 19 samples of 19 populations, so the hereditary diversity of populations of Feirana was very high (Hd=1.0), phylogenetic information in ND2 gene is more than fragment sequence of 12SrRNA and 16SrRNA genes. (2) Result of molecular phylogeny indicate that the phylogenetic trees constructed using different methods based on different sequence data sets showed the revised genus Feirana is monophyletic since the 19 populations of Feirana were firstly clustered together as one large clade, which was further clustered into two major clades, corresponding to F. quadrana(GroupⅠ) and F. taihangnicus(GroupⅡ), respectively. So populations of Qinshui and Lishan in Mt. Zhongtiao, populations of Luanchuan and Neixiang in Mt. Funiu, and populations of Zhashui, Dabagou of Chang’an and Ningshan in eastern Mt. Qinling should belong to the species F. taihangnicus; (3) Subspecific differentiation. on the basis of genetic distance, phylogenetic trees and geographical distribution, F. quadrana should have two subspecies, i.e., F. quadrana qudadrana, consisting of the populations Guanghuojie of Chang’an and Zhouzhi in Mid-Mt. Qinling, populations in Wushan area and northern Mt. Wuling (Lichuan), and F. qudadrana anxianensis, consisting of the populations in eastern Mt. Ming shan-Mt. Longmen-western Mt. Daba-western Mt. Qinling (Anxian, Qingchuan, Wenxian, Nanjiang and Fengxian); F. taihangnicus should also has two subspecies, i.e., F. taihangnicus taihangnicus, consisting of the populations in Mt. Zhongtiao and eastern Mt. Qinling, and F. taihangnicus funiuensis, consisting of the populations in Mt. Funiu. 4. Zoogeography of populaions of Feirana Analysis for divergent time of 19 populations of Feirana: Using the dates of run-through of Wushan segment of Changjiang River as the time when the population of Lichuan started differentiated from the populations of Wushan and Shennongjia, and the dates of Sanmenxia segment of Yellow River as the time when the populations in Mt. Zhongtiao started differentiated from the population of Dabagou in Chang’an, molecular clock was established using sequences with 1953 bps of 19 populations of Feirana and outgroup including N. pleski, P. yunnanesis, P. robertingeri, F. limnocharis in order to estimate divergent time of all clades. Result of that indicated that: ① the tribe Paini started to evolve independently at about 70Ma when is in consistent with that estimated by Roelants et al.(2004)with result of about ~60±15Ma, they were corroborated by each other, this confirms the validity of this molecular clock; ② divergent time for speciation of Feriana is early, ancestral populations of F. quadrana and F. taihangnicus were found about 46Ma~50Ma; differentiation of populations within species is greatly late to the divergence of the two species, divergent time for F. quadrana is 10Ma and divergent time for F. taihangnicus is 6Ma. Proceeding of distribution pattern of Feirana. Phylogenetic relationships of populations of Feirana matched quite with distribution pattern of them, the relationships among clades showed in phylogenetic trees is direct ratio to geographical distance of them; the estimated date of speciation between two species of Feirana was as early as speciation of Paa yunnanesis and Nanara pleski; middle part of Mt. Qinling is the center of speciation of Feirana, combination of mult-events of dispersal and vicariance are probably the mechanism of speciation of Feirana, F. quadrana colonized the mid-Mt. Qinling and then differentiated into two subspecies in southwest direction, ancestral population of F. taihangnicus colonized the mid-Mt. Qinling and then differentiated into two subspecies in northeast direction. On geological history of the distribution of Feirana. According to molecular clock and speciation model of populations of Feirana, some geological events are confirmed, including special rise of Mt. Minshan- Mt. Longmen-western Mt. Qinling, glacial age.
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Algae have been part of Chinese life for thousands of years. They are widely used as food and have been cited in Chinese literature as early as 2500 years ago. However, formal taxonomic studies on Chinese algae were initiated by foreign scientists only about 200 years ago, and by Chinese phycologists only about 90 years ago. This paper summarizes the history of modern phycological studies on Chinese algae and provides an overview of the achievements of phycological studies by Chinese scientists, especially on algal taxonomy, morphology, genetics, ecology and environmental research, physiology, biotechnology, algal culture, applied phycology and space phycology, in the last century. Recent development in phycological research focuses on algal floristic and molecular systematics, algal molecular biotechnology, applied phycology including micro and macroalgal cultivation and algal product development, and the roles of algae in environmental pollution control. These areas will also be the main focuses of Chinese phycological research in the foreseeable future.
Resumo:
Prolonged floral longevity and bumblebees as dominate pollinators in alpine ecosystem have been suggested to overcome pollination limitation of alpine plants arising from the decrease of pollinator activity with increasing altitude. However, this conclusion has never been examined in the Qinghai-Tibetan Plateau (QTP), the highest and largest plateau in the world. In this study, we intended to test year-to-year correlations between floral longevity, visiting frequency and pollen limitation of this species between two populations (at 3200 m and 4000 m) of Gentiana straminea in this plateau. Pollinator exclusion elongated both male and female phases greatly at both sites, and durations of both male and female phases in natural condition varied greatly over three years. The visiting frequency of bumblebees varied greatly at the higher altitude, but seemed to be stable at the lower altitude. Seed production was pollination limited in both populations in most studied years. The floral durations, pollinator frequency and pollination limitation showed no significant and consistent variations with the increase of altitude. The previous hypothesis that the prolonged floral longevity of alpine plants can compensate for low levels of pollinator visitation therefore could not be confirmed, and our results further suggested that in the QTP platform, the altitude shows no consistent effect on the reproductive performance of this species, despite that the fluctuation of visit frequency intensified at the higher altitude.
Resumo:
Floral closure may be induced by pollination and various other factors, but is rarely studied comprehensively. Different kinds of floral closure should have various effects on reproductive fitness of plants. Two contrasting types of floral closure were observed in the flowers of Gentiana straminea Maxim. in the eastern Qinghai-Tibetan Plateau. The first type occurred prior to pollination during both gender phases, in response mainly to decreasing air temperatures. Flowers closed when decreasing temperatures approached 20 degrees C and subsequently began to reopen the following day during mid-morning when air temperatures warmed to approximately 13-15 degrees C. This kind of floral closure can protect pollen grains on either stamens or stigmas, increasing fitness of both male and female. Following pollination, permanent floral closure occurred, although there was a delay between the dates of pollination and permanent closure, during which flowers continued to show temporary closure in response to low temperature episodes. The time required for permanent, pollination-induced closure varied according to the age of the gender phase, including a prolonged time before closure if pollination occurred early in the female phase. The retaining of permanent closed flowers increased both approaching (to inflorescences) and visiting (to unpollinated flowers) frequencies of individual plants when with fewer open flowers and the persisting corolla is further beneficial for seed sets of these pollinated flowers. Thus, two separate types of floral closure, one in response to environmental cues and the other in response to the age of each gender stage, appeared to have a strong influence on reproductive fitness in this species. These results revealed a different adaptive strategy of alpine plants in the sexual reproduction assurance in addition to the well-known elevated floral longevity, dominant role of more effective pollinators and increased reproduction allocation in the arid habitats.
Resumo:
Floral organogenesis and development of two Solanaceae species, Anisodus tanguticus and Atropa belladonna, were studied by using scanning electron microscopy (SEM) as part of a project on systematics and evolution in the tribe Hyoscyameae. These two species share the following common characters of floral organ initiation and development: (1) initiation of the floral organs in the two species follows Hofmeister's rule; (2) the mode of corolla tube development belongs to the "late sympetaly" type, namely, petals are initiated separately and later become joined by fusion of their basal meristem, then rise together and form a corolla tube; (3) primordia of the floral appendages are initiated in a pentamerous pattern and acropetal order: sepals are initiated first, followed by the petals and stamens, and finally the carpels. The whorl of five stamen primordia forms almost simultaneously and originates opposite the sepal primordia, but initiation of the sepal primordia shows different modes in the two species. The sepal primordia of Anisodus tanguticus have simultaneously whorled initiation, while those of Atropa belladonna have helical initiation. The systematic significance of the present results in the genera Anisodus and Atropa is discussed in this paper.