从线粒体Cyt b基因探讨红瘰疣螈物种地位的有效性

疣螈属的红瘰疣螈（Tylototriton shanjing）和棕黑疣螈(T. verrucosus) 的物种界限一直不清楚。测定了来自中国西南地区14个地点的T. shanjing和T. verrucosus共40只标本的线粒体DNA Cyt b基因(753 bp)。结果表明：（1）用邻接法、最大简约法和贝叶斯法等3种系统发育分析法分别重建棕黑疣螈种组系统发育树的拓扑结构不支持T. shanjing是单系群；（2） T. shanjing与T. verrucsus的mtDNA Cyt b序列差异平均值仅为1. 2％, 未达到种级水平。因此, 全部T. shanjing样品都属于同一个物种, 即T. verrucosus, 不支持T. shanjing的物种地位, T. shanjing为T. verrucosus的同物异名，并建议恢复T. verrucosus的中文名红瘰疣螈。根据基于40个样品Cyt b基因序列的系统发育树和遗传变异以及地理分布, 这些红瘰疣螈（T. verrucosus）样品聚为3 支, 即中国西南地区的红瘰疣螈可分为片马、滇中滇西和滇东南3个地理居群。     

我国棘螈属(Echinotriton)和疣螈属(Tylototriton)的研究概况

棘螈属（Echinotriton）和疣螈属（Tylototriton）均属于两栖纲有尾目蝾螈科.两属主要分布于我国西南、亚洲西南部、东南亚及日本.棘螈属在我国已知3种：Echinotriton andersoni（琉球棘螈）、E. Chinhaiensis（镇海棘螈）、E. Asperrimus（细痣棘螈）.疣螈属在我国已知4种：Tylototriton kweichowensis（贵州疣螈）、T. Shanjing（红瘰疣螈）、T.taliangensis（大凉疣螈）、T. Verrucosus（棕黑疣螈）.本文回顾了棘螈属和疣螈属物种的命名史,阐明了两属之间的关系,并从形态学、生态学、细胞遗传学和分子生物学方面对这两属的研究工作进行了综述.     

降雨决定繁殖期红瘰疣螈的活动性

有尾两栖类的繁殖活动常常受到环境因子,特别是如温度、湿度和降雨等气候因子的限制。红瘰疣螈Tylototriton shanjing是适应云南山地环境的典型有尾两栖类动物。本研究期望通过对繁殖期红瘰疣螈活动个体数量的野外调查和气候因子的分析,弄清影响红瘰疣螈繁殖行为活动的关键气候因子。研究结果显示,繁殖期红瘰疣螈活动个体数量与气温呈显著的负相关关系,与空气相对湿度和降雨量呈显著的正相关关系。然而偏相关和多元回归分析则表明,红瘰疣螈繁殖行为活动与相对湿度和降雨量关系更密切。红瘰疣螈总是在降雨后引起空气湿度增加以及气温下降时进行各种繁殖行为活动,降雨是影响红瘰疣螈繁殖行为活动关键的气候因子。红瘰疣螈的繁殖行为活动与降雨节律保持一致是对云南山地环境的重要适应。     

PHYLOGENETIC RELATIONSHIPS OF SUBGENUS ΥAOTRITON ( CAUDATA, SALAMANDRIDAE, TΥLOTOTRITON) BASED ON PARTIAL MITOCHONDRIAL DNA GENE SEQUENCES

对疣螈属Υaotriton亚属5个已知物种23个个体的mtDNA序列数据(ND2、tRNATrp、tRNAAla、tRNAAsn、tRNACys和tRNATyr,1 421 bp),使用贝叶斯(BI)和最大似然(MP)方法重建了疣螈属Υaotriton的系统发育关系.结果表明:1)Υaotriton亚属的所有物种形成1个单元群;2)海南疣螈T.hainanensis是Υaotriton亚属的1有效物种,不是细痣疣螈T.asperrimus的同物异名;3)文县疣螈T.wenxianensis雷山种群应是细痣疣螈的地理种群,细痣疣螈绥阳种群应是文县疣螈的地理种群;4)6个文县疣螈地理种群和3个细痣疣螈地理种群分别形成单系群,文县疣螈是Υaotriton亚属的1有效物种.     

基于部分线粒体DNA序列的疣螈属亚属(有尾目,蝾螈科,疣螈属)系统发育关系

对疣螈属Yaotriton亚属5个已知物种23个个体的mtDNA序列数据(ND2、tRNATrp、tRNAAla、tRNAAsn、tRNACys和tRNA Tyr,1421bp),使用贝叶斯(BI)和最大似然(M P)方法重建了疣螈属Yaotriton的系统发育关系。结果表明:1)Yaotriton亚属的所有物种形成1个单元群;2)海南疣螈T.hainanensis是Yaotriton亚属的1有效物种,不是细痣疣螈T.asperrimus的同物异名;3)文县疣螈T.wenxianensis雷山种群应是细痣疣螈的地理种群,细痣疣螈绥阳种群应是文县疣螈的地理种群;4)6个文县疣螈地理种群和3个细痣疣螈地理种群分别形成单系群,文县疣螈是Yaotriton亚属的1有效物种。     

红瘰疣螈的体温调节

红瘰疣螈(Tylototriton shanjing)为我国Ⅱ级重点保护野生动物。本实验测定了在不同环境温度条件下红瘰疣螈体温及代谢率变化。结果表明,在10～35℃环境温度范围内红瘰疣螈体温(Tb)与环境温度(Ta)呈正相关,其直线回归方程为:Tb=3.99+0.86Ta(R2=0.99,P0.01);其代谢率(MR)在15～30℃的环境温度范围内随环境温度的升高而升高,在35℃时,其代谢率由于体温过高而急剧降低;在15～35℃之间的6个温度条件下雄性代谢率的回归方程为:MR1=0.374 1-0.355 1Ta+0.113 9T2a-0.010 5T3a(R2=0.47,P0.01,df1=3,df2=46);雌性代谢率的回归方程为:MR2=0.478 8-0.420 3Ta+0.130 4T2a-0.011 8T3a(R2=0.40,P0.01,df1=3,df2=46)。不同于内热源动物的代谢特征,红瘰疣螈的体温调节表现出外热源动物的特点:其体温受环境影响较大,体温生理调节能力较弱。     

捕食风险对红瘰疣螈幼体生长发育的影响

捕食风险是两栖动物幼体表型和生活史进化重要的选择压力之一。红瘰疣螈Tylototriton shanjing为云南山地环境中典型的有尾两栖类,山地环境水体水量的迅速减少常导致红瘰疣螈在幼体发育阶段捕食风险增加。本研究通过实验,观察红瘰疣螈幼体的体长和体质量在不同捕食风险环境中的变化、变态时体型以及完成变态发育的时间差异,探讨捕食风险对红瘰疣螈幼体个体早期发育的影响。实验设计4个不同的捕食风险处理:无任何捕食者的无捕食组、有同种个体化学信号的同种异体组、有同种尾受伤个体化学信号的断尾组、有入侵物种——克氏原螯虾Procambarus clarkii信息的外来物种组。结果显示,红瘰疣螈幼体在不同捕食风险环境中的生长发育过程不同。在生长发育前期,所有处理组的幼体生长均相似,而在中后期,有捕食风险存在的3个处理组生长发育显著加快,最终变态时的体长和体质量要比无捕食风险组更长和更重,体型更大。幼体在有捕食风险存在的处理组完成变态的时间要比无捕食风险组显著更短。这表明,红瘰疣螈幼体在面对捕食风险增加时,通过在胚后发育后期加快生长和缩短发育时间,尽快完成变态,离开幼体发育水体来适应高捕食风险的水环境。     

红瘰疣螈皮肤的显微结构观察

对我国Ⅱ级重点保护野生动物红瘰疣螈(Tylototriton shanjing)成体的皮肤结构进行了显微观察。观察结果表明,其皮肤厚薄、微血管、色素分布,以及腺体的分布和大小等方面在身体的不同部位存在差异:头和背部的皮肤厚于腹部;黑色素细胞多分布于真皮浅层,以腹部及背侧无瘰粒处多见;真皮层富含黏液腺和颗粒腺,但分布不均匀;头嵴棱部及背部瘰粒下方颗粒腺的数量多、体积大,并充满分泌物;表皮下腺体外突,其表皮细胞层数减少,形成分泌物有效通道。同时,将红瘰疣螈皮肤与其他两栖类相比可知,其以上皮肤结构特征均体现了红瘰疣螈对山区阴湿环境中陆栖生活的重要适应。     

氧化乐果对红瘰疣螈胚胎及蝌蚪生长发育的影响

本文研究了氧化乐果对红瘰疣螈Tylototriton shanjing胚胎及蝌蚪生长发育的影响。结果表明,氧化乐果对红瘰疣螈胚胎发育过程中的出膜期和开口期毒性较大,其余各期毒性较小。随着氧化乐果浓度的增大,红瘰疣螈的畸形率和死亡率逐渐增大。gosner22期蝌蚪的安全浓度是0.05 mg·L~(-1)。在安全浓度内,0.03 mg·L~(-1)氧化乐果溶液对蝌蚪的生长具有明显的促进作用,浓度高于0.03 mg·L~(-1)则对蝌蚪的生长发育有明显的滞育作用,对其生长的影响主要表现在10 d以后,这与处理时间延长,毒物在蝌蚪体内富集有关。氧化乐果对红瘰疣螈胚胎及蝌蚪生长发育有显著的影响和损伤,该研究为农业生产科学合理使用农药提供了依据。     

六种常见两栖类动物皮肤分泌物的生物活性比较

对6种常见两栖类动物皮肤水溶性分泌物的生物学尖性与酶学活性进行了研究,其中,红瘰疣螈（Tylototriton verrucosus),大蹼铃蟾（Bombina maxima),华西蟾蜍（Bufo andrewsi)皮肤分泌物对小白鼠具有致死毒性,对小白鼠腹腔注射的半数致死剂量分别为11．5,18．8和264mg/kg。而沼蛙（Rana nigromaculata),泽蛙（Rana guentheri),黑斑蛙（Rana limnocharis)的皮肤分泌物在小白鼠腹腔注射剂量达到500mg/kg时,仍不显示致死毒性。红瘰疣螈,大蹼铃蟾皮肤分泌物的毒性成分为3－60kDa的多态与蛋白质。6种两栖类动物皮肤分泌物都具有蛋白酶水解活性与胰蛋白酶抑制活性。红瘰疣螈,大蹼铃蟾和华西蟾蜍皮肤分泌物具有广谱抗菌活性,大蹼铃蟾,华西蟾蜍皮肤分泌的具有肿瘤细胞细胞毒活性。6种皮肤分泌物对哺乳类血液凝固系统无显著影响。仅发现红瘰疣螈皮肤分泌物具有磷脂酶A2活性。6种皮肤分泌的均无乙酰胆碱酯酶活性。     

云南被子植物蔷薇分支的进化历史研究

本文以云南被子植物蔷薇分支为研究对象,基于物种间的演化关系,结合其地理分布,从进化历史的角度探讨了物种、特有种、受威胁物种的种类组成及系统发育组成的分布格局,并整合自然保护地的空间分布,对生物多样性的重点保护区域进行识别。结果显示：云南被子植物蔷薇分支的物种密度与系统发育多样性、特有种密度、受威胁物种密度均呈显著正相关,云南南部和西北部是物种丰富度与系统发育多样性最为丰富的区域;就云南整体而言,蔷薇分支的标准化系统发育多样性较低;云南南部、东南部、西北部是蔷薇分支的重点保护区域。     

基于线粒体COI、Cytb和COII基因的中国草地螟不同地理种群遗传分化分析

【目的】揭示中国草地螟Loxostege sticticalis不同地理种群的遗传分化程度。【方法】采用PCR技术扩增中国西北和华北地区草地螟11个地理种群的线粒体 COI, Cytb和COII基因序列,基于其序列变异及单倍型贝叶斯系统发育树和单倍型网络图分析,探讨不同地理种群间的遗传距离、分子系统发生关系及遗传分化程度。【结果】草地螟11个地理种群的线粒体 COI, Cytb和COII基因序列分别有24, 12和69个变异位点(分别占总序列的3.6%, 2.7%和8.8%),检测到的单倍型分别为22, 14和16个,单倍型多样度(Hd)分别为0.7600, 0.5842和0.7341,核苷酸平均差异度(K)分别为1.704, 0.752和3.997,不同单倍型间的遗传距离平均值分别为0.004, 0.005和0.013。总种群的Tajima’s D和Fu’s Fs值皆不显著,表明草地螟不同地理种群间的遗传分化不明显,群体大小稳定。根据各地理种群的单倍型建立的系统发育树和单倍型网络图表明,各单倍型散布在不同的地理种群中,无明显的地理分布格局。【结论】草地螟各地理种群的遗传距离与地理距离间不具有显著的相关性,其遗传分化不明显。     

Phylogenetic relationships of the southern African freshwater crab fauna (Decapoda: Potamonautidae: Potamonautes) derived from multiple data sets reveal biogeographic patterning

The phylogenetic relationships among the southern African freshwater crab species were examined using partial sequence data from three mitochondrial genes (12S rRNA, 16S rRNA, and mtDNA COI) 26 morphological characters and 14 allozyme loci. The aims of the present study were firstly to determine whether freshwater crab species that live in the same geographic region share a close phylogenetic relationship. Secondly, to investigate whether hybridizing species are genetically closely related and thirdly, to test for the validity of subgenera based on the genetic data sets. Phylogenetic analysis based on sequence data revealed largely congruent tree topologies and some associations had consistently high bootstrap support, and these data did not support Bott's subgeneric divisions. The morphological data were less informative for phylogenetic reconstruction while the allozyme data generally supported patterns recovered by the sequence data. A combined analysis of all the data recovered two monophyletic clades, one comprised of small-bodied mountain stream species and the other clade consisting of large-bodied riverine species. The combined analyses reflected clear biogeographic patterning for these river crabs. In addition, there was a clear correlation between genetic distance values and the ability of sympatric species to hybridize.     

Mitochondrial genomes and divergence times of crocodile newts: inter-islands distribution of Echinotriton andersoni and the origin of a unique repetitive sequence found in Tylototriton mt genomes

Crocodile newts, which constitute the genera Echinotriton and Tylototriton, are known as living fossils, and these genera comprise many endangered species. To identify mitochondrial (mt) genes suitable for future population genetic analyses for endangered taxa, we determined the complete nucleotide sequences of the mt genomes of the Japanese crocodile newt Echinotriton andersoni and Himalayan crocodile newt Tylototriton verrucosus. Although the control region (CR) is known as the most variable mtDNA region in many animal taxa, the CRs of crocodile newts are highly conservative. Rather, the genes of NADH dehydrogenase subunits and ATPase subunit 6 were found to have high sequence divergences and to be usable for population genetics studies. To estimate the inter-population divergence ages of E. andersoni endemic to the Ryukyu Islands, we performed molecular dating analysis using whole and partial mt genomic data. The estimated divergence ages of the inter-island individuals are older than the paleogeographic segmentation ages of the islands, suggesting that the lineage splits of E. andersoni populations were not caused by vicariant events. Our phylogenetic analysis with partial mt sequence data also suggests the existence of at least two more undescribed species in the genus Tylototriton. We also found unusual repeat sequences containing the 3' region of cytochrome apoenzyme b gene, whole tRNA-Thr gene, and a noncoding region (the T-P noncoding region characteristic in caudate mtDNAs) from T. verrucosus mtDNA. Similar repeat sequences were found in two other Tylototriton species. The Tylototriton taxa with the repeats become a monophyletic group, indicating a single origin of the repeat sequences. The intra-and inter-specific comparisons of the repeat sequences suggest the occurrences of homologous recombination-based concerted evolution among the repeat sequences.     

云南被子植物菊类分支的系统发育多样性及其分布格局

全球气候变化与人为活动等因素导致的生物多样性丧失,引起了全球各界对生物多样性保护的高度关注。传统生物多样性保护主要对物种、特有种、受威胁物种的种类组成及其分布模式开展研究,忽视了进化历史在生物多样性保护中的作用。云南是全球生物多样性热点地区的交汇区,生物多样性的保护历来受到广泛关注,为了更好地探讨云南生物多样性的保护措施,该研究以云南被子植物菊类分支物种为研究对象,基于物种间的演化关系,结合其地理分布,从进化历史的角度探讨物种、特有种、受威胁物种的种类组成及系统发育组成的分布格局,并整合自然保护地的空间分布,识别生物多样性的重点保护区域。结果表明：云南被子植物菊类分支的物种、特有种及受威胁物种的物种密度与系统发育多样性均显著正相关;通过零模型分析发现,由南向北标准化系统发育多样性逐渐降低;云南南部、东南部、西北部是云南被子植物菊类分支的重点保护区域,加强这些区域的保护,将最大化地保护生物多样性的进化历史和进化潜能。由此可见,融合进化历史信息的植物多样性格局分析不仅有助于更加深入地理解植物多样性的形成与演变,也为生物多样性保护策略的制定提供更多的思路。     

The geography of speciation in narrow‐range endemics of the ‘Haenydra’ lineage (Coleoptera,Hydraenidae, Hydraena)

Aim We test whether species of western Mediterranean aquatic Coleoptera of the ‘Haenydra’ lineage (Hydraenidae, Hydraena) originated through: (1) successive periods of dispersal and speciation, (2) range fragmentation by random vicariance, or (3) range fragmentation by geographic isolation owing to a general reduction of population density. Location Europe. Methods To discriminate between scenarios we use contrasting predictions of the relationship between phylogenetic and geographic distance. The phylogeny was based on 3 kb of four mitochondrial and two nuclear gene fragments of about half of the known species of ‘Haenydra’, including most western Mediterranean taxa. Divergences were estimated using a molecular clock. The relationship between phylogenetic and geographic distance was tested using bivariate plots, Mantel tests and comparison of the observed phylogeny with the one minimizing geographic distances between species, as measured using Euclidean minimum spanning trees (EMSTs). Results The monophyly of ‘Haenydra’ was strongly supported, although its phylogenetic placement was not resolved. ‘Haenydra’ was estimated to be of late Miocene age, with most species originating during the Pleistocene. In two clades (Hydraena tatii and Hydraena emarginata clades) there was a significant association between geographic and phylogenetic distance, and the reconstructed phylogeny was identical to that obtained through the EMST, demonstrating a strong non‐randomness of the geographic distribution of the species. In two other clades (Hydraena iberica and Hydraena bitruncata clades) there was no association between geographic and phylogenetic distance, and the observed phylogeny was not the one minimizing geographic distances. In one of the clades this seems to be due to a secondary, recent range expansion of one species (H. iberica), which erased the geographic signal of their distributions. Main conclusions We show that it is possible to obtain strong evidence of stasis of the geographic ranges of narrow‐range endemic species through the study of their phylogenetic relationships and current distributions. In at least two of the studied clades, current species seem to have originated through the fragmentation of a more widely distributed species, without further range movements. A process of range expansion and fragmentation may have occurred repeatedly within the ‘Haenydra’ lineage, contributing to the accumulation of narrow‐range endemics in Mediterranean Pleistocene refugia.     

基于线粒体COI基因的中国西南地区木领针蓟马地理种群的遗传分化分析

【目的】木领针蓟马Helionothrips mube近年来成为芋头Colocasia esculenta上的一种常见害虫。本研究旨在探讨其中国西南地区地理种群间的遗传变异。【方法】通过Sanger法测定了21个地理种群132头木领针蓟马的线粒体COI基因序列,利用MEGA, DnaSP, Arlequin和Network等软件对木领针蓟马种群间的遗传多样性、遗传分化、分子变异等进行分析。【结果】获得的木领针蓟马132条线粒体COI序列(643 bp)中共发现34个变异位点、16种单倍型,其中单倍型H1出现频率最高、分布最广。木领针蓟马总群体的遗传多样性较高(Hd=0.712, Pi=0.00413, K=2.655),遗传分化程度极大(Fst=0.3443),基因交流水平不高(Nm=0.96)。分子方差分析(AMOVA)表明,木领针蓟马的遗传分化主要来自种群内部,Mantel检测出种群地理距离与遗传距离呈正相关。总群体中性检验Tajima’s D值显著负值,Fu’s Fs值不显著,错配分布曲线呈多峰。综合种群间遗传距离、单倍型系统发育树及中介网络图结果,表明四川成都(CHD)、云南昌宁(CHN)和贵州遵义(ZY)3个种群的遗传分化程度均高于其他种群。【结论】中国西南地区木领针蓟马总群体的遗传多样性较高,遗传分化明显,种群间的基因交流受到地理距离的影响,总群体在较近的历史时期内没有出现扩张现象。     

野生干巴菌(Thelephora ganbajun M. Zang)在中国的新分布

报道福建北部山区三明地区及台湾中部南投山区所采集的真菌标本,经过形态特征、显微构造及ITS序列分析与鉴定,确认为干巴菌(Thelephora ganbajun M. Zang)。结合文献分析,认为干巴菌的生长分布范围在21°N～27°N之区域。此发现提供了干巴菌在中国新的分布地区,丰富了中国干巴菌的分布资料。     

Floral and vegetative morphometrics of five Pleurothallis (Orchidaceae) species: correlation with taxonomy,phylogeny, genetic variability and pollination systems

Morphometric analyses of vegetative and floral characters were conducted in 21 populations of five Pleurothallis (Orchidaceae) species occurring in Brazilian 'campo rupestre' vegetation. A phylogenetic analysis of this species group was also carried out using nuclear ribosomal DNA internal transcribed spacers (ITS1 and ITS2). Results of the ordination and cluster analyses agree with species' delimitation revealed by taxonomic and allozyme studies. The groups formed in ordination analysis correspond to the pollinator groups determined in a previous pollination study. Relationships among the species in the cluster analysis using only vegetative characters are similar to those found in a previous allozyme study, but those indicated by cluster analysis using only floral characters differ. These results support the hypothesis that floral similarities are due to convergence driven by similar pollination mechanisms, and therefore floral traits may not be good indicators of phylogenetic relationships in this group. The results of the phylogenetic analysis support this conclusion to some extent. There is no correlation between genetic (allozyme) and morphological variability in the populations nor in the way this variability is distributed among conspecific populations. We describe a new subspecies of Pleurothallis ochreata based on differences in vegetative and chemical characters as well as geographic distribution. Absence of differentiation in floral characters, attraction of the same pollinator species, interfertility and genetic similarity support the argument for subspecific rather than specific status.