首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
中南半岛紫金牛科植物志预报   总被引:1,自引:1,他引:0  
紫金牛科是一个典型的热带分布科,中南半岛种类非常丰富。Pitard(1930)在“Flore Generale de L'Indochine”中记录了6属109种。此后,对这一地区的种类无人作过全面深入的研究。最近作者在编研《柬埔寨、老挝和越南植物志》的过程中,对紫金牛科作了全面的修订,被确认的种类增加到7属142种,其中包括紫金牛属,酸藤子属和杜茎山属的30个新种,10个新变种,另外还有紫金牛属  相似文献   

3.
利用AFLP分子标记结合形态学指标,采用UPGMA法进行聚类分析,对桤木属17个种57份材料进行了亲缘关系研究及一个模糊种鉴定。结果表明:7对引物扩增出369条带,其中346个多态位点,多态位点百分率为93.77%;根据AFLP标记位点聚类分析,在相似系数为0.782时,17种桤木属植物可分为4类,第一类为日本桤木(Alnus japonica);第二类为绿桤木(A.viridis)、意大利桤木(A.cordata)、欧洲桤木(A.glutinosa)、模糊种、四川桤木(A.cremastogyne)、江南桤木(A.trabeculosa)、斑点桤木(A.incana ssp.rugosa)、东北亚灰桤木(A.hirsuta)、台湾桤木(A.formosana)、日本特有桤木(A.firma)和裂叶桤木(A.sinuata);第三类为灰桤木(A.incana)、红桤木(A.rubra)及薄叶桤木(A.tenifolia);第四类喜马拉雅灰桤(A.nitida)和尼泊尔桤木(A.nepalensis)。根据形态学聚类分析,在距离为1.4时可分为三类,意大利桤木(A.cordata)单独为一类;日本桤木(A.japonica)、台湾桤木(A.formosana)、喜马拉雅灰桤木(A.nitida)、江南桤木(A.trabeculosa)和东北亚灰桤木(A.hirsuta);第三类包括模糊种、灰桤木(A.incana)、斑点桤木(A.incana ssp.rugosa)、裂叶桤木(A.sinuata)、红桤木(A.rubra)、欧洲桤木(A.glutinosa)、绿桤木(A.viridis)、四川桤木(A.cremastogyne)、薄叶桤木(A.tenuifolia)和尼泊尔桤木(A.nepalensis)。经形态特征和AFLP分析鉴定模糊种为欧洲桤木。形态学聚类与AFLP聚类结果基本一致,但仍存在一定的差异,说明桤木属植物遗传背景丰富,种的分子分类地位和形态学分类地位具有一定的差异。  相似文献   

4.
ABSTRACT Taxonomic study of the genus Anterhynchium from the Eastern Asia is carried out. A total of 15 forms included in four species were reviewed: A. melanopterum, A. flavopunctatum flavopunctatum, A. flavopuntatum opulentum, A. yunnanensis, A. flavomarginatum flavomarginatum, A. f. koreanum, A. f. tsushimarum, A. f. umenoi, A. f. micado, A. f. procella, A. f. insulicola, A. f. sulphreum, A. f. amamense, A. f. hanedai and A. f. formosicola. However, the A. flavopunctatum opulentum and A. yunnanensis are only cited for future work, due to the lack of available materials. Key to the other species and subspecies are revised, and photos showing diagnostic characters and coloration are presented. The male genitalic characters for accurate identification were separately discussed.  相似文献   

5.
BACKGROUND AND AIMS: Fifty-two populations were sampled in order to establish the taxonomic delimitation and relationships of eight taxa belonging to the A. majus L. and A. siculum Miller groups. METHODS: Data on 13 allozyme loci were recorded after extraction of fresh leaves and electrophoresis on horizontal 10% starch gels. KEY RESULTS: Genetic distances between conspecific populations are lower than for other species of the genus. CONCLUSIONS: These results support the recognition of A. majus, A. tortuosum, A. linkianum, A. cirrigherum, A. litigiosum and A. barrelieri at specific rank. The genetic distances, together with the lack of morphological differences and the sympatric distribution ranges, support the inclusion of A. australe into A. tortuosum, A. dielsianum into A. siculum, and A. latifolium subsp. intermedium as a synonym of A. latifolium. The results support separation of the taxa studied into two groups, coinciding with series Sicula Rothm. and Majora, but disagreeing with the arrangement of species into them. According to our results, Sicula consist of A. siculum and Majora consists of A. latifolium, A. majus, A. tortuosum, A. linkianum, A. cirrigherum, A. litigiosum and A. barrelieri.  相似文献   

6.
VAN RAAMSDONK, L. W. D., WIETSMA, W. A. & DE VRIES, J. N., 1992. Crossing experiments in Allium L. section Cepa . A full diallel was carried out with six diploid species of Allium section Cepa and A. roylei of section Rhizirideum , High isolation barriers were found between the related species A. cepa and A. oschaninii , between A. oschaninii and A. vavilovii , and between A. galanthum and A. pskemense . On the contrary, the species A. cepa and A. roylei , belonging to different sections, show only slight isolation barriers. The Wallace effect, which is the development of internal isolation barriers as such, is likely to have taken place in the evolution of A. oschaninii and A. vavilovii , and possibly also between A. galanthum and A. pskemense .  相似文献   

7.
七种蒿属植物种子重量形状及萌发特性的比较研究   总被引:22,自引:3,他引:19  
在实验室条件下 ,对 7种蒿属植物种子 (差巴嘎蒿、乌丹蒿、万年蒿、大籽蒿、黄蒿、野艾蒿和冷蒿 )进行重量、形状及萌发特性的比较研究。沙生先锋植物乌丹蒿和差巴嘎蒿的种子重量较大、形状扁平 ,这些特征是植物对流沙环境进化的适应机制之一。黄蒿种子小且呈圆形 ,具有持久土壤种子库 ,因此黄蒿抗干扰能力较强。 7种蒿属植物有 3种萌发格局 :大籽蒿、万年蒿、差巴嘎蒿和冷蒿的萌发前期快 ,后期平缓 ;野艾蒿和黄蒿整个萌发过程平缓 ;乌丹蒿早期和后期萌发平缓 ,中间快。乌丹蒿推迟萌发高峰是它比差巴嘎蒿更适应流沙环境的机制之一。从种子萌发格局分析 ,黄蒿种子具有生理后熟或休眠机制 ,大籽蒿种子萌发是典型的机会主义。黄蒿、野艾蒿和冷蒿种子具有风险分摊的萌发机制。种子重量和形状与发芽率之间无相关性 ,重量和形状则显著相关。  相似文献   

8.
At the functional level, the majority of human leukocyte antigen (HLA) class I MHC variants can be classified into about ten different major groups, or supertypes, characterized by overlapping peptide binding motifs and repertoires. Previous studies have detailed the peptide binding specificity of the HLA A2, A3, B7, and B44 supertypes, and predicted, on the basis of MHC pocket structures, known motifs, or the sequence of T cell epitopes, the existence of the HLA A1 and A24 supertypes. Direct experimental validation of the A1 and A24 supertypes, however, has been lacking. In the current study, the peptide-binding repertoires and main anchor specificities of several common HLA A molecules (A*0101, A*2301, A*2402, A*2601, A*2902, and A*3002) predicted to be members of the A1 or A24 supertypes were analyzed and defined using single amino acid substituted peptides and a large peptide library. Based on the present findings, the A1 supertype includes A*0101, A*2601, A*2902, and A*3002, whereas the A24 supertype includes A*2301 and A*2402. Interestingly, A*2902 is associated with a motif and peptide binding repertoire that overlaps significantly with those of all of the A1- and A24-supertype molecules studied, representing—to our knowledge—the first report of significant cross-reactivity among molecules belonging to different supertypes.  相似文献   

9.
广义青篱竹属(Arundinaria)核糖体DNA ITS序列及亲缘关系研究   总被引:8,自引:0,他引:8  
利用PCR扩增产物直接测序的方法分析广义青篱竹属(Arundinaria)中有关争议类群的代表种或模式种(毛竹为外类群)等18种竹种的核糖体DNA内转录间隔区(Internal Transcribed Spacers,ITS)序列。通过最简约性分析产生的ITS系统发育树表明,供试竹种形成一个自然的单系类群,这说明广义青篱竹属中这些不同的类群归属青篱竹属是合理的。17种竹种可聚为2大分支:其中斑苦竹(A,oleosa)、仙居苦竹(A.hsienchuensis)、茶秆竹(A.amabilis)、长叶苦竹(A.chino)、苦竹(A.amara)、宜兴苦竹(A.yixingensis)、菲白竹(A.fortunei)、翠竹(A.pygmaea)为一个分支;而大明竹(A.graminea)、巴山木竹(A.fargesii)、冷箭竹(A.faberi)、凤竹(A.hupehense)、鼓节矢竹(Pseudosasa japonica cv.Tsutsumiana)、矢竹(Pseudosasa japonica)、短穗竹(Brachystachyum densiflorum)、肿节竹(A.oedogonata)、少穗竹(A.sulcata)组合在另一分支。ITS系统发育树还表明,大明竹与巴山木竹、鼓节矢竹与矢竹、少穗竹与短穗竹和肿节竹关系极为密切,均得到较高的Bootstrap(分别为99%、100%和87%)的支持;茶秆竹与仙居苦竹关系非常密切,茶秆竹可归隶到青篱竹属中;翠竹和菲白竹关系密切,且与苦竹类竹种分为两个分支。  相似文献   

10.
The variability of the nuclear 18S rDNA was examined for 10 species of freshwater eels: Anguilla anguilla, A. australis, A. dieffenbachii, A. japonica, A. marmorata, A. mossambica, A. nebulosa labiata, A. obscura, A. reinhardtii and A. rostrata. We observed that a single nucleotide polymorphism (SNP) separated A. anguilla and A. japonica from the remaining taxa. While this SNP marker may be used to identify hypothetical hybrids of A. japonica and sympatric eel species, we focused on Atlantic eels to evaluate the potential for this diagnostic chromosomal marker to discriminate between individuals of A. anguilla, A. rostrata and their hybrids.  相似文献   

11.
12.
The role of conserved polar glutamine, asparagine and threonine residues in the large extracellular loop, and glycosylation, to agonist action at human P2X1 receptors was tested by generating alanine substitution mutants. For the majority of mutants (Q56A, Q95A, T104A, T109A, Q112A, Q114A, T146A, N153A, T158A, N184A, N191A, N242A, N300A) alanine substitution had no effect on ATP potency. The mutants Q95A, Q112A, Q114A and T158A showed changes in efficacy for the partial agonists BzATP and Ap5A, suggesting that these polar residues may contribute to the gating of the channel. The mutants T186A, N204A and N290A had six-, three- and 60-fold decreases in ATP potency, respectively. For T186A and N290A, the partial agonists BzATP and Ap5A were no longer agonists but still bind to the receptor as shown by the ability to modulate the response to co-applied ATP. N153, N184 and N242 are glycosylated in the endoplasmic reticulum and N300 acquires complex glycosylation in the golgi. These results aid in refining a model for ATP binding at the P2X1 receptor where the residues F185T186, and the conserved triplet N290F291R292, are likely to play a role in ATP action at the receptor.  相似文献   

13.
Genetic characterization of Artemia tibetiana (Crustacea: Anostraca)   总被引:1,自引:0,他引:1  
The brine shrimp Artemia consists of a number of bisexual species and a large number of parthenogenetic forms, which collectively, inhabit a wide range of hypersaline habitats. A recently described species (A. tibetiana) from a carbonate lake (Lagkor Co) in Tibet at an altitude of 4490 m has been tested with New World (A. franciscana USA, and A. franciscana feral population Vietnam) and Old World species (A. salina, A. urmiana, A. sinica) for cross fertility. These tests show complete infertility between A. tibetiana and A. franciscana . Between A. tibetiana and A. urmiana, A. sinica partial fertility through to F2 and F3 generations is evident. Allozyme and RAPD comparison of A. tibetiana with A. franciscana (USA), A. franciscana (Vietnam), A. sinica (Mongolia) and A. urmiana (Iran) show that A. tibetiana is similar to other bisexual species in mean heterozygosity (0.074) but has a somewhat higher proportion of polymorphic loci (40%, similar to that of A. urmiana ). The genetic distance between A. tibetiana and A. franciscana is 0.730, between A. tibetiana and A. urmiana is 0.475 and that between A. tibetiana and A. sinica is 0.114. FIS estimates for A. tibetiana differ significantly from zero for six loci, mainly because of lack of fit to Hardy-Weinberg expectations. This may suggest that even within the limited area of Lagkor Co there are Genétically distinct populations. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 75 , 333–344.  相似文献   

14.
Tumor suppressor RASSF1A (RAS association domain family 1, isoform A) is known to play an important role in regulation of mitosis; however, little is known about how RASSF1A is regulated during the mitotic phase of the cell cycle. In the present study, we have identified Cullin-4A (CUL4A) as a novel E3 ligase for RASSF1A. Our results demonstrate that DNA damage-binding protein 1 (DDB1) functions as a substrate adaptor that directly interacts with RASSF1A and bridges RASSF1A to the CUL4A E3 ligase complex. Depletion of DDB1 also diminishes intracellular interactions between RASSF1A and CUL4A. Our results also show that RASSF1A interacts with DDB1 via a region containing amino acids 165-200, and deletion of this region abolishes RASSF1A and DDB1 interactions. We have found that CUL4A depletion results in increased levels of RASSF1A protein due to increased half-life; whereas overexpression of CUL4A and DDB1 markedly enhances RASSF1A protein ubiquitination resulting in reduced RASSF1A levels. We further show that CUL4A-mediated RASSF1A degradation occurs during mitosis, and depletion of CUL4A markedly reverses mitotic-phase-stimulated RASSF1A degradation. We also note that overexpression of CUL4A antagonizes the ability of RASSF1A to induce M-phase cell cycle arrest. Thus, our present study demonstrates that the CUL4A·DDB1 E3 complex is important for regulation of RASSF1A during mitosis, and it may contribute to inactivation of RASSF1A and promoting cell cycle progression.  相似文献   

15.
Abstract. The species of Apocephalus , subgenus Mesophora , are revised and twenty-eight species are recognized, including the following twenty-two new to science: from the Nearctic Region A. brunnipes, A. gemursus, A. pristinus, A. setialvus and A. unitarsus , and from the Neotropical Region A. absentis, A. adustus, A. anfractus, A. angustistylus, A. bisetus, A. brevicercus, A. curtus, A. gracilis, A. hansoni, A. leptotarsus, A. longistylus, A. micrepelis, A. moraviensis, A. prolatus, A. trisetus, A. tritarsus and A. truncaticercus. Additionally, three species known only from female specimens are described but not formally named. A lectotype is designated for A. mortifer Borgmeier, and immature stages of A. borealis, A. antennatus and A. mortifer are described. Unlike larvae of other Apocephalus species, all of which are parasites of ants (Hymenoptera: Formicidae), those of Mesophora species are parasites of various other hosts.  相似文献   

16.
S100A8 and S100A9 and their heterocomplex calprotectin (S100A8/A9) are abundant cytosolic constituents in human neutrophils previously shown to possess antifungal activity. This study was designed to investigate mechanisms involved in the modulation of the antifungal properties of S100A8/A9. S100A8, S100A9 and site-directed mutants of both proteins were tested for their antifungal effect against Candida albicans in microplate dilution assays. Whereas S100A8 alone did not inhibit fungal growth, S100A9 by itself had a moderate antifungal effect. Combining both proteins had the strongest effect. Supporting a potential role for oxidation in S100A8/A9, substitution of methionine 63 or 83 of S100A9 resulted in the loss of antifungal activity. Additionally, the substitution to alanine of cysteine 42 of S100A8 also caused a loss of S100A8's ability to enhance S100A9's antifungal effect. Overall, our data indicate that both S100A8 and S100A9 are required for their fully active antifungal effect and that oxidation regulates S100A8/A9 antifungal activity through mechanisms that remain to be elucidated and evaluated. Finally, together with our previous work describing the oxidation-sensitive anti-inflammatory effects of S100A8/A9, we propose that S100A8/A9 exerts an anti-inflammatory activity in healthy state and that conditions associated with oxidative stress activate the antifungal activity of S100A8/A9.  相似文献   

17.
The aim of the study was to verify the similarity of 13 species and 5 cultivars of ornamental alliums and classify them into groups based on morphological and isozyme variation. The work embraced: Allium aflatunense, A. caeruleum, A. christophii, A. giganteum, A. karataviense, A. moly, A. nigrum, A. pyrenaicum, A. rosenbachianum, A. schubertii, A. siculum (syn. Nectaroscordum siculum), A. sphaerocephalon, A. strictum, A. stipitatum 'Album', A. 'Ivory Queen', A. 'Lucy Ball', A. 'Mont Blanc', and A. 'Purple Sensation'. Scape length, inflorescence diameter, and flowering period were recorded. Isozyme marker polymorphism was assessed by starch gel electrophoresis. Eight polymorphic isozyme systems (AAT, GPI, PGM, ALAT, ACP, DIAP, ALDO, PGD) were selected from 16 analysed in the taxa. Besides the differences between the taxa, the isozymes revealed intraspecific polymorphism in 5 systems. A total of 37 markers were obtained and used for dendrogram construction. The most similar taxa were A. karataviense with A. 'Ivory Queen', and A. karataviense with A. christophii (similarity level 0.78). A high similarity of 11 taxa belonging to one group (A. aflatunense, A. christophii, A. giganteum, A. karataviense, A. nigrum, A. schubertii, A. 'Ivory Queen', A. 'Lucy Ball', A. stipitatum 'Album', A. 'Mont Blanc', A. 'Purple Sensation') suggested that this group could be identified with the subgenus Melanocrommyum.  相似文献   

18.
林平 《昆虫分类学报》1996,18(3):157-169
桂毛异丽金龟物种群(Anomalahirsutulaspeciesgroup)是山居类群,外部形态彼此十分近似,容易混淆。体型中等,全体被不甚密可见红褐底色的短毛,背面刻点甚密,鞘翅背面有6条深沟行,行距圆脊状隆起。本篇包括国内迄今已知种类15种,其中新种10种,新异名1种,新纪录3种,恢复原种名1种。篇内对旧种的分类间题进行了讨论。种名有:闽毛异丽金龟A.hirsutndessp.nov,桂毛异丽金龟A.hirsutulaNonfried,湘毛异丽金龟A.trichophorasp.nov.,赣毛异丽金龟A.montanasp.nov.,川毛异丽金龟A.piloellaFairmaire,黔毛异丽金龟A.subpilosasp.nov,长毛异丽金龟A.subtrinatasp.nov,叉毛异丽金龟A.subtomentellasp.nov,疣毛异丽金龟A.planicaudasp.nov,云毛异丽金龟A.iwaseiMiyake,斧毛异丽金龟A.sapaMiyake,缅毛异丽金龟A.ligneaArrow,脊毛异丽金龟A.capillulasp.nov,短毛异丽金龟A.brevihirtasp.nov.和  相似文献   

19.
乌兰布和沙漠沙蒿与油蒿群落的物种组成与数量特征   总被引:4,自引:0,他引:4  
沙蒿与油蒿群落均是我国最典型的沙地植被类型,在沙漠地区发挥了重要的生态防护作用,掌握其分布、组成及其数量特征对沙漠化防治具有一定的指导作用。调查研究表明,沙蒿与油蒿群落是乌兰布和沙漠典型的沙地植被类型,其中沙蒿群落多分布于沙漠中东部、南部和东北部,而油蒿群落仅分布于沙漠东部、东北部和东南部;其群落类型可划分为沙蒿群落、油蒿群落、沙蒿+油蒿群落、沙蒿+沙竹群落、沙蒿+花棒+沙拐枣群落、油蒿+白刺群落、沙蒿伴生群落和油蒿伴生群落;群落的物种组成比较简单,其中沙蒿群落共有9科21属22种,油蒿群落共有10科35属37种。草本植物是沙蒿与油蒿群落的主体,所占总物种数的比例均超过70%;Simpson、Shannon多样性指数和Pielou均匀度指数高,反映了沙蒿与油蒿群落具有较高的物种多样性。与沙蒿群落相比,油蒿群落物种丰富度、单位面积个体数、盖度、Simpson和Shannon物种多样性指数均明显大于沙蒿群落,而群落相似性显著低于沙蒿,说明乌兰布和沙漠油蒿群落较沙蒿群落具有更丰富的物种组成、多样性和群落结构,更具保护和人工促进潜力。研究结果可为乌兰布和沙漠沙蒿、油蒿群落的保护及人工促进提供理论基础,对区域沙漠治理物种选择具有一定的指导意义。  相似文献   

20.
Two monoclonal antibodies, specific for A type 3 and A type 4 blood group determinants, are described. These antibodies recognized A1 but not A2 erythrocytes. A third monoclonal antibody showing specificity for A type 3 and A type 4, and also for H type 3 and H type 4, did not discriminate between A1 and A2 erythrocytes. On red cells these three antibodies recognized glycosphingolipids and binding to glycoproteins could not be demonstrated. On paraffin-embedded tissue sections the three antibodies labelled a supranuclear area, characteristic of the Golgi apparatus, of all cells producing A antigens. This labelling occurred irrespective of the A1, A2 status.The results suggest that glycolipids of erythrocytes and possibly of other cell types bear the A type 3/4 determinant specific for the A1 subgroup and that A type 3/4 determinants of glycoproteins might be present in both A1 and A2 subgroups on short oligosaccharide chains which are only detectable at the level of the Golgi apparatus.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号