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.
崔现举 《植物研究》1987,7(3):123-130
长柄山蚂蝗属Podocarpium(Benth.)Yang et Huang属蝶形花科,间断分布于东亚和中北美洲,广布种分布到非洲和大洋洲。北美有4种,亚洲约有14种.我国约有该属植物11种,以西南和长江以南地区分布种类最多。国外已有人做过本属一半以上的种的染色体记数和核型。本文对本属的三个种.长柄山蚂蝗P.podocarpum(DC.)Yang et Huang,大苞长柄山蚂蝗P.williamsii(Pamp.)Yang et Huang和云南长柄山吗蝗P.du-clouxii(Pamp.)Yang et Huang进行了染色体的记数和核型描述,其中后两个种的工作属于首次。此外,本文还首次报道了山蚂蝗属两个种:Des-modium caudatum(Thunb.)DC.和D.yunnanense Franch.的染色体数目。  相似文献   

2.
The Diospyros (Ebenaceae) species which colonized the Mascarene Islands, namely Mauritius, Reunion and Rodrigues, have been decimated over the years by human settlements. Of the 14 endemic species that have been described and collected for herbaria, Diospyros angulata is now believed to be extinct in Mauritius. The phylogenetic relationships of the 14 Diospyros species were determined using maximum parsimony analysis of 35 morphological characters. This analysis separated the Mascarene Diospyros into two major clades, with D. revaughanii , D. egrettarum and D. leucomelas grouped in the same strongly supported most basal clade while the rest of the species formed the other major clade. High bootstrap values were obtained for the sister species D. angulata and D. boutonania , and the clade clustering the upland species D. neraudii , D. nodosa and D. pterocalyx . There was also relatively strong support for the clade comprising D. hemiteles and D. melanida , which are located in mid altitude regions. These results indicate that Diospyros species most probably colonized the coastal areas of Mauritius and then moved to mid altitude habitats before finally reaching the upland regions. There are also strong indications that D. borbonica and D. diversifolia , endemic to Reunion and Rodrigues, respectively, resulted from migrations from Mauritius.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 307–313.  相似文献   

3.
Fatty acid profiling was used to study variation amongst strains of Xanthomonas campestris pv. vasculorum (Xcv). They could be divided into five groups using cellular fatty acid profiles. Group A strains represent a new and little known taxon and all came from plants of broom bamboo (Thysanolaena maxima) from Mauritius. Group B strains included the Xcv pathotype reference strain and were from palms, broom bamboo and sugarcane from Mauritius, Reunion and Australia. Group C contained southern African and Malagasy strains from sugarcane and maize, together with X. campestris pv. holcicola strain. No Mascarene strains fell into this group. Group D strains isolated from sugarcane, maize and royal palm (Roystonea regia) were from Mauritius and Reunion, the earliest known strains coming from Réunion. These groups represented in the Mascarene Islands possibly belong to three different Xanthomonas species. A further Group E comprised one Xcv strain (NCPPB 182) from Puerto Rico, one X. vasicola pv. holcicola strain plus 6 other unclassified Xanthomonas strains causing red stripe disease symptoms in sugarcane. Three of these groups occur on Mauritius and two occur on Réunion. Group B strains originally caused serious problems in noble canes. As resistant interspecific hybrids were introduced, group D strains appeared in Mauritius possibly being introduced from Reunion but having similar host ranges within the Gramineae and Palmae. The findings that 3 of these groups (A, B, D) can cause gumming disease in a grass species (T. maxima) and that 2 of them (B, D) also cause gumming disease in sugar cane (Gramineae) and palms (Palmae) is unusual.  相似文献   

4.
Although the vast majority of Prunus L. (Rosaceae) species have clearly differentiated sepals and petals, two former genera Maddenia and Pygeum have been described as having an undifferentiated perianth. However, floral morphological and morphogenetic data are scarce, and a renewed investigation is essential to understand the evolution of the perianth differentiation. Here, floral morphogenesis in Prunus hypoleuca (Koehne) J.Wen (=Maddenia hypoleuca Koehne) and Prunus topengii (Merr.) J. Wen & L. Zhao (=Pygeum topengii Merr.) were examined with scanning electron microscopy. The floral development demonstrates that the ten perianth parts can be distinguished as five sepals in an external whorl and five petals in an internal whorl. The sepal primordia are broad, crescent-shaped, and truncate. The petal primordia are rounded and initially resemble the androecium. However, at maturity petals and sepals look much the same in the two species, differing from other Prunus species. The ovule is anatropous and unitegmic, but there is a basal appendage near the ovule of P. hypoleuca which is absent in P. topengii. The direction of development of floral nectaries in the hypanthium is basipetal in P. hypoleuca but acropetal in P. topengii. Perianth segments are differentiated in the two groups and the similarity of the perianth parts is secondarily acquired. Our results support the separation of the Maddenia and Pygeum groups as well as their inclusion in a broader monophyletic Prunus based on molecular phylogenetic studies. We herein provide a new nomenclatural change: Prunus topengii (Merr.) J. Wen & L. Zhao, comb. nov.  相似文献   

5.
6.
7.
When the genus Paravahlkampfia was distinguished from the genus Vahlkampfia on the basis of significant differences in small subunit ribosomal DNA sequences, Paravahlkampfia ustiana was the only described species of this new genus. More recently, a vahlkampfiid strain has been isolated (from soil from an upland farm in Scotland) which has trophozoite and cyst morphology more similar to P. ustiana than to other non-flagellating vahlkampfiid species. Also, it clusters with P. ustiana in phylogenetic trees derived from 5.8S ribosomal DNA sequences. However, it is significantly different from P. ustiana in both phenotype and internal transcribed spacer sequence. Consequently, a new species, Paravahlkampfia lenta, is proposed.  相似文献   

8.
Panax stipuleanatus (Araliaceae) is an endangered and medicinally important plant endemic to China. However, phylogenetic relationships within the genus Panax have remained unclear. In this study, we sequenced the complete plastome of P. stipuleanatus and included previously reported Panax plastomes to better understand the relationships between species and plastome evolution within the genus Panax. The plastome of P. stipuleanatus is 156,069 base pairs (bp) in length, consisting of a pair of inverted repeats (IRs, each 25,887 bp) that divide the plastome into a large single copy region (LSC, 86,126 bp) and a small single copy region (SSC, 8169 bp). The plastome contains 114 unigenes (80 protein-coding genes, 30 tRNA genes, and 4 rRNA genes). Comparative analyses indicated that the plastome gene content and order, as well as the expansion/contraction of the IR regions, are all highly conserved within Panax. No significant positive selection in the plastid protein-coding genes was observed across the eight Panax species, suggesting the Panax plastomes may have undergone a strong purifying selection. Our phylogenomic analyses resulted in a phylogeny with high resolution and supports for Panax. Nine proteincoding genes and 10 non-coding regions presented high sequence divergence, which could be useful for identifying different Panax species.  相似文献   

9.
滇西南四个自然保护区鱼类多样性及评价指标探究   总被引:1,自引:0,他引:1  
周伟  李明会  李有兰 《生物多样性》2016,24(3):313-1127
为了解滇西南怒江水系的南滚河自然保护区、南捧河自然保护区、永德大雪山自然保护区及澜沧江水系的澜沧江自然保护区鱼类多样性和变化趋势, 探讨其差异和变化的原因, 本文采用β多样性指数分析了4个保护区的鱼类多样性, 并比较了鱼类分类阶元的特有性、单型性和古老成分的有无等多项指标。结果显示, 4个自然保护区共有土著鱼类85种, 隶属于6目13科45属。在中国仅见于怒江水系的4个特有属有异鲴属(Aspidoparia)和新条鳅属(Neonoemacheilus)分布于这3个保护区中; 18种特有种中, 仅分布在这3个保护区的狭域特有种5种。在中国仅分布于澜沧江水系的属有31个, 但仅安巴沙鳅属(Ambastaia)分布于澜沧江保护区; 在澜沧江保护区分布着中国仅见于澜沧江水系的特有种20种, 其中狭域特有种3种。怒江水系的3个保护区分布有1个单型属, 即鳗鲡属(Anguilla), 但没有单型种; 澜沧江自然保护区无单型属与单型种分布。4个保护区中的鱼类均系晚第三纪和第四纪形成的种类或类群, 没有古老或孑遗种类。β多样性结果显示, 在4个保护区中澜沧江自然保护区的鱼类多样性最丰富, 而南滚河自然保护区的丰富程度最低, 但是怒江水系3个自然保护区鱼类多样性的代表性及保护地位比澜沧江自然保护区的要高。而特有阶元和单型性阶元的存在体现出怒江水系3个自然保护区的保护价值及保护意义比澜沧江保护区高。地理范围跨度大小、生境空间异质性高低、保护区面积大小及支流多少等是影响鱼类多样性的主要因素。因此, 规划和设计保护区时, 如果能在水系的上、中、下游分别规划1条一级支流作为保护区, 可使该水系的绝大多数鱼类得到保护。  相似文献   

10.
The pattern of colonization by microorganisms on root surfaces from three species of seagrass belonging to the genus Posidonia was assessed. Microbial abundance on roots was measured by two electronic microscope techniques. Trends in microbial colonization between species and root order were defined. In addition, eutrophication status of the sampling sites and physiological status of Posidonia oceanica (L.) Delile roots have been taken into account. Our results show high microbial abundance in the Mediterranean species P. oceanica, in comparison with the low rates of colonization found in the Australian species P. australis Hook f. and P. sinuosa Cambridge et Kuo. Microbial density tended to decrease as root order increased, and living roots always showed higher microbial abundance than dead ones. Colonization of P. oceanica roots at the three sites with different environmental status follows different trends according to root order. It is suggested that root age influences the rate of microbial colonization of seagrass roots and that colonization of root surface by microorganisms is associated with organic exudates from the roots rather than with decaying root tissues.  相似文献   

11.
The genus Noculacia Mayer, 1903 is reviewed. Two new species, N. africana n. sp. and N. australiensis n. sp., are described based on material collected from southeast Africa and western-southern Australia, respectively. Noculacia bullata Mayer, 1903, the type species of the genus, is redescribed. Noculacia bogisa Mayer, 1903 is transferred to the genus Pseudoprotella Mayer, 1890 mainly on the basis of the presence of a well developed molar, the structure of pereopods 3 and 4, and the setal formula of the mandibular palp being 2-x-1. The genus Noculacia is presently composed of three species: N. africana n. sp., N. australiensis n. sp, and N. bullata Mayer, 1903. The genus Pseudoprotella is composed of P. bogisa (Mayer, 1903), P. inermis Chevreux, 1927, and P. phasma (Montagu, 1804).  相似文献   

12.
Burkholderia cepacia (formerly Pseudomonas cepacia) grows in media containing acetamide or propionamide as C and N sources. Chromosomal DNA from a hospital isolate of B. cepacia served as a template in PCRs using primers designed for the amplification of the P. aeruginosa amiE gene that encodes an aliphatic amidase. Partial sequencing of the PCR products gave a translated sequence 100% identical with the amino acid sequence of P. aeruginosa amidase. A search of Burkholderia genomes detected a putative amidase in B. cepacia J2315 with high identity to the P. aeruginosa amidase and predicted that other Burkholderia species also possessed CN_hydrolases that use the same catalytic triad (Glu–Lys–Cys) as amidase. Superimposition of theoretical three-dimensional models suggested that differences in the amino acid sequences between amidases from B. cepacia (hospital isolate) and B. cepacia J2315 do not affect their three-dimensional structure.  相似文献   

13.
Accurate species delimitation is fundamental to biodiversity conservation. The endangered spruce Picea brachytyla (Franch.) E. Pritz. was suggested to be polyphyletic based on a limited number of samples in previous studies. To evaluate polyphyly of P. brachytyla, we sampled 139 individuals from 16 populations across most of its distributional range, plus representatives of two related species, Picea likiangensis (Franch.) E. Pritz. and Picea wilsonii Mast. We sequenced 13 nuclear loci and three chloroplast and two mitochondrial loci for the following species delimitation. Phylogenetic analyses of nuclear loci grouped all individuals of P. brachytyla from Sichuan and Chongqing into one distinct lineage and those from Yunnan and Tibet (southern distribution) nested within the P. likiangensis species complex. Structure analyses confirmed this result. Networks of chloroplast DNA haplotypes similarly showed that P. brachytyla from the southern distribution nested within the P. likiangensis species complex, whereas haplotypes for the northern distribution comprised a separate and well-supported lineage. These results suggest that P. brachytyla from the southern distribution is a part of the P. likiangensis species complex and should be removed from P. brachytyla. Our study highlights the utility of population genetic evidence in delimitating endangered species and understanding the conservation status of such species.  相似文献   

14.
The Phrynichus deflersi species group is a well-defined group inhabiting the Arabian deserts and adjacent areas. The relationship of this group to other species of Phrynichus (the P. ceylonicus group) is obscure. The study of mating behaviour and spermatophore morphology of a member of the Phrynichus deflersi species group allows comparison with other species of Phrynichus and with Euphrynichus and evidence concerning the interrelationships of these three groups. Features of morphology, mating behaviour and spermatophore morphology of Phrynichus dhofarensis suggest that the P. deflersi species group and the P. ceylonicus species group are sister groups and that both (the genus Phrynichus) comprise the sister group of Euphrynichus. This conclusion remains tentative given that only two members of the P. ceylonicus species group and one of the P. deflersi species group have been studied. Mating success is quite variable, suggesting sexual selection.  相似文献   

15.
四川黑竹沟国家级自然保护区位于生物多样性丰富的凉山山系, 在保护和维持区域生物多样性方面具有极其重要的地位, 然而对该自然保护区兽类群落的研究却极为缺乏。为了了解该自然保护区及周边的小型兽类群落,本文作者在2018年4-10月调查了该区域的非飞行小型兽类物种多样性及其群落组成。在海拔1,537-3,830 m间共设置样方184个, 布设鼠夹9,016铗日, 捕获小型兽类536只, 隶属4目7科13属21种。包括滇攀鼠(Vernaya fulva)和等齿鼩鼹(Uropsilus aequodonenia)两个稀有物种在内的共计9个物种为该地区首次报道, 丰富了物种分布记录。结合历史资料, 黑竹沟地区共记录小型兽类43种, 隶属4目9科28属。在43种小型兽类中, 东洋界物种37种, 占绝对优势(86%), 分布型以喜马拉雅-横断山型占优, 为18种(占东洋界48.6%)。本次调查捕获的21种小型兽类中, 群落优势种为中华姬鼠(Apodemus draco, 33.2%)、北社鼠(Niviventer confucianus, 21.3%)和中华绒鼠(Eothenomys chinensis, 12.7%)。随着海拔上升, 群落优势种组成发生变化, 由北社鼠 + 中华姬鼠 + 针毛鼠(Niviventer fulvescens) + 短尾鼩(Anourosorex squamipes)群落, 转变为中华绒鼠 + 中华姬鼠 + 凉山沟牙田鼠(Proedromys liangshanensis) + 西南绒鼠(Eothenomys custos)群落。群落物种区系的分布型组成随着海拔升高而发生变化, 喜马拉雅-横断山型物种随海拔升高所占比例增大; 分布于喜马拉雅-横断山的特有种分布的下限、中点和上限平均海拔都高于非特有种, 且特有种和非特有种的中点和下限平均海拔差异显著(n = 21, df = 19, P = 0.013; n = 21, df = 19, P < 0.01), 说明该区域物种具有明显的东洋界特征, 中高海拔主要由特有种构成。本研究丰富了黑竹沟地区小型兽类及群落多样性的数据资料, 有利于该地区物种多样性的研究和保护。  相似文献   

16.
The genus Cayratia Juss. in the traditional sense (i.e., Cayratia s.l.) of the grape family has been shown to be non‐monophyletic. Previous studies supported the splitting of Cayratia s.l. into three genera, that is, Cayratia s.s., Causonis Raf., and a new genus representing the African Cayratia clade. However, the morphology of the African Cayratia clade has not been studied carefully and its phylogenetic position within Vitaceae remains unclear. Our study integrates molecular, distributional, and morphological data and supports the recognition of the new genus Afrocayratia from continental Africa and Madagascar. Phylogenetic analyses strongly support the monophyly of Afrocayratia and resolve it as a sister of Cayratia s.s. based on the chloroplast data, but it is placed sister to Cyphostemma based on the internal transcribed spacer dataset. Molecular dating suggests that Afrocayratia split with Cayratia s.s. during the Paleocene, but that the extant species of Afrocayratia did not diversify until the early Miocene. Afrocayratia differs from its allied genera in having short stigmas and seeds with subcircular ventral infold cavities in cross‐section. Three clades are detected within Afrocayratia, with A. debilis (Baker) J.Wen & L.M.Lu as the first diverged lineage. The second diverged lineage includes A. delicatula (Willems) J.Wen & Z.D.Chen and A. gracilis (Guill. & Perr.) J.Wen & Z.D.Chen. The third diverged lineage includes A. imerinensis (Baker) J.Wen & L.M.Lu, A. longiflora (Desc.) J.Wen & Rabarijaona, and A. triternata (Baker) J.Wen & Rabarijaona from Madagascar, which form a monophyletic group that diverged from the second lineage in the middle Miocene. Combining the morphological and molecular evidence, we formally describe the new genus Afrocayratia, make seven new combinations, and provide a key to species of the genus.  相似文献   

17.
中国杏属一新种   总被引:5,自引:1,他引:4  
描述了中国杏属一新种,华仁杏(Armeniaca cathayanaD.L.Fu,B.R.Li et J.H.Li,sp.nov.)。该新种与杏(Armeniaca vulgarisLam.)和山杏(A.sibirica(L.)Lam.)相似,但又有其独特特征,主要区别如下:叶两面疏被短柔毛,边缘具单锯齿和重锯齿,基部全缘;叶柄无腺体;单花或2~3朵花簇生;子房密被白色长柔毛;果核三角状卵球形,腹缝线具5~7条锐纵棱,背缝线具1条浅纵沟;种子大,两侧压扁,种仁质脆,无苦味。该新种由傅大立于2008年7月11日在河北省涿鹿县发现并采集,模式标本存于中国林业科学研究院(CAF),标本号:No.2008071101。  相似文献   

18.
Roegneria is a polyploid perennial genus in the tribe Triticeae. Some species of Roegneria are morphologically similar to genus Elymus and have been classified in Elymus. To investigate the delimitation and phylogenetic relationships of Roegneria, nuclear (ITS, Acc1, and Pgk1) and chloroplast (trnL–trnF) DNA regions were sequenced for 38 allopolyploid species and 32 diploid species of Triticeae. Phylogenetic analyses of nuclear DNA revealed that all Roegneria species were included in the St and Y genome clades, and that the Y genome was closely related to the V and Xp genomes. The chloroplast DNA dataset showed that Roegneria species were grouped with Pseudoroegneria species. The Pseudoroegneria species from the Middle East (P. libanotica and P. tauri) and Central Asia (P. strigosa) were more closely related to Roegneria species. The results suggested that: (i) the species containing the St and Y genomes should be segregated from Elymus and treated as a distinct genus, Roegneria, based on the genomic constitution; (ii) P. libanotica, P. tauri, and/or P. strigosa potentially served as the maternal donor of the St genome in Roegneria; (iii) The Y genome of Roegneria originated from a diploid Y genome species, and the V and Xp genomes may have contributed to Y genome formation; (iv) among Roegneria species of previously uncertain genomic constitution, R. seriotina was tetraploid and possessed the StY genomes, E. calcicolus was hexaploid with the StYH genomic constitution and should be classified in Campeiostachys, R. glaucifolia possessed the StStY genomes, and R. tschimganica had the genomic constitution St1St2Y.  相似文献   

19.
穆坪耳蕨及其近缘种研究   总被引:1,自引:0,他引:1  
作者对耳蕨属的穆坪耳蕨群作了分类学的研究, 共记录了国产种类18种。其中P.habaense, P.obtusipinnum, P.salminense, P.nigrum, P.melano-stipes等为新种;P.lichiangense(Wright) Ching为新组合。对P.tsuchuense等4种及P.qamdoense var.elongatum作了归并。本文还附有分类检索表。  相似文献   

20.
由于生活史特殊以及分类学历史复杂, 国内外有关梨甲藻科物种的分类学研究比较少。本研究通过形态分类学方法, 详细阐述了梨甲藻物种的分类学历史沿革, 对我国海域的11种梨甲藻科物种的孢囊进行了分类学研究。我们认为其中的1种应隶属于球甲藻属(Dissodinium), 其余10种可归为梨甲藻属(Pyrocystis)(包括2个变种, 2个变型), 对每个物种都进行了详细的形态学描述, 认为拟新月球甲藻(Dissodinium pseudolunula)与新月梨甲藻(Pyrocystis lunula)、优美梨甲藻(Pyrocystis elegans)与粗梨甲藻(Pyrocystis robusta)的分类学关系还需要进一步研究。  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