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1.
Phylogeny and Classification of Prunus sensu lato (Rosaceae)   总被引:3,自引:0,他引:3  
The classification of the economically important genus Prunus L. sensu lato (s.L) is controversial due to the high levels of convergent or the parallel evolution of morphological characters. In the present study, phylogenetic analyses of fifteen main segregates of Prunus s.I. represented by eighty-four species were conducted with maximum parsimony and Bayesian approaches using twelve chloroplast regions (atpB- rbcL, matK, ndhF, psbA-trnH, rbcL, rpL 16, rpoC1, rps16, trnS-G, trnL, trnL-F and ycfl) and three nuclear genes (ITS, s6pdh and Sbel) to explore their infrageneric used to develop a new, phylogeny-based classification relationships. The results of these analyses were of Prunus s.I. Our phylogenetic reconstructions resolved three main clades of Prunus s.I. with strong supports. We adopted a broad-sensed genus, Prunus, and recognised three subgenera corresponding to the three main clades: subgenus Padus, subgenus Cerasus and subgenus Prunus. Seven sections of subgenus Prunus were recognised. The dwarf cherries, which were previously assigned to subgenus Cerasus, were included in this subgenus Prunus. One new section name, Prunus L. subgenus Prunus section Persicae (T. T. yu & L. T. Lu) S. L. Zhou and one new species name, Prunus tianshanica (Pojarkov) S. Shi, were proposed.  相似文献   

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3.
Pine caterpillar moths, Dendrolimus spp. (Lepidoptera: Lasiocampidae), are serious economic pest of pines. Previously, phylogenetic analyses of Dendrolimus using different methods yielded inconsistent results. The chemosensory systems of insects may play fundamental roles in promoting speciation. Odorant-binding proteins (OBPs) participate in the first step of odor detection. Studying the evolution of OBPs in closely related species may help us to identify their role in speciation. We identified three OBPs - one pheromone-binding protein and two general odorant-binding proteins - from male antennae of four Dendrolimus species, D. superans (Butler), D. punctatus (Walker), D. kikuchii Matsumura, and D. houi Lajonquiere, the olfactory recognition systems of which had not been previously investigated. We analyzed their molecular characteristics and compared their sequences to those of OBPs in D. tabulaeformis Tsai et Liu. Ka/Ks ratio analyses among the five Dendrolimus species indicate that PBP1 genes experienced more evolutionary pressure than the GOBPs. Phylogenetic relationships of PBP1 and GOBP1 both indicated that D. houi was the basal species, then branched D. kikuchii, while D. tabulaeformis, D. punctatus, and D. superans evolved more recently. These relationships are consistent with the changes in sex pheromone components of these five species. Dendrolimus tabulaeformis and D. punctatus are closely related sister species. However, the distances among GOBP2 sequences in the five Dendrolimus were very short, and the relationships of D. houi and D. la'kuchii could not be resolved. Integrating our results with those of previous studies, we hypothesized that D. kikuchii, D. punctatus and D. superans evolved from the basal ancestor because of sex pheromone mutations and environmental pressure.  相似文献   

4.
In order to develop better insights into biogeographic patterns of eastern Asian and North American disjunct plant genera, sequences of nuclear ribosomal DNA internal transcribed spacer (nr DNAITS) region were used to estimate interspecific relationships of Thuja L. (Cupressaceae) and infer its biogeography based on the phylogeny. According to the phylogenetic analysis, two clades were recognized. The first clade included Thuja plicata D. Don (western North America) and T. koraiensis Nakai (northeastern Asia), and the second one contained T. occidentalis (Gord.) Cart. (Japan). The ancestral area of Thuja was inferred to be eastern Asia, and two dispersal events were responsible for the modern distribution of Thuja in North America. Both the North Atlantic land bridge and Bering land bridge were possible routes for the migration of ancestral populations to North America.  相似文献   

5.
The phylogeny of Ptychostomum was first spacer (ITS) region of the nuclear ribosomal (nr) DNA DNA rps4 sequences. Maximum parsimony, maximum undertaken based on analysis of the internal transcribed and by combining data from nrDNA ITS and chloroplast likelihood, and Bayesian analyses all support the conclusion that the reinstated genus Ptychostomum is not monophyletic. Ptychostomum funkii (Schwagr.) J. R. Spence (≡ Bryum funkii Schwaigr.) is placed within a clade containing the type species of Bryum, B. argenteum Hedw. The remaining members of Ptychostomum investigated in the present study constitute another well-supported clade. The results are congruent with previous molecular analyses. On the basis of phylogenetic evidence, we agree with transferring B. amblyodon Mull. Hal. (≡ B. inclinatum (Brid.) Turton≡ Bryum archangelicum Bruch & Schimp.), Bryum lonchocaulon Mull. Hal., Bryum pallescens Schleich. ex Schwaigr., and Bryum pallens Sw. to Ptychostomum.  相似文献   

6.
Toxicodendron is a genus in the Rhus complex of Anacardiaceae with a disjunct distribution between eastern Asia and North America, extending to southeastern Asia and the neotropics. Nuclear (internal transcribed spacer, external transcribed spacer, and NIA-i3) and chloroplast (ndhF and trnL-F) sequences were used to construct phylogenetic relationships of Toxicodendron. Phylogenetic analysis of these data strongly support Toxieodendron as a monophyletic group distinct from other genera of the Rhus complex, and the phylogeny does not fully corroborate classification at the sectional level. Two temperate disjunct lineages were detected, one from section Toxicodendron and the other between the eastern North American Toxicodendron vernix and the eastern Asian Toxicodendron vernieifluum. Their divergence times were estimated to be 13.46 (7.95-19.42) and 7.53 (2.76-12.86) mya, respectively. The disjunction between section Griffithii (taxa from warm temperate to tropical Asia) and Toxieodendron striatum (from the neotropics) was supported and their divergence time was estimated to be 20.84 (11.1 6-30.52) mya in the early Miocene. Our biogeographic results and the paleontological data support the Bering land bridge as the most likely route to explain the temperate disjunctions, yet the tropical disjunction in Toxicodendron seems to be best explained by the North Atlantic land bridge hypothesis.  相似文献   

7.
The molecular phylogenetics of sect. Parrya Myre of Pinus L. was analyzed based onchloroplast matKgene sequence data. The section was resolved as paraphyletic because members of thesect. Strobus were nested within a clade composed by the Asian members of the section, including theVietnamese P. krempfii Lecomte, which was strongly supported with a bootstrap value of 92%. [n thistopology, the three sampled species of sect. Strobus formed a strongly supported monophyletic group,while their relationships of Asian species of sect. Parrya were not clear. P. krempfii was grouped with P.gerardiana Wall. ex D. Don with low bootstrap support. The relationships among the Asian members of thesect. Parrya, i.e.P, bungeana Zucc. ex Loud., P. gerardiana and the recently described endangered pine, P.squarnata X. W. Li, was not resolved, although the monophyly of the three pines was strongly supported inthe combined analysis of four cpDNA sequences. The topology of the neighbor joining tree revealed anassemblage of the American members of the section, which also appeared in the majority rule tree withweak bootstrap support. However, this assemblage was not resolved in the consensus tree of theparsimonious analysis. The American subsect. Ba/fourianae Engelm. formed a weakly supported groupincluding P. aristata Engelm., while the relationships among and within the other two American subsections,Cembroides Englem. and tTzedowskianae Carv., were not resolved, as the members of them formed apolytomy in the consensus tree of the parsimonious analysis. The biogeographical implications of theresults are also discussed in this paper.  相似文献   

8.
Aphids harbor primary endosymbionts, Buchnera aphidicola, in specialized cells within their body cavities. Aphids and Buchnera have strict mutualistic relationships in nutrition exchange. This ancient association has received much attention from researchers who are interested in endosymbiotic evolution. Previous studies have foundparallel phylogenetic relationships between non-galling aphids and Buchnera at lower taxonomic levels (genus, species). To understand whether relatively isolated habitats such as galls have effect on the parallel relationships between aphids and Buchnera, the present paper investigated the phylogenetic relationships of gall aphids from Pemphigus and allied genera, which induce pseudo-galls or galls on Populus spp. (poplar) and Buchnera. The molecular phylogenies inferred from three aphid genes (COI, COII and EF-la) andtwo Buchnera genes (gnd, 16S rRNA gene) indicated significant congruence between aphids and Buchnera at generic as well as interspecific levels. Interestingly, both aphid andBuchnera phylogenies supported three main clades corresponding to the galling locations of aphids, namely leaf, the joint of leaf blade and petiole, and branch of the host plant.The results suggest phylogenetic conservatism of gall characters, which indicates gall characters are more strongly affected by aphid phylogeny, rather than host plants.  相似文献   

9.
The achene wail anatomy and surface sculpturing of 14 species representing Lactuca L. and related genera were Investigated to evaluate inter-and Intrageneric relationships. The achene wall anatomy of the studied species can be divided Into two types: winged and ribbed. The winged type is present in Lactuca L., Pterocypsela Shlh, Clcerblta Wallr., Chaetoserls Shlh and Stenoseris Shlh, and is characterized by protruding wings and costae in transverse section. Winged type achene mesocarps are composed of parenchymatous cells and fiber ceils, and the distinct fibrous strands are confined to the costae or wings of the achenes. The ribbed type is present in Notoseris Shih and Paraprenanthes Chang ex Shih, and Is characterized by only having costae In transverse section. Fiber cells are continuous in the costae and intercostae, in surface sculpturing, the ornamentation and the shape of epidermal cells are different among these genera. The results Indicate that L. altalca and L. serrlola should be conspeclfic, and that L. dollchophylla is probably an Intermediate taxon between Lactuca and Chaetoserls. The results also support the separation of Pterocypseia, Paraprenanthes, Notoseris, Chaetoseris and Stenoserls from Lactuca and Clcerblta as independent entitles. Close affinities between Pterocypsela and Lactuca, Paraprenanthes and Notoserls, and Chaetoserls and Stenoserls are also proposed.  相似文献   

10.
蝉科昆虫在自然界具有重要作用,是果树等林木的刺吸性害虫,同时蝉与真菌组成的虫菌共生体也具有重要经济价值。近十年来,通过对我国昆虫病原真菌资源的调查,共采集获得102株蝉科昆虫罹患病原真菌标本,并保存于安徽农业大学昆虫病原真菌研究中心(RCEF)。本研究从蝉科罹患病原真菌标本中分离得到81株菌株,并对其多样性进行了研究。基于不同培养基的形态特征观察并结合ITS、SSU、LSU、TEF、RPB1和RPB2基因构建系统发育树,发现寄生蝉科的菌株属于3科6属15种。本研究重点描述了一个中国新记录种——高水紫孢菌;此外,一些类棒束孢属菌株被修订为蝙蝠蛾萨姆森菌;除上述物种外,还鉴定出球孢白僵菌、绿色绿僵菌、蝉花虫草、柱孢绿僵菌、环链虫草、玫烟色虫草、澳洲白僵菌、布氏白僵菌、细脚虫草、棕色绿僵菌和长座细虫草。其中球孢白僵菌、蝉花虫草和绿色绿僵菌是优势种,多度达总数的58%。而其他12个物种分离频率较低。  相似文献   

11.
Leibnitzia comprises six species of perennial herbs that are adapted to high elevation conditions and is one of only two Asteraceae genera known to have an exclusively disjunct distribution spanning central to eastern Asia and North America. Molecular phylogenetic analysis of Leibnitzia and other Gerbera-complex members indicates that Leibnitzia is monophyletic, which is in contrast with our expectation that the American Leibnitzia species L. Lyrata and L. Occimadremis would be more closely related to another American member of the Gerbera-complex, namely Chaptalia. Ancestral area reconstructions show that the historical biogeography of the Gerbera-complex mirrors that of the entire Asteraceae, with early diverging lineages located in South America that were followed by transfers to Africa and Eurasia and, most recently, to North America. Intercontinental transfer of Leibnitzia appears to have been directed from Asia to North America. Independent calibrations of nuclear (ribosomal DNA internal transcribed spacer region) and chloroplast (trnL-rpl32 intron) DNA sequence data using relaxed clock methods and either mean rate or fossil-based priors unanimously support Miocene and younger divergence times for Gerbera-complex taxa. The ages are not consistent with most Gondwanan vicariance episodes and, thus, the global distribution of Gerbera-complex members must be explained in large part by long-distance dispersal. American species of Leibnitzia are estimated to have diverged from then- Asian ancestor during the Quaternary (ca. 2 mya) and either migrated overland to North America via Beringia and retreated southwards along high elevation corridors to their- present location in southwestern North America or were dispersed long distance.  相似文献   

12.
The evolution of the inflorescence head in Asteraceae is important in the diversification of this largest angiosperm family. The aggregation of heads into higher-order capitulescences (secondary heads or syncephalia) is considered evolutionarily advanced. The genera Moscharia, Nassauvia, Polyachyrus, and Triptilion of the subtribe Nassauviinae (Mutisieae) have syncephalia with differing degrees of capitula condensation. ITS and plastid trnL-trnF regions were analyzed separately and together using maximum parsimony and maximum likelihood to examine the evolution of syncephalia in the Nassauviinae. The four genera displaying syncephalia do not form a clade minus taxa without syncephalia, indicating that secondary heads in Nassauviinae have either convergently evolved twice in the subtribe (or, very unlikely) once with multiple reversions. Strong support was obtained for a sister relationship between Leucheria (without syncephalium) and Polyachyrus, and both sister to Moscharia. Nassauvia and Triptilion form a distinct clade but are sister to other genera, Perezia and Panphalea, without syncephalium. Previous hypotheses postulated the evolution from simple to more complex secondary heads. We show that the ancestor of Moscharia, Polyachyrus, and Leucheria, in a more arid habitat, had a complex type of secondary head, and loss of complexity occurred in response to a shift from arid to mesic conditions.  相似文献   

13.
Abstract Leibnitzia comprises six species of perennial herbs that are adapted to high elevation conditions and is one of only two Asteraceae genera known to have an exclusively disjunct distribution spanning central to eastern Asia and North America. Molecular phylogenetic analysis of Leibnitzia and other Gerbera‐complex members indicates that Leibnitzia is monophyletic, which is in contrast with our expectation that the American Leibnitzia species L. lyrata and L. occimadrensis would be more closely related to another American member of the Gerbera‐complex, namely Chaptalia. Ancestral area reconstructions show that the historical biogeography of the Gerbera‐complex mirrors that of the entire Asteraceae, with early diverging lineages located in South America that were followed by transfers to Africa and Eurasia and, most recently, to North America. Intercontinental transfer of Leibnitzia appears to have been directed from Asia to North America. Independent calibrations of nuclear (ribosomal DNA internal transcribed spacer region) and chloroplast (trnLrpl32 intron) DNA sequence data using relaxed clock methods and either mean rate or fossil‐based priors unanimously support Miocene and younger divergence times for Gerbera‐complex taxa. The ages are not consistent with most Gondwanan vicariance episodes and, thus, the global distribution of Gerbera‐complex members must be explained in large part by long‐distance dispersal. American species of Leibnitzia are estimated to have diverged from their Asian ancestor during the Quaternary (ca. 2 mya) and either migrated overland to North America via Beringia and retreated southwards along high elevation corridors to their present location in southwestern North America or were dispersed long distance.  相似文献   

14.
15.
Fossil pollen grains with morphological features unique in the subtribe Nassauviinae (tribe Mutisieae, Asteraceae) occur in Miocene marine deposits of eastern Patagonia, southern South America. A new morphogenus and two morphospecies are proposed to assemble fossil pollen grains characterized by having a complex bilayered exine structure with delicate columellae, separated by an internal tectum. Subprolate specimens with Trixis exine type (ectosexine thinner than endosexine, straight internal tectum) are referred to Huanilipollis cabrerae. This species is similar to pollen of recent Holocheilus, Jungia, and Proustia. Suboblate specimens with Oxyphyllum exine type (ectosexine and endosexine equally thick, zigzag internal tectum) are referred to Huanilipollis criscii. This species is similar to pollen of recent Triptilion. The spore/pollen sequences in which Nassauviinae pollen types occur suggest a wide range of vegetation types varying from forest dominated during the Early Miocene (Chenque Formation) to virtually xerophytic ones during the Late Miocene (Puerto Madryn Formation). The subtribe Nassauviinae comprises 25 genera and ca. 320 species of vines, shrubs and low trees endemic to America with a wide range of ecological preferences; the nearest living relatives of the fossil types being mostly confined to humid landscapes. The unusual occurrence of these groups during the arid characterized Late Miocene time could be attributed to the complex interplay of the mountain uplift and global circulation patterns. These forcing factors would have created a mosaic of different habitats with both patches of forest and dry-adapted species developing in relatively small regions. This is the first fossil record of Nassauviinae and confirms that this subtribe of Asteraceae was already differentiated in the Miocene.  相似文献   

16.
Six Mexican species ofAcourtia are described. One of these novelties seems to be related toAcourtia mexicana (Lag. ex D. Don) H. Rob., whose nomenclature has been misunderstood for decades; an exhaustive literature review and examination of herbarium material supports Robinson’s combination.
Resumen  Se describen seis nuevas especies mexicanas deAcourtia. Una de estas novedades parece estar relacionada conAcourtia mexicana (Lag. ex D. Don) H. Robinson, especie cuya nomenclatura ha sido mal interpretada por décadas; una exhaustiva revisión de la literatura así como de material de herbario, apoyan la combinación de Robinson.
  相似文献   

17.
Penalized likelihood analysis of previously published chloroplast DNA (cpDNA) ndhF sequences suggests that the central-southern Andean genus Chaetanthera diverged ca. 16.5 million years (my) ago, well before the uplift of the Andes to their present heights. Penalized likelihood analysis based on new nuclear ribosomal DNA (rDNA) internal transcribed spacer (ITS) sequences indicates that the most relictual lineages occupy high elevation Andean habitats that did not exist until some 10my later. This result is contrary to the expectation that younger habitats should be occupied by phylogenetically younger lineages. The results are interpreted with respect to the development of aridity in lowland habitats during the Miocene and Pliocene, which presumably extinguished the lowland relatives of the high elevation taxa or, in effect, forced them upwards in search of adequate moisture. As the more northerly lineages were being displaced upward, others diversified in the mediterranean-type climate area of central Chile, giving rise to additional high elevation taxa again, at an early date, as well as lowland taxa. Some species of Chaetanthera from lowland central Chile appear as the phylogenetically youngest taxa, suggesting secondary adaptation to lowland aridity. At the same time, at least two high elevation species, Chaetanthera peruviana and Chaetanthera perpusilla, appear to have been derived recently from a lower elevation ancestor, while some middle to low elevation taxa seem to have evolved recently out of a high elevation complex. The results suggest that the younger high elevation habitats have served as both "cradle" and "museum" for Chaetanthera lineages.  相似文献   

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19.
The nuclear ribosomal ITS region and the chloroplast trnL-trnF (trnLF) intergenic region were sequenced for 45 accessions of Paranephelius and six accessions of Pseudonoseris, the two genera of the subtribe Paranepheliinae (Liabeae, Asteraceae) distributed in the alpine regions of the Andes. This data set was used to estimate relationships between these genera and within each genus to aid in evaluating morphological variation and classification. Our results with both ITS and trnLF markers support the monophyly of subtribe Paranepheliinae, and place Pseudonoseris discolor as the first diverged taxon sister to the clade containing Paranephelius. Pseudonoseris szyszylowiczii exhibited intraspecific divergence supporting intergeneric hybridization between Pseudonoseris and Paranephelius. Within Paranephelius, genetic divergence is low and not adequate to fully resolve phylogenetic relationships at the species level, but two genetically and morphologically recognizable groups were revealed by the ITS data. Several accessions possessing multiple ITS sequences represent putative hybrids between the two groups. These putative hybrids have caused some taxonomic confusion and difficulties in establishing species boundaries in Paranephelius. The divergence time estimates based on ITS sequences indicated that the stem of subtribe Paranepheliinae dates to 13 million years ago, but the diversification of the crown clade of the extant members began in the early Pleistocene or late Pliocene, perhaps associated with the uplift of the Andes and the climatic changes of global cooling.  相似文献   

20.
Philonthina (2864 species in 74 genera) represents almost one-half of the diversity of Staphylinini and is the largest of its subtribes. Most Philonthina species are found in tropical areas, but the origin of this diversity is still not well understood, mainly because their systematics belongs to a past era of taxonomy. Such is the case of a group of genera, most of them endemic to the Neotropical region (NT), whose monophyly has been repeatedly confirmed and which constitutes the so-called Neotropical lineage (NL). However, basal relationships have not been clarified, neither for Philonthina nor its NL. The NL includes ∼300 species and 26 genera, but two of them (Belonuchus Nordmann and Paederomimus Sharp) account for two-thirds of its species. Here, using the largest molecular-based phylogeny of Philonthina and its NL to date, a time-calibrated phylogeny, and ancestral range reconstructions for the NL, we explore the evolutionary history of Philonthina with a focus on its NL to reveal their early evolution and diversification in the NT. We show that Philonthina originated during the Late Cretaceous ∼ 67.6 Ma and diversified into five main lineages mostly during the Eocene. The NL originated in northwestern South America (SA) and the Andes not earlier than 64.2 Ma from a Laurasian lineage present in SA ∼49.1–69.9 Ma. Shortly afterward, that is, 39.9–56.9 Ma, the NL diversified into the Andean clade and the most species-rich Belonuchus-Paederomimus group. Our analyses recover northwestern SA and the Andes as the primary centers of diversification. Dispersal events to the northern landmasses took place at least three times during the Miocene in the early evolution of the NL.  相似文献   

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