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1.
Various approaches have been developed to define conservation units for plant and animal species. In this study we combined
nuclear microsatellites (from a previous published study) and chloroplast microsatellites (assessed in the present study),
leaf and seed morphology traits and abiotic variables (climate and soil) to define evolutionary significant units (ESU) of
Santalum austrocaledonicum, a tree species growing in New Caledonia. Results for chloroplast microsatellites showed that the total population heterozygosity
was␣high, (H
cp = 0.84) but varied between islands. Differentiation was strong in the total population (F
stcp = 0.66) but also within the main island Grande Terre (F
stcp = 0.73) and within Iles Loyauté (F
stcp = 0.52), highlighting a limited gene flow between populations. These results confirmed those obtained with nuclear microsatellites.
The cluster analysis on molecular markers discriminated two main groups constituted by the populations of Grande Terre and
the populations of Iles Loyauté. A principal component analysis of leaf and seed morphology traits singled out the populations
of Iles Loyauté and the western populations of Grande Terre. Quantitative genetic analyses showed that the variation between
populations was under genetic control (broad sense heritability close to 80%). A high correlation between rainfall and morphological
traits suggested an impact of climate on this variation. The integration of these results allows to define two ESUs, one corresponding
to Grande Terre and Ile des Pins and the other the Iles Loyauté archipelago. This study stresses the need to restore some
populations of Grande Terre that are currently threatened by their small size. 相似文献
2.
Y. Frenot M. Aubry M. T. Misset J. C. Gloaguen J. P. Gourret M. Lebouvier 《Polar Biology》1999,22(5):302-310
The widely distributed grass, Poa annua, is one of the most common alien species in the subantarctic islands. The historical events of its introduction remain generally
unknown, as well as the evolutionary consequences of its colonisation in these remote environments. Populations from the Crozet
archipelago and Kerguelen Islands were compared in terms of morphology, cytogenetics and enzyme polymorphism. Seeds from natural
populations were also sown in an experimental garden in France to test phenotypic plasticity. This preliminary study demonstrated
the high phenotypic plasticity in P. annua in the French subantarctic islands. This plasticity and allotetraploidy could be important factors which reinforce the colonising
capacities of P. annua. Our results revealed the low genetic diversity of the populations analysed, which could be related to the founding effect
or to the fragmentation of the populations.
Accepted: 25 April 1999 相似文献
3.
Tobias Pfingstl Andrea Lienhard Satoshi Shimano Zulfigar Bin Yasin Aileen Tan Shau‐Hwai Sopark Jantarit Booppa Petcharad 《Journal of Zoological Systematics and Evolutionary Research》2019,57(1):91-112
This study demonstrates for the first time the presence of marine‐associated mites in the Andaman Sea and Strait of Malacca and reveals a relatively high diversity of these taxa with six species from two different families: Selenoribatidae and Fortuyniidae. Indopacifica, a new genus of Selenoribatidae, is described from Thailand and Malaysia, with two new species, Indopacifica pantai n. sp. and Indopacifica parva n. sp. The genus is characterized by the unique combination of following characters: lacking lamellar ridges, incomplete dorsosejugal suture, fourteen pairs of notogastral setae, and presence of epimeral foveae. A phylogenetic reconstruction based on 18S ribosomal RNA sequences clearly confirms the distinctness of the new genus Indopacifica and places it close to the genus Rhizophobates. The lack of molecular genetic data of possible relatives impedes a clear assessment, and hence, we emphasize the need for further combined approaches using morphological and molecular genetic sequence data. All species show wide distribution areas within this geographic region suggesting that these taxa are good dispersers despite their minute size and wingless body. Molecular genetic data demonstrate recent gene flow between far distant populations of I. pantai n. sp. from the coasts of Thailand and two islands of Malaysia and hence confirm this assumption. The seasonally changing surface currents within this geographic area may favor hydrochorous dispersal and hence genetic exchange. Nevertheless, morphometric data show a slight trend to morphological divergence among the studied populations, whereas this variation is suggested to be a result of genetic drift but also of habitat differences in one population of Alismobates pseudoreticulatus. 相似文献
4.
Beno?t Pisanu St��phane Caut Sylvain Gutjahr Philippe Vernon Jean-Louis Chapuis 《Polar Biology》2011,34(2):169-180
Rats introduced on islands can affect ecosystem structure and function by feeding on terrestrial plants and both marine and
terrestrial animals. The diet and trophic position of Rattus rattus introduced on Ile de la Possession (Iles Crozet) was assessed from two sites, according to the presence or absence of a king
penguin colony. We used three complementary assays: macroanalyses of the stomach, faecal microhistology, and stable isotope
analyses of δ15N/δ13C in liver. Near the rookery, spermatophytes contributed on average 50% (confidential interval: 23–75) to the diet based on
isotopes, mainly consisting in reproductive parts of Poa spp., Agrostis magellanica, and Cerastium fontanum identified in faeces. Terrestrial animal preys were represented by insects that contributed 25% (0–56) in isotopes, dominated
in faeces by caterpillars of Pringleophaga spp. and adult weevils. Bird remains were found in faeces, forming 18% (6–30) of isotopes. Terrestrial earthworms contributed
to 7% (0–21), with chaetae observed in faeces. On the other site, spermatophytes represented 62% (51–73) of assimilated food
in rats’ livers, mainly formed by Poaceae and Acaena magellanica, insects by caterpillars [24% (10–39)], and terrestrial earthworms [13% (2–23)]. Our results suggest that rats, which were
found at the top of terrestrial food chains, may have a direct role on a such simplified ecosystem, by preying on the most
abundant and largest body-sized terrestrial invertebrates,—e.g. the keystone species Pringleophaga spp.—, and by feeding on both reproductive and vegetative parts of autochthonous and introduced plants. The discrepancies
and usefulness of employing both isotopes and faecal analyses are discussed. 相似文献
5.
Genetic structure of Micromeria (Lamiaceae) in Tenerife,the imprint of geological history and hybridization on within‐island diversification
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Geological history of oceanic islands can have a profound effect on the evolutionary history of insular flora, especially in complex islands such as Tenerife in the Canary Islands. Tenerife results from the secondary connection of three paleo‐islands by a central volcano, and other geological events that further shaped it. This geological history has been shown to influence the phylogenetic history of several taxa, including genus Micromeria (Lamiaceae). Screening 15 microsatellite markers in 289 individuals representing the eight species of Micromeria present in Tenerife, this study aims to assess the genetic diversity and structure of these species and its relation with the geological events on the island. In addition, we evaluate the extent of hybridization among species and discuss its influence on the speciation process. We found that the species restricted to the paleo‐islands present lower levels of genetic diversity but the highest levels of genetic differentiation suggesting that their ranges might have contracted over time. The two most widespread species in the island, M. hyssopifolia and M. varia, present the highest genetic diversity levels and a genetic structure that seems correlated with the geological composition of the island. Samples from M. hyssopifolia from the oldest paleo‐island, Adeje, appear as distinct while samples from M. varia segregate into two main clusters corresponding to the paleo‐islands of Anaga and Teno. Evidence of hybridization and intraspecific migration between species was found. We argue that species boundaries would be retained despite hybridization in response to the habitat's specific conditions causing postzygotic isolation and preserving morphological differentiation. 相似文献
6.
The genetic diversity and genetic relatedness of mei (Prunus mume; 2n = 16) were studied using amplified fragment length polymorphism (AFLP) markers. Eight EcoRI–PstI AFLP primer combinations were applied to 121 distinct genotypes of mei cultivars and related species. A total of 508 AFLP
product bands were produced, of which 382 were polymorphic. The unweighted pair group method with arithmetic averages analysis
was carried out based on these AFLP markers. From this analysis, “Qugeng Mei,” “Yan Mei,” “Chaodou Mei,” and mei cultivars
were seen to share the same P. mume genetic stem. The AFLP data were able to clearly discriminate P. mume from other species in the genus Prunus, with P. armeniaca aligning as its closest related species. Two major groups and nine subgroups of mei flower were identified, and there was
a strong coincidence of these AFLP-based groupings with the respective morphological characters of the accessions. The genetic
diversity of mei accessions was greatest in the Yunnan Province and decreased toward Eastern China and Japan, so supporting
the hypothesis that the southwest of China represents the genetic diversity center of the species. 相似文献
7.
In the fell-field habitat at 140–270 m altitude on the sub-Antarctic Ile de la Possession, Iles Crozet, the dimorphic beetle
Amblystogenium pacificum Putzeys (Coleoptera: Carabidae) was studied monthly throughout the southern year 1993–1994 by timed hand collections involving
turning stones on the rocky fell-field. There were many mating couples and females containing well-developed eggs in every
month and the species reproduced throughout the year, with no evidence of a winter cessation of egg production. However, the
frequency of mating couples was about twice as great in the summer half-year (October–March) as in the winter half (April–September).
Relatively small differences in monthly mean temperatures between the summer and winter at Iles Crozet render all-year reproduction
not unexpected when comparisons are made with the temperatures and phenology of Carabidae in cool habitats in other parts
of the world. Mating pairs were collected at unusually high frequencies for carabids. The frequency of such pairs, taken per
unit effort by hand collecting, was highest in October–December, lower from January to May and intermediate from June to September.
Comparison of beetles taken as solitary, non-mating individuals with those taken as mating couples showed that in summer,
females of the black morph of this dimorphic species were more frequently involved in mating than expected, but no differences
were detected in winter. Female beetles were divided into younger individuals (putative age 1–2 years) and older females (putative
age 3–5 years or more) by the amount of claw-wear on individuals of this species. This division indicated that about 40% of
the older females showed no egg development when captured, but only about 20% of the younger females were non-breeding. However,
of the reproducing beetles, young and old females matured similar numbers of eggs. An altitude transect showed that the proportion
of the black morph increased significantly with altitude. Studies at 140–270 m showed that a significantly smaller proportion
of the older females of the brown morph were breeding than in the younger brown individuals, and this effect was particularly
evident in the colder winter period. No such age differences existed amongst the black morph. 相似文献
8.
Introgressive hybridization occurs when closely related taxa overlap in distribution and is often associated with historically
isolated populations coming into contact as a result of anthropogenic disturbance. There is evolutionary and conservation
interest in detecting hybridization to determine its implications on future species composition, especially for threatened
and recovering taxa such as subantarctic (Arctocephalus tropicalis) and Antarctic (A. gazella) fur seals, which were driven to the brink of extinction by human exploitation. Hybridization between these species has been
reported at two locations and they breed sympatrically at a third site, Iles Crozet. While hybrid individuals have previously
been identified based on phenotype, individuals can be difficult to classify based on these characteristics alone. Genotypic
hybrid identification has been successful in several species, including fur seals. In this study we conducted an assignment
test using microsatellite data to identify hybrids and to measure the frequency of hybridization at Iles Crozet. Samples were
collected from 372 individuals and screened with 6 polymorphic microsatellite markers. MtDNA genotypes were also determined
for individuals identified as hybrids or backcrosses based on microsatellite genotype. Phenotype, microsatellite and mtDNA
genotype were then compared in order to identify hybrids. The results indicate that 1% of the population have hybrid genotypes
and at a minimum, 2.4% of the population are backcrossed to parental species. We found that the two species are genetically
distinct from one another and given the low rate of hybridization it is unlikely that they will fuse. These results suggest
that there is a mechanism for species recognition that acts as a barrier to hybridization. It therefore seems unlikely that
fur seals are threatened by significant introgression. Further investigation of fur seal mating systems would provide valuable
insight into the mechanisms governing hybridization and species recognition in mate choice. 相似文献
9.
Wynen LP Goldsworthy SD Guinet C Bester MN Boyd IL Gjertz I Hofmeyr GJ White RW Slade R 《Molecular ecology》2000,9(3):299-314
Commercial sealing in the 18th and 19th centuries had a major impact on the Antarctic and subantarctic fur seal populations (Arctocephalus gazella and A. tropicalis) in the Southern Ocean. The intensive and unrestricted nature of the industry ensured substantial reductions in population sizes and resulted in both species becoming locally extinct at some sites. However, both species are continuing to recover, through the recolonization of islands across their former range and increasing population size. This study investigated the extent and pattern of genetic variation in each species to examine the hypothesis that higher levels of historic sealing in A. gazella have resulted in a greater loss of genetic variability and population structure compared with A. tropicalis. A 316-bp section of the mitochondrial control region was sequenced and revealed nucleotide diversities of 3.2% and 4.8% for A. gazella and A. tropicalis, respectively. There was no geographical distribution of lineages observed within either species, although the respective PhiST values of 0.074 and 0.19 were significantly greater than zero. These data indicate low levels of population structure in A. gazella and relatively high levels in A. tropicalis. Additional samples screened with restriction endonucleases were incorporated, and the distribution of restriction fragment length polymorphism (RFLP) and sequence haplotypes were examined to identify the main source populations of newly recolonized islands. For A. tropicalis, the data suggest that Macquarie Island and Iles Crozet were probably recolonized by females from Marion Island, and to a lesser extent Ile Amsterdam. Although there was less population structure within A. gazella, there were two geographical regions identified: a western region containing the populations of South Georgia and Bouvetoya, which were the probable sources for populations at Marion, the South Shetland and Heard Islands; and an eastern region containing the panmictic populations of Iles Kerguelen and Macquarie Island. The latter region may be a result of a pronounced founder effect, or represent a remnant population that survived sealing at Iles Kerguelen. 相似文献
10.
Vicariance and isolation leading to speciation of reptiles on islands is well exemplified in a number of taxa in the Caribbean. The St. Lucia whiptail (Cnemidophorus vanzoi), considered a single species, is found on two small islets (Maria Major and Maria Minor) off the main island of St. Lucia. From lizards collected from both localities, we gathered morphological measurements and analysed the genetic divergence between populations, using a molecular survey of ∼
∼2800 mtDNA base pairs and 8 microsatellites. There are significant differences in body size and general form and fixed but small mtDNA differences between island populations. Microsatellites reveal low diversity within populations but very high differentiation between islands with non-overlapping allele size ranges at all except one microsatellite and two loci exhibiting single-base polymorphism, fixed between islands. Based on these results, we examine published criteria to determine whether the studied island forms could be considered true species. According to the phylogenetic species concept and Moritz’s evolutionary significant unit (ESU) criteria, the two lizard populations can be considered separate entities. Crandall et al.’s (2000, Trends Ecol. Evol., 15, 290–295) broader categorization of population distinctiveness, based on concepts of ecological and genetic exchangeability, produces conflicting results depending on the interpretation of the observed ecological data. Following Fraser and Bernatchez’s (2001, Mol. Ecol., 10, 2741–2752) framework for management decisions when ecological data are not sufficient we propose that the lizard populations on the Maria islands are on differing evolutionary trajectories and thus at the species boundary. The populations are of high priority to conservation, thus meriting separate management. 相似文献
11.
Morphological and electrophoretic data were studied to examine species delimitation, patterns of morphological and genetic
variation in three Korean Hepatica including two endemics, H.␣maxima and H. insularis. Based on a phenogram using 15 morphological characters, taxa were distinct; it was consistent with the phenogram based on
genetic distance. In the enzyme electrophoresis study, the genetic identities suggested that three taxa were genetically divergent
enough to be recognized as different species, falling within the range expected␣for congeners. The genetic identity between
H.␣asiatica and H. insularis was higher than the values between these two taxa and H.␣maxima, a restricted endemic of Ulleung Island. The least genetic variation was found in H. maxima and the greatest in widespread H. asiatica. These data are consistent with theoretical expectations that small populations are more likely to be genetically depauperate.
Received November 13, 2001; accepted May 10, 2002 Published online: December 11, 2002 相似文献
12.
A. C. Roa M. M. Maya M. C. Duque J. Tohme A. C. Allem M. W. Bonierbale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(5-6):741-750
Despite the worldwide importance of cultivated cassava (M. esculenta Crantz) its origin and taxonomic relationships with other species in the genus have not been clearly established. We evaluated
a representative sample of the crop’s diversity and six wild taxa with AFLPs to estimate genetic relationships within the
genus. Groupings of accessions of each species by data analysis corresponded largely with their previous taxonomic classifications.
A mixed group, consisting of Manihot esculenta subsp. flabellifolia and M. esculenta subsp. peruviana, was most similar to cassava, while M. aesculifolia, M. brachyloba, and M. carthaginensis were more distant. Species-specific markers, which may be useful in germ-plasm classification or introgression studies, were
suggested by the unique presence of AFLP products in samples of each of the three wild species. Heterogeneity of similarities
among individuals of certain species suggested the existence of intraspecific gene pools, a hypothesis that was supported
by morphological or ecogeographic evidence with varying degrees of success. Quantitative assessment of genetic diversity revealed
greater homogeneity among cassava accessions than among itsclosest wild relatives. The demonstration of unique genetic diversity
in the two M. esculenta subspecies and their genetic similarity to the crop supports the hypothesis that these materials may be the ancestors of
cassava.
Received: 4 November 1996 / Accepted: 20 December 1996 相似文献
13.
Javier Francisco-Ortega Daniel J. Crawford Arnoldo Santos-Guerra Jose A. Carvalho 《Plant Systematics and Evolution》1996,202(3-4):137-152
The genusArgyranthemum (Asteraceae: Anthemideae) comprises 38 taxa and is restricted to the archipelagos of the Canaries, Selvagens, Madeira, and Desertas in the Macaronesian biogeographic region. An electrophoretic study, including 17 enzyme loci and at least one population of each of the described taxa, was carried out. High identity (low distance) values between taxa (mean of 0.893) were obtained despite the old age of the islands, their close proximity to the African continent, and the fact thatArgyranthemum is the most species-rich and variable genus in Macaronesia. These results suggest that the genus is monophyletic and that it has evolved very rapidly in these islands. There is little correspondence between taxonomy and neighbor-joining analysis based on Roger's genetic distances, but in several instances populations from the same islands cluster together despite being from different species or even different sections. It is suggested that repeated genetic bottlenecks associated with the founding of new populations during radiation of the genus resulted in lineage sorting of ancestral allozyme polymorphisms. Because every population has a high average identity with all other populations, lineage sorting could result in populations of different taxa being slightly more similar than populations of the same taxon. Gene flow between different species on the same island could account for some populations clustering by island of origin rather than taxonomic disposition. Average allozyme diversity within populations (0.098) is 50% higher than the mean total diversity for species endemic to oceanic islands. 相似文献
14.
Kim SC 《Journal of plant research》2012,125(1):125-136
Despite numerous, well-documented evolutionary histories of plant groups which underwent rapid radiation in various oceanic
archipelagos, very little is known about the genetic basis of species differences and adaptive radiation. This paper represents
the first such study in the Macaronesian Islands using non-model endemic plants, the woody Sonchus alliance. Here I inferred the genetic basis of species differences between two Canary Island endemics, the herbaceous perennial,
shade tolerant Lactucosonchus webbii and the woody, coastal desert perennial Sonchus radicatus by quantitative trait locus (QTL) mapping using AFLP markers. A total of 23 QTL (7.3–23.8% PVE; phenotypic variance explained)
for 11 morphological traits were found, one for flowering time (31% PVE), and five QTL (7–10.7% PVE) for two physiological
traits (intrinsic water use efficiency and stomatal conductance). Interpreted cautiously, these results suggest that major
morphological and some physiological differences between the two species are controlled by numerous genes with small to moderate
effect. This implies that major morphological changes in island plants can be more complex than suggested by other studies,
such as in Tetramolopium in the Hawaiian Islands. The genetic basis of arborescence on islands, one of the most spectacular convergent features of
plants across different lineages and archipelagos, is also discussed. 相似文献
15.
Chaetomium is a fungus species that inhabits different cellulose substrates. Some species of this genus destroy books, textile, and
wood. This genus is of particular interest due to its antagonistic and enzyme peculiarities. Studies on morphological and
cultural features of Chaetomium species have both theoretical and practical output. Growth rates and development of C. globosum, C. funicola, C. elatum, and C. spirale were studied under different temperatures (17–20°C, 25°C, 27°C, 30°C, and 33–35°C) and carbon source media (glucose, saccharose,
mannite, lactose, amylum, and cellulose). The optimal growth temperature was 25–27°C for all the studied species, while the
temperature range of 33–35°C inhibited the colonies’ growth. Growth dynamics and colony shape and morphology, as well as development
of overhead mycelium and ascocarps, varied greatly in different Chaetomium species in regard to the carbon source media. When comparing the destructive effect of four studied species and C. murorum on craft paper, the highest activity was registered for C. globosum, C. funicola, and C. elatum. 相似文献
16.
Heriberto López Hermans G. Contreras-Díaz Pedro Oromí Carlos Juan 《Conservation Genetics》2007,8(3):587-598
Mitochondrial DNA cytochrome oxidase subunit I and nuclear ITS2 sequences were surveyed from Canary Islands threatened species
of the genera Purpuraria and Acrostira (Orthoptera: Pamphagidae). Phylogenetic and population analyses show that the two previously recognized Purpuraria erna subspecies are not valid as conservation units, and that there is a new unrecognized species of Purpuraria, coincident with recently discovered morphological variation within the genus. In addition, mitochondrial introgression seems
to occur between the two Purpuraria species in southwest Lanzarote. Species-delimitation based on the morphological taxonomy of Acrostira, which recognizes four single-island endemics, is only partially supported by the genetic data. It shows that currently admitted
species from the central and western islands of Tenerife, La Gomera and La Palma are closely related, with evidence of recent
gene flow between the Tenerife and La Gomera populations. MtDNA variation also showed that A. euphorbiae, currently considered as the most critically endangered grasshopper species in the Canaries, has lower population diversity
than its close relatives. 相似文献
17.
Integrated species delimitation and conservation implications of an endangered weevil Pachyrhynchus sonani (Coleoptera: Curculionidae) in Green and Orchid Islands of Taiwan
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YEN‐TING CHEN HUI‐YUN TSENG MING‐LUEN JENG YONG‐CHAO SU WEN‐SAN HUANG CHUNG‐PING LIN 《Systematic Entomology》2017,42(4):796-813
Oceanic islands are productive habitats for generating new species and high endemism, which is primarily due to their geographical isolation, smaller population sizes and local adaptation. However, the short divergence times and subtle morphological or ecological divergence of insular organisms may obscure species identity, so the cryptic endemism on islands may be underestimated. The endangered weevil Pachyrhynchus sonani Kôno (Coleoptera: Curculionidae: Entiminae: Pachyrhynchini) is endemic to Green Island and Orchid Island of the Taiwan‐Luzon Archipelago and displays widespread variation in coloration and host range, thus raising questions regarding its species boundaries and degree of cryptic diversity. We tested the species boundaries of P. sonani using an integrated approach that combined morphological (body size and shape, genital shape, coloration and cuticular scale), genetic (four genes and restriction site‐associated DNA sequencing, RAD‐seq) and ecological (host range and distribution) diversity. The results indicated that all the morphological datasets for male P. sonani, except for the colour spectrum, reveal overlapping but statistically significant differences between islands. In contrast, the morphology of the female P. sonani showed minimum divergence between island populations. The populations of P. sonani on the two islands were significantly different in their host ranges, and the genetic clustering and phylogenies of P. sonani established two valid evolutionary species. Integrated species delimitation combining morphological, molecular and ecological characters supported two distinct species of P. sonani from Green Island and Orchid Island. The Green Island population was described as P. jitanasaius sp.n. Chen & Lin, and it is recommended that its threatened conservation status be recognized. Our findings suggest that the inter‐island speciation of endemic organisms inhabiting both islands may be more common than previously thought, and they highlight the possibility that the cryptic diversity of small oceanic islands may still be largely underestimated. 相似文献
18.
Reduced dispersability of species living on islands relative to mainland has been documented in both plants and animals. One
evolutionary scenario explains this trend by strong selection against dispersal, once the species has reached the island,
to reduce dispersal out to sea. In this study, we compare the dispersal ability of three wind dispersed plant species (Cirsium arvense, Epilobium angustifolium, and E. hirsutum) from populations on mainland and three islands. Dispersal ability was estimated directly as drop time of diaspores, and
indirectly using a morphological measure relating the weight of the diaspore to the size of the pappus (Cirsium) or seed hairs (Epilobium). Positive correlation between the morphological measure of dispersal ability and drop time of diaspores were found for all
study species. Dispersal ability varied significantly among mainland and islands, and among species. C. arvense showed a significant reduction in dispersal ability on islands compared to mainland, whereas the reverse was found for the
two Epilobium species. Overall Epilobium diaspores had a 2–4 times higher dispersability than C. arvense, indicating that degree of isolation of islands vary among study species. Significant differences in dispersability among
plants within populations were detected in all species suggesting that this trait may have a genetic component. 相似文献
19.
Leptusa atriceps and L. antarctica, flightess representatives of the nearly global genus Leptusa in the remote and widely distributed subantarctic islands, are taxonomically revised. Identity and the widely disjunct distribution of L. atriceps on Falkland, South Georgia, Marion, Crozet and Kerguelen Islands are confirmed. Leptusa antarctica is found to be a complex of five species restricted to the subantarctic islands of New Zealand. Two of these species, L. sparsepunctata and L. nesiotes are here reinstated from synonymy and two others, Leptusa insulae sp. nov. and Leptusa steeli sp. nov., are described as new to science. The monophyly of subantarctic Leptusa species united in the subgenus Halmaeusa was determined by a phylogenetic study of five exemplar homalotine genera and 17 representatives of Leptusa from South America and the Holarctic based on 76 adult morphological characters. Phylogenetic placement of Halmaeusa was not firmly established. Nanoglossa, a temperate South American subgenus of Leptusa was found as a possible sister group to Halmaeusa. The distribution of Halmaeusa species with two to four species that occur sympatrically on Campbell and Auckland Islands, and other species distributed across several remote islands, provides a framework for future biogeographic study of the subantarctic Leptusa.
http://www.zoobank.org/urn:lsid:zoobank.org:act:82509B9D-4BF6-47E1-B6F7-396ED193A0FA; http://www.zoobank.org/urn:lsid:zoobank.org:act:40A3D6FC-27FF-4070-88CA-1B519ABE760A 相似文献
20.
Genetic structuring of important medicinal species of genus Warburgia as revealed by AFLP analysis 总被引:1,自引:1,他引:0
A. Muchugi G. M. Muluvi R. Kindt C. A. C. Kadu A. J. Simons R. H. Jamnadass 《Tree Genetics & Genomes》2008,4(4):787-795
The genus Warburgia (Canellaceae) contains four tree species that are of valuable medicinal importance and are all found in Africa. Genetic diversity
present in wild populations of these species is under great threat due to unsustainable harvesting for medicines and indiscriminate
felling for timber and agricultural expansion. There is therefore an urgent need for conservation of these species. Some authors
disagree about the taxonomy of the genus and list different species as synonyms. Amplified fragment length polymorphism (AFLP)
technique was used to determine the genetic relationships between three species to resolve the taxonomic confusion. The amount
of genetic variation within and among populations was assessed to guide strategies for their conservation and sustainable
utilization. Four AFLP primer pairs (EcoRI/MseI) generated a total of 185 amplification products. Analysis of molecular variance revealed most variation among individuals
within populations (63%, P < 0.0001), but variation among populations (37%, P < 0.0001) was highly significant as well. Constrained analysis of principal coordinates based on the Jaccard distance confirmed
the separation among populations (38.2%, P < 0.0001). A phenetic tree and ordination graphs showed a clear distinction of W. ugandensis from W. salutaris and W. stuhlmannii. W. ugandensis populations from Uganda and western Kenya formed a subgroup that clustered away from the rest of the W. ugandensis populations. W. salutaris and W. stuhlmannii populations showed little genetic differentiation. An implication of the data to genetic management and taxonomic clarification
is discussed. 相似文献