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1.
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Commiphora wightii is a medicinally important endangered species endemic to the Thar Desert of Rajasthan, India and adjoining areas of Pakistan. The populations of this species are declining sharply because of its extensive use as a natural herb. Random amplified polymorphic DNA analysis was conducted to find the genetic variation among 7 populations of C. wightii. Of the 100 random primers screened, 44 primers yielded 220 loci. Statistical analysis indicated low genetic diversity (H pop = 0.0958; I = 0.1498; mean polymorphic loci = 14.28%), and high genetic differentiation among the populations (G ST = 0.3990; AMOVA Φ ST of 0.3390; Bayesian θ (II) = 0.3002). The low genetic diversity may be due to geographic isolation and restricted gene flow (N m = 0.7533) between the fragmented populations. Unsustainable utilization of the plant has fragmented the population continuum which served the purpose of genetic exchange between populations. Mantel’s test was performed which revealed a highly significant positive correlation between genetic and geographic distance (r 2 = 0.614, P = 0.023) among the populations studied. Low variation can also be attributed to poor seed setting and the slow growth pattern of the species, which is also an apomict. In UPGMA dendrogram the Commiphora wightii samples were divided into two major and one minor cluster. These findings can serve as a guide to preserving the genetic resources of this medicinal plant species.  相似文献   

3.
Primula reinii var. rhodotricha is a perennial herb endemic to the limestone slope of Mt. Buko, located approximately 50 km northwest of central Tokyo, Japan. In recent years, its natural population size has decreased markedly due to limestone mining, and this species has been assigned to the ‘Critically Endangered (CR)’ category on the latest Japanese Red List. Although a remnant population of this species has been protected by a mining company outside their historical distribution range on Mt. Buko, the ex situ conservation of this endangered plant has been difficult because of insufficient low seed production. The genetic status of ex situ P. reinii var. rhodotricha and related species were investigated to develop an effective conservation plan for this species. Microsatellite analysis indicated that the ex situ population harbors lower genetic diversity than sister taxa, providing molecular evidence for the recent critical status designation of the ex situ population, whereas the presence of rare alleles may imply further potential for seed reproduction by outcrossing. Therefore, an appropriate propagation strategy that considers genetic diversity is needed for restoration and recovery of this critically endangered ex situ primrose population.  相似文献   

4.
Centaurea achtarovii Urum. is a Bulgarian endemic, distributed only in Pirin Mountain. It is protected by the Biodiversity Act and included in the Red Data Book of Bulgaria as “endangered”. Assessment of size and density was carried out of both known populations of the species, around Orelyak summit and Kazanite locality. It was conducted in 2 sampling plots of 1000 square meters in each population and revealed their good condition. Population of Orelyak was larger and with higher density than that of Kazanite: 75 ha, 0.58 individuals per m2 (an average of 0.56 rosettes and 0.02 in flowering stage), and 35 ha, 0.23 individuals per m2 (an average of 0.16 rosettes and 0.07 in flowering stage), respectively. Elucidation of the reproductive biology of C. achtarovii was important in order to find the most appropriate conservation strategy for the species. Flower buds and open flowers in different stages of development were treated by the classical paraffin methods. The structures in male and female generative spheres were stable, the processes leading to formation of embryos and seeds were balanced, and no apomixes was noticed. Pollen viability assessed by acetocarmine test was over 50%, and seed viability estimated by tetrazolium test was 17.5%. In vitro seed germination was poor and culture growth was slow. The low viability of seeds, and the small amount of pollen, although with relatively high fertility, determined a low reproductive capacity of the species. In situ strategies reducing competitive species like Juniperis sibirica were recommended.  相似文献   

5.
Many species differ genetically, physiologically, and morphologically between geographically distinct populations, typically in response to variation in ecological and climatic variables. Little is known, however, about geographical variation in sperm morphology. Sperm morphology is under strong sexual selection, has been shown to evolve rapidly, and often co-varies with other reproductive traits (e.g., testis size or mating system) that differ between populations in some species. The aim of this study was to establish whether sperm morphology varies between populations of the red-winged blackbird (Agelaius phoeniceus), a species with an enormous breeding range and marked inter-population variation in both body size and mating system. We found (1) highly significant variation in sperm morphology among study sites, (2) a gradual increase in sperm length from the southwest to the northeast of the breeding range, and (3) a strong negative association between sperm length and body size. However, the relationship with the mating system remains unclear. Several hypotheses to explain these patterns are proposed.  相似文献   

6.
In the Azores Islands, two Euphrasia L. (Orobanchaceae) endemic species are recognized: Euphrasia azorica H.C.Watson, an annual herb, in Flores and Corvo, and Euphrasia grandiflora Hochst. ex Seub., a semi-shrub, in Pico, São Jorge and Terceira. Both species are highly endangered and protected by the Bern Convention and Habitats Directive. A population genetics study was conducted with new microsatellite primer pairs in 159 individuals of E. azorica and E. grandifolia, sampled from populations in Flores, Corvo, Pico and São Jorge. Allele sizing suggested that E. azorica is a diploid while E. grandiflora is a tetraploid. Euphrasia grandiflora revealed higher genetic diversity then E. azorica. The E. grandiflora population of Morro Pelado in São Jorge, displayed higher genetic diversity when compared with all others, while the E. azorica population of Madeira Seca in Corvo, showed the lowest. Private and less common bands were also overall higher in E. grandiflora populations. Population genetic structure analysis confirmed a distinctiveness between the two Azorean endemic Euphrasia, in addition to island-specific genetic patterns in E. azorica. The genetic structure obtained for E. grandiflora was complex with the populations of Cabeço do Mistério in Pico Island and of Pico da Esperança in São Jorge sharing the same genetic group, while a putative spatial barrier to gene flow was still retrieved between both islands. Although some populations of both species might benefit from propagation actions, studies are needed on plant host species and translocations between islands or between some populations of a same island should be avoided, due to the occurrence of putative ESUs. Eradication of invasive species and control of grazing will be fundamental to promote in situ restauration.  相似文献   

7.
Summary   Funastrum rupicola Goyder, a new species of Apocynaceae: Asclepiadoideae from Bolivia, is described and illustrated. The conservation status of this species is assessed.  相似文献   

8.
The salt marsh harvest mouse (SMHM, Reithrodontomys raviventris) is an endangered species endemic to the San Francisco Bay region of California, USA, where habitat loss and fragmentation over the past century have reduced the mouse’s distribution to <25 % of its historical range. To aid in conservation prioritization, we first investigated the possibility of hybridization with the morphologically similar western harvest mouse (WHM, R. megalotis) in areas of sympatry and developed genetic tools to differentiate the two species. We then investigated the phylogeography and genetic structure of the SMHM, including support for currently recognized SMHM subspecies designations. Lastly, we evaluated the morphological criteria currently used for the identification of species in the field. Analyses using mtDNA cytochrome b sequences and 11 microsatellites from 142 mice indicated complete and substantial separation of the SMHM and WHM, with no evidence of hybridization. These genetic markers as well as the mtDNA control region also identified a deep genetic division within the SMHM concordant with the current subspecies designations, R. r. raviventris and R. r. halicoetes. We identified the lowest genetic diversity within the southern subspecies, which inhabits a much reduced and highly fragmented portion of the species range. Morphological field identification of harvest mouse species was more successful at identifying SMHM (92 %) than WHM (44 %), with a large portion of WHM being incorrectly identified as SMHM. Field identification of harvest mouse species in the range of the southern SMHM subspecies was just above 50 %, indicating that current methods for morphological differentiation of species in that area are insufficient. Our confirmation of genetically distinct SMHM subspecies highlights the importance of determining the status and genetic composition of relict populations in the remaining patches of marshland in the central San Francisco Bay where the two subspecies may occur, as well as developing better tools for the discrimination of species, particularly in the range of the southern subspecies  相似文献   

9.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.  相似文献   

10.
Genes involved in mating type determination and recognition were examined in Metschnikowia and related species, to gather insights on factors affecting mating compatibility patterns among haplontic, heterothallic yeast species of the genus. We confirmed the universality of the special mating locus organisation found in Clavispora lusitaniae across and exclusive to the family Metschnikowiaceae (i.e., Metschnikowia and Clavispora). Timing of the divergence between idiomorphs was confirmed to coincide with the origin of the larger (CUG-ser) clade comprising the Debaryomycetaceae and the Metschnikowiaceae, exclusive of Cephaloascus fragrans. The sequence of the a mating pheromone is highly conserved within the large-spored Metschnikowia species, including Metschnikowia orientalis and Metschnikowia hawaiiana, but not Metschnikowia drosophilae or Metschnikowia torresii, which have a pattern of their own, as do other clades in the genus. In contrast, variation in α pheromones shows a more continuous, although imperfect correlation with phylogenetic distance as well as with in vivo mating compatibility.  相似文献   

11.
During a study on the biodiversity of yeasts and yeast-like ascomycetes from wild plants in Iran, four strains of yeast-like filamentous fungi were isolated from a healthy plant of Euphorbia polycaulis in the Qom Province, Iran (IR. of). All four strains formed small hyaline one-celled conidia from integrated conidiogenous cells directly on hyphae and sometimes on discrete phialides, as well as by microcyclic conidiation. Two strains additionally produced conidia in conidiomata that open by rupture. The internal transcribed spacer (ITS) sequences suggested the placement of these strains in the genera Collophorina (Leotiomycetes) and Coniochaeta (Sordariomycetes), respectively. Blast search results on NCBI GenBank and phylogenetic analyses of ITS, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the translation elongation factor 1α (EF-1α) sequences, and the nuclear large subunit ribosomal gene (LSU), partial actin (ACT), and β-tubulin (TUB) sequences, respectively, revealed the isolates to belong to three new species, that are described here as Collophorina euphorbiae, Coniochaeta iranica, and C. euphorbiae. All three species are characterised by morphological, physiological, and molecular data.  相似文献   

12.
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.  相似文献   

13.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.  相似文献   

14.
Disanthus cercidifolius Maxim. var. longipes H.T. Chang usually has two inflorescences growing in opposite directions in the axillae, but occasionally three inflorescences grow paratactically. The typical flowering process could be divided into 4 periods: “Pre-dehiscence”, “Initial dehiscence”, “Full dehiscence” and “Withering”. Both the natural population and the planted population had a flowering peak of 15–35 days after the first flower bloomed. There were significant differences between the time courses of flowering of the two populations. Out-crossing is the main breeding system in this species. And autogamy decreases the risk of reproductive failure of this species. The main insect pollinators of D. cercidifolius var. longipes are Episyrphus balteatus de Geer, Scaptodrosophila coracina Kikkawa and Peng, Polistes olivaceus de Geer, Apis cerana Fabricius, Nezara viridula L. and Coccinella septempunctata L., and so on. Among the insects, S. coracina and E. balteatus are the most important and efficient pollinators, but others are inefficient pollinators. Though wind pollination is not efficient, it guarantees reproduction when insect pollinators are not available. “Mass flowering” is an adaptive behavior and reproductive strategy of this species, and “few fruiting” could be caused by the lack of pollinators.  相似文献   

15.
In this work, in vitro clonal propagation of Drosophyllum lusitanicum (Dewy pine) was obtained from seedlings germinated in vitro. Seeds were collected in various populations identified in the Algarve region and germinated in vitro on MS medium supplemented with 0.5 mg l–1 BA (6-benzyladenine) and 0.1 mg l–1 GA3 (gibberellic acid). The obtained shoots were used in several multiplication assays. The best results were observed in MS medium supplemented with 0.2 or 0.5 mg l–1 zeatin. The highest rooting frequency (83%) was observed on 1/4MS medium supplemented with 0.2 mg l–1 IBA (indole-3-butyric acid). Fifty percent of the plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development. Plans are underway to reintroduce the in vitro produced plants from this study in selected locations in their natural habitat.  相似文献   

16.
Lao leaf monkeys (Trachypithecus (francoisi) laotum) are endemic to a small area of central and, marginally, north Lao. They are known from a few, mostly vague, historical records. We here present a detailed examination of the distribution of this little-known taxon and discuss its conservation status. Surveys since 1992 show its range to be centered upon the karst-dominated Phou Hin Poun National Protected Area (NPA), Nam Sanam Provincial Protected Area, and the southern part of Nam Kading NPA. The known range encompasses <2000 km2, within which occurrence is patchy, reflecting habitat availability. The taxonomic identity of leaf monkeys plausibly of this group reported to the north of this area is not known. In the south of Phou Hin Poun NPA, village reports that the monkeys have black heads are corroborated by the few sightings; their taxonomic relationship with typical Trachypithecus laotum is unknown. In the mid–late 1990s large populations remained and individuals were easily seen. There is no apparent large-scale threat to their habitat. There has been no significant reassessment of status since the late 1990s, nor is there any active conservation action in place. Although the monkeys are to a significant extent protected by the arduous terrain, this cannot be relied upon indefinitely: Trade-directed hunting, although apparently limited in the 1990s, is a potential threat that could cause rapid population declines. Local traditions offer significant starting points for conserving these monkeys.  相似文献   

17.
A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.  相似文献   

18.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.  相似文献   

19.
Gut bacterium Pantoea sp. is one of the predominant bacterial species in the larval gut of the diamondback moth, Plutella xylostella. The phenotypic characters of Pantoea sp. were investigated with BIOLOG phenotype MicroArray (PM) in this study. Totally 950 different metabolic phenotypes were tested using the PM plates 1–10. Results exhibited that Pantoea sp. was able to metabolize 37.37 % of the tested carbon sources, 91.32 % of nitrogen sources, 100 % of sulfur sources, and 98.31 % of phosphorus sources. Most informative utilization patterns for carbon sources of Pantoea sp. were organic acids and carbohydrates, and for nitrogen were various amino acids. The bacterium had 94 different biosynthetic pathways. It had a wide range of adaptabilities, and could still metabolize in osmolytes with up to 9 % sodium chloride, 6 % potassium chloride, 5 % sodium sulfate, 20 % ethylene glycol, 4 % sodium formate, 4 % urea, 5 % sodium lactate, 200 mmol/L sodium phosphate (pH 7.0), 100 mmol/L ammonium sulfate (pH 8.0), 100 mmol/L sodium nitrate, and 100 mmol/L sodium nitrite, respectively. It also exhibited active metabolism under pH values between 4.5 and 10. Pantoea sp. showed active decarboxylase activities while poor deaminase activities in the presence of various amino acids. The phenotypic characterization of Pantoea sp. increased our knowledge of the bacterium, in particular its interactions with insect hosts and the adaptability in gut environments, and showed us some possible approaches to controlling diamondback moth through decreasing Pantoea sp. density.  相似文献   

20.
The Alhambra ( Alh) gene is the Drosophila homologue of the human AF10 gene. AF10 has been identified as a fusion partner of MLL, a human homologue of the fly gene trithorax, in infant leukemias. The endogenous function of human AF10 is not known, but may be vital to its role in acute leukemia. This prompted us to analyse Alh function. We describe here the genetic organisation of the Alh locus in D. melanogaster. We show that an independent lethal complementation group encoding a muscle protein ( Mlp84B) is located within an Alh intron. We have already shown that the leucine zipper (LZ) domain of ALH activates several Polycomb group-responsive elements. We further demonstrate that the LZ domain on its own bears the Alh vital function, since it is necessary and sufficient for rescue of Alh mutant lethality. Finally, we demonstrate that, in contrast to a previous report, Alh does not affect position-effect variegation.Communicated by G. Reuter  相似文献   

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