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1.
The motacú palm (Attalea phalerata) is widespread in Bolivia and is an economically valuable species as a source of vegetable oil. In Bolivia it is utilized as construction material, food, medicine, cosmetic, and edible oil. Oil extracted from the kernel (60–70% of dry weight) is high in lauric and myristic oils and compares favorably with other tropical oil crops. The palms reach reproductive maturity in 7–10 years and potential oil production from cultivated stands is 1.1-2.4 tons/ha/yr.  相似文献   

2.
A total of 322 records were available from the literature on faunal taxa endemic to the Cape Peninsula, South Africa. Excluding possible pseudoendemics, dubious records and many invertebrate groups for which little or no information exists, these records represent 112 species (1 vertebrate and the rest invertebrates) in 47 families. This number excludes many other potential endemics having distributions that extend just off the Peninsula. When mapped according to a 590 1 km×1 km grid, these endemics were clustered in several, largely montane nodes and palaeogenic (palaeoclimatically stable) zones typically located in upper reach forest streams, riverine forest and caves (the latter supported 14 endemics). Endemics were over-represented on steep slopes. For many taxa, a very high percentage of the Peninsula representatives were endemics. There were more plant than animal endemics per 1 km2 cell, although in total there were more animal than plant endemics. A significant correlation existed between the distribution of plant and animal endemics on the Peninsula, and especially on Table Mountain. The relationship, however, appears not to be causal, and is possibly related to parallel responses to historical isolation and topography. As the endemic fauna is mostly relictual, conservation of umbrella plant communities and the sandstone caves is essential. This may avert further extinction (some invertebrate endemics are likely to be extinct at this stage). Others have suffered declines in population numbers through development, invasion of alien vegetation, and possibly through predetion by the introduced Argentine ant.  相似文献   

3.
Omphalogramma souliei Franch. is an endangered perennial herb only distributed in alpine areas of SW China. ISSR markers were applied to determine the genetic variation and genetic structure of 60 individuals of three populations of O. souliei in NW Yunnan, China. The genetic diversity at the species level is low with P=42.5% (percentage of polymorphic bands) and Hsp=0.1762 (total genetic diversity). However, a high level of genetic differentiation among populations was detected based on different measures (Nei's genetic diversity analysis: Gst=0.6038; AMOVA analysis: Fst=0.6797). Low level of genetic diversity within populations and significant genetic differentiation among populations might be due to the mixed mating system in which xenogamy predominated and autogamy played an assistant role in O. souliei. The genetic drift due to small population size and limited current gene flow also resulted in significant genetic differentiation. The assessment of genetic variation and differentiation of the endangered species provides important information for conservation on a genetic basis. Conservation strategies for this rare endemic species are proposed.  相似文献   

4.
A recent molecular phylogeny of the Arid clade of the genus Hemidactylus revealed that the recently described H. saba and two unnamed Hemidactylus species from Sinai, Saudi Arabia and Yemen form a well-supported monophyletic group within the Arabian radiation of the genus. The name ‘Hemidactylus saba species group’ is suggested for this clade. According to the results of morphological comparisons and the molecular analyses using two mitochondrial (12S and cytb) and four nuclear (cmos, mc1r, rag1, rag2) genes, the name Hemidactylus granosus Heyden, 1827 is resurrected from the synonymy of H. turcicus for the Sinai and Saudi Arabian species. The third species of this group from Yemen is described formally as a new species H. ulii sp. n. The phylogenetic relationships of the members of ‘Hemidactylus saba species group’ are evaluated and the distribution and ecology of individual species are discussed.  相似文献   

5.
6.

Premise of research

A large number of fossil coryphoid palm wood and fruits have been reported from the Deccan Intertrappean beds of India. We document the oldest well-preserved and very rare costapalmate palm leaves and inflorescence like structures from the same horizon.

Methodology

A number of specimens were collected from Maastrichtian–Danian sediments of the Deccan Intertrappean beds, Ghughua, near Umaria, Dindori District, Madhya Pradesh, India. The specimens are compared with modern and fossil taxa of the family Arecaceae.

Pivotal results

Sabalites dindoriensis sp. nov. is described based on fossil leaf specimens including basal to apical parts. These are the oldest coryphoid fossil palm leaves from India as well as, at the time of deposition, from the Gondwana- derived continents.

Conclusions

The fossil record of coryphoid palm leaves presented here and reported from the Eurasian localities suggests that this is the oldest record of coryphoid palm leaves from India and also from the Gondwana- derived continents suggesting that the coryphoid palms were well established and wide spread on both northern and southern hemispheres by the Maastrichtian–Danian. The coryphoid palms probably dispersed into India from Europe via Africa during the latest Cretaceous long before the Indian Plate collided with the Eurasian Plate.  相似文献   

7.
The evolutionary history and geographical isolation of the Antarctic continent have produced a unique environment rich in endemic organisms. In many regions of Antarctica, cyanobacteria are the dominant phototrophs in both aquatic and terrestrial ecosystems. We have used microscopic and molecular approaches to examine the cyanobacterial diversity of biotopes at two inland continental Antarctic sites (80-82°S). These are among the most southerly locations where freshwater-related ecosystems are present. The results showed a low cyanobacterial diversity, with only 3-7 operational taxonomic units (OTUs) per sample obtained by a combination of strain isolations, clone libraries and denaturing gradient gel electrophoresis based on 16S rRNA genes. One OTU was potentially endemic to Antarctica and is present in several regions of the continent. Four OTUs were shared by the samples from Forlidas Pond and the surrounding terrestrial mats. Only one OTU, but no internal transcribed spacer (ITS) sequences, was common to Forlidas Pond and Lundstr?m Lake. The ITS sequences were shown to further discriminate different genotypes within the OTUs. ITS sequences from Antarctic locations appear to be more closely related to each other than to non-Antarctic sequences. Future research in inland continental Antarctica will shed more light on the geographical distribution and evolutionary isolation of cyanobacteria in these extreme habitats.  相似文献   

8.
Earliest cetaceans (whales) originated from the early Eocene of Indo-Pakistan, but the group dispersed through most of the oceans of the planet by the late middle to late Eocene. This late Eocene global distribution indicates that important dispersal events took place during the middle Eocene (Lutetian), a globally undersampled time interval that is well documented in the Togolese phosphate series. We report here the first discovery of a partial cetacean cranium from middle Eocene deposits of Togo (West Africa). A 3D model of the cranium and teeth was reconstructed in order to reveal hidden anatomical features. The dental and cranial characteristics of the Togolese specimen recall those of protocetid taxa described in Africa, Asia, and North America, but also display significant differences. In particular, we show that the new specimen shares a number of morphological features with the Togolese taxon Togocetus. Such a hypothesis is further supported by a cladistic analysis including 45 taxa and 167 morphological characters, which recovers the new specimen close to Togocetus as the first offshoot of protocetids. Phylogenetic analysis including all the protocetids remains of Kpogamé confirms the singular diversity of the Togolese phosphate basin, and enables to examine potential connections with faunas from contemporaneous localities in Africa.  相似文献   

9.
This study presents limnological and morphological characteristics, physical and chemical properties of waters, and geochemistry of surface sediments for 63 aquatic ecosystems located on the karst Yucatán Peninsula and surrounding areas of Belize and the Guatemalan highlands and eastern lowlands. Our principal goal was to classify the aquatic systems based on their water variables. A principal component analysis (PCA) of the surface water chemistry data showed that a large fraction of the variance (29%) in water chemistry is explained by conductivity and major ion concentrations. The broad conductivity range, from 168 to 55,300 μS cm−1 reflects saline water intrusion affecting coastal aquatic environments, and the steep NW–S precipitation gradient, from ~450 to >3,200 mm year−1. Coastal waterbodies Celestún and Laguna Rosada displayed the highest conductivities. Minimum surface water temperatures of 21.6°C were measured in highland lakes, and warmest temperatures, up to 31.7°C, were recorded in the lowland waterbodies. Most lakes showed thermal stratification during the sampling period, with the exception of some shallow (<10 m) systems. Lakes Chichancanab, Milagros, and Bacalar displayed sulfate-rich waters. Waters of sinkholes had relatively high conductivities (<3,670 μS cm−1) and a broad range of δ18O values (−4.1 to +3.8‰). Ca, HCO3, and SO4 dominated the waters of the lowland lakes, whereas Na was the dominant cation in highland lakes. Coastal aquatic ecosystems were dominated by Na and Cl. Cluster analysis based on surface water variables classified aquatic environments of the lowlands and highlands into three groups: (1) lowland lakes, ponds, wetlands, and coastal waterbodies (2) highland lakes, and (3) sinkholes and rivers. A broad trophic state gradient was recorded, ranging from the eutrophic Lake Amatitlán and the Timul sinkhole to oligotrophic Laguna Ayarza, with the highest water transparency (11.4 m). We used major and trace elements in surface sediments to assess pollution of waterbodies. Lakes Amatitlán, Atescatempa, El Rosario, Cayucón, Chacan-Lara, La Misteriosa, rivers Subín and Río Dulce, the wetland Jamolún, and the sinkhole Petén de Monos showed evidence of pollution and urban development. Their surface sediments displayed high concentrations of As, Cu, Fe, Ni, Pb, Se, Zn, and Zr, which suggest moderate to strong pollution.  相似文献   

10.
This study is an initial survey of the genetic diversity and population structure of the endangered Bonelli’s Eagle (Hieraaetus fasciatus) in SW Europe (Iberia) and NW Africa, two locations where the species has undergone a severe decrease in numbers during the last decades. It is also the first study in which the mitochondrial control region (CR) has been used to study the genetic diversity and population structure of this species. Samples were obtained from 72 individuals from Spain, Portugal and Morocco, and a 253-bp fragment of the mitochondrial control region was amplified and sequenced. Only three polymorphisms were present, indicating low nucleotide and haplotype diversity. No evidence of genetic structure was found. Several hypotheses may explain these results, including a possible greater genetic diversity in other regions of the mitochondrial genome or the existence of a presumed ancient bottleneck (last glaciation), possibly followed by a human-induced more recent one (twentieth century).  相似文献   

11.
Paleontological Journal - The composition of Barremian–Aptian assemblages of microfauna and palynomorphs from the north-west of the Yamal Peninsula allows to reveal local zones, which are...  相似文献   

12.
13.
Knowledge of the effects of flooding on plant survival is relevant for the efficiency of management and conservation programs. Schinus terebinthifolius is a tree of economic and ecological importance that is common in northeast Brazil. Flooding tolerance and genetic variation were investigated in two riparian populations of S. terebinthifolius distributed along two different ecological regions of the Tibagi River basin. Flooding tolerance was evaluated through the investigation of young plants, submitted to different flooding intensities to examine the morphological and anatomical responses to this stress. The growth rate of S. terebinthifolius was not affected by flooding, but total submersion proved to be lethal for 100% of the plants. Morphological alterations such as hypertrophied lenticels were observed in both populations and lenticel openings were significantly higher in plants from one population. Genetic analysis using DNA samples obtained from both populations showed a moderate degree of genetic variation between populations (13.7%); most of the variation was found within populations (86.3%). These results show that for conservation purposes and management of degraded areas, both populations should be preserved and could be used in programs that intend to recompose riparian forests.  相似文献   

14.
The orange blossom wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a significant pest of wheat (Triticum spp.) grown in the Northern Hemisphere. It was accidently introduced to North America over 200 years ago and has subsequently spread throughout the northern Great Plains. Since 2010, several Canadian spring wheat varieties containing the resistance gene Sm1 have been released. Due to the potential of wheat midge populations to evolve virulent biotypes to Sm1, cultivars containing Sm1 are grown with a susceptible cultivar in an interspersed refuge. An understanding of the genetic diversity of wheat midge populations could provide important information on the potential development of resistance to Sm1. In the current study, we used two mitochondrial genes (CO1 and ND4) from wheat midge collected across the northern Great Plains and Québec in North America to assess population structure and genetic diversity. We found limited genetic diversity and population structure across the sampled North American populations. We also assessed North American haplotype similarity to wheat midge collected from Europe and China and found high similarity between North American and European populations, although sampling in Europe was limited. This supports the hypothesis that North American populations originated from Europe.  相似文献   

15.
Mortiño (Vaccinium floribundum Kunth) is a deciduous perennial shrub endemic to the high Andes of South America. Despite a rich ethnobotanic history among indigenous communities, mortiño remains a wild species vulnerable to extinction from the ongoing fragmentation of its natural habitat. This study assessed the degree of genetic diversity and population structure of Ecuadorian V. floribundum as a preliminary step towards the establishment of effective conservation and sustainable-agriculture strategies. Mortiño individuals (126 in total) sampled from 3 regions in the northern highlands of Ecuador were characterized using 11 heterologous SSR markers originally developed for Vaccinium corymbosum. Expected heterozygosity (He = 0.49) revealed a moderate degree of genetic diversity for Ecuadorian mortiño, and pairwise F statistics between sampling regions (0.019≤ Fst ≤0.041) demonstrated low-to-moderate population differentiation. Population structure analysis clustered mortiño germplasm into 3 groups, each representing the 3 distinct regions from where samples were collected. The geographic patterning of genetic diversity for V. floribundum could be explained by an isolation-by-distance model, where physical barriers along the Andean highlands reduce genetic exchange between distanced populations. To confirm the latter, this study should extend to a wider sampling range, covering other regions along the Andean alley where the species is found.  相似文献   

16.
17.
Using sequence analyses of fragments of the small and large subunits of mitochondrial genes 12S and 16S rRNA, we studied the molecular identity of five Triops populations from the Baja California Peninsula, México. Additionally, we explored the phylogeny of the genus by comparing with sequence data from gonochoric T. longicaudatus (Zacatecas, México), commercial Triops kit (U.S.A.), T. `granarius' (Japan), T. cancriformis (Austria), T. australiensis (Australia) and Lepidurus lemmoni (U.S.A.). The 16S fragment was not useful to discriminate the American Triops forms because their sequences were more than 99% similar. Molecular and phylogenetic analyses using the 12S gene fragments, in agreement with previous allozyme studies, indicate that the nominal (morphological) species T. longicaudatus is a mixture of several species such that, of the seven Triops American populations studied, six phylogenetic species can be identified and two morphologically and reproductively highly divergent forms can be grouped into a single monophyletic clade. The molecular data, rather than supporting our previous proposal that the phylogenetic relationships of Triops species could be deduced by similarities in the number of total and legless rings, suggest that T. cancriformis may represent an independent group from the rest of the species in that genus. In spite of detectable differences among American populations, our analyses indicate these represent a single monophyletic group when compared to Triops from outside of the New World.  相似文献   

18.
The Canindé breed of goats (Capra hircus) is currently endangered. The aims of this study were to characterize the estrus behavior, ovulatory responses and progesterone profiles, and to evaluate the in vitro embryo production (IVP) in this breed. In Experiment 1, ten nulliparous and seven pluriparous females received medroxyprogesterone acetate (MAP)-containing sponges (60 mg) plus 75 μg d-cloprostenol for estrus synchronization and their reproductive parameters were evaluated. In Experiment 2, oocytes obtained by laparascopy from hormonally stimulated females (n = 15) were used for IVP. There was no difference (p > 0.05) between nulliparous and pluriparous goats in terms of estrus response (40.0% vs. 85.7%), time from progestagen sponge removal to the onset of estrus (62.0 ± 15.5 vs. 50.7 ± 19.2 h; mean ± SEM), duration of estrus (25.0 ± 16.1 vs. 30.0 ± 15.1 h), percentage of ovulating animals (60.0% vs. 85.7%), number of ovulations (1.2 ± 0.4 vs. 1.3 ± 0.8), and diameter of the preovulatory follicle (5.8 ± 0.5 vs. 6.1 ± 0.3 mm). Progesterone concentrations were also similar (p > 0.05) in both groups. During laparoscopic recovery, there were average 12.2 aspirated follicles and 9.1 oocytes per goat, resulting in a high recovery rate (74.3%, 182/245). A total of 78 embryos were produced (51.0%). The mean number of cells in the blastocysts at day 7 of in vitro culture was 170.3 ± 12.5. In conclusion, nulliparous and pluriparous Canindé goats exhibited similar reproductive profiles. It was possible to produce embryos in vitro, allowing the instigation of an embryo bank for preservation of this breed.  相似文献   

19.
Biodiversity and Conservation - Mammillaria hernandezii, M. dixanthocentron and M. lanata are endemic and threatened cactus species that inhabit the Tehuacán Valley, an arid zone in southern...  相似文献   

20.
The discovery of seeds and textiles from Gossypium (cotton) in Achaemenian levels of the mid-6th–late 4th century b.c. at Qal’at al-Bahrain, Bahrain and in early 1st millennium a.d. at Mada’in Salih, Saudi Arabia, reveals the role played by the Arabian Peninsula as a textile production centre during the centuries before and after the beginning of the Christian era. Both these sites were situated on important trade routes, overseas (Qal’at al-Bahrain) and overland (Mada’in Salih), and it is likely that at least part of the cotton production was intended for trade, complementing and perhaps competing with other sources of cotton textiles in the contemporary Middle East. In the arid climate of the Arabian Peninsula, cotton was probably grown in association with irrigated date palm gardens where a wide array of other crops was grown, as is shown by the analysis of charred seeds and wood from occupation levels at both sites. The present article places these particular finds in the larger context of cotton cultivation in the Middle East and India.  相似文献   

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