首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
On the basis of analysis of our own and published data on the distribution of the riffle minnow Alburnoides bipunctatus rossicus in rivers of the Volga Basin, the eastern boundary of the range of this subspecies included in the Red Data Book of the Russian Federation is specified. It is shown that A. bipunctatus is widely distributed in the entire basin of the Middle Volga and Kama, except the extreme northeast (mountain tributaries of the Upper Kama upstream the Chusovaya River), and rarely occurs in the Upper Volga Basin. The Tereshka River (Ulyanov oblast) and Chapaevka (Saratov oblast) should be considered the southern boundary of the distribution of the subspecies in the Volga Basin. Since the mid-1990s, a drastic and uniform increase in the number of findings and the abundance of A. bipunctatus is recorded. This species has become a common fish in many rivers and, in some cases, a dominant species in river ichthyocenoses. Possible causes of these changes are discussed, and a conclusion is made concerning the need of the revision of the status of the subspecies A. bipunctatus rossicus.  相似文献   

2.
Five species of mouse or forest shrews (Myosorex) are endemic to South Africa, Lesotho and Swaziland, four of which (Myosorex varius, Myosorex cafer, Myosorex longicaudatus and Myosorex cf. tenuis) are associated with montane or temperate grassland, fynbos and/or forest habitats while a fifth (Myosorex sclateri) is associated with lowland subtropical forests. Due to their small size, specialised habitat, low dispersal capacity, high metabolism and sensitivity to temperature extremes, we predicted that, particularly for montane species, future climate change should have a negative impact on area of occupancy (AOO) and ultimately extinction risks. Species distribution models (SDMs) indicated general declines in AOO of three species by 2050 under the A1b and A2 climate change scenarios (M. cafer, M. varius, M. longicaudatus) while two species (M. sclateri and M. cf. tenuis) remained unchanged (assuming no dispersal) or increased their AOO (assuming dispersal). While temperate species such as M. varius appear to be limited by temperature maxima (preferring cooler temperatures), the subtropical species M. sclateri appears to be limited by temperature minima (preferring warmer temperatures). Evidence for declines in AOO informed the uplisting (to a higher category of threat) of the Red List status of four Myosorex species to either vulnerable or endangered as part of a separate regional International Union for Conservation of Nature (IUCN) Red List assessment.  相似文献   

3.
Bruguiera hainesii (Rhizophoraceae) is one of the two Critically Endangered mangrove species listed in the IUCN Red List of Threatened Species. Although the species is vulnerable to extinction, its genetic diversity and the evolutionary relationships with other Bruguiera species are not well understood. Also, intermediate morphological characters imply that the species might be of hybrid origin. To clarify the genetic relationship between B. hainesii and other Bruguiera species, we conducted molecular analyses including all six Bruguiera species using DNA sequences of two nuclear genes (CesA and UNK) and three chloroplast regions (intergenic spacer regions of trnL-trnF, trnS-trnG and atpB-rbcL). For nuclear DNA markers, all nine B. hainesii samples from five populations were heterozygous at both loci, with one allele was shared with B. cylindrica, and the other with B. gymnorhiza. For chloroplast DNA markers, the two haplotypes found in B. hainesii were shared only by B. cylindrica. These results suggested that B. hainesii is a hybrid between B. cylindrica as the maternal parent and B. gymnorhiza as the paternal one. Furthermore, chloroplast DNA haplotypes found in B. hainesii suggest that hybridization has occurred independently in regions where the distribution ranges of the parental species meet. As the IUCN Red List of Threatened Species currently excludes hybrids (except for apomictic plant hybrids), the conservation status of B. hainesii should be reconsidered.  相似文献   

4.
To specify the taxonomic rank of form ciscaucasicus (independent species Sylvaemus ciscaucasicus, or intraspecific form of pygmy wood mouse, S. uralensis), a 402-bp the mtDNA cytochrome b gene fragment (402 bp) was examined in ciscaucasicus individuals from six geographic localities of the Caucasus and Ciscaucasus (Krasnodar krai and Adygeya Republic) and 17 S. uralensis individuals from seven localities of the Russian Plain (Saratov oblast, Smolensk oblast, Voronezh oblast, Tula oblast, Moscow oblast, Tver’ oblast, and northern Krasnodar krai). For comparison, the cytochrome b gene was partly sequenced in the samples of yellow necked, S. flavicollis (n = 2, Samara oblast), and Caucasian, S. ponticus (n = 6, Krasnodar krai), wood mice. One Mus musculus specimen from Western Europe, whose nucleotide sequences were deposed in the GenBank, was used as intergeneric outgroup. Phylogenetic trees for the forms examined were constructed based on the mtDNA sequence variation and using the neighbor joining and maximum parsimony methods. The network of the cytochrome b haplotypes was also constructed. The level of genetic divergence was evaluated using Kimura’s two-parameter algorithm. Based on the data on the sequence variation in a 402-bp mtDNA cytochrome b gene fragment, the hypothesis on the species status of the ciscaucasicus form was. The mean intergroup distances (d) between the geographic groups of S. uralensis varied from 0.0036 to 0.0152. At the same time, the distances between the pygmy wood mice and the group of S. flavicollis-S. ponticus varies in the range from 0.0860 to 0.0935, and the level of intergeneric genetic differentiation (Sylvaemus-Mus) is higher than the latter index (d = 0.142). Ciscaucasicus should be considered as geographic substitution form of S. uralensis. Furthermore, the Caucasian populations of S. uralensis (= ciscaucasicus) were characterized by a threefold lower value of intergroup genetic divergence (d = 0.0062) than the East European populations (d = 0.0179). This finding pointed to some isolation of Caucasian populations of pygmy wood mouse and depletion of their gene pool. However other molecular genetic data (similarity of nucleotide composition and consistence of the levels of intra-and intergroup distances) suggest the absence of geographic subdivision between Caucasian and East European populations of S. uralensis relative to the molecular marker examined.  相似文献   

5.
6.
Genetic variability of yellow potato cyst nematode G. rostochiensis from three Russian populations (Karelia, Vladimir oblast, and Moscow oblast) was investigated using two types of nuclear markers. Using RAPD markers identified with the help of six random primers (P-29, OPA-10, OPT-14, OPA-11, OPB-11, and OPH-20), it was possible to distinguish Karelian population from the group consisting of the populations from two adjacent regions (Moscow oblast and Vladimir oblast). Based on the combined matrix, containing 294 RAPD fragments, dendrogram of genetic differences was constructed, and the indices of genetic divergence and partition (P, H, and G st), as well as the gene flow indices N m between the nematode samples examined, were calculated. The dendrogram structure, genetic diversity indices, and variations of genetic distances between single individuals in each population from Karelia and Central Russia pointed to genetic isolation and higher genetic diversity of the nematodes from Karelia.Based on polymorphism of rDNA first intergenic spacer ITS1, attribution of all populations examined to the species G. rostochiensis was proved. Small variations of the ITS1 sequence in different geographic populations of nematodes from different regions of the species world range did not allow isolation of separate groups within the species. Possible factors (including interregional transportations of seed potato) affecting nematode population structure in Russia are discussed.  相似文献   

7.
The results of analysis of the variability of body shape of different Daphnia galeata morphs from geographically distinct populations—Lake Glubokoe (Moscow oblast) and Lake Chany (Novosibirsk oblast) are given. The morphological analysis was combined with the analysis of the variability of fragments of the 16S and 12S genes of the mitochondrial DNA (mtDNA) and the internal transcribed spacer 2 (ITS2) of the nuclear DNA. A reconstruction of the phylogenetic relationships between species of the genus Daphnia has been performed using a combined fragment of the 16S and 12S genes of the mtDNA. An inconsistency in the distribution of the 12S- and ITS2-haplotypes for the species D. galeata has been revealed, which indicates the introgression of mtDNA in the Lake Chany population.  相似文献   

8.
The morphology and intraspecific structure of Triplophysa orientalis inhabiting the inland basins of Tsaidam (northeastern edge of the Tibetan Plateau) and the basin of the upper reach of the Huang He River in China were studied. Significant morphological differences between the populations from the inland basins and the Huang He River were revealed; the latter were distinguished as a separate subspecies T. o. hwanghoensis subsp. n. Intermediate character of some traits of the new subspecies between the nominative subspecies and T. hutjertjuensis was found; as a result, the status of the latter was reduced to the subspecies level. The synonymy of T. o. elongata with the nominative subspecies was confirmed. The differences between T. orientalis and T. obscura—morphologically poorly distinguishable species, sympatric in the basin of the upper reach of the Huang He River—were defined more exactly.  相似文献   

9.
The Upper Yenisei grayling Thymallus svetovidovi sp. nova that inhabits the headwaters of the Yenisei River in Mongolia is described. From the other representatives of the genus Thymallus, the species differs in the elements of body coloration, dorsal fin pattern, some morphometric characters, and genetic characteristics. Besides this species, most of the Yenisei basin is inhabited by Baikal grayling T. baicalensis Dyb., and its low reaches, by the Arctic grayling T. arcticus (Pall.).  相似文献   

10.
In their first phase of expanding into new areas, invasive plants often take advantage of the inability of existing herbivores and pathogenic species to exploit them. However, in the longer term local enemies may adapt to using these invasive species as a food source. This study assesses the use of mature acorns of two oak species in Europe (the native Pedunculate Oak Quercus robur and the invasive Northern Red Oak Quercus rubra) by moths Cydia fagiglandana and Cydia splendana and beetles Curculio spp. We show that acorns of invasive oak species can be equally attractive to C. splendana but only partially so to C. fagiglandana where infestation rates where significantly lower (approximately half) compared to the native oak. The infestation by Curculio beetles of Northern Red Oak was marginal, less than 1% of the rate in the native oak species. The larval final weights did not differ significantly between host species, but emergence of C. splendana and Curculio spp. took significantly longer in acorns of Northern Red Oak. It is likely that C. fagiglandana and C. splendana have increased their niche breadths by exploiting invasive oak species and avoiding competition with the Curculio weevils. Furthermore, the occurrence of Northern Red Oak could stabilize food resources during years when native oak species have poor acorn crops.  相似文献   

11.
The large size and complex taxonomy of big genera complicates decision making for conservation. We propose that Rhododendron, comprising some 1215 taxa, divided into nine subgenera and many sections, can be used as a model for other big genera. Although Red List assessments placed 715 taxa in a threat category, or listed them as Data Deficient, and moreover Target 8 of the Global Strategy for Plant Conservation requires 75 % of Red List taxa to be held in ex situ collections by 2020, to date there have been few studies of Rhododendron ex situ collections or conservation priorities. Utilising the subgenus structure of Rhododendron as a framework for examining conservation priorities, we analysed the Red List and determined that subgenera Vireya and Hymenanthes have the most acute conservation issues. Examination of taxa in cultivation shows that 844 of 1215 taxa (70 %) are in cultivation, with subgenera varying from 45 to 100 %. Of the 715 Red List taxa, 400 (56 %) are in cultivation, with subgenera varying from 28 to 72 %. Subgenera Vireya and Azaleastrum have the poorest representation in cultivation and should have precedence for ex situ conservation. As no subgenus reaches the requirement for Target 8, further planning is needed for ex situ conservation of Rhododendron. After combining the two analyses, we propose the priorities for ex situ conservation should be ordered (i) Vireya, (ii) Azaleastrum and (iii) Hymenanthes. Finally, we propose five conservation actions for Rhododendron, and summarise our approach as a model for conservation of other big genera.  相似文献   

12.
Analysis of genetic datasets can be particularly useful in providing guidelines for conservation management of understudied species targeted by commercial activities. Here we used population genetic approaches to inform on the conservation status of the Neotropical long-nose pirá catfish, Conorhynchos conirostris. Pirá is a large migratory fish endemic to the São Francisco River Basin (SFRB). It is an evolutionarily divergent and relict species, being the sole representative of an incertae sedis family. The species is considered locally extinct in the upper and lower SFRB, listed as vulnerable on the IUCN Red List and as endangered on the Brazilian Red List (ICMBIO). Fishing prohibition has received severe criticism from middle SFRB fisheries that claim that this understudied species is relatively abundant in that region. We used information from 13 microsatellite markers and COI mitochondrial sequences to clarify the genetic diversity of this enigmatic species in the middle SFRB, to estimate contemporary effective population size (Ne), and to assess its conservation status. Results from bottleneck analyses indicated that the species has experienced recent reductions in population size, which is consistent with small estimates of contemporary Ne. The predicted amount of heterozygosity loss (Ht) in t generations ranged from 0.1152 (for an estimated Ne of 26.4; t?=?100) to 0.7573 (for an estimated Ne of 169.9; t?=?10). Our study supports the conservation status proposed by the ICMBIO to the remaining pirá population. Moreover, we highlight the need for demographic data and the re-assessment of the current IUCN classification for this evolutionary relict lineage.  相似文献   

13.
Sympetrum pedemontanum (Müller in Allioni) (Odonata: Libellulidae), which is distributed widely in the Eurasian continent and its neighboring islands, is listed as a Least Concern species in the International Union for Conservation of Nature Red List (2015). In Japan, however, the population of its subspecies S. pedemontanum elatum (Selys) has been rapidly decreasing since the 1970s. In order to conserve this subspecies, it is important to understand the seasonal microhabitat use by its larvae. However, this has been a difficult task because larvae of S. pedemontanum elatum often coexist with those of a common congener, S. eroticum (Selys), and cannot be morphologically distinguished from the latter. Thus, in this study, we first established a molecular technique based on the polymerase chain reaction to accurately identify each species. In the subsequent field survey in 2015 with its application in the Sakasegawa River, Hyogo Prefecture, we found that S. pedemontanum elatum larvae hatch in stagnant water and subsequently advance into weakly flowing water. Our results indicated a change in the microhabitats during the larval developmental process, reflecting the need for a continuous spectrum of stagnant, transitional, and flowing water. Such aquatic environments with a spectrum of water conditions are disappearing in Satoyama, a rural farming area in Japan. This has endangered species such as S. pedemontanum elatum and Oryzias latipes (Beloniformes: Adrianichthyidae) by depriving them of their favorable habitats. For their conservation, it is necessary to develop methods to recover the traditional aquatic environments in Satoyama.  相似文献   

14.
Morphological, biological, and molecular-genetic characteristics of Culex pipiens and C. torrentium, collected from two sites in Moscow and five sites in Moscow Province, were studied. Our results demonstrated the absence of any differences between females of these species in the R 2/R 2+3 ratio. Figures and photographs of the male genitalia are given. Differences between the species in the mDNA cytochrome oxydase I gene and the 1TS2 region of the rDNA were revealed. 90–100% of C. pipiens and 0% of C. torrentium were infested with the endosymbiotic bacterium Wolbachia pipientis.  相似文献   

15.
The crane fly Tipula (Platytipula) moiwana (Matsumura, 1916) occurs in the southern Russian Far East, including Sakhalin Island and the Kuril Islands, in Japan (Hokkaido), and in northeastern China. Recently this species was found in Moscow. The reason for the appearance of this species in Moscow is unknown.  相似文献   

16.

Key message

Molecular analysis of a zeta subfamily GST gene from T. hispida involved in ABA and methyl viologen tolerance in transgenic Arabidopsis and Tamarix.

Abstract

Glutathione S-transferase (GST) genes are important for the improvement of plant abiotic stress tolerance, and our previous study demonstrated that the ThGSTZ1 gene from Tamarix hispida improves plant salt and drought tolerance. To further understand the role of ThGSTZ1 in the response of plants to abscisic acid (ABA) and oxidative stress, three ThGSTZ1-overexpressing transgenic Arabidopsis thaliana lines were analyzed in the current study. The results showed that the transgenic lines exhibited higher biomass accumulation, higher activities of GST and other protective enzymes, and less reactive oxygen species (ROS) and cell damage than wild-type (WT) plants under ABA and methyl viologen (MV) stress. In addition, the analysis of a transgenic T. hispida line transiently expressing ThGSTZ1 confirmed these results. The activities of GST, glutathione peroxidase, and superoxide dismutase were markedly higher in the ThGSTZ1-overexpressing lines compared with the control lines under both ABA and MV treatments, and the transgenic lines also exhibited a lower degree of electrolyte leakage (EL) and a decreased H2O2 content. All these results suggested that ThGSTZ1 can also improve plant ABA and oxidation tolerance by regulating ROS metabolism and that ThGSTZ1 represents an excellent candidate gene for molecular breeding to increase plant stress tolerance.
  相似文献   

17.
This review summarizes the species distribution of the genus Artemisia in the Iberian Peninsula and the Canarian and Balearic Archipelagos, describing their conservation status according to the European and the Spanish Red List. Furthermore, this review covers recent studies on the phytochemical composition of species from the genus Artemisia distributed in the targeted geographical area, their biological effects if described, and points out the need of further research in the phytochemistry and activity of some Iberain species.  相似文献   

18.
Eight new species of Ligophorus Euzet &; Suriano, 1977 (Monogenea: Ancyrocephalidae) are described from two species of mullets from the Red Sea. Ligophorus bykhowskyi n. sp. and L. zhangi n. sp. from Crenimugil crenilabris (Forsskål) differ from other species of the genus in the structure of the male copulatory organ, which has a simple accessory piece and a wide copulatory tube that arises from a large, single-chambered, expanded base. Ligophorus simpliciformis n. sp., L. bipartitus n. sp., L. campanulatus n. sp., L. mamaevi n. sp., L. lebedevi n. sp. and L. surianoae n. sp. from Liza carinata (Valenciennes) are differentiated on the basis of the morphometrics of the hard parts of the haptor and male copulatory organ. The eight species represent the first records of species directly attributed to Ligophorus from the Red Sea. Measurements of the haptoral hard-parts and the male copulatory organ of the new species are analysed with the aid of Principal Component Analysis. Three morphological types of male copulatory organ, five types of anchor, and two types of ventral and three types of dorsal bars were distinguished among these species. L. bykhowskyi and L. zhangi from C. crenilabris have the same type of male copulatory organ and anchors. Those species from Liza carinata have only one common morphological character, a thick copulatory tube, but have two types of accessory piece, four types of anchors and three types of bars. All species of Ligophorus found on mullets in the Red Sea have an accessory piece without a distal bifurcation and thus differ from most species of this genus from other regions of the world’s oceans.  相似文献   

19.
Tubeufia was named for a sexual morph taxon. However, several asexual morph species have been accommodated in this genus as well. In our study, four new species of Tubeufia, viz. T. filiformis, T. latispora, T. laxispora and T. mackenziei, are described and illustrated. The phylogenetic placement of the new species is confirmed by analysis of combined ITS, LSU and TEF1α sequence data. A key to Tubeufia species is provided and the new species are compared with similar fungal taxa.  相似文献   

20.
Hybridization is regarded as a rapid mechanism for increasing genetic variation that can potentially enhance invasiveness. Tamarix hybrids appear to be the dominant genotypes in their invasions. Exotic Tamarix are declared invasive in South Africa and the exotic T. chinensis and T. ramosissima are known to hybridize between themselves, and with the indigenous T. usneoides. However, until now, it was not known which species or hybrid is the most prevalent in the invasion. With a biocontrol programme being considered as a way of suppressing the alien Tamarix populations, it is important to document the population genetic dynamics of all species in the region. This investigation sought to identify Tamarix species in southern Africa and their hybrids, describe their population structure, and reveal the geographic origin of the invasive species. To achieve this, nuclear Internal Transcribed Spacer (ITS) sequence data and the multilocus Amplified Fragment Length Polymorphisms (AFLPs) markers were used. Phylogenetic analysis and population genetic structure confirmed the presence of three species in South Africa (T. chinensis, T. ramosissima and T. usneoides) with their hybrids. The indigenous T. usneoides is clearly genetically distant from the alien species T. chinensis and T. ramosissima. Interestingly, the Tamarix infestation in South Africa is dominated (64.7 %) by hybrids between T. chinensis and T. ramosissima. The exotic species match their counterparts from their places of origin in Eurasia, as well as those forming part of the invasion in the US.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号