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1.
A checklist of 30 species ofEndotricha Zeller in China is presented in this paper. Six species (E. dumalis sp. nov., E. lunulata sp. nov. E. medogana sp. nov., E. nigra sp. nov., E. purpurata sp. nov. and E. simipunicea sp. nov.) are new to science and three (E. admirabilis Kirpichnikova, E. fuscobasalis Ragonot and E. valentis Kirpichnikova) are recorded for the first time in China. The adult features and genital structures of the new species are illustrated and a key to the Chinese species is given.  相似文献   

2.
《生态学报》2007,27(10):F0003-F0003
China,as one of the most important Range States of orchids in the world, has about 1300 species with abundant varieties of orchids. However, owing to over, abuse harvest and illegal trades, the wild populations of these species have declined dramatically, even bringing some species to the edge of extinction. In response to such challenges, the Chinese  相似文献   

3.
《生态学报》2007,27(11):F0003-F0003
China, as one of the most important Range States of orchids in the world, has about 1300 species withabundant varieties of orchids. However, owing to over, abuse harvest and illegal trades, the wild populations ofthese species have declined dramatically, even bringing some species to the edge of extinction. In response to such challenges, the Chinese government has put conservation of orchids as a priority agenda, taking a series of Innovative and effective measures to protect the orchids in the wild.[第一段]  相似文献   

4.
Several reviews have focused on the nature of HIV infection and its spread in various geographical regions of China. In contrast, this review provides a comprehensive update on the prevalence of multiple HIV- 1 subtypes, consequent emergence of recombinant and novel forms of HIV- 1 in China, and the implications this may have on HIV diversity and the development of effective vaccines. In addition it also examines the dissemination of primary drug resistance in therapy naive patients, as well as co-infections with two other important viruses-hepatitis B and C. The main purpose of this review is to provide a current snapshot of HIV-1 pathogenesis in China and possibly shed some light on the future of HIV evolution, and potential challenges for future vaccine and anti-retroviral therapeutics against HIV strains in this area.  相似文献   

5.

Key message

Ulmus pumila vary its water use strategy from seedling to maturity in a water-limited sandy land by adopting different photosynthetical capacities, water use efficiencies and morphological traits.

Abstract

Regeneration failure of natural Ulmus pumila populations has become a growing concern related to vegetation conservation and prediction of environmental change in the sandy lands of northern China. To better understand the life-history strategies of U. pumila and its adaptation to drought in semiarid environments, we studied ecophysiological and morphological traits related to water use in an age sequence of U. pumila representing four age classes: current-year seedlings (Uc), age 2- to 5-year-old saplings (Us), juveniles (Uj), and mature trees (Um). A comparison of hydrogen isotope data in xylem sap, soil water in different layers and groundwater showed that Uc relied on the soil water in the topsoil (0–40 cm), Us and Uj absorbed soil water from deeper soil (>40 cm), while Um mainly used stable groundwater with very deep (>2 m) taproots. Significantly lower predawn leaf water potentials were observed in Uc than in Uj or Um, suggesting that Uc experienced more severe water stress and had a weaker capacity to recovery. Moreover, Uc had the highest daily maximum net assimilation rate, daily maximum transpiration rate and daily maximum stomatal conductance, all of which decreased remarkably at midday. A “go for broke” strategy is probably practiced by Uc which try to provide the growth they need to become established, but with a great risk of mortality. Um used a more conservative strategy by effectively regulating the instantaneous water-use efficiency, and maintaining both stable gas exchange levels and significantly higher long-term water-use efficiency. Uj endured and adapted to drought conditions by developing steeper leaf angles, denser leaf pubescence and more stomata than differently aged plants. Our findings illustrate that significantly different water-use strategies were developed by U. pumila trees as they grew from seedlings to maturity, which were based on different water sources.  相似文献   

6.
Summary More than three hundred nematode genus-group names omitted from or published since the CIH Keys to nematode parasites are listed. These names were abstracted from the generic indices of the Host-Parasite Catalogue of the Parasitic Worms Section, British Museum (Natural History). The various taxa are arranged, as far as possible, alphabetically according to the calssification used in the CIH Keys. Abbreviated references to the authorities for the taxa are given. It is hoped that this list will form a useful supplement to these keys.  相似文献   

7.
Recent Progress in Arabidopsis Research in China: A Preface   总被引:4,自引:0,他引:4  
In 2002, a workshop on Arabidopsis research in China was held in Shanghai, when a small group of Chinese plant scientists was working on this model species. Since then, we have witnessed the rapid growth of Arabidopsis research in China. This special issue of Journal of Integrative Plant Biology is dedicated exclusively to the Fourth Workshop on Arabidopsis Research in China, scheduled on November 30, 2005, in Beijing. In addition to reports collected in this special issue, the Chinese Arabidopsis community has been able to make significant contributions to many research fields. Here, I briefly summarize recent advances in Arabidopsis research in China.  相似文献   

8.
Pollutant dynamics and bioavailability greatly differ in soil and aquatic systems. Therefore, specific approaches and models are needed to assess the impact of soil contamination to terrestrial ecosystems. Earthworms among other soil invertebrates have received more attention because of their ecological importance. They represent a dominant part of the soil biomass and are soil engineers regulating important soil processes, notably fertilization. The release in soils of pollutants known for their persistence and/or their toxicity is a concern. Exposure of terrestrial species to pollutants that may alter genomic function has become an increasing topic of research in the last decade. Indeed, genome disturbances due to genetic and epigenetic mechanisms may impair growth, as well as reproduction and population dynamics in the long term. Despite their importance in gene expres- sion, epigenetic mechanisms are not yet understood in soil invertebrates. Until now, pollutant-induced changes in genome expression in natural biota are still being studied through structural alteration of DNA. The first biomarker relating to genotoxicant exposure in earthworms from multi-contaminated soils reported is DNA adducts measurements. It has been replaced by DNA breakage measured by the Comet assay, now more commonly used. Functional genomic changes are now being explored owing to molecular "omic" technologies. Approaches, objectives and results are overviewed herein. The focus is on studies dealing with genotoxicity and populational effects established from environmentally-relevant experiments and in situ studies [Current Zoology 60 (2): 255-272, 2014].  相似文献   

9.
Seven hundred and fourteen individuals of the Scilla sinensis (Louriro) Merrill complex were sampled from 21 populations at 19 localities in 10 provinces and two cities of China and investigated cytologically in order to test its cytotype composition and cytogeographical variation still further. Five cytotypes were found (i.e. AA (2n = 16), BB (2n = 18), AABB (2n = 34), AAA (2n = 24), and AABB 9 (2n =43)). Until now, nine of the 12 cytotypes have been identified on the continent, which indicates that it is an important place for the cytotypic differentiation of the complex. The cytotype AABB 9 is a new record on the continent. AAA was recorded for the second time in this complex. The majority of populations are composed of only one cytotype (AA, BB, or AABB), whereas another four populations consist of more than two cytotypes involving AA, BB, AAA, AABB, and AABB 9. The distribution of BB covers the entire region south to Huai River, whereas AA populations are distributed in Taiwan, Fujian, Hong Kong, and Guangdong and are isolated from its major distribution. The appearance of AABB 9 is possibly evidence for the degeneration of the subglobular bulb type of AABB and the fact that AAA and AAAA exist in the interior border regions of the range of this complex probably suggests that drought is a major factor promoting plant polyploidization. In addition, the mean numbers of B chromosomes per individual, the percentage of individuals with the B chromosome in each population, and the correlation coefficients between the latter and their latitude/longitude were calculated. Generally speaking, the B chromosome number is higher in BB populations compared with AA populations and there is a prominent tendency that the B chromosome content in either AA or BB populations correlates with the latitude and longitude of the populations.  相似文献   

10.
Richard Y ZHAO 《Cell research》2005,15(11):821-822
China has come a long way in fighting against HIV/AIDS epidemic. The Chinese government has taken an active role in combating this detrimental disease and such a welcome attitude by the Chinese government will certainly provide a positive spin on its effort in reducing the HIV/AIDS epidemic in China.  相似文献   

11.
Hepatitis B in China: from Guideline to Practice   总被引:1,自引:0,他引:1  
Chronic hepatitis B infection is a very important health problem in China, which is carrying an enormous economic and social burdens. The major routs of chronic hepatitis B infection in China are mother-infant vertical transmission and early childhood horizontal transmission. After more than 10 years implementation of universal vaccination against hepatitis B in newborns and safety injection in health care settings, the prevalence of HBsAg in general population has decreased from 9.75% to around 7%. In China, patients with hepatitis are cared by either hepatologists or physicians of infectious diseases. The Chinese Society of Hepatology, and Chinese Society of Infectious Diseases jointly issued an evidence-based guideline on the prevention and treatment of chronic hepatitis B in 2005. This guideline concisely describes the virology, epidemiology, natural history and prevention, as well as diagnosis and management of chronic hepatitis B. It also highlights the importance of active viral replication in disease progression in chronic HBV infection and explicitly states the necessity of antiviral therapy in patient care. The cornerstone of anti-hepatitis B therapy is optimal use of interferons or nucleos(t)ide analogs in those patients with active viral replication and elevated serum transaminase levels. Through an independent continue medical educational agency, a panel of selected speakers were trained to give well-formatted talks on the key points of the guideline in over 60 major cities across China. This educational campaign among health care providers has greatly improved the awareness and the stand of care for antiviral therapy.  相似文献   

12.
The spread of HIV in China has lasted for over 20 years,and is marked by three periods:sporadic period(1984-1988),localized epidemic period(1989-1994),  相似文献   

13.
Super Hybrid Rice Breeding in China:Achievements and Prospects   总被引:10,自引:0,他引:10  
Hybrid rice has contributed greatly to the self-sufficiency of food supply In China. To meet the future demand for rice production, a national program on super rice breeding was established In China In 1996. The corresponding targets, breeding strategies and most significant advances are reviewed In this paper. New plant type models have been modified to adjust to various rice growing regions. In recognition of the Importance of applying parents with Intermediate subspecies differentiation In Increasing F1 yield, medium type parental lines were selected from populations derived from Inter-subspecies crosses with the assistance of DNA markers for subspecies differentiation. Results also indicate that a substantial increase of blomass Is the basis for further enhancement of the grain yield potential, and amelioration of leaf characteristics Is helpful In Increasing the photosynthetic rate. Thirty-four super hybrid rice varieties have been released commercially, growing In a total area of 13.5 million hm2 and producing 6.7 thousand million kg more rice In 1998-2005. Although remarkable progress has been made In super hybrid rice breeding In China, selections on the root system and Integration of more blotechnologlcal tools remain a great challenge.  相似文献   

14.
Aphis glycines Matsumura is an important pest of soybean in Asia and North America. Hymenoptera parasitoids play a key role in the control of the soybean aphid. Thecorrect identification of parasitoids is a critical step that precedes the assessment of their potential biological control agents. Accurate identification of the majority of the speciesattacking the soybean aphid often requires elaborate specimen preparation and expert taxonomic knowledge. In this study, we facilitated the identification of soybean aphidparasitoids by applying a DNA barcoding approach following a preliminary morphological identification. We generated DNA sequence data from the mitochondrial COI gene andthe D2 region of 28S rDNA to assess the genetic variation within and between parasitoid species emerging from the soybean aphid in China. Fifteen Hymenoptera parasitoid speciesbelonging to 10 genera of five families were identified with little intra-specific variation (0.09% ± 0.06% for 28S and 0.36% ± 0. 18% for COI) and large inter-specific divergence(30.46% ± 3.42% for 28S and 20.4% ± 1.20% for COI).  相似文献   

15.
This study identifies 'centers of endemism' for typhlocybine leafhoppers in China, revealing diversity patterns and congruence of patterns between total species rich- ness and endemism. Distribution patterns of 774 Typhlocybinae (607 described and 167 undescribed species) were mapped on a 1.5° × 1.5° latitude/longitude grid. Total species richness, endemic species richness and weighted endemism richness were calculated for each grid cell. Grid cells within the top 5% highest values of weighted endemism richness were considered as 'centers of endemism'. Diversity patterns by latitude and altitude were obtained through calculating the gradient richness. A congruence of diversity patterns between total species richness and endemism was confirmed using correlation analysis. To investigate the bioclimatic factors (19 variables) contributing to the congruence be- tween total species richness and endemism, we compared the factor's difference between non-endemic and endemic species using the Kruskal-Wallis test. Eleven centers of en- demism, roughly delineated by mountain ranges, were identified in central and southern China, including the south Yunnan, Hengduan Mountains, Qinling Mountains, Hainan Is- land, Taiwan Island and six mountain areas located in western Sichuan, northwest Fujian, southeast Guizhou, southeast Hunan, central and western Guangdong, and north Zhejiang. Total species richness and endemic species richness decreased with increased latitude and had a consistent unimodal response to altitude. The proportions of endemism decreased with increased latitude and increased with rising altitude. Diversity patterns between total species richness and endemism were highly consistent, and 'Precipitation of Coldest Pe- riod' and 'Temperature of Coldest Period' may contribute to the congruence of pattern. Migration ability may play a role in the relationship of endemism and species richness; climate, environment factors and important geologic isolation events can also play crucial effect  相似文献   

16.
Li D 《Cell research》2007,17(4):273-273
The year of 2007 is the 100th anniversary of the American Association for Cancer Research (AACR), "marking a century of progress in saving lives through cancer research" (quote from the AACR website). Despite the great progress, cancer remains a top threat to human health. Continued research will be essential to winning the battle against cancer, as only through continued research would it be possible to gain better understandings, generate deeper insights, uncover new preventive and therapeutic strategies, design and test more effective treatments, and ultimately, save more lives.  相似文献   

17.
The first case of AIDS was reported in 1985 in China, but by the early 21st century, the government estimated that there were 840,000 citizens living with HIV/AIDS. The number is increasing rapidly. The major risk groups are injection drug users (IDUSs; 43%) and former plasma donors (27%), but rates among heterosexual groups are rising rapidly. Sentinel surveillance was initiated in 1986, and now includes IDUs, men-who-have-sex-with-men, sexually transmitted disease clinic attendees, antenatal women, long-distance truck drivers, and sex workers. Although the government was slow to respond to the epidemic in the late 20th century, it has made a vigorous response in the early 21st century. Components of that response include implementation and evaluation of harm reduction programs for IDUs, education to increase knowledge and reduce stigma, treatment and social support for rural and poor HIV/AIDS patients, widespread testing, and increased funding for HIV/AIDS programs. International agencies have been generous in their support of the government initiatives. To successfully combat the epidemic, China needs to develop and train the necessary infrastructure to implement its intervention programs, particularly in the rural areas, to vigorously combat stigma and discrimination, support research especially in the universities and research institutions other than the China Centers for Disease Control, develop a system for efficient exchange of research and program information, and update legislation to reflect the current situation.  相似文献   

18.
Twenty strains of Microcystis Kütz were isolated from different freshwater bodies in China to analyze the diversity, geographical distribution and toxin profiles. Based on whole-cell polymerase chain reaction of cpcBA-IGS nucleotlde sequence, the derived neighbor-joining (NJ) and maximum parsimony (MP) trees Indicate that these strains of Microcystis can be divided into four clusters. The strains from south, middle and north region of China formed distinct lineages, suggesting high diversity and a geographical distribution from south to north locations. Moreover, the results being indicating high variable genotypes of the strains of the Microcystis strains from the same lake show that there Is high diversity of Microcystis within a water bloom population. Comparing the results of the present study with those reported for compared with 43 strains of Microcystis from other locations, also reveals Chinese strains have high similarity with those from regions in the North Hemispherical. This suggests that the Microcystis strains In the world might have a geographical distribution. Analysis of 30 strains using the primers MCF/TER and TOX2P/TOX2M showed that there was no correlation between the gene of cpcBA-IGS and the presence of racy. Toxic strains were founded to be predominant in different water bodies throughout China.  相似文献   

19.
20.
Clonostachys phyllophila and Clonostachys rogersoniana were isolated from rhizosphere soil of Allium tuberosum in Chaoyang, Liaoning Province. It is the first report of the genus in China. The species was described morphologically and illustrated in this paper, the culture was stored in the Culture Collection of Liaoning Center of Culture Collection (LCCC).  相似文献   

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