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1.
Abstract: The Se San is an important tributary river basin of the Mekong. In 1993, Vietnam began building the Yali Falls Dam 80 kilometres upstream of the point at which this westward flowing river enters Cambodia. Ninety indigenous communities along the Se San River in two provinces of north‐eastern Cambodia have been impacted severely by flooding, and a dramatically altered hydrological regime that affects fisheries and all other aspects of livelihood, such as river bank agriculture. Since 2000, when the first turbines were commissioned, the affected communities have been increasingly vocal regarding the impacts of Yali and the plans for several more dams on upper reaches of the river. A complex set of actors including non‐governmental organisations, village, district and provincial authorities, national committees in Cambodia and Vietnam, the Mekong River Commission and a range of international players have become involved in a two‐track process, which has nevertheless allowed little space for negotiation over the Se San River on the part of those most directly affected. This case has fundamental implications for governance and conflict management in the Mekong and more widely. The Australian Mekong Resource Centre has been working with local actors to document the Se San case as part of an international project on River Basin Management: a negotiated approach, in support of six cases that involve up‐scaling of grassroots river basin initiatives in Africa, Latin America and Asia. In this article, we illustrate the significance of and problematise negotiation as a socially and politically embedded conflict management principle, with reference to the Se San case.  相似文献   

2.
H. De Haan 《Euphytica》1961,10(2):201-204
In this article a survey is given of motives for publishing on plant breeding research. The spate of publications should be welcomed.There is no need for a radical reorganization of publishing the results. It is a utopia to include all publications in one international journal. However, as concerns documentation in the field of plant breeding, it is advisable to adhere to one international journal (Plant Breeding Abstracts).  相似文献   

3.
Summary Utilization of exotic germplasm is one way to broaden genetic variation in breeding populations. This approach has recently been adopted in Sweden and Finland, where experimental barley populations has been established for research and pre-breeding purposes. The aim of the project is threefold: (1) to increase overall genetic diversity of Nordic barley breeding material; (2) to develop breeding material which possesses a high level of resistance for various barley diseases; and (3) to study effects of exotic germplasm on adaptation and agronomic performance. Both the Finnish and the Swedish barley populations include the same exotic material i.e. unadapted landraces from different parts of Asia and wild barley (Hordeum vulgare ssp. spontaneum) accessions. Locally adapted high-yielding barley lines were included in the populations. The establishment of these populations involved six crossing generations in order to promote recombination and enhance the break-up of linkage blocks. The paper discusses the third aim of the project. Studies on agronomic performance and adaptation showed that (1) agronomically valuable genotypes can be constructed through recombination using exotic germplasm for Nordic conditions, (2) that incorporation of exotic material is most successful when made in a local genetic base and (3) that exotic germplasm has an effect on adaptation.  相似文献   

4.
Summary During the last decades extensive progress has been achieved in winter barley breeding with respect to both, yield and resistance to fungal and viral diseases. This progress is mainly due to the efficient use of the genetic diversity present within high yielding adapted cultivars and – with respect to resistance – to the extensive evaluation of genetic resources followed by genetic analyses and introgression of respective genes by sexual recombination. Detailed knowledge on genetic diversity present on the molecular level regarding specific traits as well as on the whole genome level may enhance barley breeding today by facilitating efficient selection of parental lines and marker assisted selection procedures. In the present paper the state of the art with respect to virus diseases, i.e. Barley mild mosaic virus, Barley yellow mosaic virus, and Barley yellow dwarf virus is briefly reviewed and first results on a project aiming on a genome wide estimation of genetic diversity which in combination with data on yield and additional agronomic traits may facilitate the detection of marker trait associations and a more efficient selection of parental genotypes are presented. By field tests of 49 two-rowed and 64 six-rowed winter barley cultivars the genetic gain in yield for the period 1970–2003 was estimated at 54.6 kg ha−1 year−1 (r2 = 0.567) for the six-rowed cultivars and at 37.5 kg ha−1 year−1 (r2 = 0.621) for the two-rowed cultivars. Analysis of 30 SSRs revealed a non-homogenous allele distribution between two and six-rowed cultivars and changes of allele frequencies in relation to the time of release. By PCoA a separation between two and six-rowed cultivars was observed but no clear cut differentiation in relation to the time of release. In the two-rowed cultivars an increase in genetic diversity (DI) from older to newly released cultivars was detected.  相似文献   

5.
Abstract: Policies of decentralisation and democratisation since the end of the New Order of Indonesia in 1998 have seen a major shift of economic and political attention to the regions and widespread clamouring from local communities for more power in decision making and control over local resources. This regionalisation has led to a resurgence in interest in ‘tradition’ and a shift in the understanding of ‘culture’ as it was formed during the New Order. This article looks at contestations over the use of traditional culture in the regency of Manggarai (in Flores Island, Eastern Indonesia) and how, while political elites retain an image of culture similar to the New Order, local communities struggle to reform tradition in their own way and to regain local governance.  相似文献   

6.
气候变暖和人类活动导致青藏高原高寒草地生态系统面临空前挑战,为增强青藏牧区应对气候变化的能力,合理利用高寒草地资源,减少天然畜牧业温室气体排放,增加牧民收入和生计韧性。本研究团队承担实施了农业农村部(MARA)-世界银行(WB)-全球环境基金(GEF)气候智慧型草地管理技术研究,在青海省祁连县默勒镇实施牧民参与式的春季休牧和免耕补播等天然草地管理技术,监测草地植被多样性和生产力,通过卫星影像计算了研究区植被的归一化植被指数(NDVI),并对气候智慧型草地管理产生的社会影响、满意度和牧民经济情况进行调查的任务。气候智慧型草地管理技术试点和调查在默勒镇取得了丰富成果,草地生产力在春季休牧和免耕补播下分别提高了34.1%和50.0%,2种恢复措施均在一定程度上增加了草地植被多样性,NDVI显示恢复措施下的植被长势要好于对照地,此外,牧民对气候智慧型草地管理技术的满意程度达88.6%,实施管理技术直接或间接的增加了项目户牧民的收入,当地约80.0%的牧民的科学素养都有所提高。气候智慧型草地管理技术可以提高草地植被多样性、生产力和绿度覆盖,并且可以增加牧民收入,改善牧民生活环境,提高牧民科学素质,增强牧民应对气候变化的能力,从而助力牧区振兴。  相似文献   

7.
Abstract: Forest resource management in Thailand bears the mark of its historical position on the margins of colonial power and its present position in a biodiversity hotspot. During the colonial era, British forestry in Burma and India had a fundamental influence on the knowledge and techniques used in Thai forest management. More recently, international conservation agendas and organisations have influenced the ways in which the Thai government regulates the forest within its boundaries. The treatment of forests as a national and international resource, defined in interaction with colonial neighbours and global partners, has resulted in legal constructs, spatially simplistic conservation mechanisms and a conception of nature ill‐suited to managing forests as a local resource. This paper investigates the manifestation of Thailand's historical legacy in local park‐people conflicts by drawing on research conducted in a region where the government is establishing a national park. It finds that the continued use of laws, tools and concepts derived from colonial and global influences undermines the forestry department's ability to address the contemporary challenge of managing forests as a local, as well as a national/global, commons.  相似文献   

8.
Commercial productivity of watercress (Rorippa nasturtium-aquaticum) can be adversely affected by the pathogenic crook-root fungus, Spongospora subterranea f.sp. nasturti, and watercress viruses. As there are no effective control measures for these diseases, attempts have been made to breed varieties resistant to the crook-root pathogen. This work has been hindered by a lack of knowledge of the genetic base of commercial watercress, and the genetic distance between watercress and allied Brassicaceae which have been identified as candidates for hybridisation programmes. We measured the diversity within these two groups using the RAPD-PCR fingerprinting technique and analysed the data by both distance methods and principal co-ordinate analysis. Little genetic diversity was found within commercial watercress populations. However, watercress formed a unique cluster genetically distinct from other Rorippa species, but equidistant to Cardamine species. It was placed closer to Barbarea verna. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

9.
The tepary bean (Phaseolus acutifolius A. Gray) is grown mainly in and regions of Mexico and the southwestern U.S. as a subsistence crop by small farmers. It is also a store of genetic variability for traits such as disease and pest resistance and stress tolerance to improve the common bean (P. vulgaris L.). To determine geographic patterns of variation and the influence of domestication on genetic variability, the genetic diversity of phaseolin, the major seed storage protein, was characterized among 55 wild and 8 cultivated teparies using polyacrylamide gel electrophoresis. Fifteen electrophoretic phaseolin patterns were identified among wild forms, whereas only one pattern was exhibited by cultivars. This result suggests a single domestication in this species leading to a strong reduction in diversity. An additional finding is the divergence m phaseolin types between populations east and west of the Sierra Madre Occidental mountains.  相似文献   

10.
The renewed interest in spelt (Triticum spelta L.) for wheat improvement programmes requires the study of the available genetic diversity. The purpose of this study was to assess genetic diversity within a Spanish spelt collection. Sixty‐six Spanish spelt accessions, 19 accessions of T. spelta and T. macha from different origins, three bread wheat cultivars (T. aestivum) and one accession of T. dicoccum were screened using simple sequence repeats (SSRs). The diversity observed within the Spanish group was comparable with that observed in the other wheat varieties, despite their broader geographical diversity. Indeed, the highest polymorphic information content value calculated with SSRs for Spanish material (0.90) is similar to that observed for the other wheat varieties (0.98). Principal component analysis explained 46.5% of the cumulative variation and confirmed the Spanish accessions as a separate group. This study showed the Spanish spelt collection to be a variable and unique genetic resource for wheat and spelt breeding programmes.  相似文献   

11.
Summary The availability of a wide genepool is a prerequisite for crop improvement and the material involved is usually conserved in collections. The genetic resources of most crops can be conserved as seed but some vegetatively propagated crops and those that produce recalcitrant seeds cannot. In vitro (tissue culture) storage methods including cryopreservation in liquid nitrogen are being developed to conserve such problem materials in a complementary way to the maintenance of whole plants in the field. To aid the effective utilization of plant genetic resources, it is essential that as much associated information as possible be available to potential users — the plant breeders. The International Board for Plant Genetic Resources (IBPGR) has taken the lead in genetic conservation work including related areas of information management. A significant example is the promotion of in vitro conservation. The IBPGR's In Vitro Programme includes the establishment of databases holding data on technological developments. An international survey of the in vitro research community is conducted by questionnaire every two years. Data are gathered on the crop under investigation, field of interest, propagation method, problem areas, characterization, disease indexing, exchange of cultures, and storage of material under normal or slow growth conditions or by cryopreservation. The survey returns are computerized into databases that are available for consultation by request. Such databases have been compiled for in vitro research carried out in 1980, 1983 and 1985. The 1985 database, for example, covers the work of 589 scientists who contributed information on 654 different species. The most recent phase of the project involved the circulation of a new questionnaire to approximately 2,500 scientists in over 70 countries. All databases are available for search requests.  相似文献   

12.
Summary A survey of allozyme polymorphism at 11 loci was carried out on 439 accessions from the genus Lens. This comprised 153 Lens culinaris subsp. orientalis, 35 L. odemensis, 117 L. ervoides, 32 L. nigricans, 2 of a differentiated cytotype of L. nigricans and 100 landrace accessions of the cultivated lentil (L. culinaris subsp. culinaris), from 10 different countries. The aim of the survey was to determine intra-specific genetic diversity and species relationships, based on phylogenetic and phenetic analyses, particularly regarding the position of L. odemensis and the differentiated cytotype of L. nigricans. Diversity was described by three statistics. The level of diversity in the cultivated taxon was lower than in any of the wild species according to two of these statistics, the percentage of polymorphic loci and mean number of alleles per locus. For the third measure (Nei's mean genetic diversity) it was only greater than L. ervoides. Genetic diversity statistics of the wild species indicated differences in the nature of between-population genetic diversity within the different taxa. Phylogenetic analysis suggests that L. odemensis and L. ervoides evolved from a common ancestor, and L. culinaris subsp. orientalis subsequently evolved from L. odemensis. Phenetic analysis, however, places L. odemensis closer to L. culinaris subsp. orientalis than to L. ervoides. Nei's mean genetic distance of L. odemensis from both L. culinaris subsp. culinaris (0.204) and L. culinaris subsp. orientalis (0.110) was greater than the distance between them (0.062). This evidence is not conclusive in determining whether L. odemensis should retain its specific status. Further crossability studies should be carried out on a range of genotypes to assess the potential for gene flow. The evidence presented shows the differentiated cytotype of L. nigricans to be quite distinct from other L. nigricans accessions, both phenetically and phylogenetically. This indicates that the differentiated cytotype of L. nigricans may constitute a new taxon. Discriminant function analysis reveals that isozymes may be useful in validating species classification.  相似文献   

13.
Jute is one of the most important fibre crops, which is second only to cotton in providing environment-friendly (biodegradable and renewable) ligno-cellulose fibre. In order to improve this largely neglected crop, we conducted a preliminary study involving the following: (i) analysis of nature and extent of the genetic variability for fibre yield and four other related traits in a set of 81 genotypes belonging to two commercially cultivated Corchorus species (45 genotypes of C. olitorius + 36 genotypes of C. capsularis), (ii) development and analysis of a set of simple sequence repeat (SSR) markers from C. olitorius, and (iii) use of a sub-set of SSRs for assessment of genetic diversity in the above set of 81 genotypes. The results suggested quantitative nature of fibre yield and other related traits, with a preponderance of dominance component in genetic variance. A sub-set of 45 SSRs derived from C. olitorius, when used for a study of DNA polymorphism and genetic diversity, showed high transferability of these C. olitorius SSRs to C. capsularis. The average number of alleles for individual SSRs was surprisingly low (3.04 for both species, 2.02 for C. capsularis and 2.51 for C. olitorius), and so was the average polymorphic information content (PIC; 0.23 and 0.24 in two species). In the dendrogram obtained using a similarity matrix, the 81 genotypes were grouped into three clusters, which largely corresponded to the two species, Cluster I belonging mainly to C. capsularis and the other two closely related clusters (clusters II and III) belonging to C. olitorius. It was also shown that a minimum of 15 SSRs could give the same information as 41 SSRs, thus making many SSRs redundant. The SSR markers developed during the present study and to be developed in future will prove useful not only for evaluation of genetic diversity, but also for molecular mapping/QTL analysis, and for comparative genome analysis of the two Corchorus species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

14.
Wild soybean (Glycine soja), as the progenitor of soybeans (G. max), is widely distributed in China and has been collected as a supplementary germplasm pool of soybeans. In this study, 375 wild soybean accessions from a set of genebank core collection were analysed for genetic diversity by using 42 simple sequence repeat primer pairs. The mean allele number per locus was 19.62. Ten‐percent unique alleles involving 35 or 83.33% loci differentiated among the geographical regions. The mean gene diversity (h) per locus was 0.89. A very low mean coefficient of gene differentiation (GST = 0.08) for geographical regions and a high mean within‐region gene diversity (HS = 0.81) were observed, indicating that most genetic diversity existed within the regions. There was an obvious relationship between genetic distance and geographical distance. The results showed multiple centers of genetic diversity for Chinese wild soybean in North China, the Huanghe River Valley, and Central China as well as the Changjiang River Valley, implicating multiple site origins of soybeans within China.  相似文献   

15.
This paper reports on a recent research project into rural–urban labour migrants in Shanghai, China, who are members of ethnic minorities, inquiring into the role of ethnicity in national labour migration. It introduces some of the main features of the ethnic nationalities (minzu) in China and considers some of the literature on rural–urban migration in China which may be considered as relevant to ethnicity. The case of a Miao minority family in Shanghai is described in detail to argue that what remains important to them in the city is not their formal ethnic affiliation (minzu) so much as a sub‐ethnic identity of connectedness and intimacy, importantly related to kinship and place.  相似文献   

16.
It is important to couple phenotypic analysis with genetic diversity for germplasm conservation in gene bank collections. The use of molecular markers supports the study of genetic marker-trait associations of biological and agronomic interest on diverse genetic material. In this report, 19 Greek traditional sweet cherry cultivars and two international cultivars, which were used as controls, were grown in Greece and characterized for 17 morpho-physiological traits, 15 simple sequence repeat (SSR) loci and 10 inter simple sequence repeat (ISSR) markers. To our knowledge, this is the first report on molecular genetic diversity studies in sweet cherry in Greece. Principal component analysis (PCA) of nine qualitative and eight quantitative morphological parameters explain over 77.33% of total variability in the first five axes. The SSR markers yielded a combined matching probability ratio (MPR) of 9.569 × e−12. The 15 SSR loci produced a total of 92 alleles. Ten ISSR primers generated 91 bands, with an average of 9.1 bands per primer. Expected heterozygosity (gene diversity) values of 15 SSR loci and 10 ISSR markers averaged at 0.683 and 0.369, respectively. Based on stepwise multiple regression analysis (MRA), SSR alleles were found associated with harvest time and fruit polar diameter. Furthermore, three ISSR markers were correlated with fruit harvest and soluble solids and four ISSR markers were correlated with fruit skin color. Stepwise MRA identified six SSR alleles associated with harvest time with a high correlation (P < 0.001), with linear associations with high F values. Hence, data analyzed by the use of MRA could be useful in marker-assisted breeding programs when no other genetic information is available.  相似文献   

17.
Genetic diversity of wheat wild relatives in the Near East detected by AFLP   总被引:3,自引:0,他引:3  
In order to reveal the molecular genetic diversity of wheat wild relatives, an AFLP analysis was conducted with 16 accessions of five Triticum andAegilops species originating from the Near East. Variation within population was studied with at least seven individuals per accession. Four primer combinations were used for selective amplification. Based on the scored bands, we estimated percentage of polymorphic bands, 1 – proportion of shared bands (1-psb) and nucleotide diversity (π). Of the five species used in this study, Ae. speltoides had the highest level of `within population' variation. This species had also the highest value of the variation among populations. As for Triticum species, the level of variation within population was low in diploid species (T. urartu and T. boeoticum),whereas two tetraploid species (T. dicoccoides and T. araraticum) had relatively high levels of variation within population. While the two diploid Triticum indicated a clear interspecific divergence, the two tetraploid wild wheats were not clearly divergent in this study. The variance portioning analysis indicated that the variation detected for diploid Triticum species was mainly composed of `between species' variation, on the other hand that for tetraploid Triticum was mostly composed of `within population' variation. In conclusion, AFLP analysis reveals molecular variation in all accessions used in this study, suggesting a potential genetic diversity of the wheat wild relatives in natural populations. These results have implications for the design of strategies to maintain genetic diversity within genebank collections. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

18.
In the present study diversity in a collection of the Garden Beet Group,consisting of 40 accessions from the BAZ Gene Bank and Polish cultivars, was evaluated in a two-year field trial. Thirteen morphological and yield traits were evaluated as well as content of betanin, vulgaxanthine, sugars, and nitrates in root tissue. The study revealed that accessions characterised by circular root shape and dark red skin, flesh and ring colour were the most common. It was also possible to identify several highly distinct accessions. The results allowed to assess genetic diversity and to make suggestions on rearranging of the Garden Beet Group core collection, which was previously set up a priori.Accessions showing a high nutritional value, potentially useful for quality breeding, were indicated. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

19.
Abstract: The Vietnamese state's interaction with international capital has been influenced by the Communist Party's strategy to develop a ‘socialist market economy’ which aims to maintain the leading role of the state and its one party dominance while implementing economic reforms. This is at odds with alternatives proposed by neo‐liberal institutions such as the IMF and World Bank who favour a progression towards a more fully‐fledged market economy coupled with political pluralism. As a result, foreign investors and the Vietnamese government have had a turbulent relationship over the past decade stemming in large part from differing perceptions of a market economy and what foreign investment should entail. This paper depicts the principal issues that lay behind the restrictive policies toward foreign tour operators through a case study of their management and regulation in Vietnam throughout the 1990s. It is argued that foreign tour operators and Vietnamese tourism authorities perceive the role of international capital in tour operations quite differently. Over‐regulation has provided little space for foreign tour businesses to operate in a manner that has met their expectations, while government policies have been intent on ensuring that profits remain in the country. This paper also illustrates how social networks undermine top‐down government policy directives and allow foreign tour businesses to continue operating, albeit in a complex and insecure environment.  相似文献   

20.
D. Sicard    L. Nanni    O. Porfiri    D. Bulfon    R. Papa 《Plant Breeding》2005,124(5):464-472
The genetic diversity of 66 Phaseolus genotypes was investigated, which included 14 local varieties of Phaseolus vulgaris and nine local varieties of P. coccineus, collected in Marche, central Italy. Their genetic diversity was assessed using three types of molecular marker: inter simple sequence repeats (ISSRs), nuclear gene‐tagged simple sequence repeats (SSRs) and chloroplast simple sequence repeats (CpSSRs). Phaseolus vulgaris shows a higher genetic diversity than P. coccineus for the SSRs and CpSSRs, but not for the putative neutral ISSR markers. These data suggest that selection by farmers and adaptation to heterogeneous environments has maintained the diversity in landraces of the common bean. Comparing genetic diversity in Marche with that of the American controls reveals that 71% of the local P. vulgaris varieties in Marche are of Andean origin. The two gene pools of the common bean can be found on the same farm, and there is some evidence of past hybridization events between these two gene pools.  相似文献   

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