Long chain alkanes in silk extracts of maize genotypes with varying resistance to Fusarium graminearum     

Miller SS  Reid LM  Butler G  Winter SP  McGoldrick NJ 《Journal of agricultural and food chemistry》2003,51(23):6702-6708

The alkane content of the silks of nine maize genotypes was analyzed to investigate the role of silk wax in resistance to Fusarium graminearum. Silk samples were collected 2, 4, 6, and 8 days after silk emergence and divided into three sections: exposed silk, silk channel silk, and silk that is under the husk and overlying the kernels. Four major unbranched alkanes (C(25), C(27), C(29), and C(31)) and three isoalkanes (C(27i), C(29i), and C(31i)) were identified. Total alkane contents were highest in the exposed silk followed by the silk channel silk, with the lowest in the youngest silk closest to the kernels. In the silk channel and overlying kernel silks, the moderately resistant inbred CO272 consistently had the highest alkane content. None of the other inbreds with improved resistance had as high a level of alkanes as CO272, indicating that alkane content is not a major mechanism of resistance.  相似文献   

优化灌溉和施肥对冬小麦产量的影响   总被引：6，自引：4，他引：6       下载免费PDF全文

范仲学  王璞M．Boening-Zilens 梁振兴 W．Claupein 《麦类作物学报》2003,23(4):99-103

为了探讨传统水氮管理和优化水氮管理对冬小麦产量的影响，于1999～2000年在中国农业大学中德合作项目北京试验基地进行了包括灌溉、氮肥和秸秆3因素共18个处理组合的田间试验。传统水氮管理尽量模仿当地农民的生产实际，优化水氮管理以冬小麦生长发育的需要为原则，结合土壤水分和土壤养分的实测值来具体确定。结果表明，优化灌溉在节水11mm的情况下，小麦产量与传统灌溉无显著性差异；优化施氮与传统施氮相比，氮肥用量降低了75％，但产量并不降低；秸秆还田与秸秆不还田相比，冬小麦产量无明显变化。上述结果表明，在保持产量不降低的前提下，华北平原小麦生产中节水的空间相对较小，而节肥(指氮肥)的空间相对较大，优化施氮管理值得大力推广。  相似文献   

Dietary patterns of two herbivorous rodents: Otomys unisulcatus and Parotomys brantsii in the Karoo     

A. du Plessis  G.I.H. Kerley  P.E.D. Winter 《African Zoology》2013,48(2):51-54

Differences and overlap in the diets of two sympatric, herbivorous rodents Otomys unisulcatus and Parotomys brantsii were investigated. Frequency of occurrence of plant species in the diets were compared with availability of the plants in the rodents' habitats. Both rodents are generalist herbivores, eating plants species in proportion to the availability in their habitats. Dietary patterns, diversity of diet and degree of overlap between rodent's diets are a function of food availability in the different habitats. It is suggested that these rodents separate niches on a spatial rather than trophic basis. Differences in dietary patterns are therefore not critical for niche separation but are the result of habitat segregation.  相似文献   

The plant viruses and viroids database and collections of Q‐bank     

J. W. Roenhorst  N. Boonham  S. Winter  W. Menzel  R. A. A. van der Vlugt 《EPPO Bulletin》2013,43(2):238-243

The availability of characterised reference isolates of plant pathogens is of crucial importance for research and diagnostic laboratories. The Q‐bank Plant Viruses and Viroids database contains data and information on plant viruses and viroids, with the unique feature that it is linked to specimens present in publicly available physical collections. The Q‐bank database aims to share data and information on the virus and viroid species and their availability between research and diagnostic laboratories. Currently the database focuses on regulated virus species. In future more plant viruses and viroids will be included to provide a comprehensive data and information system. The curators invite virologists worldwide to participate in this international initiative by making their data and isolates available via Q‐bank ( http://www.q-bank.eu ).  相似文献   

Diagnostic ultrasonography in cattle with diseases of the mammary gland     

Flöck M  Winter P 《Veterinary journal (London, England : 1997)》2006,171(2):314-321

Fifty-two cattle with diseases of the udder were evaluated by means of sonography between 2000 and 2004. The udders were examined with 3.5 and 5.0 MHz convex transducers and 7.5 and 13.0 MHz linear transducers. Bacteriological examinations were also performed on individual quarter samples. Ultrasonography gave additional information on the status of the udder and showed findings specific for some causal agents, e.g., Enterobacteriaceae and Arcanobacterium pyogenes as well as udder haematomas. All forms of mastitis required bacteriological confirmation for the final diagnosis.  相似文献   

The role of community policies in defensible space compliance   总被引：1，自引：0，他引：1  

Greg Winter  Sarah McCaffrey  Christine A. Vogt 《Forest Policy and Economics》2009,11(8):570-578

Recently enacted federal and state policies provide incentives, including financial assistance, for local jurisdictions to manage risks associated with wildland fire. This has led to an array of local-level policies designed to encourage homeowners to create fire-safe landscapes. This qualitative study collected data from focus group interviews with homeowners in three diverse communities and used the theory of reasoned action to interpret dimensions of local-level wildland fire policies that are associated with homeowner acceptance of or compliance with defensible space guidelines or regulations. Common factors emerged in two policy evaluation categories: acceptance and compliance. WUI homeowners are more accepting of policies that are seen as fair and part of a more comprehensive risk reduction strategy. Topics that shaped acceptance of voluntary versus mandatory approaches included perceived risk severity, views about the proper roles of government, and beliefs about alternatives to regulatory approaches (e.g. private insurance, education, ignition source reduction). Program characteristics that were found to be related to beliefs about defensible space and acceptance included provision of one-on-one expert consultation, direct mail communication modes, needs-based financial assistance, and enhanced yard waste disposal options. Homeowner compliance is related to the feasibility in terms of household costs and yard waste disposal options, neighborhood norms, competing land use objectives, insurance considerations, and whether or not the policy is mandatory. These findings led to a proposed conceptual model of vegetation management policy acceptance and compliance that local governments can use to develop or amend defensible space vegetation management policies to increase policy acceptance and compliance.  相似文献   

Possibilities for harmonizing national forest inventory data for use in forest biodiversity assessments   总被引：1，自引：0，他引：1  

Winter  Susanne; Chirici  Gherardo; McRoberts  Ronald E.; Hauk  Elmar; Tomppo  Erkki 《Forestry》2008,81(1):33-44

Representatives of the national forest inventories (NFIs) of27 European countries and the USA evaluated possibilities fora common approach to forest biodiversity reporting. The projectwas conducted under the auspices of COST (European Cooperationin the field of Scientific and Technical Research) Action E43,‘Harmonisation of National Forest Inventories in Europe:Techniques for Common Reporting’. Based on the analysisof responses to an initial questionnaire regarding the mostecologically important and technically feasible variables formonitoring forest biodiversity using NFI data, 16 key variableswere selected. Responses to a second questionnaire consistingof six questions regarding assessment of the 16 key variablesrevealed that the NFIs of most responding countries alreadyassess a large proportion of these variables. Each of the 16variables is assessed in at least eight NFIs. However, the responsesregarding assessment methods and necessary field crew expertisevaried considerably. As a first example, although tree diametersat breast height (d.b.h.) are assessed by every country, thereis a wide range of minimum d.b.h. thresholds from 0 mm in Finlandto 12 cm in Cyprus and Switzerland. As a second example, eightcountries estimated that almost all inventory variables requirehighly skilled forest staff with specialized training, but mostcountries agree that a middle level of expertise is sufficient.Despite differences in current NFI methods, overall, the resultsof the study indicate positive possibilities for achieving amoderate level of European-wide harmonization.  相似文献   

Adapting clonally propagated crops to climatic changes: a global approach for taro (<Emphasis Type="Italic">Colocasia esculenta</Emphasis> (L.) Schott)     

V. Lebot  V. Tuia  A. Ivancic  G. V. H. Jackson  F. Saborio  G. Reyes  S. Rodriguez  G. Robin  R. Traoré  L. Aboagye  J. Onyeka  W. van Rensburg  V. Andrianavalona  A. Mukherjee  M. S. Prana  D. Ferraren  B. Komolong  F. Lawac  S. Winter  M. A. A. Pinheiro de Carvalho  T. Iosefa 《Genetic Resources and Crop Evolution》2018,65(2):591-606

Clonally propagated crop species are less adaptable to environmental changes than those propagating sexually. DNA studies have shown that in all countries where taro (Colocasia esculenta (L.) Schott) has been introduced clonally its genetic base is narrow. As genetic variation is the most important source of adaptive potential, it appears interesting to attempt to increase genetic and phenotypic diversity to strengthen smallholders’ capacity to adapt to climatic changes. A global experiment, involving 14 countries from America, Africa, Asia and the Pacific was conducted to test this approach. Every country received a set of 50 indexed genotypes in vitro assembling significant genetic diversity. After on-station agronomic evaluation trials, the best genotypes were distributed to farmers for participatory on-farm evaluation. Results indicated that hybrids tolerant to taro leaf blight (TLB, Phytophthora colocasiae Raciborski), developed by Hawaii, Papua New Guinea and Samoa breeding programmes outperformed local cultivars in most locations. However, several elite cultivars from SE Asia, also tolerant to TLB, outperformed improved hybrids in four countries and in one country none of the introductions performed better than the local cultivars. Introduced genotypes were successfully crossed (controlled crossing) with local cultivars and new hybrids were produced. For the first time in the history of Aroids research, seeds were exchanged internationally injecting tremendous allelic diversity in different countries. If climatic changes are going to cause the problems envisaged, then breeding crops with wide genetic diversity appears to be an appropriate approach to overcome the disasters that will otherwise ensue.  相似文献   

Identification of mungbean lines with tolerance or resistance to yellow mosaic in fields in India where different begomovirus species and different <Emphasis Type="Italic">Bemisia tabaci</Emphasis> cryptic species predominate     

R. M. Nair  M. Götz  S. Winter  R. R. Giri  V. N. Boddepalli  A. Sirari  T. S. Bains  G. K. Taggar  H. K. Dikshit  M. Aski  M. Boopathi  D. Swain  A. Rathore  V. Anil Kumar  E. C. Lii  L. Kenyon 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(2):349-364

The segmentation of symptoms during image analysis of diseased plant leaves is an essential process for detection and classification of diseases. However, there are challenges involved in the task, many of them related to the variability of image and host/symptom characteristics and conditions. As a result of those challenges, the methods proposed in the literature so far focus on a specific problem and are usually bounded by tight constraints regarding image capture conditions. This research explores a new automatic method for segmenting disease symptoms on plant leaves that was designed to be applicable in a wide range of situations. The proposed technique employs only color channel manipulations and Boolean operations applied on binary masks, thus being simpler and more robust compared to many previously described automatic methods. Its effectiveness is demonstrated by tests performed over a large database containing images of 77 different diseases of 11 plant species. A comparison with manual segmentation is also presented, further reinforcing the advantages of the proposed approach.  相似文献   

Intraoperative use of a transarticular circular fixator construct to facilitate reduction and stabilisation of a proximal tibial physeal fracture in a dog          下载免费PDF全文

MD Johnson  DD Lewis  MD Winter 《Australian veterinary journal》2017,95(5):161-166

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