Development of puberty in the White Fulani (Bos indicus) bull calf.     

T A Aire  J U Akpokodje 《The British veterinary journal》1975,131(2):146-151

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Impact of environmental factors on infestation of tea leaves byHelopeltis theivora, and associated changes in flavonoid flavor components and enzyme activities     

U. Chakraborty  N. Chakraborty 《Phytoparasitica》2005,33(1):88-96

Attack of tea plant (Camellia sinensis (L.) O. Kuntze) leaves by the tea mosquito bugHelopeltis theivora (Hemiptera: Miridae) was positively correlated to temperature and rainfall, and partially to humidity, as determined in 12 varieties during the period 2000–2002. The insect attack was severe during the months of May–September, which had high temperature and rainfall, and led to severe loss of biomass due to curling and drying up of the leaves. The biochemical response of these 12 varieties of tea to attack by the insect was determined with special reference to oxidative enzymes and flavonoid flavor components. Insect attack led to an increase in the activities of the oxidative enzymes peroxidase, ascorbate peroxidase and polyphenol oxidase. Activities of phenyl alanine ammonia lyase generally decreased as a result of insect attack, which was significant in the United Planters Association of South India (UPASI) varieties. A significant decrease in polyphenols was also obtained in UPASI varieties. HPLC analysis of catechins revealed a decrease in some of the catechins in the infected leaves. Analysis of theaflavins from infusion of healthy andHelopeltis-infested tea leaves revealed no changes. http://www.phytoparasitica.org posting Dec. 19, 2004.  相似文献   

Nutrition and Health of Dogs and Cats: Evolution of Petfood     

V. Bontempo 《Veterinary research communications》2005,29(2):45-50

Maintaining the health of dogs and cats by feeding wholesome nutritional diets is becoming an important component of responsible pet ownership. Pet owners now seek a long and healthy life for their pet and look to nutrition, as well as to veterinary medicine, to provide such support. Quality of life, measured in terms of reduced incidence of diseases and the ability to maintain an active life, would appear to be able to be enhanced by appropriate nutrition and nutraceutical supplementation. As a consequence numerous improvements in companion animal nutrition have resulted in development of a wide array of foods that provide complete and balanced nutrition. As a result emphasis also has to be placed on product safety and quality parameters, in connection with traceability. The origin of products, including product characteristics and properties, processing conditions and further handling throughout the period chain, is becoming ever increasingly an issue for collective chain management.  相似文献   

Sanitary Monitoring Models for Wild Ungulate Stock Farms in Tuscany     

A. Martini  P. Marconi  M. P. Ponzetta  A. Giorgetti  M. Viliani 《Veterinary research communications》2005,29(2):77-82

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Serodiagnosis of Burkholderia mallei Infections in Horses: State‐of‐the‐art and Perspectives     

H. Neubauer  L. D. Sprague  R. Zacharia  H. Tomaso  S. Al Dahouk  R. Wernery  U. Wernery  H. C. Scholz 《Zoonoses and public health》2005,52(5):201-205

Burkholderia mallei causes glanders or farcy in solipeds, a disease that must be reported to the OIE (Office International des Epizooties, Paris, France). The number of reported outbreaks has increased steadily during the last decade. Serodiagnosis is hampered by the considerable number of false‐positives and ‐negatives of the internationally prescribed tests. The major problem leading to low sensitivity and specificity of complement fixation test (CFT) and enzyme‐linked immunosorbent assay (ELISA) has been linked to the test antigens currently used, i.e. crude preparations of whole cells. Future perspectives for the development and evaluation of serological test kits using well‐characterized single antigens are discussed in the light of recent molecular research on B. mallei and the closely related saprozoonotic agent B. pseudomallei.  相似文献   

Characteristics for Practical Use of Attenuated Isolate UA-Fukushima of <Emphasis Type="Italic">Tomato mosaic virus</Emphasis>     

Tsutomu MATSUMOTO  Yuichiro NARA  Hiromitsu FURUYA  Harumi TAKAHASHI  Kiichi TAIRAKO  Hideki YAMAMOTO 《Journal of General Plant Pathology》2002,68(4):382-384

L₁₁A-Fukushima (L₁₁A-F) derived from attenuated isolate LuA of Tomato mosaic virus (ToMV) has the highest ability to cross protect against virulent ToMV among LuA and its derivatives and is stably inherited. Growth, yield, fruit quality and symptom attenuation of inoculated tomato plants did not differ significantly between L₁₁A-F and L₁₁A. The infectivity of progeny viruses in tomato infected with LuA-F was less than 4% of that with virulent ToMV. From these results, L₁₁A-F appears to possess the properties necessary for practical use. To manage L₁₁A-F strictly, a PCR-based assay to detect trace contamination of virulent ToMV in L₁₁A-F preparations was established. Received 10 June 2002/ Accepted in revised form 30 October 2002  相似文献   

Effects of Latent Infection of Stock Plants and Abundance of Thrips on the Occurrence of <Emphasis Type="Italic">Tomato spotted wilt virus </Emphasis>in Chrysanthemum Fields     

Shohei MATSUURA  Shigeru HOSHINO  Hideaki HAYASHI  Tetsuyuki KOHGUCHI  Kyoji HAGIWARA  Toshihiro OMURA 《Journal of General Plant Pathology》2002,68(1):99-102

DAS-ELISA proved to be reliable enough to detect a latent infection by Tomato spotted wilt virus (TSWV) in asymptomatic stock plants of chrysanthemum. A high density of Frankliniella occidentalis, the predominant vector, in the presence of latently infected stock plants resulted in a high incidence of disease in the chrysanthemum production field. The incidence of disease was low when the vector thrips were not abundant in spite of the presence of latently infected stock plants. These results suggest that an infestation of the vector thrips causes severe secondary spread of TSWV originating from latently infected stock plants in chrysanthemum production fields. Received 27 July 2001/ Accepted in revised form 27 November 2001  相似文献   

Modelling spatio-temporal dynamics of herbicide resistance     

O RICHTER  P ZWERGER  & U BÖTTCHER 《Weed Research》2002,42(1):52-64

A mathematical model has been developed for the risk assessment of the spread of genes conferring herbicide resistance in plant populations. The model combines an age-and-stage-structured population dynamic model, a population genetic model and a model of spatial spread. This is achieved by embedding a local matrix population model into a cellular automaton model with raster cells as spatial units. The dynamics of each cell is determined by both its local dynamics and the interaction with neighbouring cells. The model is applied to the evaluation of management strategies to delay or even to prevent long-term evolution of resistance in an annual grass weed. The results show that the appearance and spread of resistant genes is a highly non-linear process exhibiting threshold phenomena, which occur for a wide range of parameters. The properties of the seed survival curve constitute the `genetic memory' of the system and thus determine its long-term dynamics. It is possible to delay the evolution of resistance by suspension of treatment, reduction in herbicide application rate and introducing fallow periods. Spatial spread from an infested plot is inhibited by leaving untreated strips between adjacent fields.  相似文献   

Identification of ALS inhibitor‐resistant Amaranthus biotypes using polymerase chain reaction amplification of specific alleles     

J Wagner  H U Haas  K Hurle 《Weed Research》2002,42(4):280-286

Summary Polymerase chain reaction (PCR) amplification of specific alleles (PASA) was adapted as a molecular marker‐based method for the rapid detection of point mutations in Amaranthus retroflexus and Amaranthus rudis leading to ALS inhibitor resistance. Two pairs of primers were designed for the specific amplification of alleles of the ALS gene of susceptible and resistant biotypes. The allele‐specific primer matched the desired allele, but mismatched the different allele at its 3′ end. Differentiation was carried out by comparison of the amplified DNA fragments in gel electrophoresis after PASA‐PCR. In A. rudis, differentiation was possible with one PCR and genomic DNA as probe. A ‘nested’ PCR was necessary for the differentiation of sensitive and resistant A. retroflexus. PASA is useful for the identification of resistant weed biotypes and also as a monitoring tool to map resistance occurrence and distribution. Advantages include the fast and clear separation of those plants with and without mutations at an early stage of development, its easy and consistent performance and quick results compared with existing resistance detection tests. These advantages, when combined with management strategies, enable further activities to reduce herbicide resistance.  相似文献   

Variation in the response of melon genotypes to Fusarium oxysporum f.sp. melonis race 1 determined by inoculation tests and molecular markers     

Y. Burger  N. Katzir  G. Tzuri  V. Portnoy  U. Saar  S. Shriber  R. Perl-Treves  R. Cohen † 《Plant pathology》2003,52(2):204-211

Screening of genotypes of melon ( Cucumis melo ) for resistance to wilt caused by Fusarium oxysporum f.sp. melonis is often characterized by wide variability in their responses to inoculation, even under carefully controlled conditions. The variability at the seedling stage of 17 genotypes susceptible to race 1 was examined in growth-chamber experiments. Disease incidence varied from 0 to 100% in a genotype-dependent manner. Using four combinations of light (60 and 90  µ E m⁻² s⁻¹) and temperatures of (27 and 31°C), only light intensity showed a statistically significant effect. Marker-assisted selection for fusarium resistance breeding using cleaved amplified polymorphic sequence (CAPS) and sequence-characterized amplified region (SCAR) markers were compared using a single set of genotypes that included 24 melon accessions and breeding lines whose genotype regarding the Fom-2 gene was well characterized. The practical value of the markers for discriminating a range of genotypes and clarifying the scoring of phenotypes was also tested using a segregating breeding population which showed codominant SCAR markers to be useful in marker-assisted selection.  相似文献