小麦对条锈病的水平抗病性研究初报   总被引：4，自引：0，他引：4  

曾士迈  王沛有  武修英  张万义  王吉庆  宋位中  王生元 《植物保护学报》1979,6(1):1-10

将小麦品种采用随机区组的田间设计种于小种病圃中,以鉴定和测定其水平抗性。根据各个“品种——小种”组合的相对病情指数的方差分析的结果,有些品种,如农大311、西农6028和丰产3号,其品种——小种互作高度显著,被鉴定为具有垂直抗性,另外一些品种,对试验所用的小种并无专化性,并且在大田生产中已显出20多年的持久的中度抗性,初步推测为属水平抗性。在后一类中,有些品种,如平原50,表现为中等反应型,其余则属于呈典型感病的迟锈慢锈类型。在迟锈慢锈品种的病指的对数矫正值(logits)和病圃的锈病强度(以感病对照品种的病指表之)的对数矫正值之间发现了直线回归。  相似文献   

Decay of female sexual behavior under parthenogenesis     

Carson HL  Chang LS  Lyttle TW 《Science (New York, N.Y.)》1982,218(4567):68-70

A laboratory strain of Drosophila mercatorum has existed for 20 years without males and therefore without natural selection operating to maintain the genetic basis of female mating behavior. The females of this strain have recently experienced a genetic impairment of mating capacity. This observation exemplifies the mode of evolution of vestigial characters and supports Muller's theory that random mutation will tend to destroy the genetic basis of a character from which selection has been removed.  相似文献   

‘Plantibodies’: a flexible approach to design resistance against pathogens     

A. Schots  J. De Boer  A. Schouten  J. Roosien  J. F. Zil Verentant  H. Pomp  L. Bouwman-Smits  H. Overmars  F. J. Gommers  B. Visser  W. J. Stiekema  J. Bakker 《European journal of plant pathology / European Foundation for Plant Pathology》1992,98(2):183-191

Engineering resistance against various diseases and pests is hampered by the lack of suitable genes. To overcome this problem we started a research program aimed at obtaining resistance by transfecting plants with genes encoding monoclonal antibodies against pathogen specific proteins. The idea is that monoclonal antibodies will inhibit the biological activity of molecules that are essential for the pathogenesis. Potato cyst nematodes are chosen as a model and it is thought that monoclonal antibodies are able to block the function of the saliva proteins of this parasite. These proteins are, among others, responsible for the induction of multinucleate transfer cells upon which the nematode feeds. It is well documented that the ability of antibodies to bind molecules is sufficient to inactivate the function of an antigen and in view of the potential of animals to synthesize antibodies to almost any molecular structure, this strategy should be feasible for a wide range of diseases and pests.Antibodies have several desirable features with regard to protein engineering. The antibody (IgG) is a Y-shaped molecule, in which the domains forming the tips of the arms bind to antigen and those forming the stem are responsible for triggering effector functions (Fc fragments) that eliminate the antigen from the animal. Domains carrying the antigen-binding loops (Fv and Fab fragments) can be used separately from the Fc fragments without loss of affinity. The antigen-binding domains can also be endowed with new properties by fusing them to toxins or enzymes. Antibody engineering is also facilitated by the Polymerase Chain Reaction (PCR). A systematic comparison of the nucleotide sequence of more than 100 antibodies revealed that not only the 3′-ends, but also the 5′-ends of the antibody genes are relatively conserved. We were able to design a small set of primers with restriction sites for forced cloning, which allowed the amplification of genes encoding antibodies specific for the saliva proteins ofGlobodera rostochiensis. Complete heavy and light chain genes as well as single chain Fv fragments (scFv), in which the variable parts of the light (V_L) and heavy chain (V_H) are linked by a peptide, will be transferred to potato plants. A major challenge will be to establish a correct expression of the antibody genes with regard to three dimensional folding, assembly and intracellular location.  相似文献   

Comparison of morphology, viability, and function between blood and milk neutrophils from peak lactating goats          下载免费PDF全文

Sui Zhi Tian  Chai Ju Chang  Chih Chi Chiang  Huo Cheng Peh  Mu Chiou Huang  Jai-Wei Lee    Xin Zhao 《Canadian journal of veterinary research》2005,69(1):39-45

The morphological features of blood and milk neutrophils from peak lactating goats were compared using light microscopy, scanning electron microscopy and flow cytometry in order to investigate the cytological changes of neutrophils after migration into the mammary gland. The kinetics of reactive oxygen intermediates (ROI) generation and gelatinase release of blood and milk neutrophils, with or without stimulation of phorbol 12-myristate, 13-acetate ester (PMA), were used to characterize their responses to inflammatory stimuli. Neutrophils isolated from goat milk were highly segmented and contained multi-lobed nuclei. Ultrastructurally, milk neutrophils were more ruffled on the surface compared to blood neutrophils. Approximately 30% of milk neutrophils were undergoing cell death, either necrosis or apoptosis, in contrast to 8% of blood neutrophils. The ROI production of activated milk neutrophils peaked earlier than blood neutrophils, but the duration and the intensity were much less. Neutrophils from both sources augmented the release of gelatinase in response to PMA (1 ng/mL). However, the amount of gelatinase released from milk neutrophils was lower (P < 0.05) than that of blood neutrophils. In summary, more neutrophils become apoptotic and necrotic in the mammary gland, presumably due to spontaneous aging, the process of diapedesis, and the interaction with milk components. Milk neutrophils have impaired functionalities in comparison with blood neutrophils. The information is relevant when studying mammary gland immunity and related diseases, such as mastitis.  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   

棉铃虫性诱剂诱捕器的改进及其应用研究     

刘定忠  王荣龙  余昌喜 《中国植保导刊》2002,22(7):8-10

利用废弃的食用油油壶制成棉铃虫诱捕器,可提高诱蛾的效果。挡板距诱捕器器口的距离以3cm的效果最佳。与常规水钵、水盆诱捕器相比较,全年诱蛾总量分别增加116.3％和减少79.8％,但诱蛾灵敏度均高出18.72％。  相似文献   

Distribution of citrus viroids and <Emphasis Type="Italic">Apple stem grooving virus</Emphasis> on citrus trees in Japan using multiplex reverse transcription polymerase chain reaction     

Takao Ito  Nobuyuki Namba  Tsutae Ito 《Journal of General Plant Pathology》2003,69(3):205-207

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Indole-3-acetic acid biosynthesis in <Emphasis Type="Italic">Aciculosporium take</Emphasis>, a causal agent of witches' broom of bamboo     

Eiji Tanaka  Chihiro Tanaka  Atsushi Ishihara  Yasumasa Kuwahara  Mitsuya Tsuda 《Journal of General Plant Pathology》2003,69(1):1-6

 Aciculosporium take (Ascomycota; Clavicipitaceae) is a causal agent of witches' broom of bamboo plants. The symptoms of this disease are believed to be induced by plant hormones, particularly auxins. Indole-3-acetic acid (IAA) was identified in cultures of this fungus in an l-tryptophan-supplemented liquid medium. IAA production was confirmed on 30 isolates of A. take from various hosts and locations at levels up to 1 mg/l. The biosynthetic pathway of IAA in A. take culture was examined by analyzing intermediate products and by feeding experiments. The results showed that the indole-3-pyruvic acid pathway (l-tryptophan → indole-3-pyruvic acid → indole acetaldehyde → IAA) was the dominant pathway in A. take. Received: June 3, 2002 / Accepted: July 25, 2002  相似文献   

Inconspicuous restraint of rice seedling growth by root-infecting fungi in soil of a rice paddy field     

Hiromitsu Furuya  Tsutomu Matsumoto  Shin-ichi Fuji  Hideki Naito 《Journal of General Plant Pathology》2003,69(2):115-119

 Rice seedling growth, estimated by plant height and root development and discoloration, was better in pasteurized soil than in unpasteurized soil obtained from a flooded rice field. Rice seedlings also grew better in sterilized soil modified by adding roots harvested from the pasteurized soil than in soil modified by adding roots harvested from the unpasteurized soil. The results demonstrate that seedling growth in the rice field soil was inhibited by soil microorganisms, even though no typical symptoms such as seedling blight or damping-off appeared. Pythium aristosporum is suggested to be involved in the inhibition. Thus, it appears that inconspicuous restraint of rice seedling growth could occur in soils of rice paddy fields. Received: May 20, 2002 / Accepted: October 16, 2002 Acknowledgments The authors thank Dr. T. Ichitani, former professor at Osaka Prefectural University, for providing an isolate of Pythium aristosporum for comparison, and Mr. Mitsuaki Sato of Akita Prefectural College of Agriculture for technical assistance.  相似文献