蒋白纹枯病菌菌丝融合群及其致病性测定     

梁继农 《长江蔬菜》2002,(12):33-34

菌丝融合型测定结果表明，32个茭白纹枯病菌菌株隶属于两个菌丝融合群：30个属AG1群，占测定菌株的93．95％，其中AG1-IA、AG1－IC两亚群菌株依次为24与6，有两菌株为AG4，占6．25％。显然，AG1－IA为优势融合群，占测定菌株的75％。融合群致病性测定结果表明，AG1－IA致病性强，AG1－IC弱，AG4基本不致病。茭白与水稻两种纹枯病菌交互接种，其发病基本一致。由此，作者认为这两种纹枯病菌为同一病原物，或者说茭白、水稻是同一病原物的两个寄主植物。  相似文献   

Microscopic detection of reactive oxygen species generation in the compatible and incompatible interactions of Alternaria alternata Japanese pear pathotype and host plants     

Takeshi Shinogi  Tomoko Suzuki  Takayuki Kurihara  Yoshihiro Narusaka  Pyoyun Park 《Journal of General Plant Pathology》2003,69(1):7-16

 Reactive oxygen species (ROS) generation was examined in the interaction of Alternaria alternata Japanese pear pathotype and host plants using three methods: nitro blue tetrazolium (NBT) method for microscopic detection of O₂ ⁻, diaminobenzidine (DAB) methods for microscopic detection of H₂O₂, and cerium chloride methods for ultrastructural detection of H₂O₂. ROS generation was detected by NBT and DAB methods at appressoria on leaves of susceptible cultivars and heat-shocked leaves of resistant cultivars but not in leaves of resistant cultivars. Ultrastructural detection by the cerium chloride method identified ROS generation at cell walls of appressoria and penetration pegs in susceptible, resistant leaves and heat-shocked leaves. These differences in the ultrastructural and microscopic data in resistant areas were due to the restriction of ROS generation in limited areas, the side facing the plant surface, of appressoria and penetration pegs. Therefore, ROS generation was apparently induced regardless of the resistance or susceptibility of the cultivar with the difference being in the volumes generated. After evaluating the pathological role of ROS generation in fungal structures, such generation was found to be associated with early penetration of cell walls in pear plants. Additionally, ROS generation in plants was also found in degrading pectin layers near infected hyphae and in plasma membrane modification sites in susceptible leaves but not in resistant leaves. ROS generation in susceptible leaves might be accompanied with plasma membrane damage, although the role of ROS generation in the pectin layers is not clear. ROS generation in both fungal and plant cells during their interaction was likely associated with the expression of susceptibility. Received: June 3, 2002 / Accepted: July 31, 2002  相似文献   

辣椒新品种亚华205的选育     

张海斌  张章  粟建文  刘虎  刘福清 《长江蔬菜》2003,(1):44-45

亚华205辣椒是由母本2105和父本K6242配制的一代杂种。该品种中早熟，丰产，果实长牛角形，果长18－25cm，横径3．5cm,平均单果重45g，果皮黄色，果面光滑，果条顺直，竦味中等，肉厚，空腔小，耐贮运，商品性好，一般667m^2产量3500－4500kg，适于华南、吕南及华北地区露地丰产栽培。  相似文献   

亚硫酸氢钠处理减轻低温对温州蜜柑光合作用的影响   总被引：12，自引：0，他引：12  

郭延平  苏吉虎  王宏炜  沈允钢  张良诚 《园艺学报》2003,30(2):195-197

 低温胁迫使温州蜜柑叶片的净光合速率(Pn)、光系统Ⅱ的光化学效率(Fv/Fm)及光合电子传递速率(ETR)下降，反映跨膜质子动力势的叶绿素毫秒延迟发光(ms-DIE)减弱，叶片中的ATP含量降低。低温胁迫前，用NaHSO₃ 5 mmol/L涂于叶片表面，可使处理植株叶片的Pn和Fv/Fm分别少下降了11.5%和11.6%，ETR和ATP含量几乎没有下降，ms-DLE的下降幅度减少。可见，在柑橘上施用NaHSO₃能够减轻短期低温对光合机构及光合作用的影响。  相似文献   

不同基因型越橘果实中4种花色苷含量的研究   总被引：7，自引：0，他引：7  

李亚东  孟凡丽  郑毅男  苏晓田 《园艺学报》2004,31(3):367-370

 采用反相高效液相色谱法测定了越橘2个野生种和3个栽培品种中4种花色苷的含量。结果 表明：总花色苷含量最高的是‘芝妮’，其它依次是CA-206、NB-3、笃斯越橘和红豆越橘。果实所含花色苷的种类和含量因种和品种而不同，其中矢车菊色素-3-半乳糖苷普遍存在的，而矢车菊色素-3-葡萄糖不存在于笃斯越橘和红豆越橘果实中，红豆越橘果实中只含4种花色苷的1种。  相似文献   

球根海棠离体培养的形态发生研究   总被引：5，自引：0，他引：5  

刘福平  苏明华  章宁  林清洪 《园艺学报》2004,31(5):694-696

 球根海棠外植体可在同一条件下同时诱导不定芽和胚状体, 经间接途径和直接途径的体细胞胚胎发生频率均很高, 体细胞胚为单细胞起源或多细胞起源。以再生嫩叶为继代中间体, 在较高温度(28 ℃) 下诱导, 可建立高效扩繁体系。纵切芽丛继代形成大量愈伤组织, 愈伤组织继代半年后几乎完全丧失分化能力, 发生激素驯化作用, 而且愈伤组织细胞染色体数目已发生广泛变异。  相似文献   

生姜根结线虫病原鉴定及发生规律   总被引：5，自引：1，他引：5  

郭衍银  徐坤  王秀峰  张广民  苏保乐 《植物保护学报》2004,31(3):241-246

采用田间调查、接种试验、电镜与显微镜观察以及酯酶同工酶电泳等方法,对引发生姜癞皮病的病原及发生规律进行了研究.结果表明,引起生姜癞皮病的病原为南方根结线虫Meloidogyne incognita.该病在每年6月中旬开始发生,8、9月份危害严重.病原在生姜上一年可发生完整的4代,完成1代平均约需35天.病原主要在0～40cm的土层内分布和危害,但具体分布情况依寄主生长状况而稍有差异.南方根结线虫繁殖速率受初始接种密度的影响也很大,当初始接种密度较低时,线虫繁殖速率较高,初始接种密度增大,繁殖速率降低,其平衡密度为每100g干土746.20个卵.  相似文献   

徐州地区烟粉虱发生规律及治理措施初探   总被引：4，自引：0，他引：4  

戴率善  刘宗泉  杜予州  周福才  张贵永  高素兰  仇保华  李建树  李艳红 《中国植保导刊》2004,24(3):17-20

通过近2a观察表明,徐州地区烟粉虱在田间消长大致分4个阶段,成虫有4个主要迁移期;其喜干热、耐高湿的生活习性、冬季保护地栽培面积的扩大、外来虫源的传入及防治不力是烟粉虱种群数量累积并引起暴发的主要原因;主要寄主有9科20余种栽培作物;寄主植株上虫量垂直分布:棉花上部>中部>下部,温室蔬菜一般中、下部>上部。可采取严格检疫、清洁田园、轮作换茬、黄板诱杀、覆盖防虫网、保护和利用天敌、药剂防治等措施进行治理。  相似文献   

Adherence of Actinobacillus pleuropneumoniae serotype 1 to swine buccal epithelial cells involves fibronectin          下载免费PDF全文

Roberto Hamer-Barrera  Delfino Godínez  V. Idalia Enríquez  Sergio Vaca-Pacheco  Rodrigo Martínez-Zú?iga  Patricia Talamás-Rohana  Francisco Suárez-Güemez    Mireya de la Garza 《Canadian journal of veterinary research》2004,68(1):33-41

The swine pathogen Actinobacillus pleuropneumoniae serotype 1 was investigated for its ability to adhere to swine, rat, and human buccal epithelial cells (BEC). The highest number of bacteria adhered was to swine BEC. This binding ability was affected by heating, extreme pH, treatment with sodium dodecyl sulfate, ethylenediamine tetraacetate, or periodate, and proteolysis, suggesting that cell-surface glycoproteins participate in adherence and that adherence is based mostly on ionic interactions. Mannose and swine fibronectin may play a direct role in this interaction. Convalescent-phase serum from naturally infected pigs inhibited the adhesion. There was a correlation between bacterial pathogenicity as well as host specificity and the capacity for adherence to swine BEC. Adhesion to swine BEC provides a convenient method to study in vitro the adherence of A. pleuropneumoniae and other pathogens of the pig respiratory tract.  相似文献   

Effect of recombinant canine IFNγ on canine atopic dermatitis evaluated by clinical signs,histopathology and expression of Th1/Th2 cytokine mRNA     

T. Iwasaki  Y. Kagawa  S. J. Park  N. Kanazawa  Y. Momoi  H. Tanikawa 《Veterinary dermatology》2004,15(Z1):5-5

Atopic dermatitis (AD) is thought to be caused by immunologic abnormalities expressed as a Th1/Th2 cytokine imbalance in both humans and dogs. Several studies have focused on the therapeutic effects of IFNγ in human AD with successful results; however, the mechanism of action of IFNγ is not fully understood. We investigated the effect of recombinant canine interferon gamma (rCaIFNγ) on 10 dogs with AD and evaluated the ratio of IL‐4 mRNA to IFNγ mRNA in peripheral blood mononuclear cells, serum total IgE levels, and histological changes in skin. After six injections of rCaIFNγ over a span of 2 weeks, seven of the 10 dogs showed improvement, and six of these seven dogs exhibited decreased IL‐4:IFNγ mRNA ratios. Two of the three cases that did not improve had increased IL‐4:IFNγ mRNA ratios. Total serum IgE levels were significantly decreased in nine of 10 cases. The number of IgE‐positive cells detected by immunostaining and the number of mast cells in skin biopsy samples were decreased. A reduction of epidermal cell layers was demonstrated by histopathology after treatment. These results demonstrated that rCaIFNγ may be a novel safe and effective therapeutic option for the treatment of canine AD, and the mechanism of action of rCaIFNγ may be related to the modulation of Th2 cytokines to Th1 cytokines with the reduction of serum IgE production. Funding: Self‐funded.  相似文献