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1.
 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   
2.
棉花黄萎病菌致病型的AFLP分析   总被引:16,自引:0,他引:16  
 选用41个棉花黄萎病菌(Verticillium dahliae)代表菌系,在温室条件下,对4个棉花品种鄂荆1号(感)、中棉所12(耐)、文-5(抗)和唐棉2号(抗)进行致病性测定,结果可将供试菌系分为落叶型与非落叶型2类。选取8对AFLP引物PCR扩增的结果中,统计带型稳定、清晰且有多态性的条带,共169条作系统聚类分析,将上述菌系分为2大类,第一类为非落叶型菌系,包括10个非落叶型菌系和1个过渡菌系;第二类为30个落叶型菌系。根据聚类分析建立树状图,发现菌系与地理来源存在一定的相关性,而依据菌系致病力强弱分类则相关关系不大。选用25对EcoRⅠ和MseⅠ引物组合,对供试的41个V.dahliae进行AFLP扩增,筛选到2对引物E64(GACTGCGTACCAATTCGAC)、M53(GATGAGTCCTGAGTAACCG)和E49(GACTGCGTACCAATTCCAG)、M65(GAT-GAGTCCTGAGTAAGAG),能分别扩增出433bp和110bp2条仅为V.dahliae非落叶型菌系独有的特异片段,可将落叶型与非落叶型菌系分开,这2条特异片段被命名为EM433和EM110。  相似文献   
3.
江汉平原水稻白叶枯病菌致病型的变异研究   总被引:2,自引:0,他引:2  
 从水稻和稻田周围常见的10种杂草上来集梨孢属菌株,以涂沫法作交互接种,分离自牛筋草、狗尾草、法氏狗尾草、李氏禾、罗氏草、铺地黍、稗和马唐的梨孢菌与分离自水稻的梨孢菌可以交叉侵染其寄主,茭白和碎米莎草梨孢菌与稻梨孢菌不能交互侵染;自然诱发条件下来自牛筋草和狗尾草的梨孢菌与来自水稻的梨孢菌对其寄主同样发生交叉侵染。直接从杂草寄主上分离的梨孢菌株对水稻的致病性较弱,接种到水稻感病品种发病后再分离的菌株,对水稻致病性增强,对原寄主的致病性基本保持不变。推断稻瘟病区稻田周围牛筋草、狗尾草、法氏狗尾草、李氏禾、罗氏草、铺地黍、稗和马唐等杂草寄主上的梨孢菌在稻瘟病菌的积累和传播方面具有作用。  相似文献   
4.
应用聚合酶链式反应鉴定新疆棉花落叶型黄萎病菌   总被引:9,自引:0,他引:9  
张莉  段维军  李国英  宋蓓 《植物检疫》2004,18(5):266-268
用一对棉花落叶型黄萎病菌的特异性引物D1和D2进行PCR扩增,对于落叶型黄萎病菌,该对引物可特异性地扩增产生一段550bp的产物,而非落叶型黄萎病菌则不能被扩增.供试的35个新疆黄萎菌系中,有3个菌系扩增出550bp大小的落叶型黄萎病菌特异性片段,表明目前新疆已存在落叶型黄萎病菌,用此技术可快速、准确地检疫和鉴定落叶型黄萎病菌.  相似文献   
5.
Irrigation water disinfestation is an unexplored option for reducing Verticillium dahliae inoculum in water and consequently for more efficiently managing Verticillium wilts in Andalusia. We assessed Suppressive Efficacy (SE; water was infested and subsequently treated) and Preventive Efficacy (PE; previously treated water was subsequently inoculated) of OX-VIRIN®, OX-AGUA AL 25® and Deccoklor® in reducing water infestations by V. dahliae conidia. Five concentrations of each disinfestant, the lowest three being recommended by the manufacturer, were tested in vitro against six V. dahliae isolates. Validation assays were carried out in experiments under natural environmental conditions in spring. The four highest concentrations of OX-VIRIN® (0.8–51.2 mL L−1), the three highest of OX-AGUA AL 25® (46.4–417.5 μL L−1) and the two highest of Deccoklor® (0.375 and 3.75 mL L−1), showed an in vitro-efficacy (SE and PE) of 96.2, 80.0 and 100.0% after 30, 5 to 30 and 15 days respectively. Therefore, recommended concentrations for OX-VIRIN® and OX-AGUA AL 25® showed a greater in vitro-effectiveness than those recommended for Deccoklor®. Assays in natural environmental conditions proved that OX-VIRIN® at the recommended concentration of 3.2-mL L−1, applied every 28 days to water, was the most effective treatment (SE and PE), with a 100% reduction of the average relative viability after 56 days. Other chemical treatments showing high in vitro-efficacy, such as OX-VIRIN® at 0.8 mL L−1 and OX-AGUA AL 25® at 46.4 μL L−1 showed an SE of 99.9% after 14 and 28 days when applied every 28 and 14 days, respectively. However, PE of OX-AGUA AL 25® at 46.4 μL L−1 was only 59 and 38% after 28 and 14 days respectively, depending on the experiment.  相似文献   
6.
为持续控制小麦叶锈病及促进小麦的抗叶锈病育种工作,2019—2020年自江苏、浙江和安徽3个省采集自然感叶锈病的小麦病叶,经分离获得小麦叶锈菌单孢分离物,利用43个小麦叶锈病鉴别寄主材料对其致病类型进行鉴定,并对其毒性结构进行分析。结果显示,从170份小麦叶锈菌单孢分离物中共鉴定出67个致病类型,主要致病类型为THS、SHJ、PHS和SHS,出现频率分别为8.8%、7.6%、5.9%和5.9%。江苏、浙江和安徽3个省的单孢分离物对携带抗叶锈基因Lr10、Lr12、Lr22a、Lr22b、Lr29、Lr33、Lr35和Lr36的鉴别寄主材料的苗期毒性频率均超过90.0%,而对携带抗叶锈基因Lr9、Lr24、Lr25、Lr28、Lr38、Lr40、Lr41、Lr42、Lr43和Lr13+3ka的鉴别寄主材料的苗期毒性频率均小于10.0%。卡方检验及Fisher精确检验显示,3个省小麦叶锈菌群体对抗叶锈基因Lr1、Lr2a、Lr3、Lr14b、Lr18、Lr21、Lr26、Lr27+31、Lr32和Lr37的毒力存在显著分化。浙江省小麦叶锈菌群体具有较少的毒性因子(4.73)和毒性值(600...  相似文献   
7.
Host-specific AAL-toxins and mycotoxin fumonisins are structurally related and were originally isolated from the tomato pathotype of Alternaria alternata and from Fusarium verticillioides, respectively. Previous reports on the production of fumonisin derivatives by the tomato pathotype suggested a possible involvement in the pathogenicity of the pathogen. Here, we have evaluated the role of fumonisin in A. alternata–tomato interactions. The results indicate that highly pathogenic isolates of A. alternata tomato pathotype produce AAL-toxin as the sole toxin, strongly implicating it as a pathogenicity factor. The related compound, fumonisin, is also toxigenic and has infection-inducing activity on susceptible tomato plants.  相似文献   
8.
【目的】分析中国不同稻区白叶枯病菌(Xanthomonas oryzae pv. oryzae)致病型,建立近等基因系鉴别寄主,为白叶枯病菌群体结构田间实时准确监测、抗性品种应用以及抗病育种提供科学依据。【方法】利用中国鉴别寄主、IR24以及15个抗白叶枯病近等基因系等共21个鉴别寄主,采用人工剪叶接种方法,对2018—2021年采自广东、广西、海南、浙江、湖南、辽宁、云南共7个省(自治区)的954个单菌落分离菌株进行致病型测定,探明白叶枯病菌致病型种类、分布及毒性分化;基于测试菌株与15个近等基因系及IR24的抗感互作,应用主成分因子分析法,开展近等基因系与病菌互作的变量因子分析,构建白叶枯病菌致病型近等基因系鉴别寄主;基于抗病基因与测试菌株的抗感反应,分析抗病基因聚合效应。【结果】954个测试菌株在中国鉴别寄主上鉴定出11个致病型,包括SRRRR(I)、SSRRR(Ⅱ)、SSSRR(Ⅲ)、SSSSR(Ⅳ)、SSRRS(V)、SRSRR(Ⅵ)、SSSSS(Ⅸ)、SSSRS(新型1)、SRSRS(新型2)、SRSSS(新型3)以及SSRSS(新型4),占测试菌株的比率分别为11.53%、4.82%、7.34%、6.18%、7.23%、1.05%、59.96%、1.57%、0.10%、0.10%、0.10%。Ⅸ型菌作为致病性最广的强毒菌系已上升为华南和长江中下游湖南和浙江稻区的优势致病型,西南稻区的云南以Ⅳ型菌为主,东北稻区的辽宁以I型菌为主。15个水稻抗白叶枯病近等基因系对954个菌株的抗感性分析结果表明,测试的15个近等基因系可分为5种类型,第Ⅰ类为高感基因系,包括IRBB1、IRBB2、IRBB10、IRBB11、IRBB4;第Ⅱ类为中感基因系,包括IRBB3、IRBB203、IRBB14;第Ⅲ类为中抗基因系,包括IRBB8、IRBB13;第Ⅳ类为抗病基因系,有IRBB21;第Ⅴ类为高抗基因系,包括IRBB5、IRBB7、CBB23、GDBB23;测试菌株中,出现可侵染抗病基因xa5的有42个、Xa7的有34个、Xa23的有31个。对以白叶枯病近等基因系为主的16个品种(系)与954个菌株组成的抗感互作变量数据矩阵进行因子分析,以解释总变量>85.0%为界,提取出8个主成分因子,组建了以近等基因系为主的10个品种(系)组成白叶枯病菌近等基因系鉴别寄主,按其对变量方差贡献大小,这些寄主分别为IRBB10(Xa10)、IRBB4(Xa4)、GDBB23(Xa23)、IRBB5(xa5)、IRBB7(Xa7)、IRBB21(Xa21)、IR24(Xa18)、IRBB13(xa13)、IRBB3(Xa3)、金刚30;新鉴别寄主可将954个测试菌株划分为55个致病型,对测试稻区的白叶枯病菌菌株表现出较好的鉴别力。基因聚合联合抗性分析表明,不同抗病基因聚合对病菌的抗性频率有一定的提升,不同抗病基因对测试菌株的抗性具有一定的互补性。【结论】监测稻区的白叶枯病菌系趋向多样化,毒性分化明显,强毒菌系Ⅸ型菌在部分稻区已上升为优势致病型,侵染xa5、Xa7Xa23等广谱抗性基因的菌株有上升趋势;抗病基因聚合可拓宽品种对病原菌系的抗性谱,是培育广谱抗性品种的有效途径;近等基因系鉴别寄主的建立与应用可为白叶枯病发生流行的精准监测以及田间实时预警提供技术支撑。  相似文献   
9.
The pathogenicity of 36 isolates of Xanthomonas oryzae pv. oryzae (Xoo), which were collected from japonica rice varieties in the Yunnan Plateau, China, was evaluated. It was evaluated on 29 rice varieties including a set of seven varieties to identify pathogenicity, i.e., Haonuoyang, TN1, Kogyoku, Zhenzhu'ai, IR26, Nanjing 33, and Kinmaze, which may be considered as a set of differential varieties for Xoo races from Yunnan japonica rice. The efficiency of the seven varieties was further confirmed. The results showed reversible and specific interactions between isolates and varieties. The isolates were classified into nine pathotypes from pathotyp Ⅰ to Ⅸ according to their pathogenic reactions on the seven rice varieties. The pathotype V was the epidemic, whereas pathogen Ⅶ was the most pathogenic. Most japonica varieties grown in the Yunnan Plateau were susceptible to Xoo. The rice lines IRBB21 (Xa-21), Zhachanglong (Xa-22,, Xa- 24,), and IR1545-339 (xa-5), which were resistant to all the isolates tested, can be used as donors of resistant genes for bacterial blight in japonica rice breeding in the Yunnan Plateau.  相似文献   
10.
广东水稻白叶枯病菌新致病型的发现及致病性测定   总被引:10,自引:0,他引:10  
在对广东省水稻白叶枯病菌的致病型变异动态监测中 ,发现了在中国鉴别寄主金刚 3 0、Tetep、南粳 15、Ja va14、IR2 6上的反应为SSSSS模式的菌株。该菌株有别于SRRRR(Ⅰ型 )、SSRRR(Ⅱ型 )、SSSRR (Ⅲ型 )、SSSSR(Ⅳ型 )、SSRRS(Ⅴ型 )、SRSRR(Ⅵ型 )、SRSSR(Ⅶ型 )、RRRSR(云南菌型 ) 8个类型 ,是一个新致病型菌系。对该菌系致病性测定的结果显示 ,其致病谱广、毒性强 ,是一个高致病性菌系  相似文献   
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