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641.
提取苦参主要活性成分黄酮类化合物和生物碱,分别测定其抑菌活性|并通过苦参提取物对茄子黄萎病菌菌丝干质量、菌丝毒素含量与胞外酶活性的影响来分析其化感抑制作用机理。结果表明:经过抑菌活性测定,对茄子黄萎病菌具有化感抑制作用的苦参活性成分主要是黄酮类化合物。在苦参黄酮类化合物浓度为4.00 mg?mL-1培养7 d时抑菌率达100.00%,培养9 d时抑菌率为98.28%,与其他处理差异均达显著水平|培养12 d时,苦参黄酮类化合物浓度大于1.00 mg?mL-1的抑菌率还维持在90%左右。苦参生物碱处理的抑菌率均低于同浓度的黄酮类化合物处理的抑菌率。经过苦参提取物处理后,茄子黄萎病菌菌丝干质量随着提取物浓度的增加呈下降的趋势,菌丝毒素含量也随之下降,同时胞外酶活性降低。在苦参提取物浓度大于10 mg?mL-1时,抑制作用均与对照差异达显著水平。苦参提取物通过降低茄子黄萎病菌胞外酶活性、菌丝毒素含量,从而达到对菌丝生长的化感抑制作用,主要表现为菌丝干质量的降低。 相似文献
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Refined PCR protocol for detection of plant pathogens in soil 总被引:3,自引:0,他引:3
645.
由大丽轮枝菌引起的棉花黄萎病是一种难以防治的土传病害,西兰花残体还对其有一定的防治作用,防效为62.82%。为解析西兰花残体对棉花黄萎病的防治机制,本研究通过土壤杆菌转化的方法构建了大丽轮枝菌的绿色荧光标记菌株,采用共聚焦显微镜观察标记菌株在添加西兰花残体营养基质中和空白对照营养基质种植的棉花体内的侵染和扩展情况。结果表明构建的标记菌株gfp-wx-1与野生菌株wx-1的生物学特性无显著性差异。同时发现大丽轮枝菌在添加西兰花残体营养基质中棉花体内扩展较慢,具体表现为:在空白营养基质种植的棉花体内,大丽轮枝菌在接种第2 d时就可侵染根尖表层及根内部,第3 d到达茎部维管束,第5 d叶片可观察到少量病原菌,第7 d第一片子叶呈现大量病原菌,后期迅速扩展,叶片出现黄萎病斑;而在营养基质中添加西兰花残体种植的棉花体内,大丽轮枝菌在接种第2 d时就可侵染根尖表层,第3 d侵染根尖内部,第5 d侵染茎部维管束,直到第7 d第一片子叶才出现少量病原菌,后期扩展慢,叶片病斑较少。本研究通过荧光定量PCR方法检测了大丽轮枝菌在两个处理棉花根部定殖情况,结果表明西兰花残体能够显著降低大丽轮枝菌在棉花根部定殖的量。该研究初步明确了西兰花残体对棉花黄萎病的防治机制,为棉花黄萎病的绿色防治提供了一条新的途径。 相似文献
646.
Nadia Korolev Encarnación Pérez-Artés José Bejarano-Alcázar Dolores Rodríguez-Jurado Jaacov Katan Talma Katan Rafael M. Jiménez-Díaz 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(4):443-456
Genetic diversity and phenotypic diversity in Verticillium dahliae populations on cotton were studied among 62 isolates from Spain and 49 isolates from Israel, using vegetative compatibility grouping (VCG), virulence and molecular assays. In Spain, defoliating V. dahliae isolates (D pathotype) belong to VCG1, and non-defoliating isolates (ND) belong to VCG2A (often associated with tomato) and VCG4B (often associated with potato). The D pathotype was not identified in Israel. The ND pathotype in Israel is comprised of VCG2B and VCG4B. Isolates in VCG2B and VCG4B ranged in virulence from weakly virulent to highly virulent. The highly virulent isolates induced either partial defoliation or no defoliation. Virulence characteristics varied with inoculation method and cotton cultivar. Highly virulent isolates from Israel were as virulent as D isolates from Spain under conditions conducive to severe disease. The D pathotype is pathologically and genetically homogeneous, whereas the ND pathotype is heterogeneous with respect to virulence, VCG, and molecular markers based on single-primer RAPD and on PCR primer pairs. 相似文献
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Marina Soković Leo J.L.D. van Griensven 《European journal of plant pathology / European Foundation for Plant Pathology》2006,116(3):211-224
Essential oils of Matricaria chamommilla, Mentha piperita, M. spicata, Lavandula angusti folia, Ocimum basilicum, Thymus vulgaris, Origanum vulgare, Salvia officinalis, Citrus limon and C. aurantium and their components; linalyl acetate, linalool, limonene, α-pinene, β-pinene, 1,8-cineole, camphor, carvacrol, thymol and menthol were assayed for inhibitory activity against the three major pathogens of the button mushroom, Agaricus bisporus, i.e. the fungi Verticillium fungicola and Trichoderma harzianum and the bacterium Pseudomonas tolaasii. The highest and broadest activity was shown by the Origanum vulgare oil. Carvacrol possessed the highest antifungal activity among the components tested. 相似文献
649.
The application of the nonpathogenic isolate Fusarium oxysporum 47 (Fo47) reduced the symptoms of verticillium wilt, phytophthora root rot and phytophthora blight in pepper plants. Botrytis cinerea was also tested on the leaves of plants treated with Fo47, but no protection was observed. Verticillium dahliae colonies cultured in the presence of Fo47 grew slower than control cultures, but Phytophthora capsici growth was unaffected by Fo47. At least part of the protection effect observed against V. dahliae could therefore be due to antagonism or competition. In order to search for induced resistance mechanisms, three defence genes previously related to pepper resistance were monitored over time. These genes encode a basic PR‐1 protein (CABPR1), a class II chitinase (CACHI2) and a sesquiterpene cyclase (CASC1) involved in the synthesis of capsidiol, a phytoalexin. These three genes were transiently up‐regulated in the roots by Fo47 in the absence of inoculation with the pathogen, but in the stem only CABPR1 was up‐regulated. In plants that were inoculated with V. dahliae after the Fo47 treatment, the three genes had a higher relative expression level than the control in both the roots and the stem. 相似文献
650.