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Sheng Zhu S Li Liu X Fei Liu P Li Y Qiang Li J Min Wang H Kui Yuan S Guo Si N 《Phytopathology》2007,97(5):643-649
ABSTRACT The mechanism of the effects of flumorph (a novel fungicide) was investigated by analyzing alterations of hyphal morphology, cell wall deposition patterns, F-actin organization, and other organelles in Phytophthora melonis. Calcofluor white staining suggested that flumorph did not inhibit the synthesis of cell wall materials, but disturbed the polar deposition of newly synthesized cell wall materials during cystospore germination and hyphal growth. After exposure to flumorph, zoospores were able to switch into cystospores accompanied with the formation of a cell wall, whereas cystospores failed to induce the isotropic-polar switch and did not produce germ tubes but continued the isotropic growth phase. In flumorph-treated hyphae, the most characteristic change was the development of periodic swelling ("beaded" morphology) and the disruption of tip growth. Newly synthesized cell wall materials were deposited uniformly throughout the diffuse expanded region of hyphae, in contrast to their normal polarized patterns of deposition. These alterations were the result of F-actin disruption, identified with the fluorescein isothiocynate (FITC)-phalloidin staining. The disruption of F-actin also was accompanied by disorganized organelles: each swelling of subapical hyphae was associated with a nucleus. Vesicles did not undergo polarized secretion to the apical hyphae, but diffused around nuclei for the subapical growth; thus, the cell wall was thickened with periodic expansion along the hyphae. Upon removing flumorph, normal tip growth and organized F-actin were observed again. These data, as well as data published earlier, suggest that flumorph may be involved in the impairment of cell polar growth through directly or indirectly disrupting the organization of F-actin. The primary site of action by flumorph in the disruption of the F-actin organization is under investigation. 相似文献
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流动沙丘沙埋对沙柳生长特性的影响 总被引：2，自引：0，他引：2
对毛乌素沙地流动沙丘上沙柳的根系分布、冠层特征进行研究.结果表明:沙柳在不同的环境中其生长状况有所差异,沙柳遭流沙掩埋后,被掩埋的枝条发展为根系.且萌发新的不定根,有效的增加了沙柳地下部分的深度、广度和生物量,增强了沙柳根系吸收水分和养分的能力.从而引起地上部分的覆盖面积和生物量较未沙埋沙柳都有了明显的增加. 相似文献
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农业经济管理专业非农化趋势辩析方天（沈阳农业大学经贸学院沈阳１１０１６１）一、农业经济管理专业非农化趋势的表现近年来,随着农经管理学科的迅猛发展,在一些农业院校中,农业经济管理类专业出现了一种明显的弱化农业特色即“非农化”趋势。主要表现在下列方面：... 相似文献
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为研究母猪卵巢在不同发育阶段的组织学变化规律和探讨磷酸二酯酶3A(PDE3A)在卵巢发生发育和成熟过程中的生物学意义,选用二花脸母猪胎90日龄及1日龄、20日龄、120日龄和180日龄的母猪卵巢进行组织学观察,并利用RT-PCR检测PDE3A mRNA的表达情况。结果显示:胎90日龄主要由原始卵泡组成;1日龄、20日龄、120日龄卵巢内特征发育明显;180日龄卵巢内的形态特点与120日龄相似。卵巢PDE3A mRNA表达水平在20日龄时与其他各个阶段相比显著降低。提示:PDE3A在猪从原始卵泡募集到初级卵泡形成过程中可能具有生物学作用。 相似文献
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The rapid development of biotechnology has provided a greater understanding of the biological functions of major candidate genes that have important functions regarding economic traits, and new materials for livestock breeding have been obtained through gene editing (GE) and embryo manipulation with the purpose of improving quality and output and reducing the costs and risk of disease. Public concerns, particularly over safety risks and production performance, must be addressed. Evaluation is the most important component of the regulation of gene-edited livestock and is a crucial guarantee of public safety before the marketing of gene-edited animal products. Here, the system of evaluation of gene-edited livestock is discussed in terms of public safety and production performance. The search for safe and ethical applications in the GE of livestock, a case-by-case evaluation strategy, and classification and simplification are used in order to promote a more efficient, objective, comprehensive and operable evaluation system. 相似文献
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Present Status and Development of Synthesis Technologies for TiC,TiN,Ti(C, N) Powders 总被引：1，自引：0，他引：1
The preparation technologies of TiC?TiN?Ti(C, N) powders used home and abroad in recent years are reviewed, and the technical processes and characteristics are analysed. The existing problems and development trends of these technologies are also discussed. By seeking cheaper raw materials and achieving new high temperature technologies by plasma, microwave, laser, and electric arc and combining SHS and MA the low-cast and large-scale preparation of high quality TiC, TiN, Ti(C, N) powders are becoming one of the hot research topics. With the development of research and the improvement of preparation techniques, more convenient, more economic and more efficient preparation techniques will provide TiC, TiN, Ti(C,N) powder a broader prospective application. 相似文献
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You Kui Wu Zeyuan 《保鲜与加工》1988,(6)
In this paper, dust deposition from turbulent gas streams in mine airways is studied both theroetically and experimentally. Base on the practical situation of mine airways, we only considered the effects of Brc-wnian, turbuleut diffusion and gravitation and suggested a mathematical model of dust deposition from turbulent gas streams in mine airways. The comparison of the experimental result is consistent with the model suggested in this paper. 相似文献