共查询到15条相似文献,搜索用时 62 毫秒
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随着植物源农药的发展,具有优良农用活性的禾本科植物香根草Vetiveria zizanioides (L.) Nash越来越受到重视。文章首先介绍了香根草中挥发性成分的提取分离方法及结构鉴定,列举了其主要挥发物的结构;进而综述了其对二化螟 Chilo suppressalis (Walker) 等螟蛾科害虫的引诱作用、家白蚁Coptotermes formosanus Shiraki 等白蚁的驱避及拒食作用、对蚬木曲脉木虱Macrotermes barneyi Light等的毒杀作用,对水稻纹枯病菌Rhizoctorzia solani、香蕉炭疽病菌Calletotrichum musae等多种真菌和金黄色葡萄球菌Staphylococcus aureus Rosenbach 等多种细菌的抑菌活性,以及对藜Chenopodium album L.、豚草Ambrosia artemisiifolia L.等常见杂草的除草活性等;最后总结了香根草中活性化合物诺卡酮的化学及生物合成方法。可为进一步将香根草应用于植物源农药研究和开发利用提供参考。 相似文献
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昆虫几丁质酶可以降解昆虫体壁和围食膜中的几丁质,在昆虫蜕皮等生命活动中发挥重要功能。作为参与昆虫几丁质降解系统的关键酶,Ⅱ家族几丁质酶(ChtⅡ)是少见的多结构域、性质复杂的几丁质酶。对昆虫中编码ChtⅡ的基因沉默会导致昆虫蜕皮失败及死亡率增加。对ChtⅡ的生化性质及晶体结构分析表明,其在几丁质降解系统中起到了“先锋及攻坚”的作用。因此,ChtⅡ有望成为新的杀虫剂靶标。本文综述了近年来关于ChtⅡ的生理功能、结构特征及其抑制剂的研究成果,可为基于昆虫几丁质酶的新杀虫剂创制提供参考。 相似文献
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由于农用化学品存在靶标有限性和耐药性等问题,新靶标的开发成为农药研发的重中之重。几丁质是昆虫表皮和真菌细胞壁的主要组成成分,具有重要的生物学功能。几丁质脱乙酰酶(chitin deacetylase, CDA)可将几丁质脱乙酰化为壳聚糖,这一过程除了影响昆虫体壁和真菌细胞壁的形成外,还可调控昆虫的生长发育或决定病原菌的致病性。越来越多的研究表明,CDA有望成为新农药创制的候选靶标。本文介绍了CDA作为作物保护潜在靶标的研究进展,主要综述了当前不同来源CDA的生化功能、晶体结构、酶与底物的结合模式和以及近年来已报道的以CDA为靶标的抑制剂的研究进展,可为以几丁质脱乙酰酶为靶标的抑制剂的筛选以及新型农药的开发提供指导。 相似文献
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Resistance to powdery mildew in wheat: a review of its use in agriculture and breeding programmes 总被引:26,自引:2,他引:26
FIONA G. A. BENNETT 《Plant pathology》1984,33(3):279-300
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Malcolm D. Devine 《Pest management science》1997,51(3):259-264
Resistance to acetyl-coenzyme A carboxylase (ACCase) inhibitors has developed in at least 10 grass weed species in recent years. In most instances, resistance is conferred by an ACCase alteration in the resistant biotypes that reduces sensitivity to aryloxyphenoxypropionate (AOPP) and cyclohexanedione (CHD) herbicides. Analysis of ACCase from many of these resistant weed biotypes suggests the presence of different mutations, each conferring a different pattern and level of resistance to various AOPP and CHD herbicides. In all cases analyzed to date, resistance is controlled by a single dominant or semi-dominant nuclear gene. In several weed biotypes, resistance is conferred by enhanced herbicide detoxification, primarily through elevated expression or activity of cytochrome P450 monooxygenase(s). This mechanism can confer cross-resistance to herbicides from other chemical classes with different modes of action. Finally, multiple herbicide resistance, i.e. the acquisition of several different resistance mechanisms, has been reported in some weed biotypes. ©1997 SCI 相似文献
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Protectant fungicides rely for their selectivity on physical barriers (e.g. the leaf cuticle) between their deposits and the protoplasts of the host plant. Systemic fungicides, by contrast, come into direct contact with host cells and need to be more selective. Nevertheless, important side-effects can occur, involving higher plants, animals and other microorganisms; examples of these are cited. Sometimes mycelium and spores of the target fungus show differing susceptibility; also, activity of a fungicide in vitro does not always reflect its effectiveness in vivo. An extreme form of selectivity is the undesirable emergence of insensitive strains from an otherwise sensitive fungal species. 相似文献
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Franz J. Schwinn 《Pest management science》1984,15(1):40-47
Over the past 15 years, an increasing number of ergosterol biosynthesis inhibitors (EBIs) have been introduced in crop protection as fungicides, and in medicine as fungicides and bactericides. Their spectrum of activity and their systemic properties vary widely, depending on structural elements. By their high protective and curative activity the EBIs have greatly improved the level of disease control, both in plants and in man. However, the chemical and biological potential of this group has not yet been fully explored, particularly in the field of growth regulation. 相似文献
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宁夏干旱及其对农业生产的影响 总被引:14,自引:3,他引:14
以1951年1月-2000年5月全区19个气象台站的逐月降水资料为基础,采用降水量距平百分离和旱灾指数作为干旱灾害的指标,建立了寄存地区各种干旱类型的旱灾序列,并进行统计分析,较确切地反映出该区域内各年干旱轻重的程度,综合研究了干旱对农业生产的影响。结果表明,宁夏主要以春旱为主,春夏连旱最多,对宁夏影响最大的是秋春夏连旱;近年来干旱与非干旱的程度、范围差距进一步加大,出现干旱极值情况比以前增多,受旱面积有逐年增加的趋势;气候正在向干旱化发展。根据实际情况提出了抗旱对策。 相似文献
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