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昆虫病原线虫的共生细菌 总被引:1,自引:0,他引:1
昆虫病原线虫与其共生细菌二者互惠共生 :共生细菌需要昆虫病原线虫作为载体以寄生寄主昆虫并做为自己的营养来源 ,而昆虫病原线则需要依靠共生细菌来杀死昆虫。综述了共生细菌的病原作用、抗菌作用与杀虫作用 ,评述了共生细菌的基因工程进展 ,讨论了昆虫共生细菌在昆虫病原线虫致病性的作用。 相似文献
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昆虫病原线虫作为生物杀虫剂近年来已被人们所认识,并已广泛应用于防治多种农林害虫.本文介绍了昆虫病原线虫与其他杀虫因子之间相互作用的研究概况. 相似文献
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昆虫病原线虫共生菌BP品系杀虫毒素基因簇中各基因与杀虫活性的关系 总被引:12,自引:1,他引:12
昆虫病原线虫共生菌Xenorhabdus nematophilus BP的多个杀虫毒素基因集中在一起形成一个约40kb的基因簇。为研究这个基因簇中各基因与杀虫活性的关系,对该共生菌粘粒文库中5个粘粒克隆XnBP76、XnBP83、XnBP203、XnBPp378 和XnBP414及XnBP83的3个亚克隆插入DNA片段的基因结构和它们对棉铃虫的杀虫活性进行了比较,结果显示,xptB1, xptC1和xptA2 3个基因或后两者的联合表达产物具有最强的杀虫效果,缺失其中的任何1个或2个会使杀虫活力大幅度地下降或完全消失;而xptD1和xptA1的缺失对毒素基因簇的表达产物的杀虫活力影响很小;杀虫毒素的物理混合没有明显的增效作用。 相似文献
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昆虫病原线虫共生细菌是寄生在昆虫病原线虫肠道的一种细菌,二者互惠共生。实验采用6个不同种的菌株为筛选材料。共生细菌菌株的培养液经85%饱和度的(NH4)2SO4盐析,浓缩冻干得到杀虫粗提物。以粗提物注射大蜡螟Galleria mellonella、饲喂玉米螟Ostrinia furnacalis和棉铃虫Helicoverpa armigera,发现Xenorhabdus nematophilus D43、X.bovienii A54、Photorhabdus luminescens HZL和CB-8等4个菌株发酵液的粗提物对昆虫有高的血腔毒性,菌株A54对昆虫又有高的胃毒效果。由此确立A54为高毒力的菌株,其杀虫活性表现为:注射大蜡螟48 h的死亡率为80%,96 h为93.3%;粗提物饲喂玉米螟,72 h死亡率为53.3%,120 h死亡率为100%;饲喂棉铃虫,72 h死亡率为80.1%,120 h死亡率为90%。杀虫粗提物经DEAE-52柱层析分离,得到一个穿透峰和三个盐的梯度洗脱峰,其中穿透峰对昆虫有很好的胃毒效果,但没有血腔毒性;三个盐峰均有很高的血腔毒性,但没有胃毒作用。穿透峰样品饲喂2龄、3龄棉铃虫也有很好的杀虫活性,96 h 2龄棉铃虫的死亡率为65%,3龄棉铃虫的死亡率为30%;处理96 h的棉铃虫同处理前相比体重下降,未死棉铃虫体重明显低于对照。 相似文献
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H.M. Aatif N. Javed S.A. Khan S.P. Lali M.I. Ullah 《Archives Of Phytopathology And Plant Protection》2013,46(20):2447-2457
Keeping in view the staid health and ecological apprehensions coupled with the use of pesticides, entomopathogenic nematodes have the potential to supersede pesticides for the management of various pests. Brinjal plants are the most seriously affected by Meloidogyne incognita. The main objective of this study was to evaluate the persistence effectiveness of bacterial cell suspensions (Xenorhabdus and Photorhabdus spp.) and their culture filtrates in soil up to 7, 14 and 21?days and their response against M. incognita as a source of biological control for nematode management. In a life cycle study, Xenorhabdus and Photorhabdus spp., isolated from Steinernema asiaticum and Heterorhabditis bacteriophora, were proved more effective in influencing the life cycle of RKNs. It was found that all the treatments of bacterial cell suspensions and their culture filtrates at all persistent times proved effective in reducing the number of females and egg masses as compared to control. It delayed penetration of nematode juveniles (J2) into host roots. It was concluded that persistence effectiveness of bacteria and their metabolites decreased in soil with time. 相似文献
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药用真菌桑黄的研究进展 总被引:20,自引:1,他引:20
以近年来国内外发表的文献为依据 ,从形态特征、生物学生长特性、主要化学成分、药理学研究等方面综述了文献中称为“桑黄”[包括 :鲍氏针层孔菌 (Phellinusbaumii)、火木针层孔菌 (P .igniarius)、裂蹄针层孔菌 (P .linteus) 3种 ]的药用菌子实体、发酵菌丝体、发酵胞外物的研究进展。结果 :桑黄的人工栽培 (日本、韩国学者采用的室外荫棚段木埋畦栽培法 ) ,固体、液体发酵培养均已获成功。其主要化学成分是子实体、菌丝体多糖以及发酵液中的胞外多糖 ,此外还有黄酮及其衍生物、香豆素类、甾醇类化合物。其子实体、菌丝体及提取物 (主要为多糖 )、胞外多糖在抗发炎、抗氧化、抑制肿瘤生成、增强免疫力、保护肝脏、预防和治疗关节炎等方面有显著的功效。桑黄的各种产品 (包括 :子实体、菌丝体微粉末、提取物浸膏、桑黄茶、桑黄口服液等 )市场需求量很大 ,表明桑黄有广阔的发展前景。 相似文献
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对951个样品分离鉴定,有747个样品含芽孢杆菌,有菌率为78.55%.共分离得到芽孢杆菌1138株,其中苏云金杆菌(Bacillusthuringiensis,简称B.t)143株,占12.5%;球形芽孢杆菌(Bacillussphaericus,简称B.s)11株,占0.97%;其他芽孢杆菌984株,占86.40%.从芽孢杆菌中选出产生晶体、苏云金素或磷酸酯酶C(PhosphalipaseC,简称PLC)的毒素菌株168株,其中B.t占143株,B.s有5株,其他芽孢杆菌10株.在产毒素菌株中,经测定有120株菌对供试昆虫毒性达标.占77.92%.不同菌株的杀虫毒素、杀虫范围和毒力各异,认为这种差异取决于毒素和虫种两方面的特异性. 相似文献
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Fifteen invited experts from 10 Organisation for Economic Cooperation and Development (OECD) and European countries participating in the European Commission's Cooperation in the Field of Science and Technical Research (COST) Action 819, along with 12 other participants, met to review and debate the potential problems associated with the introduction and commercial use of non-indigenous nematodes for insect biological control. The consensus view of the participants was that entomopathogenic nematodes (EPNs) possess specific biological and ecological features, which make their use in biological control exceptionally safe. All the scientific evidence available supports the conclusion that EPNs are safe to the environment, as well as to production and application personnel, the general public and the consumers of agricultural products treated with them. Only a few potential, but very remote, risks could be identified. Therefore, it was recommended that EPNs should not be subject to any kind of registration. The introduction of non-indigenous nematode species, however, should be regulated. Species should be accurately identified, and details of the origin, known distribution, probable host range and safety to the user must be provided. In addition, an expert opinion, based on available information, of the possible impact on non-target organisms must be available. 相似文献