一株球孢白僵菌的分离鉴定及其对草地贪夜蛾的致病性

草地贪夜蛾Spodoptera frugiperda(J. E.Smith)是我国于2019年新发现的一种迁飞性重大害虫。为了寻找对草地贪夜蛾有高致病性的昆虫病原真菌,本实验对采自广东省广州市华南农业大学湿地的感菌稻黑蝽Scotinophara lurida若虫僵虫进行了室内分离培养,结合形态学和rDNA-ITS序列分析,采用浸虫法研究了该菌对草地贪夜蛾各龄幼虫的致病力。鉴定结果表明该病原真菌为球孢白僵菌Beauveria bassiana,编号为GZSL-1菌株。菌株GZSL-1可侵染草地贪夜蛾6个龄期的幼虫,随孢子浓度的升高,草地贪夜蛾幼虫感病死亡率增加,当浓度达到1×10~8孢子/mL时,1～3龄幼虫的累计校正死亡率皆为100%,4龄和5龄幼虫也达到57.47%和55.06%,6龄仅25.28%。接菌6 d后1～5龄幼虫的LC_(50)值分别为1.32×10~3、3.42×10~3、1.01×10~4、1.61×10~5和1.23×10~7孢子/mL。幼虫LT_(50)值随孢子悬浮液浓度增加而递减,在孢子浓度为1.0×10~4～1.0×10~8孢子/mL范围内,1龄、2龄和3龄幼虫的LT_(50)值分别为3.58～1.69 d、4.30～1.78 d和5.70～3.12 d;浓度为1.0×10~5～1.0×10~8孢子/mL时,对4龄幼虫的LT_(50)为5.45～4.85 d;浓度为1.0×10~7～1.0×10~8孢子/mL时,对5龄幼虫的LT_(50)为5.04～5.02 d。上述研究结果表明,鉴定的球孢白僵菌菌株GZSL-1对草地贪夜蛾幼虫具有较强致病性,可为草地贪夜蛾微生物防治提供候选菌种资源。     

草地贪夜蛾高致病力绿僵菌菌株的筛选与鉴定

为获取对草地贪夜蛾Spodoptera frugiperda具有高致病力的生防真菌，从福建省不同地区分离得到8株寄主为鳞翅目和半翅目幼虫僵虫的绿僵菌Metarhizium，采用浸渍法测定了其对草地贪夜蛾2龄幼虫和蛹的致病力，并根据形态学和分子生物学方法对高致病力菌株进行种类鉴定。结果表明，8株绿僵菌菌株对草地贪夜蛾2龄幼虫和蛹均表现出不同程度的致病力，其中菌株FJMR2和FJXY7表现出较强的致病力。在5×107个/mL孢子浓度下，FJMR2和FJXY7对草地贪夜蛾2龄幼虫的致死率分别为88.76%和82.13%，对蛹的致死率分别为86.57%和84.00%；对草地贪夜蛾2龄幼虫的LT50分别为4.81 d和4.93 d，对蛹的LT50分别为4.94 d和4.83 d。经鉴定菌株FJMR2和FJXY7均为莱氏绿僵菌Metarhizium rileyi。本研究获得2株对草地贪夜蛾2龄幼虫和蛹具有高致病力的莱氏绿僵菌菌株，在草地贪夜蛾的生物防治中具有较大应用潜力。     

3种药剂对广东地区草地贪夜蛾3龄幼虫室内毒力测定及其田间药效评价

为明确几种药剂对广东地区草地贪夜蛾Spodoptera frugiperda幼虫的室内毒杀作用及田间防治效果,合理使用化学农药对草地贪夜蛾进行科学防治提供理论依据.本研究采用浸叶法测定了氯虫苯甲酰胺、高效氯氟氰菊酯和甲氨基阿维菌素苯甲酸盐对草地贪夜蛾3龄幼虫的室内毒杀作用;采用茎叶喷雾法,测定了 200克/升氯虫苯甲酰胺悬浮剂、150克/升氯虫苯甲酰胺?高效氯氟氰菊酯微囊悬浮-悬浮剂、25克/升高效氯氟氰菊酯乳油和5％甲氨基阿维菌素苯甲酸盐水分散粒对田间玉米上草地贪夜蛾幼虫的防治效果.室内毒力测定试验结果表明:甲氨基阿维菌素苯甲酸和氯虫苯甲酰胺对草地贪夜蛾3龄幼虫都有较好的毒杀作用,LC50分别为0.037 mg/L和0.094 mg/L;而高效氯氟氰菊酯对草地贪夜蛾的毒杀作用较一般,LC50为5.336 mg/L.田间试验结果表明,供试的3种药剂对草地贪夜蛾幼虫速效性一般,药后1 d的防治效果为40.79％～59.67％;药后3 d的防治效果为67.27％～88.55％;药后7 d其防治效果为55.75％～90.97％.氯虫苯甲酰胺和甲氨基阿维菌素苯甲酸盐对草地贪夜蛾具有较好室内的毒杀作用和田间防治效果,是目前防治草地贪夜蛾的理想药剂;高效氯氟氰菊酯对草地贪夜蛾室内的毒杀作用和田间防治效果较差,不推荐用来防治草地贪夜蛾.     

室内测定6种化学杀虫剂对草地贪夜蛾幼虫的毒力

2019年草地贪夜蛾Spodoptera frugiperda入侵我国多个省份和地区,对我国农业生产造成重大影响。化学防治是应对入侵害虫的主要措施,因此,本研究测定了6种不同作用机制杀虫剂对草地贪夜蛾初孵和3龄幼虫的生物活性。结果表明,对初孵幼虫具有较高毒力作用的为氯虫苯甲酰胺、多杀菌素、茚虫威、阿维菌素和甲氧虫酰肼;对3龄幼虫具有较高毒力作用的为氯虫苯甲酰胺、多杀菌素和茚虫威;与初孵幼虫相比,阿维菌素、茚虫威、多杀菌素和甲氧虫酰肼的LC 50分别提高了78.06、1.70、11.73和23.09倍。本研究筛选出了对草地贪夜蛾初孵幼虫和3龄幼虫杀虫效果较好的药剂,证明了低龄幼虫对部分农药抵抗力较弱,而3龄后的幼虫抵抗力显著增加,为田间草地贪夜蛾的化学防治提供了科学的用药指导。     

四氯虫酰胺玉米全株喷雾和喇叭口点施防治草地贪夜蛾的药效评价

评价四氯虫酰胺玉米全株喷雾和喇叭口点施处理对草地贪夜蛾的活性与防效,为草地贪夜蛾综合防控提供技术支持。采用叶片喷雾法,测定了对草地贪夜蛾2龄幼虫毒力;以40%辛硫磷乳油为对照药剂,采用喷雾和喇叭口点施两种方式田间施用10%四氯虫酰胺悬浮剂,药前1 d和药后1 d、3 d、7 d,调查挂牌标记玉米上草地贪夜蛾活虫数,计算防治效果。结果表明:四氯虫酰胺对草地贪夜蛾2龄幼虫具有良好的毒力;10%四氯虫酰胺悬浮剂制剂用量600 g/hm 2喷雾处理后1 d、3 d、7 d对草地贪夜蛾的防效分别为75.90%、91.91%和92.02%,制剂用量300 g/hm 2喇叭口点施处理后1 d、3 d、7 d对草地贪夜蛾的防效分别为82.28%、89.52%和91.23%,40%辛硫磷乳油制剂用量1500 g/hm 2处理,两种施药方式防效均不佳。四氯虫酰胺对草地贪夜蛾具有良好的防治效果,喇叭口点施方式节省药剂可达50%以上,在防治草地贪夜蛾等害虫方面具有广阔的应用前景。     

螟黄赤眼蜂对草地贪夜蛾卵寄生效果评价

为了明确螟黄赤眼蜂Trichogramma chilonis对草地贪夜蛾Spodoptera frugiperda (J.E. Smith)卵寄生效果,室内组建了螟黄赤眼蜂在草地贪夜蛾卵上的实验种群生命表,调查统计了释放螟黄赤眼蜂后田间草地贪夜蛾卵的寄生率和幼虫的虫口减退率,并分析了释放距离对寄生效果的关系。结果显示,螟黄赤眼蜂在草地贪夜蛾卵上的净生殖力R0=10.8407,内禀增长率rm=0.2220,周限生长率λ=1.2486,单雌平均产雌率R0′=13.8877。放蜂区草地贪夜蛾卵块寄生率64.44%,卵粒寄生率35.42%,显著高于对照区,释放赤眼蜂第7天田间草地贪夜蛾虫口减退率58.92%,防效50.50%。释放距离为5 m内螟黄赤眼蜂对草地贪夜蛾卵寄生效果的无显著影响。结果表明螟黄赤眼蜂对草地贪夜蛾卵有较高的寄生效能,田间释放螟黄赤眼蜂对草地贪夜蛾卵具较高的寄生率和明显的幼虫虫口减退率,释放螟黄赤眼蜂对降低草地贪夜蛾虫源基数起着重要的作用。     

氯虫苯甲酰胺对草地贪夜蛾的毒力及田间防效

草地贪夜蛾Spodoptera frugiperda(Smith)是威胁粮食安全的重要害虫,本文测定了氯虫苯甲酰胺对草地贪夜蛾的室内毒力及田间防效,从中筛选出高效的施药方法和施药剂量,为当前草地贪夜蛾防治提供合理用药的参考。结果表明,在室内条件下,使用氯虫苯甲酰胺直接喷雾处理对草地贪夜蛾3龄和4龄幼虫毒力最高,LC_(50)值分别为0.42 mg/L和0.57 mg/L,使用0.5 mg/L 20%氯虫苯甲酰胺悬浮剂对草地贪夜蛾幼虫毒力较高,在处理后第5天均有超过90%的死亡率。在田间条件下使用氯虫苯甲酰胺对草地贪夜蛾幼虫有较好的防效,使用60.0 g.a.i./ha 0.4%氯虫苯甲酰胺颗粒剂喇叭口点施防治低龄幼虫防效较好,药后第1天、第3天和第7天低龄幼虫(1～3龄)的防效分别为90.3%、100%和100%,使用22.5 g.a.i./ha 20%氯虫苯甲酰胺悬浮剂喇叭口喷雾防治高龄幼虫(4～6龄)的防效较好,药后第1天、第3天和第7天高龄幼虫的防效分别为71.7%、84.5%和95.3%。     

不同虫态叉角厉蝽对草地贪夜蛾幼虫的室内捕食作用

为了明确叉角厉蝽 Eocanthecona furcellate (Wolff)对草地贪夜蛾 Spodoptera frugiperda (J.E.Smith)幼虫的控制作用,在实验室条件下测定了叉角厉蝽不同虫态对草地贪夜蛾不同龄期幼虫的捕食能力,研究了该蝽捕食功能反应、搜寻效应以及种内干扰作用。结果表明,叉角厉蝽3龄若虫、5龄若虫、成虫均可捕食草地贪夜蛾幼虫,总体呈现叉角厉蝽低龄若虫捕食草地贪夜蛾低龄幼虫的数量较多,高龄若虫和成虫捕食中间龄期幼虫数量较多的规律;叉角厉蝽3个虫态对草地贪夜蛾2~3龄幼虫的捕食功能反应均符合Holling II方程和HollingⅢ型功能反应新模型;5龄若虫对草地贪夜蛾2~3龄幼虫的捕食效能(a/Th)最强（214.0）、日最大捕食量(1/Th)最大（256.4头）。不同虫态叉角厉蝽的搜寻效应与草地贪夜蛾密度均呈负相关。建立了叉角厉蝽成虫密度、草地贪夜蛾4龄幼虫密度对捕食作用的干扰反应方程,干扰作用发生后该蝽的平均捕食量和捕食作用率均逐渐下降。本研究结果可为田间释放叉角厉蝽防治草地贪夜蛾提供依据。     

草地贪夜蛾对5种寄主植物和6种杂草的取食选择性和适应性

为明确草地贪夜蛾Spodoptera frugiperda J. E. Smith对不同寄主植物和主要杂草的取食选择及适应性,以玉米Zea mays、甘蔗Saccharum officinarum、花生Arachis hypogaea、大豆Glycine max、香蕉Musa nana、稗草Echinochloa crusgalli、马唐Digitaria sanguinalis、牛筋草Eleusine indica、莎草Cyperus rotundus、马齿苋Portulaca oleracea、鹅肠草Malachium aquaticum作为寄主,采用叶碟法测定草地贪夜蛾各龄幼虫对5种寄主植物和6种杂草的取食偏好,并测定了不同虫态的发育历期、单头蛹重、化蛹率以及单雌产卵量等。结果表明,草地贪夜蛾在5种寄主植物和6种杂草上均可完成世代发育。寄主作物中,香蕉处理的草地贪夜蛾成虫前期最长,为29.66 d;甘蔗处理下草地贪夜蛾蛹重和化蛹率分别为250.44 mg和71.67%,显著低于玉米和花生处理的蛹重和化蛹率;草地贪夜蛾取食花生后单雌产卵量最高,为768.93粒,与玉米上产卵量差异不显著,香蕉上最低,为498.76粒;1~2龄幼虫对玉米和香蕉的取食选择率有显著差异,3~6龄幼虫对玉米取食选择率显著高于其他寄主植物。6种杂草中取食莎草的成虫前期最长30.21 d,且单雌产卵量最低526.33粒;取食鹅肠草蛹重最低188.00 mg;取食马齿苋化蛹率最低为72.37%;草地贪夜蛾取食马唐后其蛹重、化蛹率、单雌产卵量最高,与取食其它5种杂草有显著性差异;2~4龄幼虫更偏向取食马唐,与其它5种差异显著。研究结果表明：寄主植物种类对草地贪夜蛾的生长发育有显著影响,其中草地贪夜蛾对玉米和马唐具有较高的取食偏好。     

草地贪夜蛾幼虫对常用杀虫剂相对敏感基线的建立

【目的】本研究旨在建立草地贪夜蛾Spodoptera frugiperda对常用杀虫剂的相对敏感基线,为我国草地贪夜蛾的抗药性系统性监测提供依据。【方法】从玉米田采集草地贪夜蛾在室内不接触任何杀虫剂连续饲养5~7代,采用浸叶法和点滴法测定了草地贪夜蛾3龄幼虫以及采用饲料药膜法测定了草地贪夜蛾2龄幼虫对6大类共7种常用杀虫剂(甲维盐、乙基多杀菌素、虫螨腈、茚虫威、四氯虫酰胺、虱螨脲和氯虫苯甲酰胺)的敏感性,并据此建立了草地贪夜蛾幼虫对这7种杀虫剂的相对敏感基线。【结果】浸叶法测得上述7种药剂对草地贪夜蛾幼虫的LC₅₀值在0.054~12.131 mg/L之间;点滴法测得上述6种药剂(不含虱螨脲)对草地贪夜蛾幼虫的LD₅₀值在0.355~4.707 μg/g之间;饲料药膜法测得上述7种药剂对草地贪夜蛾幼虫的LC₅₀值在0.003~0.238 μg/cm²之间。【结论】采用3种生测方法建立了草地贪夜蛾幼虫对几种常用杀虫剂的相对敏感基线,为我国草地贪夜蛾的抗药性监测和化学防治提供了依据。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.