不同生物源药剂对小麦白粉病的防治效果及机理探讨

以化学药剂三唑酮为对照,3测定了种新研制的生物药剂对感病春麦品种辽春10白粉病的防治效果及机理。结果表明:植物源杀菌剂处理的小区病情指数增长慢,最终数值低(22.90,20.33);植物源杀菌剂保护和治疗作用防效分别为66.78%和73.33%,防效均优于其他生物药剂。直接测定不同药剂对白粉病无性孢子萌发的抑制作用,对孢子萌发抑制的EC50值为24.47,比三唑酮的EC50值(35.04)低,说明具有很强的抑制作用。在不接种白粉病条件下,辽春10小麦喷施植物源杀菌剂等药剂后,出现了类似抗病品种的反应,体内的重要防御酶苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、多酚氧化酶(PPO)、酯酶(EST)和-β1,3-葡聚糖酶活性都有显著升高,这可能是控制病害发展的相关生理机理。     

辣椒疫病生防放线菌筛选及其对辣椒根系微生物区系的影响

为了获得对辣椒疫病具有实际防效的生防放线菌菌株,在盆栽条件下检验了108株辣椒疫霉拮抗放线菌对辣椒疫病的防病和促生作用,并对拮抗菌接种后土壤和辣椒根系微生物区系的影响进行了研究。结果表明,经无菌土纸钵初筛和未灭菌自然土盆栽复筛试验,从108株辣椒疫霉拮抗放线菌中筛选出2株防效最佳的拮抗放线菌0108和0110。在盆栽条件下,接种0108和0110拮抗放线菌14 d后相对防效分别达到75%和81%,21 d后相对防效分别达到65%和56%,且2株拮抗放线菌都能通过影响辣椒根系微生物数量控制辣椒疫霉菌的生长繁殖,降低辣椒疫霉对根系的侵染,并对辣椒根系生长有显著促进作用。     

浅谈生物防治中的生物农药

讨论生物防治中生物农药的定义、分类及特点，对生物农药的研究和应用现状进行简述认为生物农药很有发展前景，并提出我国发展生物农药的方向和侧重点。     

草莓枯萎病拮抗菌JM-3的鉴定及生防效果评价

为明确草莓枯萎病拮抗菌JM-3的分类地位,并评价其防治效果,本研究通过生理生化分析、16S rDNA、gyrA和gyrB基因序列比对进行菌种鉴定,同时采用抑菌活性测定、盆栽和田间防效试验评价其生防效果。结果表明,生防菌JM-3属于贝莱斯芽孢杆菌Bacillus velezensis,其对草莓枯萎病菌的平板对峙抑制率为57.42%。盆栽试验发现,处理后90天,拮抗菌JM-3固体制剂对草莓枯萎病病情指数的防效为83.02%,高于菌液和多菌灵处理,表明固体制剂的持效性较高。田间试验结果趋势与其基本一致。生防菌JM-3液体和固体制剂处理的果实糖酸比分别为8.88和8.90,显著高于多菌灵处理和对照。可见拮抗菌JM-3对草莓枯萎病具有较高的生防效果,且有助于提升草莓品质,具有较好的应用前景。     

Combined application of Trichoderma harzianum SH2303 and difenoconazole-propiconazolein controlling Southern corn leaf blight disease caused by Cochliobolus heterostrophus in maize

Southern corn leaf blight(SCLB) disease caused by Cochliobolus heterostrophus is one of the major threats to corn production worldwide. The synergistic application of low toxic chemical fungicide and biocontrol agents could improve biocontrol stability and efficiency against plant diseases, which ultimately reduce use of chemical fungicide. Trichoderma spp., well-known biocontrol fungi have been used to control some foliar diseases. However, few works have been reported on synergistic application of chemical fungicide and Trichoderma against foliar diseases. This study was aimed to investigate the control effect on the synergistic application of Trichoderma harzianum SH2303 and difenoconazole-propiconazole(DP) against SCLB. Results showed that the synergistic application of DP and SH2303 reduced the leaf spot area compared to the control. The efficacy of synergistic application of DP+SH2303 against SCLB could last for 15–20 d in pot trial under the greenhouse condition. Under the natural field condition, maize treated with DP+DP and DP+SH2303 showed 60% control, which was higher than that of SH2303+DP(45%) and SH2303+SH2303(35%). All these treatments induced the synthesis of defense-related enzymes(phenylalanine ammonia lyase(PAL), catalase(CAT), and superoxide dismutase(SOD)) and the defence-related gene expression of SA pathway(PR1). Taken together the in-vitro leaf test and field trial, the control of SCLB by synergistic application of DP+SH2303 was similar to that of DP+DP. Among synergistic application, the sequential application of DP+SH2303 showed better control than the sequential application of SH2303+DP. It was concluded that the synergistic application of chemical fungicide(DP) and biocontrol agent(T. harzianum SH2303) could be used to reduce the chemical fungicide and to reduce the SCLB diseases in maize, which provided alternative approach to realize an eco-friendly controlling of the foliar disease.     

辣椒疫病生防真菌F1的生物学特性及生防作用

采用形态鉴定,碳、氮源利用及耐药性试验对生防真菌F1的分类地位和生物学特性进行了研究,并利用盆栽、温室生物实验及离体实验研究了F1对辣椒疫病的防效及防病机理。结果表明:(1)F1为曲霉属[A s-p erg illusM iche li ex F r]舒展曲霉(A.effusus T irabosch i);(2)F1对辣椒疫病防效明显,在盆栽线椒和温室甜椒生防实验中的相对防效分别为83.3%和94.1%;(3)F1对辣椒疫霉菌丝生长相对抑菌率为57%~100%,对游动孢子萌发相对抑制率为78.9%;(4)F1能在辣椒根内定殖,单独接种F1与F1+P3混合接种后8,24和42 d时,F1的定殖密度分别为4×103/g,5×103/g,3×103/g和13×103/g,3.5×103/g,2.3×103/g;(5)接种F1对辣椒叶片苯丙氨酸解氨酶(PAL)与多酚氧化酶(PPO)活性有影响。接种24 d时,单独接种F1处理辣椒叶片PAL与PPO酶活分别较不接菌对照降低47.9%与26.3%,而F1+P3混合接种处理辣椒叶片PAL活性较对照提高86.7%,PPO活性较对照降低29.9%。     

陕西设施蔬菜根结线虫生防菌株JXC224的分离筛选

几丁质及蛋白质是构成根结线虫体壁和卵壳的主要物质。几丁质酶和蛋白酶活性的高低是评价生防真菌防治潜力的重要生化指标。从陕西省陕北关中陕南根结线虫病害严重的设施蔬菜大棚中采集土样、根结样106份,用分离培养基分离到真菌436株。液体发酵测定分离菌株的几丁质酶活及蛋白酶活,筛选获得几丁质酶活≥0.06 U/mL的菌株11株,蛋白酶活≥100 U/mL的菌株3株。其中JXC224几丁质酶活达0.087 U/mL,蛋白酶活125.8 U/mL,对根结线虫二龄幼虫的侵染率达67%,是一株具有开发潜力的生防菌株,经ITS测序分析,鉴定其为枝顶孢霉(Acremonium sp.)。     

花角蚜小蜂对松突圆蚧的防治

根据近年来泉州市应用花角蚜小蜂防治松突圆蚧的工作实践,总结了应用花角蚜小蜂防治松突圆蚧的主要技术措施,包括林间放蜂点的选择和管护、室内收蜂、补充营养与配对、林间放蜂、效果检查与巩固等,为推广应用花角蚜小蜂生物防治提供参考。     

胡瓜钝绥螨控制大棚甜椒烟粉虱的研究

在我国山东省寿光市的蔬菜基地开展利用胡瓜钝绥螨控制日光大棚甜椒烟粉虱的研究.结果表明:(1)胡瓜钝绥螨能够捕食烟粉虱卵、成虫、若虫和伪蛹.在(25±1)℃、(30±1)℃、(35±1)℃下胡瓜钝绥螨以烟粉虱为猎物的发育历期与其取食柑橘全爪螨Panonychus citri(Mc Gregor)和二斑叶螨Tetranyc...