六种土传病原真菌被木霉抑制作用机理的初步研究

７０年代以来,关于木霉的拮抗作用及其机制有很多研究报道,同时温室和田间试验也从防治土传病原真菌进一步深入到叶面病原真菌研究,并且有商品化木霉制剂问世。我国在木霉研究和应用方面也有较大进展。本文通过比较木霉和土传病原真菌在单独和对峙培养中生长速度的差异...     

豌豆种传花叶病毒检测鉴定

豌豆种传花叶病毒(pea seed-borne mosaic virus,PSbMV)世界广泛分布,在国外已造成豌豆大量减产,国内有仅小范围低密度分布的报道。加拿大豌豆种子中挑拣皱缩、黑斑等症状的豌豆,先采用双抗体夹心酶联免疫吸附(DAS-ELISA)方法检出PSbMV阳性,再利用反转录PCR(RT-PCR)、序列比对分析和构建系统进化树对阳性样本进行验证鉴定,结果显示与PSbMV序列相似度为99.25%,综上确定从进境豌豆种子中检出豌豆种传花叶病毒。     

木霉对土传病原真菌的拮抗作用

 分别在体外及温室测定了筛选菌株哈茨木霉Trichoderma harzianum(T₈₂)和Tricho-derma sp.(NF9)对土传病原真菌的拮抗作用。体外测定表明,木霉菌株T₈₂和NF₉对白绢病菌Sclerotium rolfsii,立枯丝核菌Rhizoctonia solani,瓜果腐霉Pythium aphanidermatum刺腐霉P.spinosum和尖镰孢Fusarium oxysporum在对崎培养中的拮抗系数分别为2或2~3和2。温室测定表明,用0、6%(W/W)T₈₂麸皮培养物(10⁷cfu/g)处理土壤。在人工接种白绢病菌,立枯丝核菌及瓜果腐霉20天后,黄瓜发病率分别比未用木霉处理的对照减少46、5%,28.4%和81。2%;用T₈₂和NF₉木霉孢子悬浮液(10⁸cfu/ml)处理黄瓜种子,人工接种白绢病菌11天后,黄瓜成苗率分别比未用木霉处理的对照增加14%的20%。分别在光学显微镜和扫描电镜下观察到木霉T₈₂对白绢病菌菌丝和菌核的重寄生以及木霉T₈₂和NF₉对立枯丝核菌菌丝的缠绕。穿入及寄生。作者认为重寄生可能是试验木霉菌株T₈₂和NF₉对白绢病菌和立枯丝核菌的主要拮抗机制。     

几种土传病原真菌的分离培养技术

旨在针对当前普遍发生的、危害严重的镰刀菌、辣椒疫霉、腐霉菌等重要土传病原真菌进行分离培养,探索合适的病原真菌分离培养技术,分离重要致病菌。在常规培养基的基础上加入抗生素和杀菌剂等,摸索出合适的浓度,制成多种选择性培养基,筛选适于病原真菌分离的最佳组合。成功分离出辣椒疫霉、番茄晚疫、镰孢菌、链格孢、腐霉菌等重要致病菌。对土传病原真菌的分离方法研究具有一定的指导意义,为了解土传病原菌的种类、发生规律及综合防治等奠定了一定的基础。     

不同种衣剂对花生土传真菌病害田间防治效果

为筛选出对多种花生土传真菌病害综合防治效果理想的种衣剂,本研究选用7种种衣剂开展了一年两地田间药效试验。结果表明,7个处理对花生出苗时间和出苗率均无影响,11%精甲·咯·嘧菌悬浮种衣剂(FSC)对花生冠腐病、根腐病和白绢病具有较好的防治效果,对两地的3种病害防效可达78.58%以上,其次为25%噻虫·咯·霜灵FSC,防效达72.71%以上。与空白对照相比,11%精甲·咯·嘧菌FSC处理增产率最高,两地分别增产13.42%和10.25%,其次为25%噻虫·咯·霜灵FSC处理,两地分别增产11.83%和10.09%。综合安全性、防治效果、增产效果,11%精甲·咯·嘧菌FSC和25%噻虫·咯·霜灵FSC具有较好的推广前景,一次处理可以同时降低花生冠腐病、根腐病和白绢病的危害。     

种传植病细菌血清学检测的新趋势

种传植病细菌血清学检测的新趋势赵友福（农业部植物检疫实验所１０００２９）１种传植病细菌的常规血清学检测方法早在１９１８年，血清学试验就已应用于植病细菌。由于血清学方法不仅迅速、可靠，而且应用方便，因此非常适合于诊断种子是否携带病原细菌，特别是大批量种...     

菌根真菌菌剂防治作物土传病害潜力分析

 菌根真菌(mycorrhizal fungi,MF)对植物土传病害有一定的拮抗或抑制作用,能提高植物对土传病害的抗/耐病性。MF菌剂尤其是丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)及外生菌根真菌(ectomycorrhizal fungi,ECMF)菌剂作为一种生物防治剂在生产实践中的应用也是人们关心和感兴趣的问题。本文对MF菌剂防治土传病害的可能性、MF生态生理学、MF菌剂的生产、MF菌剂应用方法以及今后努力的方向进行了系统分析,并对MF菌剂防治土传病害的潜力和应用范围进行了评价。     

进境豇豆种子携带种传病毒的检测与鉴定

 Imported cowpea seeds were detected with growing test, ELISA assay and RT-PCR method. The ELISA results showed that cowpea seedlings with symptoms reacted positively with antibody against Southern bean mosaic virus (SBMV). The 979 bp of fragment could be amplified from two positive ELISA samples using primers specific for Southern cowpea mosaic virus (SCPMV), and the sequence determination results proved that the pathogen existing in imported cowpea seeds was SCPMV. The positive ELISA results with SBMV antibody could be further confirmed by RT-PCR amplification with specific primers designed to amplify the coat protein gene and 3' noncoding region of SCPMV and SBMV. The RT-PCR method presented here was suitable for molecular identification of SBMV and SCPMV in entry-exit plant quarantine laboratories.     

赤豆种内寄藏真菌的分离与鉴定

采用吸水纸法和琼脂平板法,从河北省6个赤豆品种中分离和鉴定出种内寄藏真菌6属,包括5个种和1个未定名种。对常见致病菌的侵入机理进行了初步分析探讨。     

小麦黑胚病种子菌的光镜和扫描电镜观察

检测表明京双１６、聊８９－２,聊９１－１,聊９１Ｂ１８－２７－１及鲁麦１２６个小麦品种（品系）的黑胚病病粒率为７．６％￣４５．７％,病情指数为３．２％￣１３．５％,以聊８９－１最轻,鲁麦１２最重。借助光学显微镜和扫描电子显微镜对６个品种（品纱）的黑胚种子和健康胚种子进行了比较观察,证实了黑胚种子胚中链格孢菌的存在,此外,亦观察到黑胚种子寄藏有类似于长蠕孢属,枝孢属等真菌的菌体。     

The seed-borne fungi of Chinese cabbage (Brassica pekinensis), their pathogenicity and control

The pathogenicity and control of seed-borne fungi of Chinese cabbage ( Brassica pekinensis ) were studied to evaluate the quality of imported seed lots on the Finnish market and to develop practical methods for seed health testing. Amongst the numerous fungal species in the seed lots, nine were found to be pathogenic on B. pekinensis seedlings, Alternaria raphani and A. brassicicola being the most common and the most pathogenic. A. brassicicola was effectively controlled by dressing seed with thiram or powdered Streptomyces griseoviridis . unlike A. raphani which was mostly located in the inner parts of the seed. Water agar was successfully used as an incubation medium for seed health testing. Surface sterilization of the seeds with sodium hypochlorite was used to determine the internal infection of A. raphani . A linear relationship between the incidence of A. brassicicola and A. raphani was demonstrated. Ten per cent of the seed lots were excluded from seedling production because of high infection with A. raphani .     

新疆食葵种子健康检测和杀菌剂消毒处理初步研究

采用PDA平板法检测了来自新疆自治区的2个品种的食葵种子带菌情况,并测定了9种不同杀菌剂对食葵种子带菌消毒处理效果和对种子发芽及苗期生长的影响。结果表明,食葵种子表面携带的优势菌群主要为镰孢霉属(Fusarium)、链格孢属(Alternaria)和青霉属(Penicillium),种子内部寄藏真菌主要有链格孢属和曲霉属(As-pergillus),其他分离频率较高的真菌还有根霉属(Rhizopus)和枝孢属(Cladosporium)等;2个食葵品种种子表面携带真菌种类有较大差异,种子内部寄藏真菌种类差异不大。杀菌剂苯醚甲环唑、咯菌腈和咪鲜胺具有良好的种子带菌消毒处理效果。     

辽宁五味子种子带菌检测及药剂消毒处理研究

采用PDA平板检测法对辽宁省6个地区的五味子种子进行带菌检测,并测定了6种杀菌剂对五味子种子的消毒效果。结果表明,五味子种子表面携带的主要真菌类群为曲霉属和青霉属,种子内部寄藏真菌主要包括曲霉属、青霉属、镰刀菌属、根霉属和链格孢属等。供试的6种杀菌剂对五味子种子均有一定的消毒效果,福美双对五味子种子消毒处理效果最显著。     

Detection and identification of seed-borne pathogenic bacteria of imported tomato seeds in Egypt

Imported tomato seed lots of different cultivars were assayed for the presence of seed-borne bacterial pathogens. The liquid assay method was used for detection of the bacteria, and seed extracts were plated on different semi-selective media. Pseudomonas corrugata and Xanthomonas campestris pv. vesicatoria were detected in 14.7% and 12% of the seed samples tested respectively. These pathogens were identified by means of biochemical, physiological and pathogenicity tests as well as the Biolog GN Microplate System for X. campestris pv. vesicatoria. Both P. corrugata and X. campestris pv. vesicatoria were more easily identified on Tween B and CKTM media than on other media. This is the first report of the occurrence of these important pathogens on tomato seeds in Egypt.     

几种进口花卉种子寄藏真菌的检测与鉴定

采用分离培养检验法分别对8种进口花卉种子共计14个批次的种子样品进行了种子奇藏真菌的检测、纯化和鉴定。研究结果表明，每种样品均带菌，共检测出进口花卉种子寄藏真菌13属24种，链格孢菌、枝孢菌、镰孢菌、毛壳菌是这些进口花卉种子寄藏真菌的优势菌群。     

甘草种子带菌检测及药剂消毒处理效果

采用PDA平板检测法分别对来自内蒙古、新疆、宁夏和甘肃等10个地区的甘草种子进行带菌检测。结果表明,甘草种子表面携带的优势菌群主要是曲霉属、青霉属和根霉属,其中来自于内蒙古鄂托克前旗和新疆阿勒泰甘草种子镰刀菌的分离频率达到11.1%和1.9%;种子内部寄藏真菌主要是曲霉属、青霉属、根霉属和交链孢属。来自于内蒙古鄂尔多斯杭锦旗和翁都特旗两个地区的甘草种子镰刀菌的带菌率分别达到5.6%和14.2%,其他来源的种子都未检测到镰刀菌属真菌。同时检测了来自于10个不同地区硬实种子的带菌情况,结果显示只有3个地区的硬实种子带菌,带菌率是0～2.5%。福美双、口恶霉灵、甲霜灵、苯醚甲环唑、百菌清和嘧菌酯几种药剂对甘草种子带菌消毒处理具有良好效果,种衣剂咯菌腈抑菌效果显著。     

Detection and identification of seed-borne viruses from cowpea (Vigna unguiculata (L.) Walp.) germplasm

Seedlings from 182 cowpea ( Vigna unguiculata ) pre-introductions/germplasm accessions from 12 countries were tested under greenhouse conditions for six seed-borne viruses. Twenty-one (13.3%) accessions from eight countries were found to be seed-infected with one of the three following viruses: blackeye cowpea mosaic (BlCMV) and cowpea aphid-borne mosaic (CABMV) potyviruses, and cucumber mosaic cucumovirus (CMV). Natural seed transmission incidence of 0–6.9%, 0–13.3%, and 0–2.0% were determined for BlCMV, CABMV and CMV respectively.   Another set of 2930 cowpea germplasm accessions, mostly from Botswana and Senegal (Africa), were examined under field conditions for detection and identification of seed-borne viruses. Only CABMV was detected in this material. Most of the lines were free from other viruses reported in cowpea seed. Eight isolates of BlCMV and 28 isolates of CABMV were derived from cowpea pre-introductions/germplasm accessions evaluated under greenhouse and field conditions.     

贵州烟仓害虫天敌种类及优势天敌初步研究

贵州烟仓害虫天敌种类多,优势、有效天敌为麦蛾茧蜂(Habrobracon hebetor)、米象娜金小蜂(Lariophagusdistinguendus)。天敌对降低和减轻害虫的发生量及控制其对烟叶的危害发挥了重要作用。在烟叶储藏中开展生物防治,保护利用天敌有着广泛的前景。