Screening of field performance of entomopathogenic fungi and nematodes against cabbage root flies (Delia radicum l. and d. floralis (fall.); Diptera,Anthomyiidae)     

Irene Vänninen  Heikki Hokkanen  Johanna Tyni‐Juslin 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):167-183

Finnish isolates of Beauveria bassiana (8 isolates), Metarhizium anisopliae (7), Tolypocladium sp. (2), Paecilomyces farinosus (2), P. fumosoroseus (1), Steinernema feltiae (3) and Bacillus thuringiensis ('Muscabac') were tested for efficacy against mixed populations of Delia radicum and D. floralis under field conditions in 1986–90. All pathogens were applied preventatively, the fungi as aqueous conidial or mycelial suspensions, dry conidia or dry mycelial powder. In only two of the nine experiments did B. bassiana or M. anisopliae give some control. In 1986, B. bassiana SF85–2 and Tolypocladium sp. SF85–4 (both at rate 1.2 x 10⁹ conidia plant‐ 1), and ‘Muscabac’ (25 g 1^?1, 1 dl plant^?1) reduced the number of pupae by 80%, 60% and 50%, respectively, as compared with untreated and chemical (isophenphos) controls. In 1990, M. anisopliae SF86–39 at rate 1.6 x 10⁹conidia plant^?1 and 1.5 x 10⁸ CFU plant^?1 and S. feltiae SFS‐22 (35000 plant^?1), increased the yield of cauliflower 2.2, 1.8, and 2.3‐fold, respectively, as compared with the untreated control, but these yields were only 19%, 15% and 19% of those of the chemical (diazinon) control. Paecilomyces isolates were ineffective in the 1986 experiment in which they were included. Our results suggest that it is difficult to find efficient control agents among the fungal and nematode species tested for use as biopesticides against cabbage root flies, but that the potential of M. anisopliae against these pests deserves further study.  相似文献   

23个欧美杨无性系苗期叶锈病抗性测定   总被引：2，自引：0，他引：2  

潘姝慧  孙佳音  刘春华  吕晓亮  滕文飞 《辽宁林业科技》2010,(1):5-7,46

以引进23个欧美杨无性系为研究对象,通过对苗木叶锈病感病指数的调查,借助SPSS统计软件对调查数据进行统计分析,结果表明:对叶锈病的抗性表现超过对照品种I108的有19个,其中02-36-1、02-36-4、N177、N197和N195这5个无性系对叶锈病完全免疫;无性系02-34-334对叶锈病表现为高度抗病;02-01-119、324、03-04-111、03-04-97和02-34-278表现为抗病;03-04-141、03-04-170、02-34-347和03-05-184表现为感病;02-01-219、03-04-167、03-04-288和02-34-228表现为高感;对叶锈病的抗性表现不及对照品种I108的有3个,即03-05-206、03-04-171和03-05-156,均表现为高感。  相似文献   

Morphological Basis of Resistance in Cotton to the WhiteflyBemisia Tabaci     

N. S. Butter  B. K. Vir 《Phytoparasitica》1989,17(4):251-261

The morphological basis of resistance to the whiteflyBemisia tabaci Genn. (Aleyrodidae: Hemiptera) was studied. The plant characters examined were leaf area, thickness of leaf lamina, hair density, hair length, angle of insertion of leaf hair, and density of gossypol glands. Hair density and leaf thickness were positively correlated with the population ofB. tabaci, and a positive correlation was obtained between the adult whitefly population and gossypol glands on stem internodes. Cotton genotype USA-22 (sparsely hairy) was found to be more tolerant toB. tabaci than was genotype USA-13 (velvety hairy). The use of thinner and glabrous leaved cotton varieties is suggested to minimize the whitefly menace in cotton.  相似文献   

增效浏阳霉素防治叶螨的效果和对智利植绥螨影响的研究     

董慧芳 《中国生物防治》1990,(3)

在实验室内用5％增效浏阳霉素乳油1000倍液防治截形叶螨,24小时后的死亡率为95.5％。对三氯杀螨醇有较强抗性的二斑叶螨和朱砂叶螨,48小时后的死亡率也达90％左右。浏阳霉素对3种叶螨均无杀卵作用,但施药5～6天后,对初孵幼螨仍能杀死90％以上。低温能降低浏阳霉素的药效。在温室中施药一周后。对二斑叶螨的雌成螨无残效,但幼螨和前若螨的死亡率可达97.4％。以磷酸兰苯酯作增效剂的浏阳霉素比亚磷酸三苯酯作增效剂的药效好。在同一剂量下,对二斑叶螨的死亡率分别为98.2％和53.4％。5％浏阳霉素的1000倍液对智利植绥螨成螨的生存率、在叶上的定居率及着卵量均无影响。在温室栽培月季上喷药1次防治二斑叶螨,36天后防治效果仍保持在99％,而用三氯杀螨醇和敌敌畏防治,施药一周后需再次防治。  相似文献   

一种对桃小食心虫高毒力的斯氏线虫Steinernema sp.(CB-2Y)     

周瑗玥  杨怀文 《中国生物防治》1991,(2)

本研究在室内用“沙埋法”比较了两种斯氏属昆虫病原线虫Steinernema sp.(CB-2Y)和S.feltiae Agriotos对桃小食心虫的侵染力,结果表明CB-2Y线虫对桃小食心虫幼虫和冬茧的侵染力都高于Agriotos线虫。接线虫笫7天桃小食心虫LD50,CB-2Y组为49条线虫,而Agriotos组为158条;冬茧的LD50分别为1330条和24046条。在桃小冬茧开始活动期(6月15日)分别施用两种线虫,一个月后检查桃小食心虫成虫羽化率,CB-2Y线虫的控制效果明显优于Agriotos,在1024条线虫/桃小食心虫冬茧时(75条/cm~2),越冬代桃小食心虫的羽化率分别为8.2％和29.2％。  相似文献   

麦田蚜茧蜂的初步研究   总被引：2，自引：0，他引：2  

宗良炳  雷朝亮  刘作甫 《中国生物防治》1986,(2)

武昌麦田蚜茧蜂共有5种,以燕麦蚜茧峰、烟蚜茧蜂为优势种;重寄生蜂有三种,以黄足分盾细蜂为优势种。蚜茧蜂4月中、下旬进入麦田,5月中旬种群数量达到高峰:蚜茧蜂种群数量主要受寄主—蚜虫密度和4～5月的雨量,相对湿度的影响。麦田蚜茧蜂对麦蚜有一定的控制作用,寄生率最高可达40％以上。解决好重寄生和跟随现象的问题,可提高好苗蜂对麦蚜的控制效果。  相似文献   

Potato plant response to seed tuber bacterization in the field in various rotations     

F. P. Geels  J. G. Lamers  O. Hoekstra  B. Schippers 《European journal of plant pathology / European Foundation for Plant Pathology》1986,92(6):257-272

The effects of a seed tuber treatment with antagonistic isolates of fluorescentPseudomonas spp. were investigated on potato plants from 1981 to 1984. The experimental plots were located in fields in short and long rotations of potato. The short rotations are characterized by serious yield reductions which are caused by unknown microbial factors. The reductions varied from 30% in 1982 to only 3% in 1983 in the 3-year rotations. A statistically significant increase in yield (four to five months after planting) of ware potatoes varying from 9 to 20% was obtained in these plots through tuber bacterization, but only in 1981. In 1982 and 1983 initially significant improvements in shoot or tuber weight of seed potatoes were no longer detectable at ware potato harvest at the end of the growing period. Seed tuber bacterization had no effect on tuber yield in long rotations. Initial colonization of basal root parts by 53×10⁴ colony forming units (cfu) of antibiotic-resistant mutants per gram of root (fresh) dropped significantly to 20×10⁴ cfu per gram after three months. The bacterization effect on tuber yield depended on the development of harmful microbial activity and of introduced antagonists during the growing period. Seed tuber bacterization is more promising for seed potatoes than for ware potatoes in short rotations, the latter being harvested two months later.Samenvatting De invloed van pootgoedbehandeling met antagonistische isolaten van fluorescerendePseudomonas-soorten op de aardappelteelt, werd onderzocht in de periode van 1981 tot en met 1984. De proefvelden maakten deel uit van zowel ruime als nauwe rotaties met aardappelen. Kenmerkend voor de nauwe rotatie is, dat de opbrengst aanzienllijk gereduceerd wordt als gevolg van de aanwezigheid van nog onbekende microbiële factoren. Deze opbrengstverlaging varieerde van 30% in 1982 tot slechts 3% in 1983 in de 3-jarige rotaties. Pootgoedbacterisatie had in deze proefvelden een significante toename van de eindopbrengst (vier tot vijf maanden na pootdatum) van consumptieaardappelen tot gevolg, die varieerde van 9 tot 20%, echter allen in 1981. In 1982 en 1983 werd het effect van bacterisatie ook in de loop van de groeiperiode onderzocht. Aanvankelijk significante toenames van zowel spruit-als knolgewicht waren aan het einde van het groeiseizoen niet meer aantoonbaar. Pootgoedbacteristie bleek geen effect te hebben op aardappel in ruimte rotaties. Aanvankelijk werden de basale wortelgedeelten gekoloniseerd door antibioticum-resistente mutanten met 53×10⁴ kolonievormende eenheden (kve) per gram wortel(vers); dit aantal liep (drie maanden na pootdatum) echter significant terug tot 20×10⁴ kve per gram. Het effect van bacterisatie op de eindopbrengst werd bepaald door de ontwikkeling van de schadelijke microbiële activiteit en de ontwikkeling van de geïntroduceerde antagonisten tijdens het groeiseizoen. Pootgoedbacterisatie in nauwe rotaties biedt meer mogelijkheden voor de teelt van pootaardappelen dan die van consumptieaardappelen, die geruime tijd later geoogst worden.  相似文献   

PCR-based detection of Xanthomonas campestris pathovars in Brassica seed     

T. Berg  L. Tesoriero  D. L. Hailstones† 《Plant pathology》2005,54(3):416-427

Xanthomonas campestris is a seedborne bacterium that causes black rot of crucifers. Substantial crop losses may result from the rapid spread of the bacteria under favourable conditions, especially those occurring during seedling production. A PCR-based method has been developed for the rapid and sensitive detection of the pathovars of X. campestris that affect crucifers. Primers were designed to specifically amplify a 619 bp fragment of the hrpF gene from X. campestris . Amplification products were not detected from other Xanthomonas species, or from other pathogenic or epiphytic bacteria occurring on these plants. To avoid false-negative results arising from the presence of amplification inhibitors in plant extracts, primers targeting a 360 bp section of the internal transcribed spacer (ITS) region from Brassica spp. were included in a multiplex PCR. The assay readily detected X. campestris pv. campestris infections in diseased plants and from bacterial colonies isolated on growth media, and was more sensitive and specific than traditional plating methods and a commercially available ELISA. A seed-washing protocol was optimized to allow the detection of a single artificially infected seed among 10 000 healthy seeds using the multiplex PCR.  相似文献   

猪肺炎支原体膜蛋白P46基因在大肠杆菌中的表达   总被引：1，自引：0，他引：1  

覃青松  宁宜宝  沈青春 《中国预防兽医学报》2005,27(2):94-97

把猪肺炎支原体(Mycoplasma hyopneumoniae)国际标准株232的P46基因克隆进pGEM-T-EASY载体上,通过PCR方法把该基因中三个编码Trp的密码子TGA突变为TGG,然后将该基因亚克隆到载体pMAL-P2X上,得到重组表达载体pMAL-P2X-P46.用该重组载体转化大肠杆菌TB1,得到表达重组菌TB1-pMAL-P2XA-P46,用终浓度为0.3 mM的IPTG在37℃下诱导表达,获得可溶性表达的融合蛋白MBP-P46,在免疫印迹试验中,兔抗MBP高免血清和兔抗猪肺炎支原体高免血清都能与目的蛋白发生阳性反应,证明猪肺炎支原体P46基因在大肠杆菌里获得了可溶性表达.该融合蛋白对于建立特异性和敏感性好的EIISSA方法具有重要意义.  相似文献   

Long-term tillage and crop rotation effects on weed seedbank size and composition   总被引：5，自引：1，他引：5  

P Bàrberi  & B Lo Cascio 《Weed Research》2001,41(4):325-340

Size and composition of the weed seedbank was assessed after 12 years of application of four tillage systems in two crop rotations. Mouldboard and chisel ploughing at 45 cm, minimum tillage at 15 cm and no tillage were compared in continuous winter wheat and a pigeon bean/winter wheat 2-year rotation. Weed control was based upon post-emergence herbicide application. Weed seedling emergence from soil samples taken at 0–15, 15–30 and 30–45 cm depths was assessed in a non-heated glasshouse for 12 months. The tillage system influenced weed seedbank size and composition to a much greater extent than crop rotation. Total weed seedling density was higher in no tillage, minimum tillage and chisel ploughing plots in the 0–15, 15–30 and 30–45 cm layers respectively. Density in the whole (0–45 cm) layer did not differ significantly among tillage systems. With no tillage, more than 60% of the total seedlings emerged from the surface layer, compared with an average 43% in the other tillage systems. Crop rotation did not influence either weed seedbank size or seedling distribution among soil layers, and only had a small influence on major species abundance. The weed seedbank was dominated (>66%) by Conyza canadensis (L.) Cronq. and Amaranthus retroflexus (L.), which thrived in chisel ploughing and no tillage respectively. Results suggested that crop rotation and substitution of mouldboard ploughing by non-inversion tillage (especially by minimum tillage) would not result in increased weed problems, whereas use of no tillage might increase weed infestations because of higher seedling recruitment from the topsoil.  相似文献