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1.
本研究以‘浚单20’为供试玉米品种,以棉铃虫为供试昆虫,以拟轮生镰孢为供试病原菌,分别进行单独及复合处理,以明确棉铃虫和拟轮生镰孢单独处理和复合处理对玉米穗腐病发病程度及籽粒中伏马毒素污染水平的影响。结果表明,2011年和2012年均以棉铃虫与拟轮生镰孢侵染复合处理对穗腐病发病程度及籽粒中伏马毒素污染水平的影响最大,穗腐病平均病级分别为0.68±0.05和1.08±0.19;单独接种棉铃虫,2011年和2012年的穗腐病平均病级分别为0.31±0.05和0.71±0.06;单独接种拟轮生镰孢,穗腐病平均病级分别为0.24±0.03和1.05±0.29。复合处理的籽粒中伏马毒素污染水平,2011年和2012年分别为(0.85±0.56)mg/kg和(2.36±0.98)mg/kg;单独接种棉铃虫处理分别为(0.17±0.12)mg/kg和(0.01±0.002)mg/kg;单独接种拟轮生镰孢处理分别为(0.10±0.03)mg/kg和(1.14±0.62)mg/kg。相同处理条件下,降水量大和相对湿度高的气候条件更有利于穗腐病的发生及籽粒中伏马毒素的积累。  相似文献   

2.
杀菌剂对玉米穗腐病菌的毒力及毒素产生的影响   总被引：2，自引：1，他引：2  
为筛选防治玉米穗腐病同时减少病原菌毒素积累的化学药剂,采用菌丝生长速率法、涂布平板法分别测定了4种药剂多菌灵、百菌清、吡唑醚菌酯和氰烯菌酯对玉米穗腐病的3种主要致病镰孢菌拟轮生镰孢菌、层出镰孢菌和禾谷镰孢菌菌丝生长和孢子萌发的影响,并采用高效液相色谱法测定了4种药剂对其毒素积累的影响。结果表明:层出镰孢菌菌株127-1和禾谷镰孢菌菌株125-3的最佳产毒时间为第10天。供试4种药剂对3种镰孢菌菌丝生长的EC50值范围为0.18~5.71μg/m L,对孢子萌发的EC50值范围为0.02~8.14μg/m L,均表现出一定的抑制作用。但对3种镰孢菌产伏马毒素、玉米赤霉烯酮和脱氧雪腐镰孢菌烯醇的影响不尽相同,吡唑醚菌酯浓度在1~500μg/m L时能够抑制拟轮生镰孢菌和层出镰孢菌产生伏马毒素,氰烯菌酯能够在0.05~0.8μg/m L浓度范围内显著抑制禾谷镰孢菌产生玉米赤霉烯酮,当多菌灵浓度为0.05~0.5μg/m L时,几乎可以完全抑制禾谷镰孢菌产生脱氧雪腐镰孢菌烯醇。  相似文献   

3.
 为明确河北省夏玉米区玉米穗腐病的发生情况、病原菌组成及地区对病原菌种类的影响,本团队于2016年和2017年在玉米收获前期对玉米穗腐病的发生情况进行调查,并通过生物学方法对随机采回的样本进行分离鉴定。田间调查结果表明,与2016年相比,2017年河北省玉米种植面积有所减少,玉米穗腐病的发病率有所下降。分离鉴定结果表明,引起河北省夏玉米区穗腐病的优势病原菌为拟轮枝镰孢菌(Fusarium verticillioides),分离频率为63.49%,其他病原菌如层出镰孢菌(F. proliferatum)、禾谷镰孢菌(F. graminearum)、变红镰孢菌(F. incarnatum)、黑曲霉(Aspergillus niger)、黄曲霉(A. flavus)、草酸青霉(Penicillium oxalicum)和哈茨木霉(Trichoderma harzianum)的分离频率分别为19.05%、6.35%、1.59%、14.29%、3.17%、9.52%和1.59%。为明确伏马毒素基因在潜在产伏马毒素镰孢菌鉴定中的作用,拟轮枝镰孢菌、层出镰孢菌和藤仓镰孢菌(F. fujikuroi)分别以EF-1α和FUM1基因序列为基础构建系统发育树。结果表明,两个系统发育树拓扑结构相似,伏马毒素基因可用于潜在产伏马毒素镰孢菌种的鉴定,基于FUM1基因的种间遗传距离大于基于EF-1α基因的种间遗传距离,而种内遗传距离的结论则与之相反。  相似文献   

4.
我国玉米穗腐病致病镰孢种群及禾谷镰孢复合种的鉴定   总被引：9，自引：4，他引：5  
为阐明中国玉米镰孢穗腐病的主要致病镰孢菌种类及其分布特征,采用形态学、培养特征及特异性分子鉴定方法,对采集自我国18省100个县的玉米籽粒样品进行分离鉴定,并通过TEF-1α基因序列测定解析禾谷镰孢复合种的构成.结果表明,在我国引起玉米穗腐病的主要致病菌为镰孢菌,分离频率为56.0%,其次还有青霉菌、曲霉菌、木霉菌等.138个镰孢菌分离物中鉴别出7个种及复合种,其中拟轮枝镰孢菌Fusarium verticillioides(56.5%)和禾谷镰孢复合种F.graminearum species complex(37.7%)为广泛分布的优势致病种类,其余为黄色镰孢菌F.culmorum(2.2%)、层出镰孢菌F.proliferatum(1.5%)、尖镰孢复合种F.oxysporum species complex(0.7%)、茄镰孢复合种F.solani species complex(0.7%)和亚粘团镰孢菌F.subglutinans(0.7%).在禾谷镰孢复合种中鉴定出3个独立种:广泛分布的禾谷镰孢菌F.graminearum sensu stricto(59.6%)、分布在云南、贵州及陕西商洛等南方生态区的南方镰孢菌F.meridionale(25.0%)和分布在内蒙古、吉林、山西、河北及北京等北方生态区的布氏镰孢菌F.boothii(11.5%).  相似文献   

5.
辽宁省玉米镰孢穗腐病病原菌的鉴定与分布   总被引：1，自引：0，他引：1  
为明确辽宁省玉米镰孢穗腐病的病原菌种类及其分布特征,采用形态学与分子生物学鉴定方法,对2015年9月采自辽宁省13个地区的84份玉米穗腐病样品进行分离鉴定,同时依据镰孢菌分离频率确定其在辽宁省玉米生态区的分布特征。结果表明,从辽宁省84个玉米穗腐病样分离物中鉴定出3个种,即拟轮枝镰孢菌Fusarium verticillioides、禾谷镰孢菌F.graminearum和层出镰孢菌F.proliferatum,分别为67、9和8株,占79.77%、10.71%和9.52%。按照柯赫式法则,验证了3种镰孢菌代表菌株FV-39、FG-1和FP-2是玉米品种郑单958穗腐病的致病菌。拟轮枝镰孢菌为辽宁省玉米镰孢穗腐病的优势致病菌,广泛分布于辽东、辽南、辽中、辽北和辽西5个玉米生态区,分别占16.67%、11.90%、21.42%、10.72%和19.05%;禾谷镰孢菌主要分布于辽西地区,层出镰孢菌主要分布于辽中和辽北地区。  相似文献   

6.
重庆及周边地区玉米穗腐病致病镰孢菌的分离与鉴定   总被引：3，自引：1，他引：2  
为明确重庆及周边地区玉米穗腐病致病镰孢菌的种群组成及其分布,于2014—2015年在32个区县98个乡镇采集玉米穗腐病样品,采用种子健康检测法分离病原物,通过形态学特性、培养特征和分子生物学等方法鉴定镰孢菌种。结果表明,在获得的111个镰孢菌分离物中鉴定出10种致病镰孢菌,分别为拟轮枝镰孢、层出镰孢、禾谷镰孢复合种、尖镰孢复合种、藤仓镰孢、木贼镰孢、黄色镰孢、变红镰孢、九州镰孢和茄镰孢,其总分离频率依次为38.70%、17.10%、17.10%、11.70%、7.20%、3.60%、1.80%、0.90%、0.90%和0.90%;除渝东南区域外,在其它区域拟轮枝镰孢的分离频率最高,其次为层出镰孢和禾谷镰孢复合种;对禾谷镰孢复合种分离物的翻译延伸因子TEF-1α基因测序比对发现,该复合种由南方镰孢和亚洲镰孢组成。研究表明,重庆地区玉米穗腐病优势致病镰孢菌为拟轮枝镰孢、禾谷镰孢复合种和层出镰孢。  相似文献   

7.
山东省小麦赤霉病菌种群组成及其致病力分化   总被引：2，自引：2，他引：0  
由禾谷镰孢菌群Fusarium graminearum clade引起的赤霉病是小麦的重要病害。为明确山东省小麦赤霉病菌的种群组成及其致病力,于2011年和2012年从山东省15地市分离了95株小麦赤霉病菌,在形态和分子生物学鉴定种的基础上,采用鉴定B型毒素化学型的特异性引物进行毒素化学型分析。在95个菌株中,93株分离物为禾谷镰孢菌F.graminearum,2株为燕麦镰孢菌F.avenaceum。94株分离物为脱氧雪腐镰孢菌烯醇(deoxynivalenol,DON)化学型,1株为雪腐镰孢菌烯醇(nivalenol,NIV)化学型。在94株DON毒素化学型菌株中,90株为15-乙酰脱氧雪腐镰孢菌烯醇(15-acetyldeoxynivalenol,15-AcDON)化学型,4株为3-乙酰脱氧雪腐镰孢菌烯醇(3-acetyldeoxynivalenol,3-AcDON)化学型。在小麦扬花期,采用单花滴注接种法对29个菌株进行了致病力测定,供试菌株的致病力分化明显。表明在山东省冬小麦产区,产15-AcDON毒素的F.gra-minearum是小麦赤霉病菌的优势种群。  相似文献   

8.
为明确新疆维吾尔自治区（简称新疆）绿洲灌溉玉米产区玉米茎腐病优势病原菌的种类组成及时空变化差异,于2020年和2021年在新疆主要玉米种植区共采集335株病样,获得601个分离物,通过形态学结合分子生物学技术对各代表菌株的rDNA-ITS和TEF-1α基因序列进行扩增和同源率比对鉴定。结果表明,镰孢菌共560株,占比93.18%,其中拟轮枝镰孢菌Fusarium verticillioides、层出镰孢菌F. proliferatum、禾谷镰孢菌F. graminearum、尖孢镰孢菌F. oxysporum和腐皮镰孢菌F. solani为主要致病菌,2020年分离频率依次为44.10%、29.77%、9.77%、5.69%和5.23%,2021年分离频率依次为50.95%、38.22%、0、2.55%和0。拟轮枝镰孢菌和层出镰孢菌在5个地州均有分布,且总分离频率显著高于其他病原菌。苗期接种结果表明,禾谷镰孢菌致病率（86.30%）、病情指数（35.33）显著高于其他4种病原菌,为强致病菌;层出镰孢菌和拟轮枝镰孢菌的致病率和病情指数分别为63.33%、16.00和55.00%、11.6...  相似文献   

9.
大豆根腐病原镰孢菌种群多样性DGGE分析及其致病性研究   总被引：4，自引：0，他引：4  
 应用变性梯度凝胶电泳(DGGE)技术以及主成分分析方法,结合植物病原菌传统分离、鉴定及致病力测定,检测位于黑龙江省海伦市大豆连作定位试验区根腐病原镰孢菌的种群构成及其致病力。采用真菌传统分离和鉴定方法共确定镰孢菌6个种,包括燕麦镰孢Fusarium avenaceum、木贼镰孢F. equiseti、禾谷镰孢F. graminearum、腐皮镰孢F. solani、尖镰孢F. oxysporum和拟轮枝镰孢F. verticillioides。其中,尖镰孢菌的分离频率最高,为56.7%。结合DGGE条带克隆测序及系统发育分析鉴定出8种镰孢菌,较传统方法增加了黄色镰孢F. culmorum和一个尖镰孢近似种。同时,DGGE图谱中尖镰孢所占百分比下降为37.4%。采用主成分分析方法将大豆生育指标相关的多种变量进行降维分析,得到第一主成分贡献值为91.2%。按照贡献值的正负结果,将30株镰孢菌分为致病和非致病类群。第二主成分贡献值为5.8%,根据其正负值可以矫正被错误估计的致病能力。综合所有研究结果,该定位试验区大豆根腐病主要病原镰孢菌为尖镰孢、禾谷镰孢和燕麦镰孢,且以尖镰孢菌为优势病原菌。  相似文献   

10.
 本研究对2015年收集的春玉米区玉米穗腐病样本的病原菌进行了分离鉴定。结果表明,禾谷镰孢复合种(Fusarium graminearum species complex)的总分离频率最高,为35.90%,为优势菌。进一步分析显示,山西、河北、吉林和黑龙江省以禾谷镰孢复合种为主,分离频率分别为81.25%、 75.00%、 44.00%和44.44%;内蒙古以拟轮枝镰孢菌(F. verticillioides)为主,分离频率为56.25%;辽宁省拟轮枝镰孢菌和哈茨木霉(Trichoderma harzianum)的分离频率分别为34.48%和31.03%;而在陕西省,禾谷镰孢复合种、拟轮枝镰孢菌和亚粘团镰孢菌(F. subglutinans)分离频率均为28.57%。以禾谷镰孢复合种的EF-1α基因序列为基础构建系统发生树,进一步对分离到的禾谷镰孢复合种进行亚种鉴定。结果表明,春玉米区禾谷镰孢复合种为禾谷镰孢菌和布氏镰孢菌,且以布氏镰孢菌为主。  相似文献   

11.
In 1975 many tumours were observed in plants ofBegonia Schwabenland grown in Aalsmeer. Submersion of the roots ofNicotiana megalosiphon seedlings in a homogenate of tumorous tissue, induced tumours after two weeks. Short periods of submergence yielded results similar to those obtained after longer periods. Tumour homogenates lost their infectivity after ten min at 50°C. Aphids transmitted the infectious agent.Treatment with propylene oxide did not inhibit infectivity completely. Filtration through a 450 nm filter removed the infectious agent.Tobacco tumor virus or a viroid could not be isolated. Cultures ofCorynebacterium fascians, isolated from tumours ofN. megalosiphon were highly infectious and induced tumours in healthyN. megalosiphon andBegonia. Tumorous tissue homogenates ofPelargonium zonale, Dahlia sp.,Gladiolus sp., andLilium sp. also caused tumours inN. megalosiphon, from whichC. fascians was isolated. It was not possible to produce tumours inN. megalosiphon with homogenates from roses with symptoms of bud proliferation.Samenvatting In 1975 werden vele tumoren waargenomen inBegonia Schwabenland op Aalsmeerse bedrijven (Fig. 1). De infectiositeit van tumorweefsel kon goed en snel worden vastgesteld door de wortels van zaailingen vanNicotiana megalosiphon in een homogenaat van tumorweefsel te dompelen. Tumoren ontstonden na twee weken, de eindbeoordeling geschiedde na een maand (Fig. 2). Ook verschillende andereNicotiana spp.,Melilotus officinalis (Fig. 3) enPisum odoratum (Fig. 4) werden aangetast.Bij de infectiositeitstoets gaven zeer korte dompeltijden even goede resultaten als langere (Tabel 1). Infectieus sap verloor zijn infectievermogen na 10 min verhitting bij 50°C. Bladluizen brachten de smetstof over. Propyleenoxide verminderde de infectiositeit wel, doch onderdrukte deze niet totaal. Bij filtratie door een 450 nm filter bleef het infectieuse agens op het filter achter. Het tumor-inducerende agens was ook aanwezig in die delen van planten met tumoren welke gezond leken en het ging voor een gering deel over met zaad (Tabel 2).Uit tumoren konden wij geen tabakstumorvirus of een viroïde isoleren. Culturen vanCorynebacterium fascians, geïsoleerd uit tumoren vanN. megalosiphon bleken zeer infectieus en veroorzaakten tumoren inN. megalosiphon enBegonia. Homogenaten van tumorweefsel vanPelargonium zonale, dahlia (Fig. 5), gladiool (Fig. 6) enLilium Mid Century Hybrid Enchantment (Fig. 7) veroorzaakten ook tumoren opN. megalosiphon, waaruitC. fascians werd geïsoleerd. Met sap van kroeskopzieke rozen konden wijN. megalosiphon niet besmetten.  相似文献   

12.
Plant Viruses Transmitted by Whiteflies   总被引：18，自引：0，他引：18  
One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.  相似文献   

13.
The epidemiology ofSitobion avenae and its natural enemies in winter wheat was studied in 1975, 1976 and 1977. Immigration was important until the end of flowering. The alate immigrants had apterous offspring. These became the driving force in population growth. Their offspring were mostly alatae which usually left the field. A model of the epidemic was developed. Quantitative relations between the aphids and their environment were obtained from literature or established in laboratory trials. The model simulated population development and population composition from the beginning of June till the population peak at the end of June or early in July. Because quantitative data on relations between aphids and their natural enemies and pathogens are scarce, and since the knowledge on wing formation is still limited, the population collapse could not be predicted. In the future, prognosis over a period of three weeks seems possible.Samenvatting De toenemende betekenis van graanbladluizen (vooralSitobion avenae) gepaard gaande met een sterke toename van het gebruik van insecticiden op granen maakte verbetering van de prognose over het schadelijk optreden wenselijk. Door gedetailleerde tellingen in het veld (Fig. 1–7) werden gegevens verkregen over het verloop van de epidemie en het optreden van natuurlijke vijanden in 1975, 1976 en 1977.Een immigratieperiode tot in de bloei kon worden vastgesteld. Daarna lijkt de aantrekkelijkheid van het gewas voor alate luizen te verminderen. De alate immigranten krijgen aptere nakomelingen. Deze vormen de stuwende kracht van de populatiegroei. De nakomelingen van apteren zijn merendeels alaat. Zij verlaten het gewas.Een model van de populatieontwikkeling gedurende de epidemie werd opgesteld. De relatiediagrammen Fig. 9 en 10 laten groei en ontwikkeling vanS. avenae en een predator (Syrphus corollae) zien. Kwantificering van de betrekkingen werd mogelijk door literatuurgegevens en laboratoriumexperimenten.Met het model kon de populatieontwikkeling vanS. avenae vanaf begin juni tot aan de populatiepiek in 1975, 1976 en 1977 vrij goed worden gesimuleerd (Fig. 12). Ook de populatieopbouw kon worden gesimuleerd (Fig. 14). De teruggang van de populatiedichtheid blijkt moeilijker te voorspellen door het ontbreken van gegevens over natuurlijke vijanden.Het lijkt waarschijnlijk dat in de toekomst met het model een prognose over de piek van de bladluispopulatie circa 3 weken tevoren mogelijk zal zijn.  相似文献   

14.
During a survey conducted from 1998 to 2002, Fusarium proliferatum was found associated with young and adult palms belonging to the genera Chamaerops, Phoenix, Trachycarpus and Washingtonia showing symptoms of wilt and dieback. The fertility and toxicological profile of 36 strains representing different locations and hosts were studied. All of them except two, which were infertile, belonged to mating population D. Both mating types (MATD-1 and MATD-2) were isolated from the same host species, showing a high potential of genetic recombination in the field. Additionally, eight strains were fertile once crossed as female. Toxin analysis showed differences in the ability of strains to produce fumonisin B1, moniliformin, beauvericin, fusaric acid and fusaproliferin. Only 17 of them produced all the toxins analyzed. Pathogenicity tests were conducted on Phoenix dactylifera and P. canariensis using nine F. proliferatum Spanish strains and two reference strains from Saudi Arabia. Eight months after inoculation all strains caused disease, with palms showing lesions on the bases of leaves and development of wilt symptoms similar to those originally observed in affected plants. This is the first report on the occurrence of F. proliferatum on P. dactylifera in Spain and also the first report of this pathogen on C. humilis, P. canariensis, P. reclinata, T. fortunei, W. filifera and W. robusta.  相似文献   

15.
Barley yellow dwarf disease is one of the most important problems confronting cereal production in Iran. Barley yellow dwarf virus-PAV (BYDV-PAV) and Cereal yellow dwarf virus-RPV (CYDV-RPV) are the predominant viruses associated with the disease. One isolate of BYDV-PAV from wheat (PAV-IR) and one isolate of CYDV-RPV from barley (RPV-IR) were selected for molecular characterisations. A genome segment of each isolate was amplified by PCR. The PAV-IR fragment (1264 nt) covered a region containing partial genes for coat protein (CP), read through protein (RTP) and movement protein (MP). PAV-IR showed a high sequence identity to PAV isolates from USA, France and Japan (96–97%). In a phylogenetic analysis it was placed into PAV group I together with PAV isolates from barley and oats. The fragment of RPV-IR (719 nt) contained partial genes for CP, RTP and MP. The sequence information confirmed its identity as CYDV. However, RPV-IR showed 90–91% identity with both RPV and Cereal yellow dwarf virus-RPS (CYDV-RPS). Phylogenetic analyses suggested that it was more closely related to RPS. These data comprise the first attempt to characterise BYD-causing viruses in Iran and southwest Asia. The nucleotide sequence data reported appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession numbers AY450425 and AY450454  相似文献   

16.
Isolates of an unidentified Rhizoctonia sp. (UR isolates) were obtained from creeping bentgrass and Kentucky bluegrass with reddish brown sheath and foliar rots. Because the UR isolates anastomosed with isolates of three varieties of Waitea circinata (var. oryzae, var. zeae, and var. circinata), colony morphology, hyphal growth rate at different temperatures, pathogenicity, sequence analysis of the internal transcribed spacers (ITS) region of ribosomal RNA genes (rDNA) were compared. The colony color of mature UR isolates was distinct from isolates of the other three varieties of W. circinata. In pathogenicity tests on creeping bentgrass, the severity of the disease caused by UR isolates was significantly higher than that caused by the three varieties of W. circinata. Sequence similarities of the rDNA-ITS region between UR isolates and between isolates within each variety were high (97–100%), but they were lower among isolates from UR and the varieties of W. circinata (88–94%). In a phylogenetic tree based on the rDNA-ITS sequences, UR isolates formed a cluster separate from each of the clusters formed by the three varieties of W. circinata. These results indicate that the UR isolates clearly differ from the three varieties of W. circinata. We therefore propose that the UR isolates be classified as new Rhizoctonia sp. that are closely related to W. circinata and that the disease on creeping bentgrass should be called Waitea reddish-brown patch disease (Sekikasshoku-hagusare-byo in Japanese).  相似文献   

17.
Corynebacterium fascians, which causes leafy gall, has been shown to be responsible for the unusual symptoms recently found in lilies. The symptoms are described and the different bacterial isolates compared by biochemical, serological and pathogenicity experiments. No evidence could be found for the existence of specialized strains even though considerable variation in virulence could be demonstrated. Although the role of variation in susceptibility of the different lily cultivars should not be underestimated, it would appear that high inoculum levels ofC. fascians in the soil may be largely responsible for these outbreaks.Also included in this study are the results of biochemical, serological and pathogenicity experiments ofC. fascians which has been isolated fromKalanchoe, Euphorbia, Brodiaea, Hebe andVerbascum.Samenvatting Reeds een aantal jaren was in lelies een woekering in stengelbollen bekend, die echter sporadisch voorkwam en economisch van weinig betekenis was. Tijdens de zomer van 1977 echter trad de ziekte op één enkel perceel zo ernstig op dat zeer aanzienlijke oogstderving het gevolg was. Behalve de stengelbol kan ook de hoofdbol misvormd zijn. Bovendien kunnen misvormde stengelbollen lange spruiten vormen, zgn. sabeltandvorming. Soms is het wortelstelsel gereduceerd; in de kas zijn verdikte stengels waargenomen. De ziekte staat nu bekend onder de naam woekerziekte.Door de PD te Wageningen en het LBO te Lisse werd de bacterieCorynebacterium fascians (Tilford) Dows. uit het zieke materiaal geïsoleerd. In gezamenlijk onderzoek werd nagegaan of de bacterie de veroorzaker is van bovengenoemde symptomen en of hier sprake is van een op lelie gespecialiseerde stam.Biochemische en serologische vergelijkingen tussen isolaten vanC. fascians uit lelie,Kalanchoe, Euphorbia, Brodiaeea, Hebe enVerbascum laten zien dat er zeer weinig verschillen bestaan. Alle isolaten reageren op een standaard antiserum met titers variërend tussen 1: 640–1: 5120.Een oriënterende inoculatieproef werd uitgevoerd op het LBO in 1977. Daarna werden op de PD 10 van de 25 isolaten uit lelie en 8 uit andere waardplanten getoetst op lelie, chrysant en lathyrus. Uit de inoculatieproeven blijkt, dat de bacterie de veroorzaker is van de waargenomen symptomen. Tussen de isolaten blijkt een groot verschil in pathogeniteit te bestaan (12–100% aantasting), zonder dat dit aan herkomst gebonden is. Het voorkomen van op lelie of andere waardplanten gespecialiseerde stammen is daarom niet aan te nemen.In hoeverre de hevige aantasting een gevolg is van een opbouw van de bacterie-populatie door een te nauwe vruchtwisseling en mechanische rooimethoden moet worden nagegaan.  相似文献   

18.
Organic amendments and green manure are potential alternatives to the harmful chemical control means currently used against plant-parasitic nematodes. In this work, Chrysanthemum coronarium was applied to the soil as a green manure to control the root-knot nematodes Meloidogyne incognita and M. javanica. Chrysanthemum coronarium significantly reduced nematode infection of tomato roots and improved plant-top fresh weight, both in the greenhouse and in microplots. Other green manures, derived from Anthemis pseudocotula, wild chickpea (Cicer pinnatifidum), Geranium spp. and wheat, were not as effective as C. coronarium. Chrysanthemum coronarium, retained its nematicidal activity even when applied as a dried material. Only mature C. coronarium plants, in their flowering stage, exhibited nematode control activity, but the green plant parts were more effective than the flowers. An aqueous extract of C. coronarium exhibited in vitro, nematostatic activity towards M. incognita and M. javanica second-stage juveniles and inhibited their hatching from eggs and egg-masses; its nematostatic activity was expressed also against other phytonematode species such as Heterodera avenae and Pratylenchus mediterraneus, but did not affect the beneficial entomopathogenic nematode Steinernema feltiae.  相似文献   

19.
Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.  相似文献   

20.
浅黄恩蚜小蜂和丽蚜小蜂对温室白粉虱的寄生潜能分析   总被引：1，自引：1，他引：0  
浅黄恩蚜小蜂Encarsia sophia GiraultDodd和丽蚜小蜂Encarsia formosa Gahan是防治粉虱类害虫的优势寄生蜂,通过生命表技术方法分析了2种寄生蜂对温室白粉虱Trialeurodes vaporariorum(Westwood)的防治潜能。结果表明,丽蚜小蜂在羽化第3天和第10天出现2次寄生高峰,占其总寄生量的13.7%和8.0%,在2次高峰之间逐日寄生粉虱数量比较平稳,单雌逐日平均产雌数保持在10.6~13.4头,10 d后寄生量呈明显的下降趋势;而浅黄恩蚜小蜂羽化10 d内逐日寄生粉虱量变化不大,单雌逐日产雌数稳定在4.2~5.4头,羽化14 d后寄生量呈明显下降趋势。丽蚜小蜂和浅黄恩蚜小蜂的R0、T、rm、λ值分别为171.5、18.0、0.2854、1.3303和61.6、16.2、0.2544、1.2897;粉虱若虫充足时,丽蚜小蜂平均单雌寄生若虫数是浅黄恩蚜小蜂的2.7倍,而后者平均单雌取食若虫数为60.6头,明显高于前者42.7头,总的来看,丽蚜小蜂通过寄生和取食杀死粉虱总量220.8头,明显高于浅黄恩蚜小蜂的127.9头。表明在应用寄生蜂防治温室白粉虱时,单独释放丽蚜小蜂比浅黄恩蚜小蜂显示出更好的防治潜能。  相似文献   

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