共查询到20条相似文献，搜索用时 250 毫秒
1.
Matthew Brown James W. Woodhall Linda K. Nielsen Daniel Tomlinson Arifa Farooqi Rumiana V. Ray 《Plant pathology》2021,70(4):862-874
This study aimed to elucidate the population dynamics of Rhizoctonia, Oculimacula, and Microdochium species, causing the stem base disease complex of sharp eyespot, eyespot, and brown foot rot in cereals. Pathogen DNA in soil, roots, and stem fractions, and disease expression were quantified in 102 English wheat fields in two seasons. Weather data for each site was collected to determine patterns that correlate with assessed diseases. Oculimacula spp. (66%) and R. solani AG 2-1 (63%) were most frequently detected in soil, followed by R. cerealis (54%) and Microdochium spp. (33%). Oculimacula spp. (89%) and R. cerealis (56%) predominated on roots and soil but were not associated with root rot symptoms, suggesting that these species used soil and roots for survival and as inoculum source. M. nivale was more frequently detected than M. majus on stems up to GS 21–30 and co-occurred on plant samples with O. acuformis. O. yallundae had higher DNA concentration than O. acuformis at the lower 5 cm basal region at GS 37–45. R. cerealis predominated in the upper 15 cm above the base beyond stem extension. Brown foot rot by Microdochium spp. was favoured by cool and wet autumns/winters and dominated in English wheat. Eyespot and sharp eyespot disease index by Oculimacula spp. and R. cerealis, respectively, correlated with wet/humid springs and summers. Results suggested that stem base pathogens generally coexisted; however, their abundance in time and space was influenced by favourable weather patterns and host development, with niche differentiation after stem extension. 相似文献
2.
Creontiades spp. (Hemiptera: Miridae) are sucking pests that attack buds, flowers and young pods in mungbeans, Vigna radiata (L.), causing these structures subsequently to abort. If left uncontrolled, mirids can cause 25-50% yield loss. Traditional industry practice has involved prophylactic applications of dimethoate to control mirids at budding and again a week later. The present trial was initiated to highlight the dangers of such a practice, in particular the risk of a subsequent Helicoverpa spp. lepidopteran pest outbreak. A single application of dimethoate halved the population of important natural enemies of Helicoverpa spp., and caused an above-threshold outbreak of Helicoverpa spp. within 11 days. This shows that even a moderate (e.g. 50%) reduction in natural enemies may be sufficient to increase Helicoverpa spp. populations in mungbeans. As a result, prophylactic sprays should not be used for the control of mirids in mungbeans, and dimethoate should be applied only when mirids are above the economic threshold. Indoxacarb was also tested to establish its effect on Helicoverpa spp., mirids and natural enemies. Indoxacarb showed potential for Helicoverpa spp. control and suppression of mirids and had little impact on natural enemies. 相似文献
3.
Constantine Uwaremwe Liang Yue Yang Liu Yuan Tian Xia Zhao Yun Wang Zhongkui Xie Yubao Zhang Zengtuan Cui Ruoyu Wang 《Plant pathology》2021,70(2):397-406
Wolfberry (Lycium barbarum) ranks in the top 10 best-selling medicinal plants in China and it has been used for centuries as a medicine and a food supplement. It is suggested to have benefits on human health due to the rich content of polysaccharides, carotenoids, flavonoids, and alkaloids contained in its fruits, leaves, and root bark. Recently, severe root rot diseases have been causing plant losses in major growing areas. Here, we report fungi causing root rot disease in Chinese wolfberry plants. The analysis of nucleotide sequences of the internal transcribed spacer (ITS) region revealed a total of 92 isolates isolated from both soil and plant material samples. Fusarium spp. were the most abundant (58%), followed by Penicillium spp. (9%), and Alternaria spp. (5%). Fusarium spp. included F. oxysporum (36%), F. solani (30%), F. chlamydosporum (9%), F. nematophilum (9%), and F. tricinctum (8%). Sequences from the translation elongation factor 1-α gene (TEF-1α) were used to confirm the identity of Fusarium spp. and showed the predominance of F. oxysporum and F. solani. To confirm the pathogenicity of isolates, four isolates belonging to Fusarium spp. and one isolate belonging to Alternaria spp., isolated from wolfberry root tissues with root rot symptoms, were tested in outdoor and laboratory conditions. Results revealed that the five tested isolates were pathogenic with varying degrees of aggressiveness and ability to induce symptoms of root rot in wolfberry seedlings. The five isolates were recovered from inoculated seedlings, completing Koch's postulates. This is the first report on causative agents of root rot in Chinese wolfberry. 相似文献
4.
L. Pritchard S. Humphris G. S. Saddler N. M. Parkinson V. Bertrand J. G. Elphinstone I. K. Toth 《Plant pathology》2013,62(3):587-596
This study used a novel computational pipeline to exploit draft bacterial genome sequences in order to predict, automatically and rapidly, PCR primer sets for Dickeya spp. that were unbiased in terms of diagnostic gene choice. This pipeline was applied to 16 draft and four complete Dickeya genome sequences to generate >700 primer sets predicted to discriminate between Dickeya at the species level. Predicted diagnostic primer sets for both D. dianthicola (DIA‐A and DIA‐B) and ‘D. solani’ (SOL‐C and SOL‐D) were validated against a panel of 70 Dickeya reference strains, representative of the known diversity of this genus, to confirm primer specificity. The classification of the four previously sequenced strains was re‐examined and evidence of possible misclassification of three of these strains is presented. 相似文献
5.
玉米茎腐病病原菌检测方法研究 总被引：4，自引：0，他引：4
为提高玉米茎腐病病原菌检测结果的准确性和可信度,以组织分离法做对比,采用分子检测法,对采自田间的189个玉米茎腐病病株进行真菌种类的鉴定和数量的统计。结果表明,分子检测法对腐霉Pythiumspp.的检出频率为29.24%,对镰孢菌Fusariumspp.的检出频率为73.68%,组织分离法对腐霉的检出频率仅为0.58%,对镰孢菌的检出频率为60.82%,两方法的符合率最高仅为35.92%,最低为0。因此,采用组织分离和分子检测相结合的方法可提高玉米茎腐病病原菌鉴定结果的准确性。 相似文献
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The reaction of six Musa genotypes to root-parasitic nematodes was evaluated under field conditions, together with the horizontal, and vertical distributions of the neomatodes within the soil profile. The numbers of Radopholus similis, Helicotylenchus spp., Meloidogyne spp. and of all nematodes in the excavated soil quadrant varied with Musa genotype. All genotypes were very susceptible to at least one nematode. Yangambi km5, Pisang Jari Buaya and FHIA-23 supported the lowest number of R. similis and Pisang Jari Buaya, the lowest number of Helicotylenchus spp. These three cultivars supported high numbers of Meloidogyne spp. Furthermore, FHIA-23 supported high numbers of Helicotylenchus spp. The horizontal and vertical distributions of R. similis in the root system of Valery, Gros Michel and FHIA-18 were very similar. By constrast, the distributions of Helicotylenchus spp., Meloidogyne spp. and the number of all nematodes varied slightly among the genotypes. Because Musa genotypes susceptible to a particular nematode showed a similar horizontal and vertical nematode distribution with populations concentrated in the vicinity of the plant base (0–30 cm horizontal distance and 30 cm depth), sampling at this site would be sufficient for the identification of the Musa plant reaction. 相似文献
7.
K.P. Hebbar M.H. Martel T. Heulin 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(1):29-36
Burkholderia cepacia (syn. Pseudomonas cepacia) strain PHQM100 applied as a seed coating was tested in growth chamber experiments for its ability to suppress preemergence damping-off, and postemergence damping-off in corn induced by Pythium and Fusarium spp. The symptoms observed in bioassays with soils naturally infested with the fungal pathogens were seed rot with Pythium spp. and mesocotyl and root tissue necrosis in the presence of Fusarium spp. Three corn cultivars that differed in their susceptibility to damping-off pathogens were used. Cultivar L was susceptible to pre- and postemergence damping-off, whereas cv. LPDP and cv. LG11 were moderately resistant and resistant to the damping-off diseases respectively. In the presence of Pythium spp., seed treatment with B. cepacia reduced seed rot, as compared to the untreated seeds, and this reduction was more consistent in the cv. LPDP than in the resistant cv. LG11 or the susceptible cv. L. In soils infested with Fusarium spp., seed treatment significantly reduced root and mesocotyl necrosis as compared to the untreated seeds, and this reduction was more consistent in the resistant cultivars LG11 and LPDP than in the susceptible cv. L. Root colonization levels by B. cepacia were similar in the three corn cultivars tested. Biocontrol efficiency of B. cepacia varied among cultivars mainly due to the differences in their susceptibility to the fungal pathogens. In spite of variability and also irrespective of the soil characteristics, B. cepacia increased seedling emergence and decreased mesocotyl and root necrosis when used as a seed coating. 相似文献
8.
产抗菌蛋白芽孢杆菌的筛选及抗菌蛋白性质 总被引：23，自引：1，他引：23
对小麦赤霉病菌（ＪＦ－１２）有拮抗作用的７６个芽孢杆菌菌株中有３０个能产生抗菌物质。根据无细胞培养滤液对氯仿和热处理的稳定性将３０个菌株分成三类。属于类型Ｉ的１４个菌株中，Ｂ３、Ａｎｔ－２７和Ａｎｔ－６４的抗菌物质可以被８０％饱和度硫酸铵沉淀，不能通过透析膜。Ｂ３的粗提抗菌蛋白对胰蛋白酶、蛋白酶Ｋ和ＲＮＡ酶均不敏感；在ｐＨ５．０￣１０．０范围内，抑菌活性与对照无显著差别；热处理（６０℃／３０ｍｉｎ 相似文献
9.
青海省樱桃叶斑病病原菌的分离与鉴定 总被引：2，自引：0，他引：2
为明确引起青海省樱桃叶斑病病原菌的种类,本研究从西宁市城北区、海东市乐都区和贵德县的樱桃上采集有叶斑症状的叶片,采用组织分离法分离出病原菌,通过观察病原菌的形态特征,结合rDNA-ITS、EF-1α和Alt a 1基因序列分析对病原菌的种类进行了鉴定,并用柯赫氏法则进行验证。结果表明,共获得279株病原菌菌株,分属链格孢Alternaria alternata、细极链格孢A.tenuissima和刺盘孢属Colletotrichum spp.,分离频率分别为84.95%、5.02%和10.03%。采用柯赫氏法则进行离体叶片致病性测定,接种叶片100%发病,说明引起青海省樱桃叶斑病的病原菌为链格孢、细极链格孢和刺盘孢属真菌,且链格孢为主要病原菌。该研究结果可为青海省樱桃叶斑病的综合防治提供理论依据。 相似文献
10.
Early diagnosis of seedborne fungal pathogens is particularly important, as often, infected seeds appear symptomless; seed diagnosis can avoid uncontrolled propagation of pathogens through long‐distance exchange of such material. This will prevent economic losses and unnecessary use of fungicides, so reducing costs and the introduction of toxic substances into the environment. Traditional techniques for detection of seedborne fungi are based on incubation and grow‐out methods. Although these are frequently used because of their simplicity of application, they are time‐consuming, require mycological skills, and are sometimes not sensitive enough to low levels of seed infection. Recently, new identification techniques, based on DNA analysis, have been applied and are very efficient due to high sensitivity and specificity. The most common technique is conventional PCR, while other recent techniques include nested PCR, to obviate low levels of target pathogens, multiplex PCR, to detect several pathogens simultaneously, real‐time PCR, to quantify fungi on seeds, and magnetic‐capture hybridization PCR. The main drawbacks of molecular methods are the inability to distinguish between vital and non‐vital inocula, and the difficulty in obtaining quality DNA template, due to PCR inhibitors in seeds. To reduce inhibitory effects, several modified PCR protocols, such as loop‐mediated isothermal amplification, and non‐destructive testing methods have been developed. Loop‐mediated isothermal amplification and next‐generation sequencing have been widely applied in nucleic acid analysis and, given the numerous advantages provided, their application can be substantially extended in the future for detection of fungal pathogens in seeds. 相似文献
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测定了致病杆菌CB43菌株代谢物对灰葡萄病菌菌丝生长和孢子萌发的影响。结果表明:CB43代谢物对灰葡萄孢菌丝生长有较强的抑制作用,500、250、125ml/L代谢物能完全抑制菌丝的生长,并具有杀死作用。62.5ml/L的发酵液处理灰葡萄病菌菌丝72h的抑制率仍达83.35%。20ml/L的发酵液处理灰葡萄孢菌丝能引起菌丝畸形,异常分支、粗短。CB43代谢物能杀死灰葡萄孢分生孢子或抑制其萌发,500~62.5ml/L的发酵液处理16h后,孢子萌发抑制率达88.1%~97.91%。温室试验表明,CB43代谢物对黄瓜灰霉病的控制效果达84.09%,化学农药40%施佳乐的效果为72.94%。 相似文献
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采用喷雾法,用几种农药对草原毛虫进行防治,结果表明,生物源农药瑞·苏1.2%微乳剂对草原毛虫,速效性较好,持效期长,药后7~14d防治效果保持在80%~90%。 相似文献
14.
近年来,植物抗根结线虫机制研究已成为线虫研究领域的热点之一。本文主要从植物对根结线虫病的抗性结构、抗性基因、坏死反应以及相关酶类等方面的机制研究进展作一综述与展望。 相似文献
15.
实验室条件下以感染沃尔巴克氏体的引进种卷蛾赤眼蜂、食胚赤眼蜂、短管赤眼蜂为材料,比较分析3种赤眼蜂连续3代喂食抗生素后子代雄蜂率、寄生和羽化情况。除卷蛾赤眼蜂F2代外,取食四环素后3种赤眼蜂各世代寄生率均降低,其中食胚赤眼蜂的寄生率与对照相比明显下降;3种赤眼蜂间寄生率没有明显差异。随着取食抗生素世代的增加,3种赤眼蜂子代雄蜂率逐渐增大,短管赤眼蜂F1代开始出现雄蜂,F3代雄蜂率高达54.54%,明显高于卷蛾赤眼蜂（20.58%）和食胚赤眼蜂（13.94%）;食胚赤眼蜂3个世代羽化雄蜂率均最低,说明其产雌孤雌生殖方式比较稳定,较适合作为赤眼蜂种间沃尔巴克氏体水平人工转染的供体。 相似文献
16.
不同苜蓿品种对镰孢菌的抗性鉴定 总被引：1，自引：0，他引：1
为探明苜蓿不同品种对能引起苜蓿根腐病的茄镰孢(Fusarium solani)、半裸镰孢(F. semitectum)、弯角镰孢(F. camptoceras)等3种镰孢菌的抗性差异,提供筛选抗耐病性材料的新来源,通过室内盆栽法,对30个苜蓿品种(系)进行了苗期抗病性鉴定,结果表明,各品种之间抗病性差异显著,其中‘德里兰德’、‘新疆大叶’、‘苜蓿王’对半裸镰孢表现为抗病,病情指数分别为18.11、19.93、19.96,占鉴定总数的10%;总体来看,‘猎人河’等7个品种表现耐病,病情指数为25.30～39.95,占鉴定总数的23.3%;‘甘农2号’等18个感病品种,病情指数为40.55～59.56,占鉴定品种总数的60.0%;‘德宝’等5个品种为高感,平均病情指数为61.7~68.6,占鉴定总品种数的16.7%,无免疫和抗病品种。 相似文献
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[目的]筛选适应水稻秸秆还田的抗水稻纹枯病的拮抗菌株.[方法]从土壤中分离出4株芽胞杆菌和9株木霉,测定其对水稻秸秆的降解能力,对具有较好降解能力的菌株测定其对水稻纹枯病菌的抑制效果和对水稻秸秆的适应性.[结果]芽胞杆菌B4菌株和木霉T3、T5、T6和T9菌株对水稻秸秆有较好的降解效果,其中木霉T5和T9的降解效果最好;芽胞杆菌B4菌株对水稻纹枯病菌的抑制率达40.48％,而且抑菌带能持久地保持,木霉T3、T5、T6和T9菌株对水稻纹枯病菌的抑制率较高,抑制率分别为46.48％、45.63％、50.99％和53.38％,这5种拮抗菌的代谢物都能抑制菌丝的生长和完全阻止菌核的形成,而且这5株菌株对水稻秸秆都有一定的适应能力.[结论]木霉T5和T9具有较好的秸秆降解和抑制稻纹枯病菌的双重效果. 相似文献
19.
不同辣椒炭疽病菌对唑菌酯的敏感性差异 总被引：1，自引：0，他引：1
辣椒炭疽病是辣椒生产上的重要病害,严重制约辣椒生产,唑菌酯防治辣椒炭疽病的相关研究未见报道。为此,本研究利用菌丝生长速率法测定了4种不同炭疽病菌对唑菌酯的敏感性,并对其作用靶标基因细胞色素b基因(Cytb)进行比较分析。结果表明:唑菌酯对Colletotrichum brevisporum YYGXZ07,C.truncatum CZHP03,C.acutatum HHBY48和C.gloeosporioides CSLL11的EC50分别为0.098、3.363、10.156和31.982μg/mL,而且供试菌株在含药培养基上的生长速率排序为C.truncatum CZHP03C.brevisporum YYGXZ07C.acutatum HHBY48C.gloeosporioides CSLL11;不同菌株的作用靶标基因细胞色素b氨基酸比对分析发现C.acutatum HHBY48、C.truncatum CZHP03和C.brevisporum YYGXZ07与C.gloeosporioides CSLL11的Cytb氨基酸序列同源性分别为82.98%、88.30%和87.77%,推测6个氨基酸位点可能与菌株对唑菌酯的敏感性存在关联。 相似文献