共查询到19条相似文献，搜索用时 500 毫秒
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为明确甘肃省党参斑枯病病原菌及其生物学特性,通过形态学和分子生物学方法进行了病原菌的鉴定,同时利用植物病理学常规培养法进行生物学特性的测定,并利用rDNA-ITS序列构建其系统发育树。结果表明:该菌形态特征与党参壳针孢Septoria codonopsidis Ziling相似,分生孢子器球形、近球形,大小为53.8~76.6μm×40.3~62.7μm;分生孢子无色,针形,1~4个隔膜,大小为15.3~38.8μm×0.9~1.2μm。系统发育树进一步显示,引起党参斑枯病的病原菌为党参壳针孢。该菌菌丝生长、分生孢子萌发和产孢的温度范围分别为5~30、5~35、15~25℃,最适温度分别为20~25、20、20℃;连续光照有利于菌丝生长、孢子萌发,连续黑暗有利于病菌产孢;此菌在相对湿度达90%以上时才可萌发,以水中萌发最好;菌丝生长、孢子萌发和产孢的适宜pH范围分别为4.0~10.0、4.51~9.19和7.0~7.5,最适pH分别为4.5、7.0和7.5;党参根浸渍液和葡萄糖液对孢子萌发有较强的促进作用。表明党参壳针孢菌丝生长和孢子萌发的适宜温度偏低,因此该病害在气温偏低及持续阴雨结露条件下发生较重。 相似文献
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自2013年起, 甘肃定西地区种植的党参出现了严重的死苗、烂根现象, 为明确该病害的病原菌并确定适宜的防治药剂, 在多年种植党参的田块进行调查、采样和防治试验研究。根据大田调查结果和发病症状分析, 发现该病害可分为急性青枯型和慢性黄腐型; 采用常规组织分离法对病原菌进行了分离和纯化, 依据柯赫氏法则进行致病性确认, 并通过形态学和分子生物学方法对病原菌进行了鉴定。结果表明:引起党参急性青枯型根腐病的病原菌为尖孢镰刀菌Fusarium oxysporum; 慢性黄腐型根腐病的病原菌为锐顶镰刀菌Fusarium acuminatum。室内药剂毒力测定表明, 25 g/L咯菌腈悬浮种衣剂、6.25%精甲·咯菌腈悬浮种衣剂、18%噻灵·咯·精甲悬浮种衣剂对两种病原的抑制效果均较好, EC50均低于1.0 mg/L; 大田防治试验表明, 18%噻灵·咯·精甲悬浮种衣剂200倍液、300倍液、600倍液对根腐病防效分别为81.78%、70.22%、64.03%。 相似文献
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华重楼斑枯病病原鉴定 总被引：1，自引：0，他引：1
2018年,四川汶川县重楼种植区的华重楼出现一种新的病害—华重楼斑枯病,该病害主要危害叶片,发生率为35%,天气适宜时可引起整株叶片枯死。为鉴定引起四川汶川县华重楼斑枯病的病原菌,本试验采用组织分离法对病原菌进行分离,利用科赫氏法则验证其致病性,依据菌株的形态学和基于rDNA-ITS和RPB2基因序列分析对病原菌进行鉴定。结果表明,分离菌株的菌落形态、分生孢子器和分生孢子形态与Didymella sp.相似;经分子生物学鉴定,该菌ITS-RPB2基因序列与亚隔孢壳属D. glomerata(登录号为FJ427013、GU371781)的同源性为100%。因此,将引起重楼斑枯病的病原菌鉴定为D. glomerata。 相似文献
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为明确甘肃省党参根结线虫病的发生、分布及病原种类,在甘肃省党参主产区调查、统计田间根结线虫病发生情况,并通过形态学和分子生物学方法进行种类鉴定。结果表明,甘肃省6个党参主产区均有根结线虫病发生,病田率、病株率分别为40.7%、13.2%,病情指数为10.4。依据根结线虫各虫态的形态测量值和雌虫会阴花纹等特征,将危害党参的根结线虫初步鉴定为北方根结线虫Meloidogyne hapla Chitwood, 1949。rDNA-ITS区段和28S rDNA D2D3区段序列比对和系统发育树显示,6个根结线虫群体无核苷酸差异,与多个北方根结线虫聚为一支且有较高的置信度。利用特异性引物Mh-F/Mh-R扩增得到北方根结线虫的特异性片段,大小为462 bp。故综合形态学和分子生物学特征,将危害甘肃省党参的根结线虫鉴定为北方根结线虫。 相似文献
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玉米三种叶斑病混发时的流行过程及产量损失研究 总被引：1，自引：0，他引：1
通过2年的田间小区人工接种试验,观察比较了玉米大斑病、弯孢叶斑病和灰斑病单独及混合发生时的流行过程及对玉米产量损失的影响。结果表明,在病害混发初期,病害间无明显的负相关性,随着病情的发展,病害间的负相关性逐渐增大并达到显著水平,说明病害间有明显的抑制作用。病害混发时造成产量损失并不完全等于各病害单独造成损失之和,其中大斑病和弯孢叶斑病、弯孢叶斑病和灰斑病混合发生所造成的损失约为各病害单独造成损失之和的76%～88%,大斑病和灰斑病混合发生所造成的损失可近似看作两种病害各自引起产量损失之和,3种病害同时发生时最终损失率约为各自造成损失之和的67%～72%。 相似文献
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ABSTRACT Association of the incidence of leaf blight (caused by Phomopsis obscurans) and leaf spot of strawberry (caused by Mycosphaerella fragariae) was assessed at multiple scales in perennial plantings at several commercial farms over 3 years (1996 to 1998). For each field, the presence or absence of each disease was recorded from n = 15 leaflets in each of N approximately 70 evenly spaced sampling units, and the proportion of leaflets with blight, spot, and total disease (blight or spot) was determined. Individual diseases and total disease incidence were all well described by the beta-binomial distribution but not by the binomial distribution, indicating overdispersion of disease. The Jaccard similarity index was used to measure disease co-occurrence at the leaflet, sampling-unit, and field scales. Standard errors of this index for the lower two scales were obtained using the jackknife (resampling) procedure, and data randomizations were used to determine the expected Jaccard index for an independent arrangement of the two diseases, conditioned on the incidence and spatial heterogeneity of the observed disease data. Results based on these statistics showed that only 4 of 52 data sets at the leaflet level and no data sets at the sampling-unit level had Jaccard index values significantly different from that expected under an independent rearrangement of the two diseases. Rank correlation and cross-correlation statistics were calculated to determine the degree of covariation in incidence between the two diseases. Additionally, covariation between diseases was tested using a new procedure in the Spatial Analysis by Distance IndicEs (SADIE) class of tests. Covariation was detected in 21% of the data sets using rank correlation methods and in 15% of the data sets using the SADIE-based approach. The discrepancy between these two methods may be due to the rank correlation procedure not taking into account the effects of spatial pattern of disease incidence. There was no relationship between mean disease incidence per field of spot and blight or between degree of heterogeneity of the two diseases (as measured by theta of the beta-binomial distribution), demonstrating lack of covariation at the field scale. Incidence of leaflets with either disease (total disease incidence) could be well predicted using a linear combination of the estimated probabilities of leaf blight and leaf spot incidence based on independence of the two diseases. Heterogeneity of total disease incidence, measured with the estimated theta parameter of the beta-binomial distribution, could also be well predicted using a linear combination of the weighted theta values for leaf blight and leaf spot, with weights proportional to incidence of the individual diseases. 相似文献
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广东省新推广大豆品种病害的初步调查 总被引：1，自引：0，他引：1
本文采用普查和定点调查以及传统的植物病害鉴定方法,在2006年6月至2010年10月对广东省新推广高产优质大豆品种的病害种类、发生危害及分布进行了调查.发现病害共有12种,其中真菌病害9种,分别是锈病、霜霉病、红冠腐病、丝核菌叶枯病、炭疽病、白绢病、白粉病、镰刀菌根腐病和煤烟病;细菌性病害、线虫病害和病毒病害各1种,分别为细菌性叶斑病、根结线虫病和花叶病.主要病害为锈病、霜霉病、红冠腐病、花叶病、丝核菌叶枯病和炭疽病等.不同季节大豆的主要病害发生情况不同.春大豆以霜霉病发生较为严重;而夏大豆则以红冠腐病、锈病、花叶病毒病和丝菌核叶枯病发生较严重. 相似文献
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C. Lannou S. Savary 《European journal of plant pathology / European Foundation for Plant Pathology》1991,97(6):355-368
Spontaneous epidemics of rust, early leaf spot, late leaf spot, andRhizoctonia blight simultaneously developed in a groudnut plot. Geostatistical techniques were used to describe and compare the spatial patterns of epidemics.Rhizoctonia blight exhibited a strong aggregative structure, contrasting with leaf spots and rust. The latter disease developed a general epidemic, in combination with local intensification. A strong negative interaction between rust and early leaf spot, and a close correspondence between rust intensification andRhizoctonia blight development were indicated. 相似文献
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S. K. Srivastava 《国际虫害防治杂志》2013,59(3):518-521
Abstract A bacterial disease of neem causing angular leaf spot, shot-hole and vein blight symptoms was found to occur in a severe form in parts of Rajasthan (India). The causal organism was found to be a species of Pseudomonas. Studies revealed that prevailing temperature had a decisive influence on the manifestations of symptoms. Shot-hole appeared to be a defence reaction operating in leaf tissues against parasitic attack. The development of vein blight symptoms might play an important role in the perpetuation of disease from season to season. 相似文献
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Epidemiology of foliar blights (spot blotch and tan spot) of wheat in the plains bordering the himalayas 总被引：1，自引：0，他引：1
ABSTRACT Helminthosporium leaf blight (HLB), a complex of spot blotch caused by Cochliobolus sativus and of tan spot caused by Pyrenophora tritici-repentis, is a major wheat disease in South Asia. This 2-year study elucidated HLB development and its impact on yield. Symptoms caused by C. sativus and P. tritici-repentis were first observed at the seedling and tillering stages, respectively. The number of airborne conidia and leaves infected by the two pathogens remained low for several weeks under lower temperatures, followed by a sharp rise as temperatures increased. The number of airborne conidia of C. sativus and incidence of infection by C. sativus were higher compared with P. tritici-repentis. The disease complex caused an average 30% reduction in yield, with greater losses under delayed seeding. Delayed seeding increased disease severity even in resistant genotypes and caused higher yield losses. 'Milan/Shanghai-7' was the most resistant among six genotypes evaluated. Despite higher disease severity, 'BL 1473' showed relatively lower yield losses, indicating its tolerance to foliar blight. The findings of this study bear implications for integrated foliar blight management in the warmer areas of South Asia by combining optimum seeding date, seed treatment and foliar spray of fungicides, and resistant wheat genotypes. 相似文献
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为了更好地防治玉米大斑病和灰斑病,于2013年和2014年采用75%肟菌·戊唑醇水分散粒剂对其进行了两年田间试验。结果表明,75%肟菌·戊唑醇水分散粒剂各处理对玉米大斑病的防效与对照药剂70%丙森锌可湿性粉剂有效成分用量1 050g/hm~2的处理防效相当;对玉米灰斑病,75%肟菌·戊唑醇水分散粒剂有效成分用量168.75和225g/hm~2处理的防效显著高于对照药剂70%代森锰锌可湿性粉剂有效成分用量2 250g/hm~2的防效。第2次药后14d对玉米大斑病两年的防治效果分别为61.9%~79.7%和66.2%~83.7%;对玉米灰斑病两年的防效分别为67.0%~78.9%和69.5%~84.2%。此外,75%肟菌·戊唑醇水分散粒剂对玉米还有显著的保产效果,采用75%肟菌·戊唑醇水分散粒剂225g/hm~2防治玉米大斑病,两年挽回产量损失分别为6.0%~9.2%和6.1%~13.2%;防治玉米灰斑病,两年挽回产量损失分别为1.7%~8.9%和13.6%~18.1%。本研究结果显示,75%肟菌·戊唑醇水分散粒剂是在生产中防治玉米大斑病和灰斑病的优良药剂。 相似文献
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Suraj Gurung Ram C. Sharma Etienne Duveiller Sundar M. Shrestha 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(2):257-266
In South Asia, foliar blight of wheat (Triticum aestivum L.) is a disease complex caused by Cochliobolus sativus (the spot blotch pathogen) and Pyrenophora tritici-repentis (the tan spot pathogen) which can reduce yields by >30?%. Little is known about the effects of wheat genotypes and their planting time on foliar blight epidemics. Field experiments were conducted to determine the infection potential and epidemic development of C. sativus and P. tritici-repentis on two susceptible (Sonalika and BL1473) and two tolerant (NL750 and Milan/Shanghai-7) wheat genotypes under optimum (November 26) and late (December 11 and December 26) planting conditions. The dynamics of airborne conidia were studied using air samplers. The highest aerial concentrations of conidia and disease incidence of both pathogens on all four wheat genotypes were detected during the first 3?weeks of March under both optimum and late seeding conditions in both years. Compared to optimum sowing time (i.e. November 26), wheat genotypes had higher disease severity when planted late on December 11 and 26. The disease complex reduced grain yield by 20.5, 27.2 and 37.3?% for November 26, December 11 and December 26 plantings, respectively in 2004. The corresponding differences were 17.7, 23.6 and 30.2?% in 2005. The findings of this study provide valuable information on the epidemiology of spot blotch and tan spot, which could help in developing strategies for managing these diseases in South Asian region through the selection of suitable genotypes and planting dates. 相似文献