小麦苗期抗纹枯病鉴定方法的改良及抗病品种筛选

Wheat sharp eyespot, caused by Rhizoctonia cerealis and R. solani, is a soil-borne fungal disease, which poses a great threat to wheat yield. In order to increase the identification efficiency of wheat sharp eyespot resistance, an improved method of rapidly identifying wheat sharp eyespot resistance was established by inoculating wheat seedlings with diseased wheat grains in greenhouse. To verify its reliability, four standard materials and 96 wheat varieties from Huanghuai wheat region were used for resistance assessment to sharp eyespot. Meanwhile, the resistance to Rhizoctonia solani of aforementioned materials in the field was identified by traditional methods. The results showed that the correlation coefficient between the four repetitions of the improved method ranged from 0.735 to 0.825, and the correlation coefficient between the average number of repetitions and the traditional method was 0.630. The results of wheat sharp eyespot resistance identification in Huanghuai wheat area showed that 66 wheat varieties were susceptible, accounting for 68.8% of tested materials. This indicated that the resistance of wheat varieties in Huanghuai wheat area to sharp eyespot was poor on the whole and needed to be improved urgently. At the same time, eleven wheat varieties which showed resistance to sharp eyespot at seedling and adult stages were screened, which include Zhengzhou 8998, Beijing 841, Handan 94-5316, Jimai 32, Jinmai 50, Jinmai 54, Longmai 157, Lumai 23, Shanhe 6, Shi 02-1 and Xinmai 18. Therefore, this study provides a method for identification of wheat sharp eyespot resistance at seedling stage, by which the resistance of wheat varieties to sharp eyespot can be quickly and efficiently identified. Furthermore, selected resistant materials provide important material resources for wheat sharp eyespot resistance breeding in Huanghuai wheat region and even in China.     

小麦苗期抗纹枯病鉴定方法的改良及抗病品种筛选

<正>小麦纹枯病又称尖眼斑(点)病,是由禾谷丝核菌(Rhizoctonia cerealis)和立枯丝核菌(Rhizoctonia solani)引起的一种以土壤传播为主的小麦真菌病害~([1])。引起小麦纹枯病的病原菌主要是禾谷丝核菌的第一菌丝融合群(CAG-1)~([2～4])。在自然条件下,病原菌首先侵染寄主植株基部叶鞘,随着     

Evaluation of diagnostic and quantitative PCR for the identification and severity assessment of eyespot and sharp eyespot in winter wheat

Diagnostic and quantitative polymerase chain reaction (PCR) provided clarification of the causes of symptoms and the extent of infection by eyespot ( Tapesia spp.) and sharp eyespot ( Rhizoctonia cerealis ) on winter wheat at early growth stages. Disease assessments made before stem extension, when decisions to apply fungicides are usually made, often did not agree with the pathogen diagnoses using PCR, suggesting that such early visual diagnoses may be unreliable. Visual and PCR diagnoses made on stems in summer generally supported each other, but there were often discrepancies in relating disease severity to amounts of pathogen present when determined by regression analyses of incidence or severity of symptoms on amount of pathogen DNA. Mixed symptoms caused by different pathogens may sometimes have been confounded. Relationships between symptoms and DNA of eyespot pathogens were less clear on some cultivars, often those with least disease. Sharp eyespot symptoms had a stronger relationship to DNA of its pathogen. Significant regressions often accounted for a small percentage of the variance, suggesting either that pathogens not assayed were contributing to symptoms or that lesions were in some cases persisting longer into the season than pathogen DNA. The frequency of pathogen detection before stem extension was a poor predictor of the amounts of pathogen DNA measured later in the season.     

小麦纹枯病的田间流行动态模糊聚类分析

 本文应用模糊聚类方法分析了小麦纹枯病的田间流行动态,结果表明:该病在田间的流行动态可以划分为5~6个阶段,即冬前发生期、冬季稳定期、返青上升期、拔节后为害期、抽穗白穗显症期等阶段。小麦纹枯病的田间分布和扩展,通过X1、X2、X3、X4几个参数来描述。聚类分析刻划了小麦纹枯病在田间的分布,水平方向和垂直方向的扩展情况,即刻划了病害在时间、空间上的变化,为小麦纹枯病的综合防治和预测提供了依据     

中国小麦纹枯病化学防治研究进展

随着秸秆还田等耕作栽培措施的推广,中国小麦纹枯病发生日趋严重,对小麦的高产、稳产造成了很大威胁。由于缺乏免疫及高抗病性小麦品种,生产中对纹枯病一直采用播期拌种及春季喷雾相结合的化学防治方法。文章总结了当前中国小麦纹枯病的发生现状及主要病原;评述了三唑类药剂对纹枯病菌的毒力及对纹枯病的防治效果,介绍了生产中小麦纹枯病菌对三唑类药剂的抗药性现状及机理,分析了三唑类药剂对小麦的安全性;同时阐述了井冈霉素、甲基立枯磷及其他种类药剂在小麦纹枯病综合防治中的应用;指出小麦纹枯病化学防治的发展方向应是将生防菌剂同化学药剂相结合,实现生物防治与化学防治的协同应用。     

湖北省小麦品种(系)对赤霉病、条锈病、白粉病和纹枯病的抗性评价

为了解湖北省小麦品种(系)的抗病性水平,对2001年以来湖北省审定的46个小麦品种和在湖北省进行区域试验的447份小麦品系进行赤霉病、条锈病、白粉病和纹枯病等4种主要病害的抗病性评价。结果表明:1)参试品系中有1份材料对赤霉病表现高抗,未发现对纹枯病表现高抗或免疫的材料;对赤霉病和纹枯病的平均抗性评价分值分别为14.30和3.49,介于中感和高感之间;对条锈病和白粉病的平均抗性评价分值分别为13.43和8.34,介于中抗和中感之间。2)审定品种的综合抗性水平不高,对条锈病的抗性评价分值为12.47,介于中抗和中感之间,对其他3种病害的抗性介于中感和高感之间;审定品种的单产呈增加趋势,株高在不断降低,生育期相应延长,综合抗病性也在增强。3)审定品种的综合抗病性与对条锈病抗性的相关系数最高,为0.738;对纹枯病的抗性与株高呈显著正相关,与单产呈显著负相关;对赤霉病的抗性与株高无显著相关。鉴于此,湖北省需加强抗病育种力度,同时应充分做好小麦病害的防控。     

小麦纹枯病品种抗性鉴定技术及抗病资源的筛选与分析

分别用玉米粉－砂、麦粒和玉米秸秆作为小麦纹枯菌生长基质,培养获得小麦纹枯病菌接种物。土壤接种诱发试验表明,三种接种物在合适的接种强度下,均能有效诱发泪科纹枯病。据此建立的人工病围２对１５份小麦产多年连续鉴定结果表明,病圃具有较稳定的发病率,表现为典型的尖眼点或云纹病斑。对我国主要冬麦区的１３００份小麦品种资源、生产品种以及新育成品系进行了病圃鉴定,共筛选出抗纹枯病材料８５份,包括菜籽黄、紫秆子、白     

小麦纹枯病流行预测的研究

作者根据小麦纹枯病在冬麦区发生具有明显阶段性的特点,利用1984～1993年连续10年在纹枯病常发区山东省文登市的多品种、多地点的病情系统调查数据,采取统计学和流行学相结合的方法,组建了具有预测秋苗冬前发病率和返青后生长期病情指数的回归模型。并通过对小麦纹枯病普遍率和病情指数相关性的研究,将二阶段的模型耦联,完成对小麦整个生长期的病害流行动态全过程的预测。     

Visual disease and PCR assessment of stem base diseases in winter wheat

Stem base disease (eyespot, sharp eyespot and brown foot rot) was assessed visually and by the polymerase chain reaction (PCR) technique on single plants sampled at four-week intervals in two crops of winter wheat grown in the UK in 1992–3. PCR assays were conducted for Fusarium avenaceum , F. culmorum , both varieties of Microdochium nivale , both eyespot-causing species of Tapesia and Rhizoctonia cerealis . PCR diagnoses were compared with visual diagnoses at each time point. Eyespot was caused principally by T. acuformis (R-type) and developed rapidly late in the season. Visual diagnoses of eyespot were largely confirmed by PCR but T. acuformis was detected in many plants lacking eyespot symptoms. R. cerealis was detected at relatively low incidences on both sites, and sharp eyespot visual diagnoses did not correlate with the incidence of any of the pathogens assayed by PCR. Brown foot rot, caused principally by Microdochium nivale var . majus , accumulated earlier in the season than eyespot. Overall, visual diagnoses of stem base disease coincided poorly with PCR data until after growth stage (GS) 30.     

河北省小麦纹枯病菌群体组成及致病力分化

为明确河北省小麦纹枯病发生特点及病菌特征,采用五点取样法调查该病的发生情况,通过细胞核染色、菌丝融合反应和r DNA-ITS序列分析测定196株纹枯病菌群体组成,并比较其对不同小麦品种的致病力差异。结果表明,河北省3个不同生态类型麦区30个监测点均有纹枯病发生,临漳县发病最重,其次是邯郸县和馆陶县,青县发病最轻;纹枯病菌可划分为AG-D、AG-B(0)、AGI、AG-4和AG-5共5种融合群,分别占菌株总数的88.3%、1.5%、5.1%、3.6%和1.5%;采自黑龙港平原区和山前平原区的纹枯病菌对石新828、良星99和邯6172的平均致病力均明显强于冀东平原区;菌株可划分为极强、强、中等和弱4个致病类型,分别占菌株总数的45.92%、33.67%、7.65%和12.76%。表明河北省小麦纹枯病发生普遍,总体呈南重北轻的趋势,纹枯病菌群体组成较简单,以强致病力AG-D融合群为主。     

Development and use of a PCR assay to detect Rhizoctonia cerealis, the cause of sharp eyespot in wheat

Random amplified polymorphic DNA assays were carried out on a range of isolates of Rhizoctonia cerealis to identify markers common to all isolates. Two fragments were isolated, cloned and used to probe Southern blots of DNA from R. cerealis and isolates from a range of anastomosis groups of Rhizoctonia solani. The two fragments hybridized specifically to DNA of R. cerealis and not to DNA of any of the isolates of R. solani. Both fragments were partially sequenced and two pairs of primers were generated for use in the polymerase chain reaction (PCR). Amplification of a fragment of the anticipated size occurred following PCR of all isolates of R. cerealis and not from any of a range of fungal species associated with disease of the stem base of cereals. The primer pairs for R. cerealis were also used, along with those for Microdochium nivale and W and R-type of Pseudocercosporell herpotrichoides , to deled these pathogens in extracts from field-grown wheat plants exhibiting symptoms of sharp eyespot, eyespot, foot rot or a combination of the diseases. No relationship was found between visual disease assessment of sharp eyespot at growth stage 37 and the results of PCR However, the results of PCR and visual disease assessment at growth stage 75 were similar, indicating that visual disease assessment may not be reliable until later growth stages. This system offers the potential to detect the presence of R. cerealis in cereals and avoid problems commonly associated with conventional diagnosis of this disease and isolation of the pathogen.     

小麦纹枯病抗性及抗性遗传的初步研究

 从一个多亲本的复式杂交后代中,选育了4个高抗纹枯病的小麦新品系,编号为MN-3、7、18和19。抗病性鉴定证明,在对照品种绵阳19病株率100%,发病等级4~5级的情况下,这4个新品系的病株率和发病等级分别在3.65%~6.98%和0~1之间。这4个品系与高感纹枯病的小麦品种绵阳19杂交,在F2代群体中植株符合抗:感=3:1的分离比率,在隐性亲本的测交后代中符合1:1的分离比率;在这4个品系之间的杂交后代群体中未观察到抗性的分离。试验结果指出,4个品系均含有同一个抗小麦纹枯病的单显性抗病基因,该基因被命名为Ses 1。本研究指出了小麦抗纹枯病育种的可能性,并为进一步研究小麦宿主和纹枯病菌原的相互关系及其遗传学提供了材料。     

防治白背飞虱的农药复配增效配方筛选

农药复配制剂的研究对于延长新农药品种的使用寿命、缓解靶标生物的抗性、扩大防治谱、降低防治成本、提高药效和环境安全性等具有重要的意义。为筛选防治白背飞虱的农药增效复配配方,采用稻茎浸渍法测定了8种农药单剂及复配剂对白背飞虱3龄若虫的毒力。利用共毒因子法定性筛选出16组共毒因子大于20的配比,并对其中15组进一步利用共毒系数法定量筛选,得到有增效作用的5组配比,分别为烯啶虫胺与毒死蜱按1∶30配比以及吡虫啉与异丙威分别按7∶40、7∶200、7∶400和7∶1 000配比;其共毒系数分别为112.5、242.1、212.4、638.1、417.7,其中吡虫啉与异丙威按7∶400配比具有最显著增效作用。     

小麦纹枯病生防芽孢杆菌的筛选及鉴定

从河南、北京等地采集小麦植株,分离得到202株内生芽孢杆菌,平板拮抗测定获得27株对小麦纹枯病菌拮抗效果明显的菌株。温室盆栽测定了27个菌株对小麦纹枯病的生防效果,其中菌株M-1、W-2和W-3的防治效果分别为60.4%、59.4%和56.6%。对3株生防菌株进行了分类学鉴定,M-1为多粘类芽孢杆菌,W-2为地衣芽孢杆菌,W-3为枯草芽孢杆菌。     

戊唑醇种子处理防治小麦纹枯病

种子处理是控制小麦纹枯病的有效措施,在小麦纹枯病的综合治理技术体系中起着举足轻重的作用。在苏南宜兴和淮北徐州,2％戊唑醇湿拌剂和6％戊唑醇悬剂胺10kg麦种拌药0.3-0.4g有效成分,对小麦的出苗没有显著影响,对根系和冬前分蘖具有促进作用。对小麦纹枯病的控制效果较为理想,表现为冬前效果显著,病析率防效60％－100％,从而有效地抑制了冬前发病高峰。戊唑醇处理区拔节期的病情指仍然极显著地低于对照区,亦显著低于对照药剂纹霉净,侵茎高峰明显推迟,最终的枯白穗防效突出,0.3-0.4g ai/10kg种子拌种的枯白穗防效达到85％以上。由于控病和对小麦生长调控的双重作用,保穗、保产效果明显,最终产量较对照增加10％－15％。     

Genetic structure and population diversity in the wheat sharp eyespot pathogen Rhizoctonia cerealis in the Willamette Valley,Oregon, USA

Wheat sharp eyespot, caused by the soilborne basidiomycete fungus Rhizoctonia cerealis group D subgroup I (AG-DI), is a common disease of wheat stems that has increased in global importance in recent years. The disease caused a severe and extensive epidemic throughout the Willamette Valley of Oregon in 2014 and has remained one of the most important wheat diseases in this region subsequently. The population structure of this pathogen is still not well understood. In this study, 572 pure cultures of R. cerealis AG-DI were isolated from five commercial fields and two experimental fields in the Willamette Valley, Oregon, in the spring of 2017 and 2018. Population structure studies were conducted using six microsatellite markers. Polymorphisms were observed at all six loci, and all seven subpopulations showed moderate gene and genotype diversity. Most of the loci were in Hardy–Weinberg equilibrium in the subpopulations, the entire population combined over locations and five of seven subpopulations were in gametic equilibrium, and the AMOVA and Mantel’s test demonstrated no differentiation among subpopulations. Though direct evidence is currently lacking, these results suggest that the sexual stage of the pathogen may be having a significant impact on pathogen population structure, and that the presence of basidiospores could be contributing to the extensive spread of this disease in the Willamette Valley in recent years.     

小麦纹枯病拮抗细菌的筛选

 从小麦纹枯病病田土壤中分离到722株细菌,通过对峙培养法筛选出拮抗细菌397株,拮抗菌率为55.0%。细菌对小麦纹枯病病原菌的拮抗作用分为两种类型:其一以竞争作用为主,表现为菌株生长快,抑菌率高但抑菌带较窄,如菌株BNT-25抑菌效果可达100.0%,抑菌带仅为2 mm;其二为抗生物质的产生,表现为菌株生长慢,菌落小,抑菌率高且抑菌带宽,如JJ-5菌株抑菌效果可达94.3%,抑菌带为12 mm。选用18株抑菌作用良好的拮抗细菌在室内测定其防治小麦苗期纹枯病的效果。结果发现,与空白对照相比,有9株拮抗细菌的防治效果达到了极显著水平,有15株拮抗细菌的防治效果达到了显著水平。在极显著水平中菌株NZT-47、MTT-8和DHT-12的防治效果分别为76.45%、64.03%和58.89%,对小麦纹枯病表现了较高的防治效果;菌株HNT-7-16、BDT-94和BNT-28的防治效果分别为43.47%、40.97%和40.97%,具有一定的防治作用。其中NZT-47的防治效果最好。     

The role of organic vs. conventional farming practice,soil management and preceding crop on the incidence of stem-base pathogens on wheat

Journal of Plant Diseases and Protection - A stem-base disease complex of winter wheat includes several causal agents, such as eyespot (Oculimacula yallundae and O. acuformis), sharp eyespot...     

利用荧光定量PCR检测禾谷丝核菌的相对生物量

小麦纹枯病是以禾谷丝核菌(Rhizoctonia cerealis)侵染为主的小麦土传病害。为建立检测禾谷丝核菌在寄主小麦(Triticum aestivum)中的相对生物量的可靠方法,促进小麦抗纹枯病机制的研究,本研究克隆了禾谷丝核菌肌动蛋白基因RcActin的部分(3′端)cDNA,并设计了RcActin的特异引物。该引物不仅能区分禾谷丝核菌与寄主小麦,还能区分全蚀病菌(Gaeumannomyces graminis)、根腐病菌(Bipolaris sorokiniana)和立枯丝核菌(Rhizoctonia solani)等常见小麦土传病害的病原菌,表明该引物能用于小麦纹枯病的分子检测,也能用于相对表达量的测定。利用相对定量法,以RcActin相对于寄主管家基因的相对表达量作为禾谷丝核菌相对生物量的指标,结果表明,此方法能准确反映禾谷丝核菌在寄主中的相对生物量和对小麦纹枯病抗性程度进行快速鉴定。     

主要栽培因子对小麦纹枯病的定量效应

研究了播期、密度和氮肥对小麦纹枯病的定量效应，组建了小麦扬花期病情指数（DI1）和黄熟期病情指数（DI2）的回归模型，并对其进行了检验和解析。结果表明：两回归模型均在0．01水平上显著，且拟合较好；各个因子对纹枯病病指的影响为：播期＞氮肥＞密度；其中播期中DI1、DI2的效应均极显著；播期与密度互作（X1X2）对DI2的效应达到0．2显著水平；晚播稀植有利于控制该病的危害。最后对回归模型进行了仿真优化，提出了控制该病发生程度的优化栽培方案。