2009年甘肃省玉米穗腐病、茎基腐病的发生危害

2009年对甘肃省9个市的21个县、区玉米穗腐病、茎基腐病的发生危害情况进行了全面调查,并采集病害标样,进行病原分离。调查结果表明,玉米穗腐病、茎基腐病在全省各玉米种植区均普遍严重发生,病田率100%,病穗率和病株率平均为63.57%和34.47%。初步分离结果表明,全省玉米穗腐病、茎基腐病的主要致病菌为禾谷镰刀菌、黄色镰刀菌和轮枝镰孢菌,但在地区间的分布有明显差异。     

玉米病害发生现状与推广品种抗性对未来病害发展的影响

 随着全球气候变化、耕作方式改变和新品种推广,我国玉米病害的发生也有所改变。在春玉米区,丝黑穗病仍然持续严重为害,大斑病呈加重趋势;在夏玉米区,局部地区小斑病发生较重,而矮花叶病普遍发生较轻;以往的次要病害已成为重要病害:如,南方锈病在夏玉米区南部严重发生,瘤黑粉病成为生产中的突出问题,土传病害日益加重,细菌性病害发生渐多。对玉米主要推广品种、近年国家和主产省份审定品种的抗病性分析表明,在北方春玉米区,由于品种抗性水平降低、个别感病品种的推广及病原菌致病力变异,大斑病在近年仍将呈现较重发生趋势;丝黑穗病的发生则由于推广抗病品种和种子包衣技术而有所减轻,但局部地区仍会严重发生;由于缺乏抗病品种,灰斑病和弯孢菌叶斑病的发生将主要取决于气候因素。在北方夏玉米区,小斑病暴发的可能性较小,但已有强致病力菌株出现;由于推广品种普遍对茎腐病抗性水平较低并受耕作制度的影响,茎腐病和苗枯病将成为主要病害;多数品种对南方锈病缺乏抗性,南方锈病发生面积将继续扩大,发病程度也将增加。     

玉米镰孢菌穗、茎腐病侵染循环的相互关系

玉米穗腐病和茎腐病是玉米主要病害。茎腐病多数病株明显发生根腐,茎基节间产生不规则状褐斑,随后很快变软,内部空松,导致果穗下垂、籽粒干瘪、整株青枯或黄枯,明显减产。玉米穗腐病的主要致病菌为串珠镰孢菌Fusarium moniliforme和禾谷镰孢菌Fusarium graminearum,茎腐病的主要致病菌除腐霉菌外,也有与穗腐病相同的禾谷镰孢菌     

重庆玉米杂交种及自交系抗病性鉴定与应用研究

通过对重庆281份玉米杂交种(组合)及自交系进行主要病虫害人工接种鉴定,抗大斑病、小斑病、丝黑穗病、纹枯病、茎腐病、玉米螟、矮花叶病的鉴定结果表明,多数材料对各病害均有一定的抗性。兼抗3种病害以上的材料占鉴定总数的70%以上。各年抗性表现的总趋势是叶斑病类轻于其他类型病害。经多年来的鉴定与重复鉴定,具有多抗和兼抗的杂交种(组合)及自交系占总参试品种的30%。其中有渝单8号、11号、16号,万单13,万单14,48—2×M212,渝糯7号、8号等近30余个,正在大面积生产上广泛推广及应用,为重庆市玉米生产作出了应有的贡献。     

玉米种子携带玉米矮花叶病毒

玉米种子携带玉米矮花叶病毒玉米矮花叶病（ＭＤＭＶ）最早于１９６８年在河南新乡、安阳、河北邯郸大发生，而后蔓延至山西、陕西、甘肃、山东等省。８０年代初，河北省的中南部平原地区病害发生严重，成为重病区，而张家口、承德等地为偶发区，病株率在５％以下。１９９...     

玉米丝黑穗病综合防治技术

丝黑穗病是玉米生产中的一种重要病害,发生比较普遍。一般病株率2%~8%,严重地块病株率可达30%以上,对玉米生产影响极大。在丝黑穗病的综合防治技术上,应首选安全高效的理想药剂,规范农药用量及方法,降低农药残留量,提高玉米品质。     

玉米丝黑穗病防治研究

玉米丝黑穗病是白城地区的重要病害,一般发病率为3—5%,重者高达30%以上,是生产上急待解决的问题。其症状以正常型为主,有时出现矮化型、矮化丛生型和多分蘖型等特异症状。病株以雌穗为黑穗、雄穗为健穗及雌雄穗皆为黑穗者居多。病穗上自然脱落的厚垣孢子萌发率高,病穗内的萌发率明显降低。此病为系统侵染病害,种子及土壤均可带菌传病,以土壤带菌为主,属土传病害。厚垣孢子在土壤里能存活三年,土壤带菌量越多,菌土覆盖种子越厚,发病率越高。丝黑穗病菌侵染玉米幼苗时间较长,从种子萌芽到四叶期最易侵染,五叶期后,侵染明显下降,八叶期后不再侵染。在幼苗叶片上接菌不能侵染致病。玉米丝黑穗病菌不能侵染高梁。高梁丝黑穗病菌能侵染玉米,但侵染率甚低。侵染玉米后的病菌,不再侵染高梁,只侵染玉米,且致病力明显增强。两菌是同一菌种的不同生理型。用来自九个省、市的丝黑穗病菌接种于不同抗性的自交系鉴定寄主,其致病力不同,陕西和新疆的致病力弱,辽宁和吉林的致病力强。在田间人工接种条件下,鉴定了二百余份自交系和杂交种的抗病性,品种间有明显差异,高抗的近于免疫,高感的发病率在90%以上。抗病性遗传规律表现为双亲高抗的,其后代亦抗,以母本的抗病性起主导作用。选百余种农药处理种子,筛选结果:个别药剂防效有高达70%以上者,但年度间效果不稳定,多数药效稳定在50%左右。     

台州新发现甘薯茎腐病

2015年新发现的甘薯茎腐病是进境检疫性病害,该病是甘薯生产上为害最严重、危险性最大的新病害,在台州已有3个县(市、区)发生为害,一般发病田块平均病株率10%~20%。为有效控制甘薯茎腐病传播扩散,本文介绍了甘薯茎腐病的发生分布情况,描述了病害各生育期症状和为害特点,提出了加强植物检疫、与非寄主作物轮作、培育无病种苗、适增磷钾肥、防积水以及化学农药浸种和喷雾预防等综合防控措施。     

玉米青枯病研究进展概述

玉米青枯病 ,又名玉米茎腐病、茎基腐病等。国外早有发生 ,2 0世纪初便开始有研究报道 ,在美国、加拿大、法国、南斯拉夫、日本、印度等发生较严重 ,其中美国因此病减产 2 0 %～ 30 % ,局部地区50 %以上 ,被称为玉米的头号病害。在我国 ,自 2 0世纪 70年代以来 ,各玉米产区也相继发生 ,一般病株率 1 0 %～ 30 % ,严重的达 80 %以上 ,遂引起各省、市、自治区生产和科研部门的极大关注 ,并予以研究 ,现将研究进展概述如下。1　症状　　玉米青枯病是典型的土传根病 ,在玉米灌浆期开始发病 ,乳熟期到蜡熟期为发病高峰期。玉米发病后 ,叶片出现青…     

黑龙江玉米茎腐病严重

近年来,由于推广抗大、小斑病以及丝黑穗病的玉米和种植面积的不断扩大,玉米茎基腐病已由次要病害上升为主要病害。此病又称青枯病、茎腐病和黑束病,全世界已有20余个国家进行过报道,其中发生较重的有美国、加拿大、印度、法国等,病区发生率常年在10—20％左右。近年来,该病在我国山东、山西、广西、云南、河北、陕西、辽宁、吉林、黑龙江以及河南等地也有不同程度的发生,发病率多在10—20％左右,重者可达50％以上。     

Agricultural and Horticultural Fungicides - Past,Present and Future

Abstract

Maize is produced primarily in temperate and warm-temperate zones of the world, but its production is increasing in many tropical regions. Some diseases are common to both of these environmental zones even though their importance may vary greatly. Other diseases are confined to a single zone. The important factors influencing the geographical distribution of maize diseases and some of their vectors are temperature, moisture, cultural practices, and the type and diversity of maize germplasm used. Within tropical zones maize diseases may be segregated into those in humid environments and those favoured by drier, upland climatic conditions. Elevation within the tropics, as this influences temperature, is a factor in distribution of maize diseases.

Late wilt, banded leaf and sheath blight, and Rhizoctonia, Botryodiplodia and grey ear rots occur only in the tropical zone and the warm, temperate areas, while the Sclerospora-incited downy mildew diseases, southern rust, Pythium and bacterial stalk rots, Curvularia leaf spot, and ear rot caused by Diplodia macrospora are much more prevalent there, occurring only occasionally beyond latitudes 34°N and 34°S. Conversely, bacterial wilt, eye spot, and yellow leaf blight have been found to occur only in the temperate zones. Ergot has been found only in a few locations at high elevation (250–270 m) in Central Mexico. Northern leaf blight, common rust, and stalk and ear rots caused by Diplodia maydis and Gibberella zeae prevail in the temperate zones and at high elevations and in winter seasons within tropical latitudes.     

Rice Diseases in Nigeria

Abstract

The two major fungal diseases of rice in Nigeria are rice blast (Pyricularia oryzae Cav.) and brown spot (Cochliobolus miyabeanus (Ito and Kuribayashi) Dreschler ex Dastur). The loss in grain yield attributable to these diseases ranges from 11.5–39.6% and 12–43% respectively, Mancozeb, blasticidin-S, fentin hydroxide, benomyl and edifenphos as foliar sprays effectively control rice blast in the laboratory and field. Brown spot is controlled by spraying with thiram, mancozeb or blasticidin-S. A more useful approach to the control of these diseases being adopted in Nigeria is the search for horizontally resistant varieties. Other fungal diseases of rice in Nigeria are the green smut (Ustilaginoidea virens (Cooke) Tak.), basal sheath rot (Rhizoctonia solani Kühn), sheath blight (Corticium sasakii (Shirai), Matsumoto.), leaf scald (Rhynchosporium oryzae Hashioka and Yokogi), narrow brown leaf spot (Cercospora oryzae Miyake) and bakanae disease, a foot rot caused by Fusarium moniliforme Sheldon. Two suspected cases of virus diseases have been reported; grassy stunt disease (transmitted by Nilaparvata lugens Stal.), and orange leaf disease (transmitted by Inazuma dorsalis (Motschulsky). No bacterial disease of rice has been found in Nigeria.     

Epidemiology of Fusarium Diseases and their Mycotoxins in Maize Ears

Fusarium species cause two distinct diseases on ears of maize, Fusarium ear rot (or pink ear rot) and Gibberella ear rot (or red ear rot), both of which can result in mycotoxin contamination of maize grain. The primary causal agent for Fusarium ear rot is Fusarium verticillioides, but F. subglutinans and F. proliferatum are also important. Gibberella ear rot is caused primarily by F. graminearum, but F. culmorum can also be important, especially in Europe. Aspects of the epidemiology of both diseases have been studied for decades, but only recently have efforts been made to synthesize this information into comprehensive models of disease development. Much of the work on F. graminearum has focused on Fusarium head blight of small-grain crops, but some of the results obtained are also relevant to maize. The primary mycotoxins produced by these fungi, fumonisins and deoxynivalenol, have differing roles in the disease-cycle, and these roles are not completely understood, especially in the case of fumonisins. Progress is being made toward accurate models for risk assessment of both diseases, but key challenges remain in terms of integrating models of pre- and post-infection events, quantifying the roles of insects in these diseases, and characterizing interactions among competing fungi and the environment.     

A survey of rice diseases in Bangladesh

Abstract

A survey conducted during 1979–81 in Bangladesh revealed 20 rice diseases, including two viral, two bacterial, 13 fungal, two nematode and one micronutrient deficiency problem. Of these diseases. 16 appeared as major during the period under report. The number of diseases were 17, 16 and 16 during the Boro. Aus and transplant Aman seasons, respectively, with 12 common in all three seasons. Thirteen diseases including bacterial blight, bacterial leaf streak, sheath blight, sheath rot, blast, brown spot, grain spot, stem rot and leaf scald were classified as major; and tungro, bakanae, cercospora leaf spot and zinc‐deficiency were classified as either major or minor, and were common to all regions. Diseases not common in all regions were stack burn, root knot, and ufra classified as major or minor, and false smut, seedling blight. Yellow dwarf and damping off which were always classified as minor. Diseases which were typical for Boro. Aus and transplant Aman seasons were seedling blight and damping off. Yellow dwarf, and false smut respectively. Aus the most humid and warmest season, and the coastal humid areas experienced more major diseases. Seasonal and regional differences in the disease incidence appeared related to agro‐climatic variations.     

玉米顶腐病鉴定

报道了玉米顶腐病发生的系统性症状特点及病原菌鉴定的结果。玉米顶腐病抽穗前主要表?叶缘缺刻、叶片枯死、扭曲卷裹、弯头、顶叶丛生;抽穗后表?为叶片基部腐烂,叶鞘、茎秆腐烂,植株畸形。叶缘缺刻和叶片撕裂是顶腐病区别于其他病害的鉴别性特征。引起玉米顶腐病的病原菌小分生孢子呈假头状着生,而不是串珠状着生,因此,将该病原菌鉴定为亚粘团镰孢霉[Fusarium subglutinans(Wr.&;Reink.)Nelson,Toussoun&;Marasas]。引起茎、叶部两种症状的亚粘团镰孢霉同源性很高,在遗传上具有较高的相似性,是同一病原。与串珠镰孢霉复合侵染可加重病害的发生,其发病率较单独接菌高11.1%。     

广东省新推广大豆品种病害的初步调查

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.     

玉米禾谷镰孢茎腐病和穗腐病抗性鉴定接种方法的比较

田间采用不同人工接种鉴定方法对92份玉米种质同步进行玉米禾谷镰孢茎腐病和穗腐病抗性评价与筛选, 明确了东北春玉米产区玉米禾谷镰孢茎腐病?穗腐病抗性鉴定的最佳接种方法:茎节注射法在玉米禾谷镰孢茎腐病抗性精准鉴定中可更好地评价玉米种质的抗病性, 综合考虑接种方法的实用性和可操作性, 菌土覆盖法对大体量的规模化种质进行田间抗病性鉴定更具有优势; 双牙签法对玉米穗腐病抗性鉴定中在种质接种后发病的严重度?田间进行接种的可操作性和实用性等方面均优于花丝通道法?同时筛选出对玉米禾谷镰孢茎腐病抗性稳定的种质52份, 对穗腐病抗性稳定的种质66份, 对2种病害均表现稳定抗性的兼抗种质33份?     

玉米穗、茎腐病镰刀菌相互关系的同工酶分析

对沈阳、河北、北京、吉林等地区玉米穗、茎腐病禾谷镰刀菌和串珠镰刀菌进行了可溶性蛋白和同工酶的聚丙烯酰胺凝胶电泳。以研究玉米穗、茎腐病镰刀菌在病原学上的相互关系。结果表明：各地区玉米穗、茎腐病串珠镰刀菌均具有高度的同源性,相似系数在0．89～0．98之间,菌株间差异表现为个体间多样性。两种病害禾谷镰刀菌病原学的相互关系因地域不同而不同。河北、吉林两地区穗、茎腐病禾谷镰刀菌间均未发现生理分化现象,相似系数均在0．93以上。沈阳地区玉米穗、茎腐病存在明显的生理分化现象,相似系数仅为0．65～0．67。     

中国玉米茎基腐病和穗腐病研究进展

 本文综述了我国在玉米茎基腐病和穗腐病病原学、致病性和寄主抗性机制与综合治理的研究进展。深入探讨了以往我国学者关于引起茎基腐病病原学的不同观点。根据2种病害的病原镰孢菌在可溶性蛋白质、血清学、同功酶和DNA等不同水平的多态性分析,镰孢菌在寄主根和茎组织内侵染过程示踪和孢子捕捉试验结果,重点讨论了2种镰孢菌病害在病原学侵染规律方面的相互关系,概述了2种病害寄主抗性生理生化机理、抗性遗传和以生物防治为核心的综合治理措施研究进展。