月季黑斑病的流行与防治

本试验采用对样枝分级,且不断更替的取样方法,进行了14个月的月季黑斑病流行的系统调查。月季黑斑病在广州地区周年发生,有2个主要的流行时期,分别在4月下旬至7月上旬及9月下旬至10月下旬。其流行与温度、湿度、降雨量及降雨次数密切相关,在适宜的温度(20—27℃)下,降雨或相对湿度高峰10—20天内出现病叶率高峰。田间10种药剂防病试验,敌力脱效果最高,达91.2％;施保克次之,为86.7％。百菌清也具有良好的防效,3年均在70％以上;如果与营养液1号混合喷雾,不仅防效提高,还可以促进月季生长、增加花枝数量和提高切花质量。     

侵染月季的香石竹潜隐病毒属新病毒鉴定及其全基因组序列分析

 2019年7月,在北京市月季叶片上观察到了黄色斑驳症状,高通量测序(High-throughput sequencing,HTS)显示在感病样本中存在一种新的正义ssRNA病毒。该病毒全基因组序列除去3′末端poly(A)后由8 393个核苷酸(nucleotide,nt)组成,含5个开放阅读框(open reading frame,ORF)。其依赖于RNA的RNA聚合酶(RNA-dependent RNA polymerase,RdRp)在氨基酸水平上与已知乙型线状病毒科(Betaflexiviridae)成员具有35.87% ~ 46.74%的序列一致性。系统发育分析表明,该新病毒与香石竹潜隐病毒属(Carlavirus)的杨树花叶病毒(poplar mosaic virus,PopMV)亲缘关系最近。发生率调查显示该新病毒在北京地区分布较为广泛。根据Betaflexiviridae的划分标准,该病毒是Carlavirus的一个新种,暂时命名为月季C病毒(rose virus C)。     

氯氟醚菌唑对月季白粉病菌的室内活性及田间防效

采用孢子萌发法测定氯氟醚菌唑对月季白粉病菌的生物活性,通过田间试验评价氯氟醚菌唑对月季白粉病的防效及对月季的安全性。室内毒力测定结果表明,氯氟醚菌唑对月季白粉病菌的EC₅₀为0.915 0μg/mL(孢子萌发法),对照药剂戊唑醇和肟菌酯的EC₅₀分别为1.298 8μg/mL和0.426 2μg/mL,3种药剂均具有较高活性。田间药效试验结果表明,400 g/L氯氟醚菌唑悬浮剂有效成分用量90～150 g/hm²处理对月季白粉病的防治效果为74.09%～78.96%,显著高于当地常规对照药剂吡唑醚菌酯和戊唑醇,且对月季生长无不良影响。     

百合鳞茎斑点病病原菌鉴定

 1991年在浙江湖州市和杭州市采集得百合(Lilium brownii F. E. Brown var. viridulum Baker)鳞茎有褐色斑点的标本104份,分离出纯菌株108个。鉴定为2个镰刀菌种:Fusarium solani(Mart.)Sacc. 和F. oxysporum Schlecht. F. solani出现频率84.3%,占优势.田间调查和接种试验证明F.solani是百合鳞茎褐色斑点病主要致病菌。在20种植物上接种试验结果表明:F.solani对百合有专化性,因此鉴定其病原菌为茄病镰孢一个新专化型:Fusarium solajni f. sp.lilii Wang.     

昆明地区发现月季根癌病

2004年8月在昆明市晋宁县首次发现月季根癌病,当地人称之为大根病.该病在月季品种彩纸(Pava votti)、瑞普索迪(Rhapsodyy)上发生严重,发病率40%～50%.相同品种繁殖的月季扦插苗上也有类似症状发生,发病率60%左右.     

43个中国小麦品种(系)抗叶锈性研究

 选用12个墨西哥叶锈菌生理小种对43个中国小麦品种(系)所携带的抗叶锈病基因进行了推导,在25个品种(系)中推导出6个抗叶锈基因Lr1,Lr10,Lr13,Lr14a,Lr16和Lr26,9个品种(系)对本试验所使有的12个叶锈菌生理小种都表现感病反应,另有9个品种(系)携带未知的抗叶锈基因。在墨西哥2个地点进行的田间成株期抗叶锈性试验表明,12个品种(系)表现慢叶锈性,在将来的抗病育种中有一定的应用价值。     

抗枯萎病棉花品种氨基酸分析

 国内外多年的生产实践证明,陆地棉(Gossypium hisutum L.)不同棉花品种抗枯萎病(Fusarium oxysporum f.sp vasinfectum(AtK.) Snyd.et Hansen)的能力差异很大。     

水稻叶尖枯病病原种类研究

 从江苏13个县市采集病叶标本,经分离、纯化后获280株菌。据鉴定结果和接种试验,稻生叶点霉(Phyllosticta oryzicola Hara)为主要致病菌,占74.6%。此外,还分离到稻盘多毛孢(Pestalotia oryzae Hara)、链格孢(Alternaria alternata(Fr.) Keissl.)、稻喙孢(Rhynchosporium oryzae Hash.et York.)、苍白弯孢(Curvularia pallescens Boed.)、新月弯孢(C.lunata(Walk.) Boed.)、膝曲弯孢(C.geniculata(Tracy et Earle) Boed.)、镰刀菌(Fusarium spp.)、平脐蠕孢(Bipolaris spp.)、稻黑孢(Nigrospora oryzae(Berk.et Br.) Perch)、球黑孢(N.sphaerica(Sacc.) Mason)等真菌。首次以透射电镜观察表明,稻生叶点霉产孢方式为全壁芽生单体式(hb-sol)。     

鹅掌柴真菌病害鉴定

 调查鉴定了广州地区鹅掌柴(Schefflera actinophylla (Endl.) Harms.)上12种真菌病害及其病原菌,以叶疫病和炭疽病危害较重。病原菌中有3个新种:鹅掌柴小球腔菌Leptosphaeria schefflerae P.G.X i,P.K.Chi et Z.D.Jiang,鹅掌柴生尾孢Cercospora schefflericola P.G.Xi,P.K.Chi et Z.D.Jiang,鹅掌柴拟茎点霉Phomopsis schefflerae P.G.Xi,P.K.Chi et Z.D.Jiang和一个新组合:鹅掌柴茎点霉Phoma scheffleri (Chen) P.G.Xi et P.K.Chi。新种提供了拉丁文简介、描述和绘图,研究的标本保存在华南农业大学真菌标本室。     

月季黑斑病防治药剂筛选初报

采用菌丝生长速率法测定了12种杀菌剂对月季黑斑病菌(M. rosae)菌丝生长的抑制活性,以多菌灵、氟硅唑、嘧菌酯、吡唑醚菌酯对月季黑斑病菌菌丝生长均有较好的抑制作用。在田间筛选了6种杀菌剂对月季黑斑病的防治效果,以氟硅唑、戊唑醇、苯醚甲环唑及嘧菌酯均有较好的防治效果。     

小麦品种对白粉病抗病性与过氧化物酶的关系

 不同抗白粉病小麦品种接种白粉菌后过氧化物酶均呈现两个酶活峰,峰Ⅰ出现在病菌分生孢子梗期,峰Ⅱ出现在分生孢子期。峰Ⅰ的相对酶活性与小麦品种的抗病性呈正相关。SDS-聚丙烯酰胺凝胶电泳扫描的结果显示峰Ⅰ中的高分子量(28,000道尔顿以上)酶带与植株的抗病性有密切关系。高抗品种MN 7213的同工酶谱多一条酶带,可能是抗性基因表达的结果。高感品种VilelaMar.的同工酶谱则在个别酶带上有所加强。     

河北省苹果主要病虫害发生现状调查

在2007-2009年对河北省唐山、保定、邢台、石家庄、沧州、衡水、秦皇岛、张家口、廊坊、承德共10个地市200余个苹果园进行了问卷调查、实地重点考察和现场访谈,调查内容包括品种名称、树龄结构以及各种病虫害发生情况。结果表明:河北省苹果以‘富士’品种为主,占调查果园面积的58%,其次为‘元帅’;从树龄结构上看,树龄超过15年的果园占69%,说明河北省苹果园老化现象比较严重。苹果上常发生的病虫害有枝干轮纹病、腐烂病、斑点落叶病、褐斑病、锈病、苹果黄蚜、山楂叶螨、金纹细蛾、苹果绵蚜、桑天牛、枣尺蠖和黑蚱蝉共12种。其中枝干轮纹病、腐烂病和山楂叶螨是全省苹果产区发生普遍且较严重的病虫害。唐山市枝干轮纹病病株率高达92%,张家口市腐烂病病株率为72.67%,苹果黄蚜、锈病、褐斑病和金纹细蛾在不同地区发生程度不同。苹果绵蚜在河北省已普遍发生。品种以及地形对病虫害发生的影响也存在不同程度差异。本文根据对河北省苹果病虫害发生状况的调查结果,提出了通过加强栽培管理、病虫害预测预报、选用抗性品种与砧木以及化学防治为手段的病虫害防治对策。     

The gene diversity pattern of Diplocarpon rosae populations is shaped by the age,diversity and fungicide treatment of their host populations

Black spot disease caused by the hemibiotrophic ascomycete Diplocarpon rosae is the most devastating disease of field‐grown roses. Although resistance to black spot is an important trait for rose breeding, little information on the diversity of the pathogen is currently available. To date, a number of single‐spore isolates have been characterized based on a set of test genotypes of the host. In this study, six polymorphic simple sequence repeat (SSR) markers for D. rosae were developed and their potential application to single‐spore isolates collected from a wide range of geographic locations within and outside Europe discussed. Populations of the fungus were then analysed in different German rose collections/populations. Gene diversity was highest in older rose collections managed without fungicide application, and lowest in the two‐ to three‐year‐old testing sites of German rose breeders. Additional analyses of a global collection of single samples and populations revealed no unique alleles from any of the locations, indicating that global trading of rose varieties has led to an admixture of the pathogen.     

On Red Rot of Sugarcane

Abstract

Red rot is a very serious disease of sugarcane. It was first described by Went in 1893 (56). Since then it has been found to cause epiphytotics in different countries. The surest symptom of the disease is the reddening of the internal internodal tissues with crossbars of white patches in the reddened area. This red colour is caused by a dye which is secreted by the host and is antagonistic to the red rot fungus. Infection takes place through mother setts, holes in the nodal regions, the cut ends of the seed canes and other injuries. The disease causes damage to the sugarcane drop mainly by reducing the crop stands and by reducing the sucrose content of the cane juice. Methods of chemical control are mentioned, although the importance of good husbandry is stressed. Use of resistant varieties of sugarcane is recommended.     

豌豆不同品种对茄病镰刀菌感病性及对其毒素敏感性之间的相关性

 茄病镰刀菌(Fusarium solani(Mart.) Sacc.)是甘肃中部干旱地区引起豌豆根腐病的主要病原菌。经测定该菌在PSC培养液内培养可产生新茄病镰刀菌烯醇、T₂等毒素。其滤液具有植物毒性效应,与病程密切相关。用10%培养滤液测定17个品种对毒素的敏感性,并用茄病镰刀菌对这些品种进行接种测定其感病性。结果表明:不同品种对茄病镰刀菌感病性及对其毒素敏感性两者之间成正相关,相关系数r=0.9216,经t测验表明;相关系数在p=0.001水平上显著。因此认为,用测定毒素对豌豆胚根抑制率的方法,可作为抗病性鉴定的一种手段。     

Evaluation of Banksia species for response to Phytophthora infection

Phytophthora cinnamomi was the species isolated most frequently from soil associated with dead or dying proteaceous plants in the Adelaide region of South Australia. The association of P. citricola with diseased Banksia species in South Australia is reported for the first time. The response of a range of Banksia species to inoculation with P. cinnamomi and P. citricola was assessed. P. cinnamomi was generally more pathogenic than P. citricola . Inoculation of 10-month-old seedlings with colonized millet seed or zoospores showed that B. hookeriana and B. ashbyi were the most susceptible of the species tested, whereas B. coccinea , B. menziesii and B. prionotes were moderately susceptible. B. ericifolia , B. serrata , B. spinulosa var. collina and B. lemanniana showed tolerance. Similarly, 2–3-week-old seedlings of B. ericifolia , B. serrata and B. spinulosa var. collina inoculated in vitro showed little disease 6 and 12 days after inoculation, whereas B. baueri, B. baxteri , B. coccinea and B. solandri , as well as B. hookeriana and B. ashbyi , showed severe symptoms of disease after 6 days. Results suggested that the in vitro assay may have potential in the evaluation of breeding material. Development of infection was studied microscopically in 2–3-week-old seedlings of B. coccinea , B. menziesii , B. serrata and B. spinulosa var. collina inoculated in vitro with zoospores of P. cinnamomi . Roots of B. coccinea and B. menziesii were colonized rapidly and root tips became necrotic within 24 h and hypocotyls by day 5. Penetration was delayed in B. spinulosa var. collina , and callose deposition was delayed in B. coccinea . Necrosis of roots of B. serrata and B. spinulosa var. collina began 3 days after inoculation but rarely extended more than half way up the root by 9 days.     

红花锈病菌Puccinia carthami Cda.的孢子阶段及生活史研究

 用本地感病的红花品种,对P.carthaml的孢子阶段和生活史进行了研究.结果指出,种子经冬孢子粉拌菌后播种,幼苗罹病后在同一块病斑上先后产生性孢子、夏孢子和冬孢子。明确了性子器后发育生成的孢子防段为初生夏孢子.为此P.carthami应归属为单主寄生,缺锈孢型锈病菌.     

大麦品种对BYMV的抗性与过氧化物酶、酯酶的关系研究

4个不同生育期的叶片过氧化物酶活力测定呈两峰两谷现象。感病品种早期叶片过氧化物酶活力大于抗病品种,感病严重度与酶活力呈正相关。三叶期叶片同工酶电泳表明,抗病品种过氧化物酶在快带区比感病品种多1条酶带,酯酶同工酶在慢带区多1条酶带,这些酶带可作为抗性品种的特异性生化指标。分蘗期叶片过氧化物酶中有1条酶带与抗性有关。拔节期叶片有3条酯酶同工酶带、根材料中有2条分别与感病性有关。本文初步探讨了同工酶与抗病性的关系。     

水稻簇矮病的研究Ⅳ:病害的发生发展和防治试验

 水稻簇矮病的两种介体中,Nephotettix cincticeps的传毒率(为45.1%)显著高于N.virescens (24.7%)。但不同虫态、龄期和性别,以及采自不同产地的同一种叶蝉,其传毒力并无显著的差异。
病害的潜育期在17~29℃下为8~44天,随温度的上升而缩短。病害的发生发展与其有效毒源(带毒虫数量)、品种抗性及外界条件有密切关系。采用抗病品种(如赤块矮3号、包胎矮、珍龙13和珍龙410等),结合测报调节播插时间,必要时辅以育秧返青阶段做好治虫防病工作,可有效控制病害的发生。