Resistance in water yam (Dioscorea alata) cultivars in the French West Indies to anthracnose disease based on tissue culture-derived whole-plant assay

Reactions of 60 water yam ( Dioscorea alata ) cultivars to three isolates of the yam anthracnose fungal pathogen ( Colletotrichum gloeosporioides ) were evaluated using tissue culture-derived whole-plant assay. Three disease parameters: single score on a scale of 0–6 at the seventh day after inoculation (SD7); area under the disease progress curve (AUDPC); and disease progress rate ( R _d) were compared, and cultivars were classified into disease-response groups using a rank-sum method based on AUDPC scores for the two most virulent isolates. A wide range of variation in resistance of the D. alata cultivars, and significant effects of pathogen isolate and isolate–cultivar interactions, were observed for all disease parameters. The three disease parameters were positively correlated; however, four cultivars showed great dispersions from the regression lines for comparisons of SD7 with the multiple assessments based AUDPC and R _d. The 60 cultivars were separated into resistant ( n  = 12), moderately resistant ( n  = 19), moderately susceptible ( n  = 18) and susceptible ( n  = 11) groups. The potential of the tissue culture-derived whole-plant assay to resistance breeding programmes and further understanding of the yam anthracnose pathosystem is discussed.     

西藏八角莲炭疽病病原鉴定及室内药剂筛选

从西藏大学农牧学院药材基地的西藏八角莲叶片病斑上分离到1种炭疽病菌,根据病害症状特点、病原菌形态特征、培养性状和致病性测定等进行鉴定,结果表明:西藏八角莲炭疽病的病原菌为半知菌亚门,腔孢纲,黑盘孢目,刺盘孢属(Colletotrichum sp.)。药剂筛选试验结果表明,对菌丝生长和孢子萌发均有强烈抑制作用的药剂有80%福.福锌可湿性粉剂、58%甲霜灵可湿性粉剂、50%多菌灵可湿性粉剂、72%霜脲.锰锌可湿性粉剂,稀释倍数在2000倍时,对菌丝和孢子的抑制率均达90%以上。     

Localized hemibiotrophy in Colletotrichum: cytological and molecular taxonomic similarities among C. destructivum, C. linicola and C. truncatum

The infection process of hemibiotrophic isolates of Colletotrichum linicola (from flax, Linum usitatissimum ) and C . truncatum (from broad bean, Vicia faba and lentil, Lens culinaris ) was studied by light microscopy. Host surfaces were penetrated directly leading to a symptomless, biotrophic phase characterized by the elaboration of large multilobed, multiseptate, vesicular primary hyphae that were restricted to the initially infected epidermal cells. Biotrophy lasted for the first 48 h of the host-pathogen interaction and was rapidly succeeded by a necrotrophic phase during which narrow, secondary hyphae invaded the surrounding leaf tissues and water-soaked spreading lesions with sporulating, monosetate acervuli were produced on infected host surfaces. Molecular taxonomic analysis of the nucleotide sequences of the amplified D2 and ITS-2 regions of rDNA revealed very close similarities (97–99%) between these isolates and those of C . destructivum obtained from cowpea ( Vigna unguiculata ) and lucerne ( Medicago sativa ), and also of C . truncatum obtained from pea ( Pisum sativum ). This association was consistent with results from a comparative assessment of some in-planta and in-vitro morphological and growth characteristics of these hemibiotrophic fungi. It was concluded that localized hemibiotrophy is an infection strategy utilized predominantly by a closely-related group of pathogens comprising C . destructivum , C . linicola and C. truncatum , and the formation of multilobed primary hyphae restricted to the first penetrated cell might therefore be a key taxonomic character which correlates consistently with ITS sequence data.     

20%氟硅·咪鲜水乳剂防治黄瓜炭疽病的试验报告

20%氟硅·咪鲜水乳剂防治黄瓜炭疽病的田间小区试验结果表明,在53.3～66.7mL/667m2剂量下,施药3～4次,间隔7～8d,可有效地控制黄瓜炭疽病的危害,并有提高产量和品质的作用。     

几种杀菌剂对南方红豆杉炭疽病的田间药效测定

在田间药效测定中,喷雾和注干两种施药方法相比,喷雾防治的效果明显好于注干的防治效果。喷雾试验中,防治效果最好的是甲基托布津,平均防治效果达到78.79%,最差的是退菌特,平均防治效果为57.20%;在注干防治试验中,防治效果最好的依然为甲基托布津,为62.50%,其次为炭克、多菌灵,最差的为退菌特,为46.57%。     

油茶炭疽病的化学防治研究

本研究使用14种杀菌剂对油茶炭疽病进行了室内和田间的防治试验。结果表明，扑菌清、叶斑净和宝宁的效果较好，同时对杀菌剂在田间的施用方法也提出了建议。     

柿炭疽菌的室内药效试验

通过在凹玻片上测试10种不同杀菌剂对柿炭疽菌分生孢子萌发、芽管伸长、附着孢形成的影响，对诱发凹玻片上菌丝孢子产生和在PDA上菌丝生长抑制作用的研究，认为不同的杀菌剂对不同菌态的炭疽菌药效不同。药剂筛选结果表明百菌清、退菌特、多菌灵3种杀菌剂药效最好，但它们对病原菌的作用机制不同。     

三华李重要病害虫防治技术

近年来随着广东省三华李（Prunus sp.）种植面积不断增加,三华李果园病虫害的危害上升趋势,对三华李水果的质量和产量影响较大。文章主要介绍了近年来三华李果园危害较为严重的几种病虫害的发生、危害情况以及主要防治技术。     

番木瓜WRKY转录因子家族基因鉴定及其响应短孢炭疽菌侵染的表达分析

【目的】在全基因组水平鉴定番木瓜(Carica papaya L.) WRKY（CpWRKY）转录因子家族基因,并对其在短孢炭疽菌侵染下的表达量进行分析,为CpWRKYs 家族的功能研究和利用奠定基础。【方法】采用生物信息学方法,鉴定和筛选CpWRKYs转录因子家族基因成员,并对其进行系统进化分析、基因结构分析、蛋白保守基序预测和启动子顺式作用元件分析;同时以番木瓜炭疽病耐性品种和敏感性品种为材料,利用短孢炭疽菌侵染采后果实,于0,24,48 h 取样,对其转录组学数据进行分析,筛选2个品种中差异表达的CpWRKY基因,并利用实时荧光定量PCR(RT-qPCR)试验对筛选结果进行验证。【结果】经系统分析从番木瓜中共鉴定出48个CpWRKYs成员,分为Ⅰ、Ⅱ和Ⅲ 3类;其中第Ⅱ类成员最多,可分为Ⅱa、Ⅱb、Ⅱc、Ⅱd和Ⅱe 5个亚类。CpWRKYs家族成员的氨基酸残基数目为97~747 个,等电点为4.83~9.71,为亲水性蛋白,大部分CpWRKYs的结构域高度保守,但有个别蛋白保守域缺失。在 CpWRKYs家族中共预测到10个保守基序,其中包括含有WRKY七肽结构域的基序1、含锌指结构的基序2和同时含有七肽序列和锌指结构的基序3,其中基序3为大多数I类CpWRKY转录因子N端WRKY结构域所特有。CpWRKYs含有1~6个外显子,同一家族或亚家族成员在基因结构上表现出一定的相似性,同时在CpWRKYs启动子中检测到大量与生物胁迫和非生物胁迫相关的元件。对短孢炭疽菌侵染番木瓜的转录组数据进行分析,在番木瓜耐性品种中筛选出了特异表达的CpWRKY22、CpWRKY11、CpWRKY2、CpWRKY33和CpWRKY25,RT-qPCR检测结果显示,这些基因在耐性品种中特异上调表达,在敏感性品种中的表达量无明显变化。【结论】番木瓜WRKY家族共包括48个成员,该家族基因结构和蛋白基序具有组间差异性和组内保守性。CpWRKYs家族成员强烈响应炭疽菌侵染,其中CpWRKY22、CpWRKY11、CpWRKY2、CpWRKY33和CpWRKY25是有潜力的抗炭疽病候选基因。     

产挥发性物质芽胞杆菌对枇杷炭疽病菌的抑制作用及其鉴定

采用二分隔特殊平板研究芽胞杆菌挥发性物质对枇杷炭疽病菌Colletotrichum acutatum的抑制作用。研究结果表明,筛选得到的8株芽胞杆菌菌株中,抑菌效果最好的菌株为FJA T-4748,抑菌率达90.06％;其次为FJAT-10011,抑菌率达54.99％。经16S rDNA序列鉴定结合菌落形态观察,确认这8株芽胞杆菌分别为解木糖赖氨酸芽胞杆菌 Lysinibacillus xylanilyticus、波茨坦短芽胞杆菌 Brevibacillus borstelensis、短短芽胞杆菌Brevibacillus brevis、土壤短芽胞杆菌 Brevibacillus agri、阿氏芽胞杆菌 Bacillus aryabhattai、美丽短芽胞杆菌Brevibacillus formosus及简单芽胞杆菌Bacillus simplex。本研究筛选的产挥发性物质芽胞杆菌菌株可为枇杷采后炭疽病的生物防治提供菌株参考。