江西槟榔芋疫病病原菌鉴定及室内药剂筛选

为明确江西省九江市槟榔芋疫病的病原菌并有针对性地对该病害进行防治,本研究采集具有典型芋疫病症状的芋叶片和叶柄对病原菌进行分离纯化,结合形态学观察、致病性测定及基于ITS、Ypt1和β-tubulin基因联合系统发育分析对该病原菌进行鉴定,并测定了其对7种杀菌剂的敏感性。根据病原菌菌落、卵孢子形态等特征初步鉴定为芋疫霉Phytophthora colocasiae,基于多基因联合系统发育分析结果与形态学结果一致,确定该病原菌为芋疫霉。室内药剂筛选结果表明,23.4%双炔酰菌胺SC对菌丝生长抑制效果最好,EC₅₀为0.006μg/mL;96.8%烯酰吗啉TC、0.3%丁子香酚SL、20%氟吗啉WP、500 g/L氟啶胺SC、97%霜脲氰TC对菌丝生长的抑制效果也较好,EC₅₀介于0.094～1.272μg/mL之间,研究结果可为槟榔芋疫病的化学防治提供参考。     

北方五省(区)马铃薯晚疫病菌对甲霜灵和精甲霜灵的敏感性检测

为了明确我国不同地区马铃薯晚疫病菌对甲霜灵和精甲霜灵的抗性状况,2007-2009年从河北、黑龙江、吉林、辽宁和内蒙古马铃薯主产区采集马铃薯晚疫病菌,采用菌丝生长速率法和叶盘漂浮法测定其对甲霜灵的敏感性,采用叶盘漂浮法测定其对精甲霜灵的敏感性.结果表明:以菌丝生长速率法检测的380株晚疫病菌中和以叶盘漂浮法检测的222株晚疫病菌中对甲霜灵的抗性菌株分别占80％和73.5％;菌丝生长速率法检测结果显示,河北省对甲霜灵的抗性菌株所占频率从2007年的100％降为2008年的66.4％,2009年又回升至74.2％,而吉林和黑龙江两省对甲霜灵的抗性菌株分布频率呈上升趋势.叶盘漂浮法检测的95个菌株中对精甲霜灵的抗性菌株占54.5％,其中河北省40个菌株对精甲霜灵的中间型菌株占优势(62.5％),抗性菌株仅占34.9％,而其他4省55个菌株对精甲霜灵的抗性菌株占优势(69.1％).受检测的北方五省(区)马铃薯晚疫病菌群体中对甲霜灵和精甲霜灵的抗性菌株已占优势,马铃薯晚疫病菌已普遍对甲霜灵及精甲霜灵产生抗性.在对甲霜灵和精甲霜灵普遍产生抗性的地区,应优先选用与甲霜灵、精甲霜灵作用机理不同的药剂防治马铃薯晚疫病.     

山茶炭疽菌对茶树的致病性及其对杀菌剂的敏感性研究

山茶炭疽菌（Colletotrichum camelliae）是引起茶树叶部病害的优势致病菌。从中国13个产茶省的茶树病叶中分离获得65株炭疽菌菌株,基于多基因系统发育树,结合菌落和分生孢子形态特征,对分离菌株进行鉴定,结果表明,分离菌株均属于山茶炭疽菌。采用离体叶片接种的方法进行致病力测试,结果显示,所有菌株均能导致茶树叶片发病,但不同菌株间的致病力存在显著差异。YCW1180、YCW1331、YCW1382、YCW1387、YCW1419、YCW1443、YCW1451、YCW1453、YCW1454、YCW1461、YCW1613和YCW2134等12个菌株致病力显著强于其他菌株,菌株YCW1378致病力最弱。采用菌落生长速率法测试65个山茶炭疽菌菌株对25%吡唑醚菌酯的敏感性,药剂敏感性结果显示,25%吡唑醚菌酯对菌株YCW1436的菌丝生长抑制率仅为36.00%,抑菌效果最差,而对大部分菌株的抑制率高于70.00%,表明大部分菌株对该药剂高度敏感。显微镜观察结果显示,25%吡唑醚菌酯影响了山茶炭疽菌分生孢子的萌发。以上研究结果为有效防治茶树叶部病害提供了理论基础。     

不同杀菌剂及混剂对番茄灰霉病菌的室内抑制效果研究

[目的]筛选高效、低毒的番茄灰霉病杀菌剂,缓解和治理其抗药性.[方法]在室内离体条件下,采用生长速率法及抑制孢子萌发法测定了几种杀菌剂对番茄灰霉病菌的敏感性.[结果]30;爱苗、50;福美双、40;施灰乐、50;扑海因,对病原菌菌丝生长的EC_(50)值在0.347 6～0.724 2 μg/mL,均小于1 μg/mL,番茄灰霉病菌对上述杀菌剂均处于比较敏感的阶段;50;农利灵和65;乙霉威的EC_(50)均大于1 μg/mL,敏感程度相对较低.孢子萌发试验中,30;爱苗、50;福美双、50;扑海因对番茄灰霉菌孢子萌发的抑制活性高,EC_(50)值在1.308 5～1.336 4 μg/mL;50;农利灵和40;施灰乐的抑制活性次之,EC_(50)分别为1.525 4和1.777 4 μg/mL;65;乙霉威的抑制活性相对较低,EC_(50)为2.173 8 μg/mL.[结论]将不同作用机理的杀菌剂50;扑海因与50;福美双以1∶1和1∶2的比例混配,联合毒力测定和评价结果表明相互作用为增效.     

打瓜白粉病的发生及化学药剂防治试验

打瓜白粉病是打瓜上最严重病害之一,给生产带来了严重影响.探讨白粉病的发生特点、防治具有很重要的意义.2008年通过调查得出,福海县打瓜白粉病的发病初期为7月初,气候条件适宜时,7月底8月初瘸害达到高峰值,发病率可达100;,发生面积广,危害程度重.2007年通过药剂筛选试验,筛选出防治效果较好的药剂为福星、敌力康,防治效果达77.02;、73.90;.因此,控制好打瓜白粉病的严重危害,必须抓住防治关键时期,于病害发生前期,即6月底7月初进行喷药预防,以后每隔7～10 d喷药防治一次,喷3～6次,可以取得好的防治效果.     

Effect of Adjuvants on the Therapeutic Activity of Dimethomorph in Controlling Vine Downy Mildew. I. Survey of Adjuvant Types

The effect of adjuvants on the performance of emulsifiable concentrate (EC) and wettable powder (WP) formulations of dimethomorph, a new systemic Oomycete fungicide, has been investigated using a two-day therapeutic (curative) assay with downy mildew (Plasmopara viticola, Berl. & de T.) on vines (Vitisvinifera L., cv. Cabernet Sauvignon) in glasshouse trials. The EC formulation had some therapeutic activity in this type of test. This activity was increased by the spray tank incorporation of 6 g litre⁻¹ of either emulsifiable rape seed oil (‘Atplus’ 412) or emulsifiable paraffinic oil (‘Atplus’ 411F). However, these improvements in performance were overshadowed by those brought about by incorporation of 3 g litre⁻¹ of a series of C₁₃/C₁₄ alcohol ethoxylates varying in ethylene oxide content from 5 to 20 moles:(‘Marlipal’ 34/6EO, 34/11EO, 34/20EO). Nearly complete fungal control was obtained in the presence of these adjuvants with a dimethomorph application rate of 25 g ha⁻¹ compared with only around 90% control at 400 g ha⁻¹ without adjuvants. The WP formulation was inactive in this therapeutic test but the presence of the adjuvants improved the performance of this formulation towards the high levels observed with the EC plus adjuvants, demonstrating that adjuvants could markedly influence the performance of solid, otherwise therapeutically inactive, dimethomorph formulations. Further trials examined other types of adjuvants (nonylphenol, alkylamine and silicone ethoxylates) but either they were no better than the alcohol ethoxylates or they induced unacceptable phytotoxicity. Trials with alcohol ethoxylates (‘Genapols’) from another source demonstrated activity equivalent to the ‘Marlipal’ surfactants. A two-factorial matrix experiment with ‘Genapol’ C050 showed that, under glasshouse conditions, >90% control could be obtained with the dimethomorph EC at 25 g AI ha⁻¹ with 375 g ha⁻¹ ‘Genapol’ C050. Applications of the WP formulation required slightly higher rates of either 50 g AI ha⁻¹ plus 375 g ha⁻¹ ‘Genapol’ C050 or 25 g AI ha⁻¹ plus 750–1500 g ha⁻¹ ‘Genapol’ C050. The overall conclusion was that alcohol ethoxylates varying in alkyl chain length from C₁₂ to C₁₈ and ethylene oxide content between 5 and 20 moles for the C₁₂ surfactants and ∽15 moles for the C₁₈ surfactants were effective adjuvants in promoting the therapeutic activity of dimethomorph formulationsagainst P. viticola on glasshouse-propagated vines.     

Effect of Adjuvants on the Therapeutic Activity of Dimethomorph in Controlling Vine Downy Mildew. II. Adjuvant Mixtures,Outdoor-Hardened Vines and One-Pack Formulations

Previous investigations have shown that certain C₁₂–C₁₈ alcohol ethoxylates with between 5 and 20 moles ethylene oxide gave large enhancements to the therapeutic activity of emulsifiable concentrate (EC) and wettable power (WP) formulations of dimethomorph in controlling two-day-old infections of downy mildew (Plasmopara viticola, Berl. & deT) on glasshouse propagated vines (Vitis vinifera, L.). In a continuation of that work it has been shown that similar enhancements could also be obtained on vines that had been grown under outdoor conditions for two to three weeks before treatment (outdoor-hardened vines) and it is concluded that the treatments would therefore be effective on field vines. Mixtures of either ammonium sulfate or the silicone ethoxylate, ‘Silwet’ L77, with the best alcohol ethoxylates, ‘Genapol’ C050 or ‘Genapol’ C080, produced slight antagonism of the action of the ‘Genapols’ and therefore were of no benefit. Trials with one-pack formulations prepared containing the ‘Genapol’ adjuvants produced good dose response curves from which estimated doses for 90% fungal control (ED₉₀ values) could be calculated by Logit analysis. These one-pack formulations were significantly more effective than the standard EC formulation (ED₉₀=335 g AI ha⁻¹, glasshouse vines and 445 g AI ha⁻¹, outdoor hardened vines) with optimum enhancements with those formulations containing an adjuvant: dimethomorph ratio of either 9:1 on glasshouse vines (ED₉₀= 13 g AI ha⁻¹) or 6:1 on outdoor-hardened vines (ED₉₀=30 g AI ha⁻¹). This last result was significantly better than that obtained with a commercial formulation of cymoxanil, ‘Fytospore’, (ED₉₀=86 g AI ha⁻¹) and encouraged the recommendation that these one-pack formulations should be examined in field trials.     

几种杀菌剂对小麦茎基腐病的防治效果

小麦茎基腐病是小麦上重要的真菌性茎基部病害,在黄淮海冬麦区呈广泛流行态势,对我国小麦生产安全构成严重威胁.本研究评价了不同拌种剂、拔节期喷施杀菌剂以及两者结合使用对小麦茎基腐病的防治效果.药剂拌种防治结果表明:60 g/L戊唑醇FS、25 g/L咯菌腈FS和25％氰烯菌酯SC拌种处理能显著降低苗期病株率,其病株防治效果...     

植物源杀菌剂国内外研究进展

从植物中提取、分离有效化合物已有悠久的历史,其提取、分离、鉴定各个步骤的研究方法都在改进,从杀菌植物活性、活性成分、研究方法以及杀菌机理等4个方面综述了植物源杀菌剂国内外的研究概况.     

番茄灰霉病菌对速克灵的抗性检测

对来自安徽省合肥、蚌埠、六安、和县的 5 4个番茄灰霉病菌株进行了对速克灵的抗性测定 ,并分析了番茄灰霉病菌生长特性与抗药性、致病力的相关性。结果表明 ,4个菌株为速克灵高抗型 ,占 7.4% ;无中抗型 ;5 0个菌株为敏感型 ,占 92 .6%。各菌株间生长速度、菌核干重差异较小 ,产孢量差异较大。产孢量与菌核干重相关极显著 ,其余性状间相关皆不显著