云南省昆明市马铃薯晚疫病菌甲霜灵抗药性监测

[目的]明确云南省昆明市马铃薯晚疫病菌对甲霜灵的抗药性水平。[方法]采用含药平板法测定晚疫病菌对不同浓度甲霜灵的相对生长量。[结果]甲霜灵浓度为5、100μg/m L时,晚疫病菌相对生长量分别为59.24%~98.81%和43.25%~94.15%。52株马铃薯晚疫病菌全部为高抗菌,未检测到敏感和中抗菌株。[结论]甲霜灵在昆明马铃薯产区已完全失效,需引进新型高效杀菌剂进行晚疫病的合理防控。     

马铃薯晚疫病菌对霜脲氰抗性动态监测及药效验证

【目的】监测河北、内蒙古和吉林北方一季作区马铃薯晚疫病菌（Phytophthora infestans）对霜脲氰的抗性时空动态,明确霜脲氰及其混剂对马铃薯晚疫病的田间防治效果,为马铃薯晚疫病菌抗药性治理和杀菌剂合理使用提供依据。【方法】2011—2019年共采集分离到824个马铃薯晚疫病菌单孢菌株,采用菌丝生长速率法测定其对霜脲氰的敏感性,并通过田间药效试验验证霜脲氰及其混剂对马铃薯晚疫病的防治效果。【结果】河北、内蒙古和吉林3个地区的马铃薯晚疫病菌群体对霜脲氰抗性水平较低且抗性发展缓慢,平均EC50、平均抗性倍数、抗性频率和抗性指数随着监测年限及地域的不同而波动,但整体上趋于低位平稳。不同年份检测的马铃薯晚疫病菌菌株对霜脲氰的平均EC50为0.06—0.44μg·mL-1,平均抗性倍数为0.29—2.18,抗性指数为0.25—0.47。2011和2017年仅检测到敏感菌株,2012—2016年抗性菌株频率为1.90%—58.57%,2018年和2019年抗性菌株频率分别为20.83%和88.14%。不同省（自治区）的马铃薯晚疫病菌菌株对霜脲氰的平均EC50为0.17—0.18μg·m...     

云南省马铃薯春作区晚疫病菌对甲霜灵敏感性测定

旨在明确云南省马铃薯春作区晚疫病菌对甲霜灵的敏感性,为马铃薯晚疫病化学防治提供参考.采用菌落直径法对2018-2020年采自云南省春作区的301株马铃薯晚疫病菌进行甲霜灵敏感性测定,结果显示:甲霜灵高抗、中抗、敏感菌株分别占测定菌株的76.41％、21.26％和2.33％.研究结果表明,2018-2020年云南省马铃薯...     

云南省马铃薯、番茄晚疫病菌对甲霜灵敏感性及地理分布

用含药平板法对2003年至2005年分离自云南省22个马铃薯和番茄产区的257个马铃薯和番茄晚疫病菌菌株的甲霜灵敏感性进行了系统的测定。结果表明,在11个马铃薯或番茄产区检测到甲霜灵抗性或中抗菌株的马铃薯和番茄晚疫病菌对甲霜灵的敏感性表现出明显的差异,马铃薯晚疫病菌主要由甲霜灵敏感群体组成,而番茄晚疫病菌主要由甲霜灵抗性和中抗群体组成。测定的167个马铃薯晚疫病菌中,甲霜灵抗性、中抗、敏感菌株分别为20.4%、7.2%和72.4%;测定的90个番茄晚疫病菌中,甲霜灵抗性、中抗、敏感菌株分别为56.7%、28.9%和14.4%。马铃薯和番茄晚疫病菌对甲霜灵抗性和中抗菌株在滇中多季作种植区内发生的比例较高。甲霜灵的药效已在云南省的少数马铃薯和大部分番茄产区下降甚至失效,因此,避免长期使用单一的杀菌剂对晚疫病进行防治是非常必要的。     

不同药剂对马铃薯晚疫病的防治效果试验

为了掌握适合在庄浪县范围内防治马铃薯晚疫病的最佳药剂种类,进行了5种不同药剂对马铃薯晚疫病的防治效果试验。结果表明：喷施250 g/L嘧菌酯悬浮剂375 g/hm2的处理防效最好,增产幅度最大,分别为84.8%、16.79%。因此,建议在庄浪县马铃薯生产中用250 g/L嘧菌酯悬浮剂喷雾防治晚疫病。     

利用甲霜灵颗粒剂防治马铃薯晚疫病的研究

本文研究了杀菌剂甲霜灵颗粒剂及其不同剂型对马铃薯晚疫病的防治效果，两年的试验结果表明：颗粒剂的防病效应明显高于直接喷雾；在所用的三种颗粒剂型中，甲霜灵与活性炭煤灰渣制成的颗粒剂防病增产效果最佳，到生长后期防效仍在７０％充上，亩增产６７９公斤，而单独应用活性炭或煤灰渣的颗粒剂之间产量无显著差异。甲霜灵煤灰渣颗粒剂随施药浓度减少，其防效和增产幅度也降低，综合经济效益分析说明亩施入２００克２５％甲霜灵可     

马铃薯晚疫病病菌对瑞毒霉抗性的研究

通过研究马铃薯晚疫病菌对瑞毒霉不同抗性菌株,结果表明抗性菌株在转移过程中,其对瑞毒霉的抗性程度不变,在叶片上接种,高抗菌株其病斑面积显著大于较敏感菌株,但它们在侵染频率上没有显著差异。薯块在４℃,１２℃,１８℃,２５℃贮存过程中,在低温条件下,不同敏感菌株在薯块上的存知力没有显著差异,随温度升高,敏感菌株相对抗性菌株有较强存活力,成为下一个季节主要侵染来源。     

番茄晚疫病菌(Phytophthora infestans)对甲霜灵的抗性测定及治理

2000～2001年连续3季从壁山、沙坝坝蔬菜基地采集番茄晚疫病病叶和病果,共分离得80株晚疫病菌.用生长速率法测定其对甲霜灵的抗性和抗性水平,结果有75.0%的菌株表现为抗性,13.8%的菌株表现为中抗,11.2%的菌株表现为敏感.以菌株TBS-2131为敏感对照,所测定的4株抗性菌株的抗性水平达5×104倍以上.此结果表明当地晚疫病菌抗性菌株已占优势,并且抗性水平已很高.同时有针对性地提出了防治番茄晚疫病的用药策略.     

不同药剂对马铃薯晚疫病的防治效果试验

马铃薯晚疫病是三都县马铃薯种植中发生最普遍且危害性较大的病害,应用化学控制马铃薯晚疫病发生的重要措施之一,试验以72%霜霉疫净、80%烯酰吗啉、58%甲霜灵锰锌、68.75%银法利四种药剂对马铃薯晚疫病进行防治效果同田对比,结果表明,喷施68.75%银法利防治的发病率较喷清水对照低38.12%、病情指数较对照低24.7,防治效果最好。     

马铃薯晚疫病菌抗甲霜灵菌株和敏感菌株在种薯上越冬能力的比较

应用浸泡法接种和越冬后薯片培养法测定了抗性菌株、敏感菌株和混合菌株在种薯上的越冬能力。结果表明，用抗性菌株和敏感菌株混合接种，病原菌存活率最高，其存活率为100％；抗性菌株接种的病原菌存活率居中，存活率为80．0％；敏感菌株接种的病原菌存活率最低，存活率为47％。从晚疫病菌混合菌株接种的种薯上，共分离得到39个分离物，测定其对甲霜灵的抗性。测定结果表明，抗性分离物的出现频率为97．4％，敏感分离物的出现频率为2．6％，这说明抗性菌株的越冬能力和竞争力明显高于敏感菌株。     

Sensitivities of Phytophthora infestans to Metalaxyl, Cymoxanil, and Dimethomorph

The isolates of Phytophthora infestans on tomato in the Guangxi Zhuang Autonomous Region, China, were determined for the sensitivities to metalaxyl, cymoxanil and dimethomorph to give the basic information for integrating disease management. Sensitivities were tested by measuring the radial growth on agar medium amended with fungicide, compared with the floating-leaf-disk method. 239 isolates were collected from eight tomato growing areas during 2000-2006. The testing results indicated that the frequencies of sensitive, intermediate, and resistant isolates to metalaxyl were 42.26, 35.98, and 23.53%, respectively. Variations in sensitivities amongst isolates from different areas or different years were very high for metalaxyl. All isolates from Tianlin and Wuxuan were sensitive to metalaxyl, but the metalaxyl-resistant isolates predominated in Tianyang, with the frequency of 51.35%. The EC50 values of certain isolates from Tianyang were higher than 500 μg mL-1 and their resistance levels were over 100000 folds. Cymoxanil has been used for nearly 10 years in Guangxi, and dimethomorph has been used for 5-6 years. However, there was no decrease in sensitivity of P. infestans populations and the sensitivities of the pathogen were nearly normally distributed. Hence, their mean EC50 value [cymoxanil (0.1647±0.0255) μg mL-1, dimethomorph (0.0970±0.0052) μg mL-1] could be used as the baseline sensitivities for monitoring the field resistance development. The comparison with the floating-leaf-disk method indicates that both the techniques provided equivalent results. These studies suggested that metalaxyl can be continuously applied in Tianlin, Wuxuan, and Nanning due to the resistant isolates that have not been found, while for those areas with resistant isolate, the use of metalaxyl should be reduced or alternated, and cymoxanil or dimethomorph was recommended for controlling late blight disease of tomato.     

番茄晚疫病菌对甲霜灵、霜脲氰和烯酰吗啉的敏感性检测

 【目的】研究广西番茄晚疫病菌对甲霜灵、霜脲氰和烯酰吗啉的敏感性,以期为该病的综合治理提供科学依据。【方法】用菌落生长直径法测定病菌对甲霜灵、霜脲氰和烯酰吗啉的敏感性,并用叶盘漂浮法加以比较。【结果】2000～2006年,从广西8个冬春植番茄区采集分离了239个菌株,测定结果表明,对甲霜灵表现为敏感型、中间型和抗性型的频率分别为42.26%、35.98%和23.53%,不同地区和年份的菌株对甲霜灵的敏感性差异很大。来自田林县、武宣县的菌株均为甲霜灵敏感性菌株,但在田阳县,抗甲霜灵菌株占优势,抗性频率高达51.35%,一些菌株的EC50值在500 µg•ml-1以上,抗性水平超过105倍。虽然霜脲氰在广西使用了近10年,烯酰吗啉也已应用了5～6年,但并未检测到番茄晚疫病菌对它们的敏感性下降的抗药性亚群体,病菌的敏感性接近正态分布,因此可以采用它们的平均EC50值（霜脲氰0.1647±0.0255 µg•ml-1,烯酰吗啉0.0970±0.0052 µg•ml-1）作为抗药性监测的敏感性基线。叶盘漂浮法测定结果与菌落生长直径法一致。【结论】广西田林县、武宣县和南宁市番茄晚疫病菌尚未出现抗甲霜灵菌株,仍可用甲霜灵来防治该病,而其它地区则应减少或不使用甲霜灵,改用霜脲氰或烯酰吗啉。     

4种药剂对马铃薯晚疫病的防效研究简

4种药剂对马铃薯晚疫病田间防效试验结果表明,4种药剂对马铃薯晚疫病防治均有不同程度的保叶增产效果,其中687．5g/L银法利悬浮剂800倍液、25％瑞儿悬浮剂1700倍液对马铃薯晚疫病防效最显著,马铃薯产量均比喷清水增产130％以上,53％金雷多米尔水分散粒剂500倍液、52．5％抑快净水分散颗粒剂1000倍液效果次之。     

马铃薯晚疫病菌对氟吡菌胺抗性突变体的获得及其生物学性状

【目的】研究抗氟吡菌胺突变体对不同杀菌剂的交互抗性并评估马铃薯晚疫病菌对氟吡菌胺的抗性风险。【方法】通过紫外线照射菌丝体、紫外线照射孢子囊和药剂驯化的方法获得抗氟吡菌胺的马铃薯晚疫病菌突变体,计算突变体的突变频率,测定抗性突变体的抗性水平,研究突变体在无药条件下继代培养10代后抗性能否稳定遗传,测定突变体在RSA培养基和离体叶片上的适合度(菌丝生长速率、产孢子囊能力及复合适合度指数),比较抗性菌株与其亲本敏感菌株的竞争力,分析对氟吡菌胺表现不同敏感性的菌株对不同药剂的交互抗性,并通过笔者实验室建立的抗性风险量化标准评定马铃薯晚疫病菌对氟吡菌胺的抗性风险。【结果】共获得21个抗性菌株,抗性水平介于61—3 157倍,紫外线诱导孢子囊的突变率为2.78×10~(-7);大多数抗性突变体的适合度与其亲本菌株无显著性差异;竞争力测定试验中,2株突变体的第1、3、7代的共18次抗药频率测定中,有3次测定的抗药频率显著低于初始频率,有4次测定的抗药频率显著高于初始频率,其余11次测定的抗药频率与初始频率均无显著性差异;所有突变菌株的抗药性均能稳定遗传;抗氟吡菌胺菌株及其亲本菌株对氟吡菌胺的lgEC_(50)与这些菌株对嘧菌酯、吡唑醚菌酯、霜脲氰、烯酰吗啉、双炔酰菌胺、甲霜灵、氟醚菌酰胺的lgEC_(50)之间的相关系数(r)分别为0.104(P=0.654)、0.311(P=0.170)、0.228(P=0.081)、0.376(P=0.093)、0.214(P=0.351)、0.122(P=0.599)、0.963(P=0.000);致病疫霉对氟吡菌胺基本抗性风险值为15。【结论】氟吡菌胺与氟醚菌酰胺之间存在交互抗性,与嘧菌酯、吡唑醚菌酯、霜脲氰、烯酰吗啉、双炔酰菌胺、甲霜灵之间无交互抗性,马铃薯晚疫病菌对氟吡菌胺的固有抗性风险为高度,应加强马铃薯晚疫病菌对氟吡菌胺的抗性风险管理,建议生产上将氟吡菌胺与其他类药剂交替或混合使用。     

Sensitivities of Phytophthora infestans to Metalaxyl, Cymoxanil, and Dimethomorph

The isolates of Phytophthora infestans on tomato in the Guangxi Zhuang Autonomous Region, China, were determined for the sensitivities to metalaxyl, cymoxanil and dimethomorph to give the basic information for integrating disease management. Sensitivities were tested by measuring the radial growth on agar medium amended with fungicide, compared with the floating-leaf-disk method. 239 isolates were collected from eight tomato growing areas during 2000-2006. The testing results indicated that the frequencies of sensitive, intermediate, and resistant isolates to metalaxyl were 42.26, 35.98, and 23.53%, respectively. Variations in sensitivities amongst isolates from different areas or different years were very high for metalaxyl. All isolates from Tianlin and Wuxuan were sensitive to metalaxyl, but the metalaxyl-resistant isolates predominated in Tianyang, with the frequency of 51.35%. The EC50 values of certain isolates from Tianyang were higher than 500 μg·mL^-1 and their resistance levels were over 100 000 folds. Cymoxanil has been used for nearly 10 years in Guangxi, and dimethomorph has been used for 5-6 years. However, there was no decrease in sensitivity of P. infestans populations and the sensitivities of the pathogen were nearly normally distributed. Hence, their mean ECs0 value [cymoxanil （0.1647 ±0.0255） μg·mL^-1, dimethomorph （0.0970 ± 0.0052） μg·mL^-1 could be used as the baseline sensitivities for monitoring the field resistance development. The comparison with the floating-leaf-disk method indicates that both the techniques provided equivalent results. These studies suggested that metalaxyl can be continuously applied in Tianlin, Wuxuan, and Nanning due to the resistant isolates that have not been found, while for those areas with resistant isolate, the use of metalaxyl should be reduced or alternated, and cymoxanil or dimethomorph was recommended for controlling late blight disease of tomato.     

辣椒疫霉病菌对内吸性杀菌剂抗药性的研究

从江西省采集分离的辣椒疫病菌（ＰｈｙｔｏｐｈｔｈｏｒａｃａｐｓｉｃｉＬｅｏｎｉａｎ）１５３个菌株对甲霜灵抗药性测定结果表明：野生已有５５．６０％的菌株存在抗药性,其中中、高抗菌株占２７．５０％;甲霜灵与恶唑烷酮、甲呋酰胺之间存在交互抗性,与霜霉威之间没有交互抗性;甲霜灵对敏感菌株菌丝生长、游动孢子囊的形成和游动孢子的释放均有明显的抑制作用,其ＥＣ５０分别为０．２７７６ｍｇ／ｋｇ、０．２６６３ｍｇ／ｋｇ、２．２９５ｍｇ／ｋｇ,而霜霉威浓度达５００ｍｇ／ｋｇ时,对菌株菌丝生长、游动孢子囊的形成和游动孢子的释放均没有明显的抑制作用,但在活体寄主上对病菌有较好的防效。