Identification, pathogenicity, and fungicide sensitivity of Eutiarosporella dactylidis associated with leaf blight on maize in China

Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.

Research Progress on Detection Techniques of Fungicide Residues in Chinese Chives

Chinese chive is a kind of medicinal and edible plant,with many diseases,and chemical fungicides are usually used for control.In order to find out the risk of pesticide residues in Chinese chives,this paper summarized relevant literatures published in recent years,and sorted out and analyzed the types of pesticides used and detection techniques of common diseases in Chinese chives.

Mitochondrial dynamics caused by QoIs and SDHIs fungicides depended on FgDnm1 in Fusarium graminearum

Fusarium head blight(FHB) caused by Fusarium graminearum is a devastating fungal disease on small grain cereal crops,because it reduces yield and quality and causes the mycotoxin contamination to the grain.Dynamins and dynamin-related proteins(DRPs) are large GTPase superfamily members,which are typically involved in the budding and division of vesicles in eukaryotic cells,but their roles in Fusarium spp.remain unexplored.Here,we found that FgDnm1,a DRP and homolog to Dnm1 in Saccharomyces cerevisiae,contributes to the normal fungal growth,sexual reproduction and sensitivity to fungicides.In addition,we found FgDnm1 co-localizes with mitochondria and is involved in toxisome formation and deoxynivalenol(DON) production.Several quinone outside inhibitors(QoIs) and succinate dehydrogenase inhibitors(SDHIs) cause fragmentated morphology of mitochondria.Importantly,the deletion of FgDnm1displays filamentous mitochondria and blocks the mitochondrial fragmentation induced by QoIs and SDHIs.Taken together,our studies uncover the effect of mitochondrial dynamics in fungal normal growth and how such events link to fungicides sensitivity and toxisome formation.Thus,we concluded that altered mitochondrial morphology induced by QoIs and SDHIs depends on FgDnm1.

In Vitro Synthetic Seed Production of Potato under Different Fungicide Levels and Storage Intervals

Potato propagation through tubers and seed is an inefficient way of propagation thus we propose an alternative method in this study which is in vitro propagation.Plantlets were raised from True Potato Seeds(TPS)in test tubes containing 10 mL of Murashige Skoog(MS)medium.Subculturing was done after every 21 days and after four subsequent subculturing,when there was an adequate quantity of stock material,uninodal cuttings of about 3-4 mm in length were prepared from in vitro proliferated potato plants by excising leaves of 1-2 mm on each side of the node.Prepared uninodal cuttings were cultured on 1/2 strength MS medium for root primordia development.The selected uninodal cuttings with root primordia were encapsulated with sodium alginate solution(3.5%(w/v)),mixed with 1.25%charcoal and different concentration of fungicide(thiophanate methyl,sigma)to enhance the viability percentage of synthetic seed.Furthermore,these encapsulated uninodal cuttings were subjected to different storage intervals to check maximum storage.Results showed that optimum dose for fungicide is 150 mg/L as it resulted in good viability percentage,shoot number,shoot length,rooting percentage,root number,root length and ideal for bead formation with sodium alginate.Similarly,results revealed that encapsulated uninodal cuttings can be stored at a temperature of 4℃ up to 45 days with a survival rate of 63.33%.Encapsulated uninodal cutting stored for 60 days showed a poor viability percentage of about 43.03%.It can be concluded that optimum dose of 150 mg/L with storage time of 45 days should be used to get a better outcome for synthetic potato seed production.

Preventive and Therapeutic Effects of New Fungicides on Rice Blast

[Objectives]The paper was to identify the characteristics and the potency of new fungicides to rice blast disease,and study their preventive and therapeutic effects on the disease.[Methods]Six new and conventional fungicides with different mechanisms of action were selected to compare their preventive and therapeutic effects on rice seedling blast in greenhouse.[Results]The agents which showed to be highly efficacious in blast prevention(greater than 90%)were 25%pyraclostrobin EC,20%fenoxanil SC,75%tricyclazole WP and 50%prochloraz-manganese WP sprayed at the dosages of 112.5-150,180-360,270-450 and 450-600 g/ha,respectively.The therapeutic effect of new fungicides 25%pyraclostrobin EC and 50%prochloraz-manganese WP on rice blast were above 90%when the dosages were 90-150 and 360-600 g/ha,respectively.The therapeutic effect of the conventional fungicide 40%isoprothiolane EC on rice blast was 69.04%when the dosage was 480 g/ha,while those of other fungicides were worse.[Conclusions]Both 25%pyraclostrobin EC and 50%prochloraz-manganese WP have good preventive and therapeutic effects on rice blast,which will provide a reference for the use of these fungicides in the field.

Evaluation of Fungicides for Effective Management of Leaf and Fruit Spot (Pseudocercospora angolensis) Disease of Citrus under Field Conditions

Leaf and fruit spot (Pseudocercospora angolensis) disease of citrus attacks leaves, fruits, and young twigs of the plant. The disease can cause a yield loss of (50% to 100%) in areas with high rainfall and humidity during the active growth stages of the crop. Currently, citrus plantations in the south, south-west and north-west of Ethiopia are seriously affected by this disease. As a result, this study was proposed to study the effect of fungicides in controlling. And candidate fungicides were: Carbonchlor 50% SC only, Benline 50% WP only, Bellis 38% WG only, Carbonchlor 50% SC combined with Bellis 38% WG, Benline 50% WP combined with Carbonchlor 50% SC and Benline 50% WP combined with Matco 72% WP for effective management of citrus leaf and fruit spot (Pseudocercospra angolensis) disease. The study was carried out in 2021 cropping season. A Randomized Complete Block Design (RCBD) with three replications was the design applied. The result showed that the highest level of efficacy (90.46%) was produced by Bellis 38% WG fungicide followed by Carbonchlor 50% SC (86.50%), Bellis 38% WG + Carbonchlor 50% SC (82.00%), Carbonchlor 50% SC + Benline 50% WP (67.89%), Benline 50% WP (65.62%) and Matco 72% WP + Benline 50% WP (49.48%). Therefore, based on the outcome of the study application of Bellis 38% WG only followed by Carbonchlor 50% SC only, Carbonchlor 50% SC combined with Benline 50% WP, Bellis 38% WG combined with Carbonchlor 50% SC, Bellis 38% WG only, Benline 50% WP only and Matco 72% WP combined with Benline 50% WP were effective fungicides to be used for the control of leaf and fruit spot disease.

中国防治果蔬灰霉病的杀菌剂应用及防控关键技术

由葡萄孢属真菌(Botrytis spp.)引起的果蔬灰霉病是一种世界性的植物病害,采收前及采收后均能对果蔬产生危害,造成严重经济损失。介绍了我国果蔬灰霉病的发生与为害、杀菌剂应用现状、防治中存在的问题、防控关键技术,以期为灰霉病的科学防控提供参考。

杨叶枯病病原菌生物学特性、防治药剂筛选及杨树抗病性评价

为防治杨树叶枯病,利用单因素试验,对中荷64杨(P.×euramericana cv.‘N3016’)上分离获得的链格孢菌(Alternaria alternata)进行了生物学特性及室内防治药剂筛选研究,并开展了不同品种杨树抗叶枯病综合评价。结果表明:链格孢菌菌丝生长的适宜培养基为马铃薯蔗糖琼脂培养基,适宜碳源为玉米粉,适宜氮源为酵母提取物,适宜培养温度范围为25~30℃,适宜pH为8,光照条件对菌丝生长影响不大,致死温度为52℃。采用生长速率法进行室内防治药剂筛选,结果显示,选用的5种生物制剂防治效果优于2种化学药剂,各药剂抑制作用排序从大到小依次为哈茨木霉(3亿菌落/g)、枯草芽孢杆菌(100亿芽孢/g)、质量分数为10%的多抗霉素、质量分数为3%的中生菌素、质量分数为2%的宁南霉素、质量分数为50%的多菌灵、质量分数为75%的百菌清,将哈茨木霉(3亿菌落/g)和枯草芽孢杆菌(100亿芽孢/g)作为防治链格孢菌的适宜药剂。选用7个黑杨派品种杨树,利用模糊数学隶属度函数法,开展了杨树抗叶枯病综合评价,确定中荷64杨为高感品种,中辽1号杨和欧美杨177为中感品种,渤丰1号杨、渤丰3号杨、辽育3号杨和欧美杨111为高抗品种。

我国小麦赤霉病流行与化学防控现状及控病降毒关键技术理论创新与应用

概述了我国小麦赤霉病发生危害现状,深入剖析了该病流行危害的原因,回顾了近年来我国小麦赤霉病化学防控历程,综述了化学防控及其抗药性发生的现状,并总结了小麦赤霉病菌抗药性检测技术的发展过程。此外,对小麦赤霉病控病降毒关键技术理论创新与应用成果进行了分析和总结,展望了小麦赤霉病精准防控的科学用药技术方案,并对其可行性和有效性进行了阐释。旨在为小麦赤霉病的精准选药、科学用药提供重要的参考数据,保障我国的粮食生产安全和食品安全,进而推动我国农业实现可持续、高质量发展。

四川辣椒炭疽病菌鉴定及防治药剂筛选研究

为明确四川辣椒产区辣椒炭疽病致病菌株,筛选有效防治药剂,采集并分离鉴定了资阳、盐源等7个辣椒产区的辣椒炭疽病菌,采用菌丝生长速率法测定10种杀菌剂对辣椒炭疽病菌的室内毒力,采用离体果实法测定6种杀菌剂对辣椒炭疽病的防治效果。结果表明,7个辣椒产区分离到的辣椒炭疽病菌均为Colletotrichum scovillei;C.scovillei菌丝对咪鲜胺、戊唑醇、氟环唑、苯醚甲环唑、氟啶胺、腈菌唑敏感性较高;6种杀菌剂对辣椒炭疽病均有较好的防治效果,防效由高到低依次为咪鲜胺(95.66%)>戊唑醇(92.43%)>氟环唑(81.00%)>腈菌唑(75.29%)>氟啶胺(72.40%)>苯醚甲环唑(67.67%)。

荔枝中20种登记农药残留分析方法研究

为解决荔枝中20种登记农药多残留的同时快速检测问题,建立并优化基于超高效液相色谱-串联质谱(UPLC-MS/MS)同时检测荔枝中7种杀虫剂和13种杀菌剂的分析方法。荔枝全果样品经80%乙腈水溶液提取后,用石墨化碳黑(GCB)净化,流动相为乙腈和水,梯度洗脱,采用Extend C18色谱柱进行分离。电喷雾正负离子交替模式采集,多反应监测(MRM),外标法定量。20种供试农药的质量浓度与其对应的峰面积之间呈现良好线性关系,相关系数均大于0.9990;20种农药在荔枝基质中的平均回收率为71%~106%,相对标准偏差(RSD)在0.9%~9.8%之间,满足残留分析的要求。该方法简便、高效,可用于荔枝样品中20种农药残留的快速检测。

湖南烟草镰刀菌根腐病病原鉴定及防治药剂筛选

为明确湖南郴州和永州地区烟草根腐病的病原种类,针对主要病原菌筛选有效的防治药剂,分别利用组织分离法和平板稀释法对两地主要烟区采集的烟草根腐病病样和根际土壤进行病原分离,通过形态学观察、翻译延伸因子1A(EF-1α)序列进化分析以及致病性测定确定病原种类,采用生长速率法测定供试杀菌剂对主要病原菌菌丝生长的抑制效果,并通过活体盆栽防效试验验证候选杀菌剂对主要病原菌的防治效果。共分离到真菌128株,其中镰刀菌87株,包括共享镰刀菌Fusarium commune、甜瓜镰刀菌Fusarium incarnatum、藤仓镰刀菌Fusarium fujikuroi、茄镰刀菌Fusarium solani、层出镰刀菌Fusarium proliferatum、Fusarium falciforme、Fusarium humuli共7个种。其中,F.commune占比最高,为39.08%,其次为F.solani和F.incarnatum,占比均为14.94%。致病力测定结果表明,这些菌株都能引起烟草发病,明确其为烟草根腐病的病原物。F.commune对40%咪鲜胺EW、43 g/L戊唑醇SC和15%氰烯菌酯SC高度敏感,EC50分别为0.026、0.079和0.169μg/mL。盆栽试验结果表明,40%咪鲜胺EW的防治效果最为显著,相对防效达到94.43%±2.79%,其次为43 g/L戊唑醇SC和15%氰烯菌酯SC,相对防效为88.63%±1.68%和83.07%±2.55%。本研究表明,湖南郴州和永州地区烟草镰刀菌根腐病病原真菌以共享镰刀为主,供试药剂中,40%咪鲜胺EW对该病原菌的抑菌效果最好。

山东省葡萄白腐病菌对氯氟醚菌唑及其他3种三唑类杀菌剂的敏感性

为明确葡萄白腐病菌对氯氟醚菌唑的敏感性,本研究采用菌丝生长速率法测定了山东省6个地市的66株葡萄白腐病菌对氯氟醚菌唑的敏感性,同时通过室内及田间试验比较了氯氟醚菌唑与丙环唑、苯醚甲环唑和戊唑醇3种三唑类杀菌剂对葡萄白腐病的防治效果。结果表明,葡萄白腐病菌群体对氯氟醚菌唑表现为敏感,氯氟醚菌唑对所有菌株的有效抑制中浓度(EC50)在0.0210~1.9464μg/mL之间,平均EC50值为(0.7578±0.4322)μg/mL,其敏感性频率呈连续单峰曲线分布,符合正态分布,因此可将该平均EC50值作为山东地区葡萄白腐病菌对氯氟醚菌唑的敏感基线。丙环唑、苯醚甲环唑和戊唑醇对随机选择的31株葡萄白腐病菌的平均EC50值分别为(1.1667±0.4456)、(2.1577±0.5007)和(5.8187±1.5538)μg/mL。结果表明,氯氟醚菌唑对葡萄白腐病菌的活性与丙环唑、苯醚甲环唑相当,优于戊唑醇,该结果可为田间葡萄白腐病菌抗药性监测及防控提供依据。

福建省芋疫霉交配型测定及防治药剂筛选

【目的】明确福建省芋疫霉交配型,筛选可用于防治芋疫病的化学药剂。【方法】对2020年采集自福建4个地区的芋疫病样本进行病原菌分离纯化,结合形态特征观察、致病性测定和Ypt1序列同源性分析对病原菌进行鉴定,通过与辣椒疫霉A1、A2交配型菌株对峙培养来测定其交配型,并利用菌丝生长法测定6种杀菌剂对病原菌的室内毒力。【结果】通过形态特征观察、致病性测定和ITS-LSU-Ypt1融合序列同源性分析,明确所分离病原菌均为芋疫霉(Phytophthora colocasiae)。交配型测定发现,所分离的125个芋疫霉菌株中,122个为A2交配型,3个为A1A2交配型。室内药剂筛选结果表明,98%甲霜灵对芋疫霉抑菌效果最好,EC_(50)值为(0.146±0.032)μg·m L^(-1);95%烯酰吗啉、98%氟吡菌胺和94%氰霜唑抑菌效果较好,EC_(50)值介于(0.239±0.011)~(0.713±0.088)μg·m L^(-1);而95%嘧菌酯的抑菌活性最低,EC_(50)值为(23.447±3.666)μg·m L^(-1)。【结论】福建省芋疫霉以A2交配型为优势群体,甲霜灵、烯酰吗啉、氟吡菌胺和氰霜唑可作为芋疫病高效防控的轮换使用药剂。

温度和药剂对台农1号芒果花粉萌发及花粉管生长的影响

利用液体培养基对芒果花粉进行离体培养的方法,探究温度和芒果花期防控白粉病、霜霉病、炭疽病、蓟马常用的药剂对台农1号芒果花粉萌发及花粉管生长的影响,筛选低毒性的药剂。结果表明,温度低于15.0℃时台农1号花粉不萌发,15.0~20.0℃花粉萌发率缓慢增加,花粉萌发率及花粉管长度在27.5℃时达到峰值,温度高于27.5℃之后花粉萌发率开始下降,但在40.0℃时仍有35.74%的萌发率。31种芒果花期常用杀菌、杀虫剂单独添加到培养基中发现,与不添加药剂的空白对照相比,英腾花粉萌发率及花粉管长度均无显著影响;势克、安泰生、美甜花粉萌发率均无显著影响,但花粉管长度均显著降低;有9种药剂花粉萌发率及花粉管长度均显著降低;18种药剂花粉完全不萌发。药剂复配添加到培养基中发现,安拓+爱苗+英腾、安泰生+爱苗+英腾2个药剂组合花粉萌发率均无显著降低,但花粉管长度均显著降低;11个药剂组合花粉萌发率及花粉管长度均显著降低;3个药剂组合花粉完全不萌发。

抗抑霉唑葡萄白腐病菌的适合度及与三唑类杀菌剂的交互抗性研究

以对抑霉唑不同敏感性的葡萄白腐病菌菌株为试材,研究抗抑霉唑菌株的适合度及抑霉唑与常用三唑类杀菌剂的交互抗性。结果显示,在菌丝生长速率、产孢量、致病力方面,部分抗性菌株显著高于敏感菌株,但致病力与菌株的EC_(50)值无显著相关性。37个葡萄白腐病菌菌株对抑霉唑、丙环唑、苯醚甲环唑、氟硅唑的平均EC_(50)值分别为16.5339、1.1159、2.2293、1.6481μg·mL^(-1),抑霉唑与丙环唑、苯醚甲环唑、氟硅唑的EC_(50)对数值之间的相关系数分别为0.6572、0.5261、0.5106,表明抑霉唑与丙环唑存在正交互抗性,与苯醚甲环唑、氟硅唑无显著交互抗性。本研究表明,对抑霉唑产生抗性的葡萄白腐病菌菌株具有较强的适合度,存在形成优势群体的潜在性,因此,用抑霉唑防治葡萄白腐病时,应尽量避免与丙环唑混合使用,以延缓其抗药性的发展。

3种杀菌剂对茶饼病的田间防治效果

茶饼病是一种茶树上重要的芽叶病害。为了筛选出防治茶饼病的安全有效药剂,选用3种杀菌剂对茶饼病进行了田间药效试验。结果表明:第2次施药后7 d, 10%苯醚甲环唑水分散粒剂40、60 g/667 m^(2)和25%吡唑醚菌酯悬浮剂30、40 mL/667 m^(2)的防效分别为93.48%、93.62%、85.17%、90.18%,而1.5%多抗霉素水剂对茶饼病的总体防效相对较差,所有供试药剂处理均对茶树生长安全。研究表明,10%苯醚甲环唑水分散颗粒剂40~60 g/667 m^(2)和25%吡唑醚菌酯悬浮剂30~40 mL/667 m^(2)对茶饼病具有良好防治效果,建议生产上推广轮换使用。

4种杀菌剂对甘薯茎腐病的防治效果研究

为筛选出防治甘薯茎腐病的有效药剂,研究了4种杀菌剂对甘薯茎腐病的防治效果,结果表明,薯苗生长前期用90%(质量分数,下同)氯溴异氰尿酸稀释液滴灌根部,防治效果可达94.64%;用70%甲基硫菌灵稀释液在栽插前浸苗20 min配合栽后每10 d滴灌1次,防治效果为68.53%;用可杀得3000(46%氢氧化铜)稀释液或6%春雷霉素水剂稀释液浸苗配合叶面喷施,防治效果均低于40%.因此,90%氯溴异氰尿酸稀释液可作为甘薯茎腐病防控的有效药剂.

苍耳茎腐病病原菌鉴定及其杀真菌剂室内筛选

【目的】探究引起苍耳茎腐病的一种病原菌,并通过室内抑菌试验挖掘在多菌灵、抑霉唑、腐霉利、噻菌灵、甲基托布津、咯菌腈和咪鲜胺7种杀真菌剂中对病原菌抑制效果最佳的农药品种。【方法】采用菌丝尖端切割法从发病苍耳茎基部分离病原菌,通过科赫氏法则验证苍耳茎腐病病原菌。对病原菌的菌落、菌丝和菌核进行形态特征观察,通过分子生物学PCR技术扩增其ITS和TEF1⁃α序列并克隆测序,进一步分析鉴定病原菌种类,并对苍耳茎腐病病原菌进行室内杀真菌剂的筛选。【结果】分离到的6株病原菌与罗耳阿太菌(Athelia rolfsii)形态特征一致。将其菌丝和菌核分别接种于健康的苍耳茎基部,约1周后实验组出现与田间发病苍耳植株相同的茎腐病病症。NCXS⁃1克隆测序序列与数据库中的多个A.rolfsii菌株的相应序列一致性为100%;所筛选的7种农药杀菌剂中,NCXS⁃1对多菌灵、抑霉唑、腐霉利、噻菌灵和甲基托布津不敏感,而咯菌腈和咪鲜胺对A.rolfsii的菌落生长具有一定的抑制作用,其中以咯菌腈的抑制作用最强,EC_(50)为0.12 mg/L。【结论】明确引起苍耳茎腐病的病原菌为A.rolfsii。7种农药中咯菌腈是抑制苍耳茎腐病病菌生长效果最佳的杀真菌剂。研究结果可为苍耳茎腐病的有效防控提供科学依据。

新疆亚麻枯萎病菌分离鉴定及室内药剂筛选

试验从新疆维吾尔自治区伊犁哈萨克自治州采集的亚麻枯萎病病株上分离获得了亚麻枯萎病病菌,经菌落形态鉴定、孢子检测、ITS检测、科赫氏法则鉴定,该病原为尖孢镰刀菌。测定了亚麻枯萎病菌对亚麻种子发芽率和幼苗生长的影响,结果表明,亚麻枯萎病菌抑制亚麻种子的萌发和亚麻幼苗生长。选取12种杀菌剂对亚麻枯萎病菌进行室内毒力测定,结果表明,EC50值最低的是98%多菌灵原药,为1.2002 mg/L,其次为97%咪鲜胺原药(6.0109 mg/L),最高的为97.1%嘧菌酯原药(1080.7229 mg/L),而生物农药2亿CFU/mL沼泽红假单胞菌PSB-S悬浮剂的EC50值为7.3919×10^(5) CFU/mL。由此可见,多菌灵、咪鲜胺和2×10^(8) CFU/mL沼泽红假单胞菌PSB-S悬浮剂这3种杀菌剂可以作为田间防治亚麻枯萎病的备选药剂。