Secondary Metabolites of Entomopathogenic Fungi, Biological Alternative for the Control of Agricultural Pests and Disease: Present and Perspectives

The use of entomopathogenic fungi (EF) in recent years has been highly effective against the different orders of insects considered pests of agricultural importance and their conidia have been commonly applied, but it has been reported that these are sensitive to the environmental conditions. For this reason, biopesticides products have been formulated based on secondary metabolites, recently. These biomolecules participate as biological control agent, such as: cyclic depsipeptides, amino acids, polyketides, polyphenols and terpenoids, affecting their morphology, life cycle and insect behavior. The use of secondary metabolites of entomopathogenic fungi opens the possibility of application in a more efficient way for the control of agricultural pests in a compatible with the environment and human health;therefore, it is important to know, analyzing the type of molecules, their effects, and their different methods of application.

Parasitoid wasps as effective biological control agents

Biological control(biocontrol) is a safe, sustainable approach that takes advantage of natural enemies such as predators, parasitic insects or pathogens to manage pests in agroecosystems. Parasitoid wasps, a very large evolutionary group of hymenopteran insects, are well-known biological control agents for arthropod pests in agricultural and forest ecosystems. Here, we summarize the recent progress on the application of parasitoid wasps in biocontrol in China for the last five years. These include species diversity of parasitoid wasps, identification of dominant parasitoid wasps associated with insect pests and biocontrol practices(three types of biological control, i.e., classical, augmentative and conservation biological control) in several Chinese agroecosystems. We then treat different mass-rearing and release technologies and the commercialization of several parasitoid wasp species. We also summarize other work that may have a potential use in biocontrol, including the effect of plant volatiles on parasitoids and recent advance in the molecular mechanisms underlying the host regulation by parasitoid wasps. Future research area and applied perspectives are also discussed, noting that advances in biocontrol technologies in Chinese agriculture informs research at the global level.

Control of Lymantria dispar L. by biological agents

The experiment on control of Lymantria dispar L by using different kinds ofbiological measures, including nuclear polyhedrosis virus (NPV) of Lymantria dispar L., BtMP-342,sex-attractant as well as botanical insecticide, was carried out in the forest regions of InnerMongolia in 2003. Two concentrations (2.632x10^6 PIB ? ml^(-1) and 2.632x10^7 PIB ?ml^(-1)) of Lymantria dispar L. NPV were sprayed on the 2rd-instar-larvae of L. dispar and 70% and77.8% control effect were obtained respectively. BtMP0-342 was applied to the 3rd- and 4th-instarlarvae and the control effect was around 80%. The sex-attractant provided by Canada Pacific ForestryResearch Center also showed a good result in trapping L. dispar adults. The self-produced botanicalinsecticide, which was extracted from a kind of poisonous plant distributed in Daxing'an Mountains,China, exhibited a good control result in controlling the larvae of L. dispar, and 82% mortalitywas observed when spraying primary liquid of the botanical insecticide on the 3rd-5th-instar-larvaein lab.

Fire Blight Disease Caused by Erwinia amylovora on Rosaceae Plants in Kyrgyzstan and Biological Agents to Control This Disease

Erwinia amylovora species were isolated from the blossoms, exudates, infected fruits, leaves and bent branches of diseased apple, pear and hawthorn trees, selected in the Chy, Osh and Jalal Abad regions. Biochemical and pathogenicity tests, alongside PCR analyses, were conducted to identify the local isolates of Erwinia amylovora. The alternative antagonistic microorganisms which combat bacterium E. amylovora were tested within in vitro and in vivo conditions. The results revealed the ability of Streptomyces antagonistic bacteria to decrease fire blight severity on pear and apple trees during the first stage of the fire blight disease in leaf tissues. Streptomyces strain C1-4 suppressed E. amylovora disease symptoms in the leaf tissues and excised apple and pear shoots. The incidence of fire blight on leaves was reduced by about 70% with two applications of bacterial antagonists. Further studies at different locations in Kyrgyzstan, using large scale application, would allow for stronger recommendations to be made, including studies and recommendations on their ability to prevent disease and to use them as main components in an integrated pest management program.

Control Effects of a New Sex Pheromone Trap and Biological Agents on Sesamia inferens Walker and Argyroploce schistaceana (Snellen)

This study was conducted to explore and seek high-efficiency and safe green control techniques on sugarcane borers,promote green control of diseases and pests of sugarcane and build a resource-conserving,environmentally friendly and sustainable governance system of diseases and pests of sugarcane.A new sex pheromone trap of sugarcane borers,abamectin· Bacillus thuringiensis (Bt) and tebufenozide were selected and applied in field trials.The use of the new sex pheromone trap of sugarcane borers (6 traps/hm 2) in combination with 0.05% abamectin·10 billion active gemmae/g B.thuringiensis (Bt) WP (1.8 kg/hm 2) or new sex pheromone trap of sugarcane borers (6 traps/hm 2) in combination with 200 g/L tebufenozide SC (1.5 L/hm 2) were the best in the sugarcane production.New sex pheromone trap of sugarcane borers should be installed in early march,and biological agents were mixed with water 900 kg per hectare and sprayed evenly sugarcane plants at the beginning of April.Their control effects of dead heart rate and bored stalk rate could be more than 69.98% and 49.09%,respectively,which were superior to that of the control pesticide 3.6% bisultap GR (90 kg/hm 2).The results showed that new sex pheromone trap of sugarcane borers in combination with abamectin· B.thuringiensis (Bt) or tebufenozide was the optimum mode of green control techniques on sugarcane borers.When it was alternately or coordinately used with other technology,it could delay the emergence and development of drug resistance,and it was worthy of widespread popularization and application in sugarcane area.

The Use and Exchange of Biological Control Agents for Food and Agriculture

The report sets out to summarize the past and current situation regarding the practice of biologicalcontrol inrelationtothe use and exchange of genetic resources relevant for BCAs.It considers the twomain categories of biological control:classical and augmentative.Allowing access to BCAs for use inanother country imposes no risk of liability to the source country.Local scientific knowledge abouthabitats,fauna andflora,can be

Dosage Screening and Effect Evaluation of Biological Agents against Cotton Verticillium Wilt through Drip Irrigation

Drip irrigation of biological agents is an important green pathway to prevent diseases in Xinjiang cotton fields, especially soil-borne diseases. In order to clear the suitable dosage of different biological agents for controlling cotton Verticillium wilt, field split plot experiment was designed to research the control effects of Bacillus subtilis WP (15, 30 and 45 kg/hm^2), Shibeijian Trichoderma harzianum (15, 18 and 24 kg/hm^2), Yufeng“99”(15, 22.5 and 30 kg/hm^2), Zhongnonglukang (30, 45 and 60 kg/hm^2) and Athomin (45, 60 and 75 kg/hm^2) on cotton Vertillium wilt in 2016 and 2017. The disease control effect against cotton Verticillium wilt, cotton growth, cotton yield and fiber quality were compared and analyzed by biometrical method. The results showed that five biological agents significantly reduced the incidence rate and disease index of cotton Verticillium wilt, and the average control effect reached 33.50%-74.94%. The control effect of Shibeijian T. harzianum dripped at the dosage of 18 kg/hm^2 was significantly higher than that dripped at 15 and 24 kg/hm^2. There was no significant difference between different application dosages in Athomin treatment. The control effect of the remaining three agents had significantly positive correlation with application dosage. Five biological agents had obvious promotion effects on cotton growth, and the cotton height, width of the top fourth leaf, fruit branch number and boll number per plant were increased in different levels. The cotton height and width of the top fourth leaf had no obvious changes with the increase of dosage, while the fruit branch number and boll number increased with the increasing dosage. Meanwhile, these biological agents significantly advanced the maturity of cotton. Except for Athomin treatment, the cotton seed yield in other treatments showed an increasing trend and increased significantly with the increasing dosage. The cotton fiber length and fiber breaking tenacity were improved slightly, but cotton quality had not been improved conspicuously. Therefore, according to disease control effect, cotton growth and yield performance, the suitable drip dosage of biological agents were as follows: Yufeng "99" 30 kg/hm^2, Zhongnonglukang 60 kg/hm^2, B. subtilis WP 45.0 kg/hm^2, and Shibejian T. harzianum 18.0 kg/hm^2. The drip dosage of Athomin still needs to be further studied.

Physical-biological Collaborative Prevention and Control of Facility Strawberry Continuous Cropping Diseases

The aim was to develop green strawberry varieties,control soil-borne diseases from facility strawberry continuous cropping,improve the safety and quality of strawberries and promote the healthy and stable development of the strawberry industry. Based on the production practices in recent years,we summarized the physical-biological collaborative prevention and control technology for the disease of facility strawberry continuous cropping facilities,established the technical goals,the main types of soil-borne diseases,and the physical-biological collaborative control prevention and control technologies,mainly including the specific methods and technical points of solar high temperature disinfection technology and biological bacterial fertilizer（ agent） treatment technology.

微生物种衣剂的研制及其对玉米茎腐病的防效评价

本研究通过平板对峙、种子发芽性状和室内盆栽试验,筛选对玉米茎腐病防效优良的木霉菌株,通过助剂理化性质测定、生物相容性分析及正交试验,明确助剂种类、用量和最佳组合,研制生物种衣剂,并进行玉米茎腐病防效验证。结果表明:从实验室保存的109株木霉中,筛选到17株木霉对禾谷镰孢具有较好拮抗活性,抑制率均>70%,6株木霉菌株对苗期茎腐病的防治效果最佳,防效80.33%~85.64%。分别以筛选的棘孢木霉Tr34和非洲哈茨木霉Tr35为活性成分,10^(6)厚垣孢子数/mL,辅以黄原胶0.2%,木质素磺酸钠2%,北农成膜剂1,5%,100 mg/mL链霉素1%,制备100万孢子/mL棘孢木霉生物种衣剂(简称Tr34生物种衣剂)和100万孢子/mL非洲哈茨木霉生物种衣剂(简称Tr35生物种衣剂)。两种生物种衣剂药种质量比例分别为1:200和1:100时,对苗期茎腐病的防效最好,分别为81.14%和83.18%。本研究研制的Tr34生物种衣剂和Tr35生物种衣剂可以有效降低玉米茎腐病的发生,为进一步田间应用奠定基础。

10种药剂处理对杨梅凋萎病的防控效果评价

为有效控制杨梅凋萎病发生,减少农残,保证果品安全,在湖南省通道县杨梅基地设置4月25日和5月10日(采果前)喷施0.5%小檗碱水剂500倍液等5种药剂各1次+7月5日(采果后)30%苯甲·咪鲜胺悬浮剂3000倍液等2种药剂1次,共10个药剂组合处理,比较不同药剂处理的病枝减退率、病情指数减退率和相对防效。结果表明,不同药剂处理的杨梅凋萎病的病枝减退率为15.29%~74.07%,相对防效为22.23%~80.00%。其中,杨梅成熟前喷施0.5%小檗碱水剂500倍液2次+采果后喷施30%苯甲·咪鲜胺悬浮剂3000倍液1次处理的防控效果最佳,其病枝减退率达到74.07%,相对防效达到80.00%;杨梅成熟前喷施0.5%小檗碱水剂500倍液2次+采果后喷施40%吡醚·戊唑醇悬浮剂3000倍液,防控效果次之,其病枝减退率为65.35%、相对防效为75.56%;其他处理的相对防效均低于55%。因此,杨梅生产上推荐在杨梅成熟前喷施0.5%小檗碱水剂500倍液,采果后喷施30%苯甲·咪鲜胺3000倍液防控杨梅凋萎病,以避免杨梅果实农残超标且达到较好防控效果。

不同药剂防控番茄潜叶蛾药效对比试验

为筛选出防控番茄潜叶蛾的高效、低毒、低残留的生物药剂,2022年选用6%乙基多杀菌素悬浮剂(艾绿士)、31%阿维·灭蝇胺悬浮剂、20%氯虫苯甲酰胺悬浮剂等3种生物药剂在阿克苏市进行药效试验。试验结果表明,3种生物药剂均对番茄潜叶蛾幼虫有一定防效及抑制作用。从防治效果来看,20%氯虫苯甲酰胺悬浮剂速效性、持效性、防效最高,药后14 d防效为90.32%;其次为6%乙基多杀菌素悬浮剂(艾绿士),在药后14 d持续性较好,防效81.49%。在实际生产中,建议轮换用药。

尖孢镰刀菌的应用研究进展

尖孢镰刀菌是一种重要的真菌资源,对其在农业、工业生产、食品安全和人类健康等方面的研究与应用具有重要意义。在农业方面,尖孢镰刀菌主要用于生物防控植物病害和杂草、农药研发及植物促生长等研究;在工业方面,尖孢镰刀菌主要用于生产有机酸、酶及其他代谢产物,还可用于工业污染处理及食品安全等研究。近年来针对尖孢镰刀菌应用的研究日益增多,本文综述了尖孢镰刀菌在多领域的应用研究进展,为促进之后实际生产中尖孢镰刀菌的应用提供思路。

不同鲜食玉米品种鞘腐病抗病性及生防菌剂防病效果研究

为明确不同鲜食玉米品种对鞘腐病抗性、鞘腐病在玉米不同生态位叶鞘的分布特征及生防菌剂对病害的防治效果,测定了15个福建省主推玉米品种对鞘腐病的田间抗性,选用6个不同抗性水平的玉米品种为研究对象,于乳熟期调查了不同玉米品种各叶鞘的病情及9种生防菌剂处理对“上品”关键叶鞘病害的控制效果。结果表明,参试玉米对鞘腐病表现中抗、中感和感病的品种分别有5个、7个和3个。在屏南自然发病试验地和福州人工辅助接种试验地,6个玉米品种“上品(感病)”、“京科糯2000(感病)”、“天贵糯932(感病)”、“农科368(中感)”、“泰鲜甜2号(中抗)”、“闽甜986(中抗)”穗上第1叶鞘至穗下第3叶鞘平均病情指数分别为35.05、44.75、45.54和39.78,而其他叶鞘平均病情指数介于6.67~28.77之间。在屏南试验地有4个玉米品种(上品和天贵糯932除外)和福州试验地有6个玉米品种病情严重度在各生态位叶鞘上均呈显著正态性分布(P>0.05)。施用生防菌剂能明显抑制感病品种“上品”鞘腐病病情,稀释20、50倍的8×10^(9) CFU/mL枯草芽胞杆菌T122F发酵液和5×10^(9) CFU/mL解淀粉芽胞杆菌NJ-1发酵液对病害的防效分别为46.37%、44.78%和44.03%、41.06%,稀释500倍的400亿芽胞/g枯草芽胞杆菌水溶性粉剂、1000亿芽胞/g解淀粉芽胞杆菌水溶性粉剂和30亿芽胞/g甲基营养型芽胞杆菌可湿性粉剂的防病效果分别达44.25%、36.81%和46.26%,比150μg/mL的25%吡唑醚菌酯乳油防效(59.50%)和12.5%氟环唑悬浮剂的防效(54.82%)略低。表明利用生防菌剂预防玉米鞘腐病具有较好的应用前景,本研究结果为鲜食玉米病害绿色防控提供科学依据。

生物菌剂对青枯病防控效果及其影响因素的优化

[目的]由茄科劳尔氏菌引起的青枯病是一种普遍的细菌性土传病害,严重威胁多种经济作物的生产。青枯病主要采用生物技术防治,但由于施用方法以及生防菌株较为多元,生防效果差异较大。因此,我们研究了生物菌剂对青枯病发病率的防控效果及主要影响因素。[方法]基于Web of Science和CNKI数据库,以关键词“青枯病”和“生物菌剂”、“Ralstonia solanacearum”或“Pseudomonas solanacearum”和“Biological bacterium agent”或“Biological bacterium control”进行检索。以具有1个不施生物菌剂对照组,且具有发病率(DI)、发病率均值和样本量为条件进行筛选,共获得113对有效数据。采用meta分析方法评估了生物菌剂的防控效果及主要影响因素。采用Metawin软件中的随机效应模型,以处理组和对照组之间的效应值(effect size, ES)评价因素的效应强弱。[结果]施用生物菌剂后,青枯病发病率从77.35%降至37.13%,防控效率为52.00%。施用模式、土壤中功能微生物与青枯菌数量比、功能微生物种类是影响青枯病防治效果的主要因素。土施、浸根、喷淋和种子处理4种施用方法对青枯病的防控效应值分别为-0.80~-0.61、-1.34~-1.15、-0.96~-0.79和-0.67~-0.49,说明4种施用方法均有显著的防控效果,以浸根法的防控效率最好,其防控效率可达66.72%。施用生物菌剂后的土壤中功能微生物与青枯菌数量比值为1∶1、10∶1、100∶1时,对青枯病均有显著防控效果,以比值为100∶1时的防控效果(63.62%)最为显著。链霉菌对青枯病的防效优于假单胞菌和芽孢杆菌,其防控效率可达74.08%。[结论]生物菌剂对青枯病的防治效果普遍较为显著,采用移栽前浸根,生物菌剂施用量达到土壤中功能微生物数量与青枯菌数量比值为100∶1,选择链霉菌属作为功能菌剂,均可获得较高且稳定的青枯病防控效果。

番石榴枯萎病菌生物学特性及生防菌和防治药剂的筛选

【目的】明确番石榴枯萎病菌的生物学特性,并进行生防菌和防治药剂筛选,为番石榴枯萎病的发生规律及高效防控提供理论依据。【方法】在不同碳源、温度、pH、NaCl浓度等培养条件下,测定番石榴枯萎病菌GS-1的生物学特性,采用平板对峙法筛选GS-1的生防菌,并利用菌丝生长速率法测定6种常用杀菌剂对病原菌的抑制效果。【结果】番石榴枯萎病菌GS-1菌丝生长的最佳碳源为果糖,产孢最佳碳源为果糖和甘露醇;菌丝最适生长温度为30℃,最适生长pH为6;温度为28~46℃时均有大量孢子萌发,52℃时孢子完全失去活性;番石榴枯萎病菌GS-1菌丝具有一定的耐盐性。生防菌解淀粉芽孢杆菌B2对病原菌GS-1生长的抑制效果最佳。番石榴枯萎病菌GS-1菌丝对咪鲜胺的敏感性最高,0.0004μg/mL咪鲜胺条件下不生长;其次为吡唑醚菌酯和甲霜灵,EC50分别为0.4912和0.8805μg/mL。【结论】番石榴枯萎病菌适生范围较广,温度较高、中性偏弱酸的环境条件利于其快速生长繁殖,咪鲜胺、吡唑醚菌酯和甲霜灵可作为防治番石榴枯萎病的药剂。

四种生物制剂防治灰斑古毒蛾试验

近年来,阿拉善左旗防沙治沙区的植物大面积发生灰斑古毒蛾虫害,严重制约其防风固沙效能的正常发挥。为寻求安全、环保、有效的防虫害药剂,文章通过室内3%甲氨基阿维菌素药剂、5%桉油精、1.0%苦参碱可溶液剂、26%阿维·灭幼脲悬浮剂四种药剂不同浓度和林间同一浓度对灰斑古毒蛾幼虫进行毒力测定试验,筛选出适合于当地、安全且防治效果较好的生物制剂为1500倍液5%桉油精,为今后大面积防控灰斑古毒蛾虫害提供一定参考。

先锋蛋白肽对茶饼病的防效及茶叶品质的影响

【目的】探明茶园喷施先锋蛋白肽对茶饼病的防控效果及茶叶品质的影响,为其在茶园病害绿色防控及茶叶提质增效上应用提供依据。【方法】采用常规喷雾法,以喷施清水(CK1)和药剂〔CK2,25%吡唑醚菌酯水剂(140.63 g a.i./hm^(2))〕为对照,研究先锋蛋白肽(600 g a.i./hm^(2))不同施用次数(茶叶采摘前喷施1次、2次和3次)对茶饼病的田间防控潜力和茶叶品质的影响。【结果】茶叶喷施先锋蛋白肽1次、2次和3次对茶饼病的相对防效分别为73.91%、69.57%和21.74%,喷施2次和3次的相对防效显著低于CK2(77.50%),与CK1相比,CK2对茶叶的增产效果仅为1.23%,而施用先锋蛋白肽1次、2次和3次的茶叶增产效果分别为4.01%、26.46%和9.32%,相应的发芽密度(1587.71个/m^(2))和百芽重(21.04 g)均以施药2次的最高。施药次数不同对茶叶中咖啡碱含量影响不显著,但对茶多酚和游离氨基酸含量影响较大。鲜味、甜味氨基酸天冬氨酸(2.68 mg/g)、甘氨酸(0.23 mg/g)和丙氨酸(0.08 mg/g)含量在施药2次的茶叶中最高,在施药3次的茶叶中则以苦味氨基酸缬氨酸(0.15 mg/g)、亮氨酸(0.37 mg/g)、酪氨酸(0.08 mg/g)和组氨酸(0.28 mg/g)含量最高;酚氨比施药2次(3.56)的最低,施药3次(4.22)的最高;施药1次的茶叶表没食子儿茶素(1.03%)、表没食子儿茶素没食子酸酯(2.65%)、表儿茶素没食子酸酯(0.71%)含量显著低于施药2次(1.22%、2.96%和0.81%),表儿茶素(0.73%)含量显著上升;苯丙氨酸(2.48 mg/g)、胱氨酸(6.57 mg/g)、蛋氨酸(6.63 mg/g)和脯氨酸(0.29 mg/g)等抗逆相关氨基酸含量以施药1次的最高。【结论】先锋蛋白肽施药2次既可高效防控茶饼病,亦可提高茶叶产质量,达到较好的防病、增产和提质效果。

Rice(Oryza sativa L.)plant protection using dual biological control and plant growth-promoting agents:Current scenarios and future prospects

Various microorganisms live in association with different parts of plants and can be harmful,neutral,or beneficial to plant health.Some microbial inhabitants of plants can control plant diseases by contesting with,predating on,or antagonizing plant pathogens and by inducing systems for plant defense.A range of methods,including plant growth-promoting microorganisms(PGPMs)as biological control agents(BCAs)(BCA-PGPMs)are used for the biological management and control of plant pathogens.Some BCAs interact with plants by inducing resistance or priming plants without direct interaction with the pathogen.Other BCAs operate via nutrient competition or other mechanisms to modulate the growth conditions for the pathogen.Generally,PGPMs can be applied alone or together with other chemicals or carriers to control various crop diseases.This review highlights the effective types of BCA-PGPMs and their applications,roles,carrier based-formulations,and responses to rice(Oryza sativa L.)pathogens.Future plant disease management prospects are promising,and growers’increasing demand for BCA-PGPM products can be exploited as an effective approach to the management of plant diseases,as well as to improve yield,environmental protection,biological resources,and agricultural system sustainability.

Biocontrol of Strawberry Anthracnose Caused by Colletotrichum fragariae

[Objective] The aim was to explore biocontrol approaches of strawberry an-thracnose. [Method] With hyphal growth inhibition method, bacteriostatic activities of Bacil us subtilis and Osthole on strawberry anthracnose were measured and field test was carried out. [Result] The results show that both of Bacil us subtilis and Osthole were of higher bacteriostatic activity on strawberry anthracnose, and the values of EC50 were 0.007 5 mg/L and 1.063 0 ml/L, respectively. The result of field test show that the prevention effects of Bacil us subtilis （600-750 g/hm2） and 25% prochloraz （600 ml/hm2） both achieved higher than 76%, 7 and 14 d after triple medical applica-tions with rains sheltered or in open field. But the effects were of extremely signifi-cant differences with that of Osthole （1 800-2 700 ml/hm2） （P〈0.01）. [Conclusion] Bacil us subtilis can be made use of for control ing strawberry anthracnose.

复合菌剂生物肥对甘薯茎线虫病的防治和增产效果研究

甘薯茎线虫病是甘薯生产中的一种常发性且较为严重的病害。为了解不同载体负载微生物菌剂的效果,以及添加复合菌剂对甘薯茎线虫及甘薯产量的影响,本试验选择不同载体和微生物菌剂,测定载体的微生物负载效果,并测定了施入不同微生物菌剂后的甘薯产量及其茎线虫病情指数等指标。结果表明,硅藻土对生防菌剂的吸附率、释放率和存活率分别为64.76%、94.61%和86.90%,能够有效实现对菌体的吸附/释放以及保证菌体存活。胶冻样类芽孢杆菌菌剂以及生防菌剂复配施用对甘薯茎线虫病的防治效果达75.4%。微生物菌剂与有机肥构建的生物有机肥施用后,线虫发病率仅为12.7%,且甘薯平均产量高达19272.23 kg/hm^(2)。生物有机肥对甘薯生长、品质、抗性、增产和增收均有一定促进作用,同时具有适用性广、绿色安全且不产生抗药性的特点,适合在甘薯茎线虫防治以及促进甘薯增产上推广应用。