Biological Control of Soilborne Pathogens （Fusarium oxysporum F, Sp. Cucumerinum） of Cucumber （Cucumis sativus） by Trichoderma sp,

In this study, the efficacy of the native isolates of Trichoderma species to promote the growth and yield parameters of cucumber and to manage Fusarium wilt disease under greenhouse conditions were investigated. Ninety native Trichoderma antagonists were isolated from Grassland and forest soil in different geographical regions of Inner Mongolia, China. Applications of T. cf. harzianum T1, T2, T3, T4, T5, T6, T7, TS, T10, T11 and T. atroviride （T9） exhibited the least disease incidence （by 0%） also the same strains shows 100% of relative control effect. Cucumber seedling treated with T. cf. harzianum （T2 and T1） isolates showed a significant stimulatory effect on plant height （by 13 and 14 cm respectively） and the highest shoot and root fresh weight were recorded by T. asperelloides （T27） and T. gamsii （T17） by 1.62 gm and 0.97 gm respectively, in comparison to untreated control and treated control （10 cm and 4 cm, 1.27 gm and 0.22 gm and 0.82 gm and 0.10 gm）. Therefore, the antagonist （T1, T2, T3, T4, T5, T6, T7, T8, T8, T10, and T1 1） is chosen to be the most promising bio-control agent for Fusarium oxysporum f. sp. Cucumerinum and further study have to be exploited for sustainable disease management program.

The composition of Fusarium species in wheat husks and grains in south-eastern Poland

Fusarium populations were investigated on 53 samples of wheat grains and husks collected approximately three weeks before harvest in 53 wheat fields in south-eastern Poland. A limited area of sample collection was chosen intentionally to avoid the effect of climate and weather variability. The study was conducted to assess the occurrence of 13 Fusarium species using species-specific PCR assays separately on grains and husks of winter wheat. The obtained data suggest that husks could take a protective role of wheat grain against Fusarium spp. The incidence of Fusarium species decreased in grains vs. husks from 29 to 100%. While Fusarium species were present in husks at 11.32% and less, they were absent in the grain. The presence of Fusarium species on husks is inversely proportional to the percentage reduction of Fusarium spp. in grain. There was a correlation of the presence of certain species of Fusarium in husks and in grains. The number of Fusarium species found on husks was about three times higher in comparison to wheat grain. In conclusion, the presented data indicate the importance of Fusarium populations analysis on wheat husk in seeds pathological studies.

Assessing the Pathogenic Ability of Six Species of Fusarium Genus on Onion Variety in Burkina Faso

Prema 178 onion variety is widely used in production in Burkina Faso. It is greatly appreciated but susceptible to basal rot. This study aimed to evaluate the pathogenic ability of six strains of Fusarium genus identified in Burkina Faso on onion. Seeds, seedlings and bulbs were used for the test. A conidial suspension of each strain was made in tubes and adjusted to 1 × 106 conidia/ml with distilled water for the different tests. Germination test in the laboratory and greenhouse showed that all treatments with the strains of Fusarium oxysporum f. sp. cepae, F. solani, F. falciforme, F. acutatum, F. proliferatum and F. sp. induced failure to emerge and showed a significant difference with the control. The different strains also induced stunting rates of coleoptile growth. Fusarium oxysporum f. sp. cepae, F. acutatum, F. proliferatum, F. falciforme and F. solani were very aggressive, as they recorded above 50% damping-off rates. The test on the bulbs revealed that the strains were classified into two groups. The first consists of F. oxysporum f. sp. cepae, F. solani, F. falciforme, F. acutatum, which caused rots with respective lengths from 2.06;1.48;1.84;1.46 and 2.12 cm, thus very aggressive according to Ghanbarzadeh scale. The second is formed by F. proliferatum which recorded 0.90 cm of rot length, thus moderately aggressive. It would be appropriate to suggest a sustainable management method for these pathogens in order to improve the yield of onion production.

Screening and Identification of an Antagonistic Bacillus Strain against Snap Bean Fusarium Wilt

With Fusarium oxysporum f.sp. phaseoli as the target bacterium,the bacterial strain with strong antagonistic activity was screened from crop rhizosphere soil using plate confrontation method and pot efficiency test. This strain was identified according to morphological observation, physiological and biochemical characteristics and sequence analysis of 16S rRNA gene and gyrB gene. The results showed that LZF-5-3 strain was identified as Bacillus methylotrophicus and the control effect of LZF-5-3 against F.oxysporum in snap bean was 71.42% in pot test.

木霉(Trichoderma spp.)对三种引起大棚蔬菜病害病原菌的影响

通过木霉属(Trichoderma) 3菌株与双鸭山蔬菜大棚中的黄瓜枯萎病菌(FusariumoxysporumSchlecht.f.cucumerinum)、黄瓜果腐病菌(PhytophthoracapsiciLeonian)、菜豆叶枯病菌(Cladosporiumsp .)的对峙培养试验,结果表明:绿色木霉1(TrichodermaviridePers.exGray 1)可作为双鸭山蔬菜大棚中的黄瓜枯萎病、黄瓜果腐病、菜豆叶枯病3种病害的生物防治拮抗菌加以利用,该拮抗菌对菜豆叶枯病菌抑制效果最好;绿色木霉2 (Tricho dermaviride 2 )对黄瓜果腐病菌抑制效果最好;而哈茨木霉(TrichodermaharzianumRifai)对以上3种病原菌都有抑制效果,对菜豆叶枯病菌抑制效果最好。从试验结果还可看出,绿色木霉2对黄瓜枯萎病菌和菜豆叶枯病菌的生长有促进作用。

Screening Winter Wheat Germplasm for Fusarium Head Blight Resistance

58 winter wheat breeding lines and 4 widely popularized varieties in Huaihe River wheat production regions of Anhui were used to screen resistant germplasms to Fusarium head blight. Incidence, disease index, percentage of infected kernels and DON content in the kernels were measured for each variety or line following artificial inoculation of Fusarium spp. pathogens. Reactions of wheat to Fusarium infection varied among genotypes and different types of resistance. The incidence of infection for each variety or line highly correlated to the severity of colonization after infection. DON content was more correlated to the percentage of kernels infected than to the overall incidence or severity. The selected control varieties were all susceptible to FHB, while seven breeding lines demonstrated good resistant performance. New FHB resistant winter wheat varieties appealing to the actual needs are expected from them.

Can Changes in Soil Properties in Organic Banana Production Suppress Fusarium Wilt?

Organic agriculture promotes disease suppression through healthy soils by increasing biological activity and diversity through the application of organic fertilizers and increasing organic inputs. Fusarium wilt of bananas (Fusarium oxysporum f. sp. Fcubense) (Foc), also known as Panama disease, has been a devastating disease throughout the world. So far, no fungicides or cultural measures have been found that control Foc sufficiently. The aim of this research was to assess whether organic-based farming systems were more resilient than inorganic farming systems to soil borne diseases, in particular Fusarium wilts. A survey was conducted comparing five organic and five conventional banana plantations at paired sites in north Queensland, Australia. Soil samples were collected and analysed for chemical, physical and biological soil health indicators. Disease development of F. oxysporum f. sp. lycopersici in tomatoes and Foc in bananas were studied in pot trials to pursue clues for identifying Fusarium suppressive soil traits. Organic soils from the survey showed higher microbial activity and lower disease symptom expression (both with tomatoes and bananas) than conventional soils. In the survey, nematode diversity and soil sulphate content were recurring indicators in all experiments showing close correlations to pathogen growth, disease expression and plant health. Organic soils were lower in plant-parasitic nematodes and sulphate sulphur levels and higher in nematode diversity, labile soil C and microbial indicators. Soil conduciveness or suppression of Foc appeared to be largely governed by competition for carbon. Measurement of soil microbial enzyme activity, nematode community structure and diversity and possibly sulphate sulphur seem to provide a relatively reliable indicator for general disease suppression. Differences between organic and conventional agriculture cannot be related to single management practices, but may be linked to synergies among system components.

Molecular identification of mango malformation pathogens in Egypt

Diagnostic tests by molecular biology is made for studying the relations among Fusarium species for linking production of proteins, degree of relationship and occurrence of malformation. Determination of proteins for isolates causing-disease by SDS-PAGE explained there’s specific band for each fungus and there are common bands among some isolates of fungi. Since, band with MW 30 KDa represented only in F. proliferatum and F. oxysporum and F. subglutinans respectively. This band considered as specific band for these isolates, which released high pathogenisity effect. RAPD–PCR markers were used to discriminate variations between Fusarium isolates and causing disease. There is specific band for each fungus which act as molecular marker for each fungus and there are some bands common among some isolates of pathogenic fungi. The dendrogram shows there is degree of relationship between F. sterilihyphosum and F. proliferatum;between F. moniliforme and F. subglutinans;between F. oxysporum and F. chlamydospore;the degree of relationship among F. subglutinans, F. proliferatum and F. sterilihyphosum and degree of relationship among F. moniliforme, F. sterilihyphosum, F. proliferatum and F.

一种新发大豆根腐病的病原鉴定及防治药剂筛选

为明确在广东新发现的一种大豆根腐病的病原菌种类,了解其生物学特性,筛选防治该病的有效杀菌剂,采用组织分离法对罹病大豆植株的根部和茎基部的病原真菌进行分离,并通过形态学和3个基因(rDNA-ITS,TEF-1α,RPB2)的联合系统发育分析对病原真菌进行鉴定,再将该病原真菌接种到原发病大豆品种桂夏2号的根部和茎基部,测定其致病性和不同培养基、温度、碳氮源、pH、光照、杀菌剂对菌丝生长的影响以及病原菌分生孢子的致死温度。结果显示,分离到2株具有不同特征的真菌,分别鉴定为新孢镰刀菌(Fusarium neocos-mosporiellum)和镰状镰刀菌(F.falciforme),后者是在我国广东大豆上的首次报道;接种试验显示,这2株真菌单独或混合接种均可引起与田间自然发生的大豆根腐病相似的症状;新孢镰刀菌(F.neocosmosporiellum)在28℃、pH 7条件下生长最快,可以有效利用多种碳氮源,乳糖和蛋白胨为最佳碳氮源,分生孢子致死温度为51℃(水浴10 min);镰状镰刀菌(F.falciforme)在25℃、pH 7条件下生长最快,碳氮源利用能力强,以乳糖、蔗糖和麦芽糖为最佳碳源,最佳氮源为蛋白胨,孢子致死温度为54℃(水浴10 min);不同光照处理对2个菌株的菌丝生长无影响;杀菌剂咪鲜胺对2个菌株的抑制作用最强。综上,引起广东新发大豆根腐病的病原真菌为新孢镰刀菌(F.neocosmosporiellum)和镰状镰刀菌(F.falciforme),而这2种真菌适应环境的能力强,对咪鲜胺敏感,该药剂可作为防治新发大豆根腐病的首选药剂。

鄂西北烟草根腐病病原菌的分离及鉴定

镰刀菌属引起的根腐病是烟草的重要病害,根腐病危害严重可导致烟草产品质量和产量出现重大损失。为明确鄂西北烟草根腐病病原,从湖北十堰烟区采集典型症状标本分离病原菌,对其进行了形态学和分子生物学鉴定,结合基因系统发育学分析和致病性验证,确定鄂西北烟草根腐病的病原为尖孢镰刀菌、腐皮镰刀菌、木贼镰刀菌和接骨木镰刀菌。

玉米茎基腐病原菌的分离及其生物学特性研究

为探明玉米茎基腐病原菌的形态特征及生物学特性,对病原菌进行分离,并在不同温度、光照、PH值、碳源、氮源下对其进行纯培养。结果表明:该病由镰孢菌引起;菌落形态为圆形,低度突起,乳白色,少透明;菌丝为有隔菌丝,分生孢子为卵圆形或圆柱形,有一至二个隔膜;25℃是该菌的最佳生长温度;最适宜生长的碳源和氮源分别是淀粉和蛋白胨;最适宜生长的PH值是8;且该病原菌对光照具有敏感性。该研究结果可为玉米茎基腐病的诊断及防控提供理论依据。

木霉拮抗黄瓜枯萎病菌菌株的筛选

通过对峙培养、拮抗作用、耐性的测定,筛选出对黄瓜枯萎菌(Fusarium oxysporumf. sp. cucum erinum)拮抗作用强的木霉菌株(Trichoderma spp.)有13株,其中T55的拮抗作用最强。该菌株对峙培养对黄瓜枯萎菌抑菌率为80.16%,拮抗作用测定其圆盘滤膜法抑菌率大于50%,其它方法的抑菌率低于30%。该菌在5、10、35℃,pH4、9、10的条件下生长良好。

黄绿木霉诱变菌株对大豆根腐病镰刀菌的拮抗

以黄绿木霉(Trichoderma aureoviride)为出发菌株,孢子经紫外线照射,亚硝酸及氯化锂复合处理后获得一株酶活增强的突变株。通过对峙培养与发酵液处理病原菌研究了该诱变株对大豆根腐病几种镰刀菌(Fusagium spp.)的拮抗作用。诱变株经传代30代后,其产酶活性仍保持增强,生防能力有所提高。拮抗试验结果明确了黄绿木霉诱变株对镰刀菌的拮抗机理以生存竞争和接触后对病原菌菌丝破坏的溶菌作用为主,且诱变株产孢速度快,分生孢子梗空间竞争优势强于原始菌株。酶活测定结果表明,诱变株的滤纸酶活提高85.7%,CMC—Na酶活提高26.7%,β- 葡萄糖苷酶活提高130.3%。

禾谷镰刀菌拮抗菌株的筛选及鉴定

禾谷镰刀菌引起的小麦赤霉病能够导致小麦产量的大幅降低和品质的严重损失。为探索赤霉病生物防治方法,本试验从扬花期被禾谷镰刀菌侵染的麦穗上分离得到28株芽孢杆菌,利用平板对峙法对其进行筛选,其中20株菌对禾谷镰刀菌表现出明显的拮抗作用。根据生理生化特性和16S rDNA序列分析,这20株拮抗菌分别被鉴定为甲基营养型芽孢杆菌(11株)、解淀粉芽孢杆菌(2株)、枯草芽孢杆菌(2株)、暹罗芽孢杆菌(3株)和特基拉芽孢杆菌(2株)。这些菌株能够有效降低小麦赤霉病的发病率、发病程度和病情指数,其中菌株JS62N、JS15E和JS29I能够将赤霉病发病率降低80%以上;菌株JS29I、JS62N、JS39C和JS39D能够将赤霉病发病程度降低80%以上。16株菌能将病情指数降低80%以上;所有菌株均能极显著增加小麦的百粒重,JS12Q效果最好(+101.4%)。本研究结果为小麦赤霉病的防治提供了生物防治材料。

河南烟草镰刀菌的分子鉴定及致病性分析

为明确河南省不同烟叶产区危害烟草的镰刀菌种类,以河南省烟叶产区典型镰刀菌根腐病烟株及烟田土壤为供试样品,采用组织分离法和土壤分离法获得纯化菌株,根据菌株形态和r DNA-ITS序列分析对病原菌进行鉴定,并采用无创接种法测定病原菌对烟草的致病性。结果表明,获得的98个菌株在PDA培养基上均产生白色菌丝,大型分生孢子呈镰刀形或马特形,无色、多孢;小型分生孢子呈肾形、椭圆形或卵形,无色、多无分隔。序列比对结果显示,所分离的98株菌分属尖孢镰刀菌(Fusarium oxysporum)、茄病镰刀菌(Fusarium solani)、层出镰刀菌(Fusarium proliferatum)、木贼镰刀菌(Fusarium equiseti)和Fusarium nematophilum。致病性分析结果表明,尖孢镰刀菌、茄病镰刀菌、层出镰刀菌和木贼镰刀菌对烟苗具有致病性;48株致病菌中豫南烟区烟草镰刀菌根腐病致病性病原菌为尖孢镰刀菌、层出镰刀菌和木贼镰刀菌,以尖孢镰刀菌为主;豫中为尖孢镰刀菌;豫东、豫西为茄病镰刀菌和尖孢镰刀菌。因此,尖孢镰刀菌为全省烟区重点防控对象,豫南烟区还需加强层出镰刀菌和木贼镰刀菌的防控,豫东、豫西需防范茄病镰刀菌的发生。

玉米茎腐病病原菌检测方法研究

为提高玉米茎腐病病原菌检测结果的准确性和可信度,以组织分离法做对比,采用分子检测法,对采自田间的189个玉米茎腐病病株进行真菌种类的鉴定和数量的统计。结果表明,分子检测法对腐霉Pythiumspp.的检出频率为29.24%,对镰孢菌Fusariumspp.的检出频率为73.68%,组织分离法对腐霉的检出频率仅为0.58%,对镰孢菌的检出频率为60.82%,两方法的符合率最高仅为35.92%,最低为0。因此,采用组织分离和分子检测相结合的方法可提高玉米茎腐病病原菌鉴定结果的准确性。

两种熏蒸剂对土传病害的防控效果及黄瓜产量的影响

在北京顺义黄瓜大棚中采用注射法施用二甲基二硫、混土法施用棉隆,对土壤进行熏蒸处理,施药后土壤表面覆盖完全不透膜,比较二甲基二硫与棉隆对黄瓜主要土传病害的防治情况及对黄瓜生长和产量的影响。结果表明,两种熏蒸剂对黄瓜根结线虫(Meloidogynespp.)、疫霉菌(Phytophthora spp.)和镰刀菌(Fusariumspp.)均有较好的防效,二甲基二硫40g·m^()-2)处理时对3种病原物的防效分别为84.29%、75.99%、79.94%,棉隆30.0g·m^()-2)处理的防效分别为80.30%、92.36%、92.27%,而且二甲基二硫、棉隆处理与空白对照相比,黄瓜净收入分别增加66%~85%和65%~71%。

玉米茎腐病研究现状与防治对策

论述了玉米茎腐病的优势病原菌、发病规律及其防治对策,阐明了玉米茎腐病的侵染机制是腐霉菌在高温条件下主要的初侵染原,而镰刀菌因其超强的定殖能力而进行二次侵染,两种病原菌侵染致病的主要活性物质为糖蛋白毒素。筛选功能菌株研制生防制剂和采取农业综合栽培措施将成为取代化学药剂防治该病的主要措施。

烟草品种对镰刀菌根腐病的抗性鉴定

采用盆栽烟株带菌麦粒接种法测定12个烟草品种(系)对烟草镰刀菌根腐病的苗期抗病性,结果表明,中烟98、贵烟6号、云烟87、7478、NC89和豫烟13号对镰刀菌具有较高抗性,KRK26、中烟100和中烟205中等抗病,小黄金1025、豫烟10号和长脖黄对镰刀菌易感,在所有测试样品中,长脖黄抗性最低。长脖黄、小黄金1025和豫烟10号可作为对镰刀菌根腐病检测预警材料及镰刀菌根腐病的感病对照样品应用于相关研究中。

北京地区西洋参根腐病病原鉴定及其致病性

根腐病是北京地区栽培西洋参的主要病害之一,为了明确引起该类病害的病原菌,对北京怀柔区罹病西洋参参根进行了病原菌的分离及鉴定。结合形态学以及rDNA ITS区、转录延伸因子TEF-1α区的分子序列特征,对分离菌株的鉴定结果显示,分离频率较高的11个菌株分属于茄镰孢(Fusarium solani)、尖镰孢(F.oxysporum)、三线镰孢(F.tricinctum)、多育镰孢(F.proliferatum)、毁灭柱孢(Cylindrocarpon destructans)。通过柯赫氏法则验证,F.solani和F.oxysporum是引起北京地区栽培西洋参根腐病的主要病原菌;致病性测定结果发现F.solani不同菌株的致病性及致病力表现出明显差异。