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1.
由尖孢镰刀菌西瓜专化型(Fusarium oxysporum f. sp. niveum,FON)引起的西瓜枯萎病是一种毁灭性的土传病害。本研究通过离体及活体试验,测定了植物源天然抑菌活性物质桧木醇对西瓜枯萎病菌的抑制活性、对西瓜枯萎病的盆栽防效以及对病原菌生理生化指标的影响。结果表明:桧木醇对西瓜枯萎病菌具有明显的抑制效果,其对病原菌菌丝生长和孢子萌发的抑制作用EC50值分别为31.1和45.2μg/mL;在250、500和1000μg/mL 3个质量浓度下,桧木醇对西瓜枯萎病均有显著的防治效果,其中1000μg/mL时防效可达75.2%,与对照药剂多菌灵500μg/mL的效果相当。生理生化指标测定及外观形态观察发现,经桧木醇处理后,西瓜枯萎病菌菌丝相对电导率上升,菌丝体内镰刀菌酸含量显著降低,菌丝呈现扭曲、畸形、缠绕等不规则外观形态。研究表明,桧木醇不仅能显著抑制西瓜枯萎病菌的生长,同时能抑制其相关毒素的生物合成或促进其代谢,从而降低病原菌的致病力,具有开发为西瓜枯萎病防治替代药剂的潜力。桧木醇处理能破坏病原菌细胞膜的完整性、干扰病原菌次生代谢物的合成或代谢过...  相似文献   

2.
番茄枯萎病和青枯病拮抗细菌的筛选、评价与鉴定   总被引:2,自引:0,他引:2  
从宁夏银川、江苏沭阳和福建厦门的番茄、辣椒、西瓜等作物根际土壤中,分离纯化获得367株细菌菌株。以番茄枯萎病菌Fusarium oxysporum f.sp.lycopersici和番茄青枯病菌Ralstonia solanacearum为靶标菌,从367株菌株中筛选出对两种病菌皆具有很强拮抗作用的菌株22株。拮抗细菌抑菌物质的研究结果表明:22株拮抗细菌均能分泌蛋白酶;不能分泌几丁质酶;3株细菌能分泌纤维素酶;3株细菌能分泌嗜铁素。盆栽试验结果表明:拮抗细菌PTS-394对番茄枯萎病和青枯病的防效最高,分别为77.4%和80%;菌株H-70、L-1和SJ-280对番茄枯萎病和青枯病的防效均大于60%。对上述4株拮抗细菌进行16S rRNA种属鉴定,均为枯草芽孢杆菌Bacillus subtilis。  相似文献   

3.
放线菌混合菌剂对西瓜枯萎病的防治作用研究   总被引:2,自引:0,他引:2  
本研究开展生防放线菌对尖镰孢西瓜专化型的皿内防效初筛,在此基础上进行多菌复配,变单一菌剂为放线菌混合菌剂使用,以期提高生防菌剂对西瓜枯萎病的防效。采用皿内抑菌试验、单一菌株的盆栽促生及定殖试验等筛选出对尖镰孢西瓜专化型防效较好的生防菌;制成混合菌剂并探究其对西瓜枯萎病的防治效果和对西瓜幼苗的促生效果。单一菌株S C 1 1、1 5 3、S F 6及其混合菌剂对西瓜枯萎病均有防治效果,其防效分别为2 5.8 7%、2 0.6 1%、1 6.7 2%和4 7.5 0%,且对西瓜幼苗有较好的促生效果,对植株鲜重的提升幅度分别达9 9.2 6%、1 2 4.4 4%、1 4 4.4 4%和1 6 2.2 2%,无论是防病方面还是促生方面,均以组合S C 1 1+1 5 3+S F 6效果最为理想。生防放线菌混合菌剂的防病促生作用明显优于单个菌株,混合菌剂各菌株间通过协同作用达到优势互补,充分发挥生防效果。  相似文献   

4.
[目的]从当归内生真菌中筛选抗小麦赤霉病菌、番茄早疫病菌、番茄灰霉病菌、水稻纹枯病菌等植物病原菌的有益菌株,并筛选代谢产物中的抑菌活性部位.[方法]采用平板拮抗法对抗性菌株进行初步筛选,采用抑制菌丝生长法以及抑制孢子萌发法筛选有益内生真菌代谢产物中的抑菌活性部位.[结果]抗小麦赤霉病菌、番茄早疫病菌的内生真菌较多,分别占24.3%和28.6%.对小麦赤霉病菌、番茄早疫病菌、番茄灰霉病菌以及水稻纹枯病菌生长抑制作用较强的内生真菌包括5个属8个菌株,其中6个菌株只对1种病原菌菌丝生长有抑制作用.此外,对4种植物病原真菌孢子萌发具有抑制作用的内生真菌超过20%,其中内生真菌Myxormia sp.2和Myxormia sp.4的提取物对4种植物病原真菌孢子萌发的抑制作用显著,抑制率达到90%以上.通过对有益内生真菌代谢产物的分析表明,乙酸乙酯提取部位对植物病原真菌菌丝体和孢子萌发的抑制作用相对较强.[结论]具有抗菌活性的当归内生真菌及其次生代谢产物具有丰富的多样性.  相似文献   

5.
黄瑞香提取物对小麦病原真菌抑制作用的研究   总被引:1,自引:0,他引:1  
采用菌丝生长速率法,研究黄瑞香提取物对小麦赤霉病病原菌(Fusarium graminearum Schw.)、小麦根腐病原菌(Helminthosporium sorokinanum Sacc.)和小麦纹枯病原菌(Rhizoctonia cerealis Vander Hoeven)的抑制作用。结果表明:黄瑞香提取物对3种植物病原真菌具有一定的抑菌活性,且在提取物质量浓度为25 mg/mL时,75%乙醇提取物抑菌效果较好,对3种植物病原菌抑制率均达到50%以上;提取时间1 h以上、提取温度70℃以上时,所得提取物抑菌效果较佳。而且加热处理对所得黄瑞香提取物的抑菌效果无明显影响。  相似文献   

6.
小麦赤霉病是小麦穗期的主要病害之一。化学防控一直是小麦主产区防控赤霉病的主要措施。为明确几种新型杀菌剂对小麦赤霉病的防效和对小麦籽粒DON毒素含量的影响,于2018年进行了氰基丙烯酸酯类和三唑类杀菌剂单剂及其复配剂对赤霉病的防效试验。结果表明:30%戊唑·多菌灵悬浮剂(SC)1500 mL/hm^2处理对赤霉病病穗防效达92.40%,病指防效达93.20%,小麦籽粒DON毒素检出量较不用药对照降低80.38%;25%氰烯菌酯SC 2000 mL/hm^2处理对赤霉病的病穗防效达86.80%,病指防效达88.78%,小麦籽粒DON毒素检出量较不用药对照降低88.19%;48%氰烯·戊唑醇SC 900 mL/hm^2和40%丙硫·戊唑醇SC 600 mL/hm^2对小麦赤霉病的病穗防效分别为77.20%、78.00%,病指防效分别为80.27%和79.59%,对籽粒DON毒素检出量较不用药对照分别降低73.87%和81.42%。在小麦赤霉病较重发生的情况下,上述4种杀菌剂单剂或复配剂1次用药既能高效控制病情,又能有效控制小麦籽粒DON毒素不超标。本试验研究进一步阐明,氰烯菌酯、戊唑醇、丙硫菌唑等杀菌剂及其复配剂均能有效控制小麦赤霉病的危害,并能有效降低小麦籽粒DON毒素含量;吡唑醚菌酯单剂及其复配剂虽然对小麦赤霉病的病穗和病指防效也较高,但控制小麦籽粒DON毒素含量效果相对较差。研究结果为小麦穗期赤霉病化学防控提供了科学参考。  相似文献   

7.
新奥苷肽对小麦赤霉病的田间防效及增产作用评价   总被引:1,自引:0,他引:1  
新奥苷肽是一种新型生物杀菌剂,为验证其对小麦赤霉病的防治效果和使用剂量,2013年进行了田间药效试验。结果表明,在小麦扬花初期一次施药,新奥苷肽4%水剂对小麦赤霉病有较好的防治效果,450、600、750m L/hm23个处理防效分别为80.96%、86.53%和96.13%,显著优于对照药剂。新奥苷肽对小麦赤霉病防效和增产效果明显,对小麦生长安全,是防治小麦赤霉病的理想药剂。  相似文献   

8.
从河北省张家口地区种植的烟草上采集的感病弯管列当植株,从中分离得到20株镰刀菌,采用孢子悬浮液浸根和灌根法对小麦、玉米、棉花、向日葵、番茄、烟草、辣椒、茄子、西瓜、甜瓜等作物和蔬菜进行了安全性检测,筛选出对主栽作物和蔬菜安全且具有促生作用的4个菌株。其中菌株Br-2对烟草、辣椒、西瓜有显著促生作用,且对弯管列当的防治效果最好:施用菌株Br-2后烟草、辣椒、西瓜增高分别为123.53%、62.16%、28.95%;其发酵上清液对弯管列当种子萌芽抑制率为71.79%;小区试验中对弯管列当的寄生率防效为50%,寄生度防效为79.38%;田间试验中对弯管列当的寄生率防效为58.27%,寄生度防效为75.70%。形态学和分子生物学鉴定结果表明菌株Br-2为尖孢镰刀菌。  相似文献   

9.
几种药剂防治烟草青枯病田间药效试验   总被引:1,自引:0,他引:1  
7种药剂防治烟草青枯病进行了田间药效试验,结果表明,7种药荆均能推迟青枯病的发病高峰期,减轻发病程度,其中荧光假单胞菌3 000亿个/克粉剂和农用链霉素的防效最好,药效稳定,持续时间长,对烟草青枯病的防治效果分别达到74.92%、74.48%.此外,罗建新菌肥和活性菌肥对烟草青枯病也具有较好的防治效果,防效分别为66.27%和69.39%.  相似文献   

10.
为获得有效拮抗烟草赤星病菌的生防资源,采用稀释分离法和平板对峙法从烟草根际土壤中分离筛选烟草赤星病菌拮抗菌株。通过形态学观察、生理生化特征和16S rDNA序列分析进行鉴定,并测定其对烟株的促生作用,验证菌株的产IAA能力,评价生防菌发酵液对烟草赤星病的田间防效。结果表明,从分离的65株细菌菌株中筛选到5株烟草赤星病拮抗细菌,其中菌株YW-2-6对烟草赤星病菌拮抗效果最好,抑制率为71.32%,初步鉴定菌株YW-2-6为解淀粉芽胞杆菌Bacillus amyloliquefaciens。菌株YW-2-6对小麦赤霉病菌、辣椒疫霉病菌、烟草靶斑病菌等病原菌具有显著的拮抗作用。YW-2-6发酵液对烟草赤星病防效为56.93%,且菌株YW-2-6对烟株有明显的促生作用。菌株YW-2-6具有良好的生防潜力和开发前景。  相似文献   

11.
海洋多黏类芽胞杆菌可湿性粉剂的研制   总被引:2,自引:0,他引:2  
以海洋多黏类芽胞杆菌Paenibacillus polymyxa为研究对象,通过单因素室内试验和田间试验,确定了可湿性粉剂配方及其对甜瓜枯萎病的田间防效。结果表明,可湿性粉剂最佳配方为:以皂土为载体的菌粉70%,稳定剂海藻酸钠14%,湿润剂蔗糖脂肪酸酯8%,分散剂聚乙烯醇8%。制得的可湿性粉剂活菌数为1.23×10^10cfu/g,含水量6%,润湿时间48 s,悬浮率75%,杂菌率0。采用7种不同方法防治甜瓜枯萎病,结果表明,可湿性粉剂对甜瓜枯萎病的综合防治效果高达84.9%。该制剂对甜瓜枯萎病具有良好防效,可作为防治甜瓜枯萎病的药剂在生产上推广应用。  相似文献   

12.
为探讨吡唑醚菌酯对小麦不同生育期病害的防治效果,采用菌丝生长速率法,测定了吡唑醚菌酯对小麦纹枯病菌Rhizoctonia cerealis、根腐病菌Bipolaris sorokiniana、全蚀病菌Gaeumannomyces tritici及赤霉病菌Gibberella zeae的室内抑制活性;通过种子发芽盒试验,测定了吡唑醚菌酯不同药种比包衣处理对小麦种子发芽的影响;采用菌土混合法,测定了5%吡唑醚菌酯种子处理悬浮剂(FS)对小麦纹枯病的盆栽防效;同时测定了5%吡唑醚菌酯悬浮剂(SC)对小麦白粉病、锈病及赤霉病的田间防效。结果表明:吡唑醚菌酯对小麦纹枯病菌、根腐病菌、全蚀病菌和赤霉病菌的EC50值分别为0.404、5.862、0.193和1.372 mg/L。25℃条件下,5%吡唑醚菌酯FS不同药种比对济麦22鲜重及干重均有一定的促进作用;10℃下,对小麦种子发芽势、发芽率、发芽指数及活力指数均显示出一定的促进作用。5%吡唑醚菌酯FS苗后20 d对小麦纹枯病的防效在74%以上,药种比1∶50时防效达99.02%;5%吡唑醚菌酯SC按3000 mL/hm  相似文献   

13.
新型杀菌剂丁吡吗啉的生物活性及作用方式初探   总被引:1,自引:1,他引:1       下载免费PDF全文
丁吡吗啉是一种结构新颖的杀菌剂,化学名(E)-3-(2-氯吡啶-4-基)-3-(4-叔丁基苯基)-丙烯酰吗啉。室内生物测定结果表明,在离体条件下,丁吡吗啉对致病疫霉Phytophthora infestans、辣椒疫霉Phytophthora capsici、立枯丝核菌Rhizoctonia solani、古巴假霜霉Pseudoperonospora cubensis等重要植物病原菌均有很好的抑制活性,其对致病疫霉、辣椒疫霉、立枯丝核菌菌丝生长的抑制中浓度(EC50)分别为1.38±0.06、0.72±0.05和4.44±0.03 μg/mL,对古巴假霜霉菌孢子囊萌发的抑制中浓度为5.33±0.05 μg/mL;但其对尖镰孢萎蔫专化型菌Fusarium oxysporum f.sp.vasinfectum、轮纹大茎点菌Macrophthoma kawatsukai、玉蜀黍赤霉Gibeberlla zeae的菌丝生长无抑制效果。用400 μg/mL的丁吡吗啉药液喷雾处理番茄幼苗,分别在施药后1、3和8 d接种致病疫霉的游动孢子,其对番茄晚疫病的防效分别为94.2%、90.8%和78.1%,说明丁吡吗啉在防治番茄晚疫病中具有较好的保护作用和一定的持效期。  相似文献   

14.
ABSTRACT The effect of the plant on the diversity of soilborne populations of Fusarium oxysporum was assessed after successive cultures of flax, melon, tomato, and wheat in separate samples of the same soil. Forty soil-borne isolates of F. oxysporum and forty root-colonizing isolates of each plant species were sampled during the first (T0) and fourth (T1) cultures. The population structures were assessed by a genotypic method based on restriction fragment analysis of polymerase chain reaction-amplified ri-bosomal intergenic spacer (IGS) DNA. Sixteen IGS types were defined among the four hundred isolates analyzed. The distributions of soil isolates among IGS types were similar at both sampling times. The structure of F. oxysporum populations associated with the roots of flax or melon did not differ from the structure of soilborne populations. In contrast, the structure of F. oxysporum populations associated with roots of wheat or tomato differed from the structure of soilborne populations. High frequencies were found for IGS type 4 among wheat isolates at both T0 and T1 and for IGS type 11 among tomato isolates at T1. Moreover, a high level of genetic divergence was obtained between IGS types 4 and 11. Our results suggest that tomato and wheat have a selective effect on soilborne populations of F. oxysporum and that this effect seems to be plant specific.  相似文献   

15.
具防病并提高植物耐旱功能的小链霉菌HS57的筛选   总被引:1,自引:0,他引:1  
本研究旨在寻找防治黄瓜枯萎病并提高植物抗逆能力的多功能菌株。从连作田健康黄瓜根际土中分离筛选到1株放线菌HS57。平板对峙法测定菌株HS57对尖孢镰刀菌、茄病镰刀菌和立枯丝核菌的抑制作用,平皿对扣共培养法测定其挥发性物质对尖孢镰刀菌的抑制作用,温室盆栽法测定其对黄瓜枯萎病的防病效果及对小麦耐旱能力的影响,结合菌株形态特征和16S rRNA基因序列分析对其进行鉴定。结果表明,菌株HS57可抑制3种病原菌生长,其中对尖孢镰刀菌的抑制率为52.4%;其挥发性物质对尖孢镰刀菌的抑制率为32.1%。浓度为10^7个/mL的HS57孢子悬浮液浸种对黄瓜枯萎病的防效最好,为51.0%;小麦种子经浓度为10^7、10^8个/mL的HS57孢子悬浮液浸种,麦苗经连续7 d缺水处理后再浇水,比对照恢复得更好。初步鉴定HS57菌株为小链霉菌Streptomyces parvus,是一株非常有潜力的多功能菌株。  相似文献   

16.
A severe root and stem rot disease of melon was observed during the 2001 growing season on four glasshouse crops in Heraklio, Greece. A total of 43 isolates of F. oxysporum , obtained in Crete from glasshouse-grown melon and showing fusarium wilt or root and stem rot symptoms, were characterized by pathogenicity and vegetative compatibility. The majority of these isolates was also fingerprinted via amplified fragment length polymorphic (AFLP) analysis. Of the total number of isolates, 22 were identified by pathogenicity tests as F. oxysporum f. sp. melonis , 20 as F. oxysporum f. sp. radicis-cucumerinum , while one isolate was nonpathogenic on cucumber, melon, sponge gourd and pumpkin. All 22 isolates of F. oxysporum f. sp. melonis were assigned to vegetative compatibility group (VCG) 0134, and all 20 isolates of F. oxysporum f. sp. radicis-cucumerinum to VCG 0260. Isolates of F. oxysporum f. sp. radicis-cucumerinum were incompatible with isolates of F. oxysporum f. sp. melonis. AFLP fingerprinting allowed for the clustering of the isolates of the two formae speciales of F. oxysporum along two separate phenetic groups: f. sp. melonis to AFLP major haplotype I, and f. sp. radicis-cucumerinum to AFLP major haplotype II. Overall, pathogenicity, vegetative compatibility grouping and AFLP analysis were correlated and effectively distinguished isolates of F. oxysporum from melon. This appears to be the first report of natural infection of melon by F. oxysporum f. sp. radicis-cucumerinum worldwide.  相似文献   

17.
为了寻找高效、低毒以及环境友好型的农药先导化合物,通过菌丝生长速率法测定了5种甾醇生物合成抑制剂类(SBIs)抗真菌药物(益康唑、氟康唑、伏立康唑、酮康唑和咪康唑)对7种植物病原菌的抑制效果,选择其中活性较高的药物进行了防治小麦白粉病和水稻纹枯病的盆栽试验及防治小麦条锈病和水稻纹枯病的田间药效试验。室内毒力测定结果表明:伏立康唑对供试的7种植物病原真菌的杀菌活性最高,其EC50值均低于0.349 mg/L,咪康唑对小麦赤霉病菌、梨黑斑病菌、西瓜枯萎病菌和香樟炭疽病菌,益康唑对梨黑斑病菌和西瓜枯萎病菌,以及酮康唑对水稻稻瘟病菌均表现出较强的杀菌活性,且均高于对照药剂苯醚甲环唑。盆栽试验结果显示:在药剂质量浓度为37.5 mg/L时,伏立康唑和氟康唑对小麦白粉病的防治效果分别为98.26%和89.11%,明显高于商品化杀菌剂三唑醇;在质量浓度为150 mg/L时,益康唑对水稻纹枯病的防治效果最好,为86.14%。田间试验结果表明:在有效剂量为240 g/hm^2时,氟康唑对小麦条锈病的防效为98.42%,益康唑对水稻纹枯病的防效为75.21%。研究结果表明,临床上的抗真菌药物氟康唑、伏立康唑和益康唑对植物病原真菌也具有很高的活性,可望作为农用杀菌剂的先导化合物进一步研究。  相似文献   

18.
采用生长速率法测定了丝柏油醇铜、钙、钠3种络合物对11种常见植物病原真菌菌丝生长的抑制作用。结果表明,3种丝柏油醇络合物对小麦全蚀病菌、小麦赤霉病菌、柑橘炭疽病菌、苹果轮纹病菌、黄瓜枯萎病菌、棉花枯萎病菌、西瓜炭疽病菌、苹果斑点落叶病菌、大葱紫斑病菌、玉米纹枯病菌和番茄灰霉病菌菌丝生长均有不同程度的抑制作用,其中对棉花枯萎病菌和番茄灰霉病菌的抑制效果相对较高,EC_(50)分别为21.69~27.13mg/L和25.18~29.43mg/L。而3种络合物对其他病菌的EC_(50),除钙络合物对柑橘炭疽病菌和西瓜炭疽病菌、钠络合物对柑橘炭疽病、西瓜炭疽病菌和小麦赤霉病菌的EC_(50)高于50mg/L外,均小于等于45.72mg/L。说明3种丝柏油醇络合物均具有防治上述植物病害的潜力,但以铜络合物的活性相对较高。  相似文献   

19.
Gibberella zeae, a causal agent of Fusarium head blight (FHB) in wheat and barley, is one of the most economically harmful pathogens of cereals in the United States. In recent years, the known host range of G. zeae has also expanded to noncereal crops. However, there is a lack of information on the population genetic structure of G. zeae associated with noncereal crops and across wheat cultivars. To test the hypothesis that G. zeae populations sampled from barley, wheat, potato, and sugar beet in the Upper Midwest of the United States are not mixtures of species or G. zeae clades, we analyzed sequence data of G. zeae, and confirmed that all populations studied were present in the same clade of G. zeae. Ten variable number tandem repeat (VNTR) markers were used to determine the genetic structure of G. zeae from the four crop populations. To examine the effect of wheat cultivars on the pathogen populations, 227 strains were sampled from 10 subpopulations according to wheat cultivar types. The VNTR markers also were used to analyze the genetic structure of these subpopulations. In all populations, gene (H = 0.453 to 0.612) and genotype diversity (GD = or >0.984) were high. There was little or no indication of linkage disequilibrium (LD) in all G. zeae populations and subpopulations. In addition, high gene flow (Nm) values were observed between cereal and noncereal populations (Nm = 10.69) and between FHB resistant and susceptible wheat cultivar subpopulations (Nm = 16.072), suggesting low population differentiation of G. zeae in this region. Analysis of molecular variance also revealed high genetic variation (>80%) among individuals within populations and subpopulations. However, low genetic variation (<5%) was observed between cereal and noncereal populations and between resistant and susceptible wheat subpopulations. Overall, these results suggest that the populations or subpopulations are likely a single large population of G. zeae affecting crops in the upper Midwest of the United States.  相似文献   

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