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1.
 由茄丝核菌(Rhizoctonia solani)引起的纹枯病是水稻生产中的重要真菌病害,严重影响水稻产量及品质。本研究评估了两株哈茨木霉菌株3S1-13和4S2-46对纹枯病生防潜力及其对水稻种子萌发和幼苗生长的促生效果。研究表明两株哈茨木霉菌株在马铃薯葡萄糖琼脂培养基(PDA)上不产生分生孢子,但在含有1%酵母粉的PDA上能恢复产分生孢子的能力。菌株3S1-13和4S2-46发酵液对茄丝核菌的菌丝生长及菌核形成均有较强抑制作用,具有防治水稻纹枯病潜力,且发酵液防效显著高于孢子液的防效。菌株3S1-13和4S2-46发酵液处理后的水稻种子发芽率和幼苗的根系、鲜重均显著高于对照,显示出有利于促进种子发芽与生长的作用。研究结果表明两株哈茨木霉菌株发酵液不仅可以用于水稻纹枯病的生物防治,而且可以促进水稻种子发芽及生长,具有较好的应用潜力。  相似文献   

2.
2株枯草芽孢杆菌对太子参4种病原真菌的抑菌效果研究   总被引:2,自引:0,他引:2  
采用枯草芽孢杆菌(Bacillus subtilis)菌株GH18和GH19对贵州省黔东南州太子参(Pseudostellaria heterophylla)的病原真菌互隔交链孢霉菌(Alternaria alternata)、博宁刺盘孢(Colletotrichum boninense)、胶孢炭疽菌(Colletotrichum gloeosporioides)和立枯丝核菌(Rhizoctonia solani)进行了抑菌效果研究。结果表明,菌株GH18和GH19对4种病原真菌都有抑菌效果,菌株GH18无细胞滤液对互隔交链孢菌孢子的抑菌效果优于GH19。菌株GH18高温杀死菌体发酵液在浓度为2.0×10~8 cfu/L和2.0×10~7 cfu/L分别处理,对互隔交链孢霉菌、博宁刺盘孢抑菌率相近。处理3d的抑菌效果优于4 d;其发酵液的抑菌率高于无细胞滤液。菌株GH18高温杀死菌体发酵液在浓度为2.0×10~8cfu/L对互隔交链孢霉菌、博宁刺盘孢抑菌效果较好,胶孢炭疽菌效果次之。因立枯丝核菌气生菌丝生长旺盛,抑菌率较低,故不适合采用生防菌GH18和GH19进行生防。  相似文献   

3.
淡紫褐链霉菌NBF715防控黄瓜猝倒病及其机制的初步研究   总被引:1,自引:0,他引:1  
为明确淡紫褐链霉菌NBF715对黄瓜猝倒病的防控效果和抑菌机制,对其进行了对峙培养、抑菌活性、抑菌物质测定和盆栽防效测定。结果表明,对峙培养条件下NBF715对瓜果腐霉抑菌率为55.6%,无菌发酵液稀释10、25、50倍和100倍对瓜果腐霉抑菌率分别为84.1%、69.2%、47.8%和36.5%。光学显微镜和扫描电镜下观察,与对照相比,NBF715处理后瓜果腐霉菌丝发生扭曲、肿胀变形和消解。NBF715菌株能产生淀粉酶、纤维素酶、β-1,3-葡聚糖酶和嗜铁素。发酵液原液和稀释5倍发酵液浸种处理,对黄瓜猝倒病防效分别为97.1%和80.2%。NBF715菌株具有较好的生防应用前景。  相似文献   

4.
木霉对玉米纹枯病的生物防治   总被引:7,自引:0,他引:7       下载免费PDF全文
为明确木霉菌在玉米纹枯病防治上的作用,研究了从雅安郊区大田玉米根际土壤中分离到的18个木霉菌株对立枯丝核菌的抑制作用及对玉米纹枯病的田间防治效果.对峙培养结果表明,这些木霉菌株对立枯丝核菌的抑制率为39.44%~84.98%;而木霉发酵滤液的抑菌作用为13.48%~85.81%.对峙培养和液体发酵滤液的抑菌测定相结合,筛选出木霉菌株T8、T2、T13,经鉴定分别为哈茨木霉Trichoderma harzianum、黄绿木霉Trichoderma aureoviride和长枝木霉Trichoderma Longibrachiatum.用这3种木霉的固体培养物作进一步的田间防治试验,防治效果分别为62.75%、64.48%、68.52%,比井冈霉素(49.68%)效果高;T13菌株的发酵滤液的防治效果仅为40.07%.3株木霉固体培养物对玉米产量影响显著,增产率依次为29.77%、43.37%、54.21%.  相似文献   

5.
水稻纹枯病菌强拮抗菌B34的分离与鉴定   总被引:9,自引:0,他引:9  
 从水稻植株上分离到1株对水稻纹枯病菌有强烈拮抗作用编号为B34的菌株,在PDA平板上表现有对水稻纹枯病菌较强作用的抑菌带,其发酵菌液对纹枯病菌丝有强烈的致畸作用,抑菌率达到71.5%,使菌核的菌丝萌发率降低69.0%。离体防效和田间小区防效分别高达81%和48.74%,高于清水和井冈霉素处理。经生理生化检测及细胞壁化学成分分析,确定其为致黄假单胞菌(Pseudomonas aureofaciens)。  相似文献   

6.
侧孢短芽孢杆菌B8对两种植物病原菌抗菌机制初步研究   总被引:3,自引:0,他引:3  
研究了侧孢短芽孢杆菌B8胞外抗菌蛋白对立枯丝核菌和辣椒疫霉菌的抗菌作用。结果表明,B8胞外抗菌蛋白可有效抑制立枯丝核菌和辣椒疫霉菌菌丝生长,抑制率分别为73.51%和47.26%。经其处理的立枯丝核菌菌丝膨大、断裂,细胞质外渗,细胞壁消解,菌丝解体;处理的辣椒疫霉菌菌丝分支增多,顶端产生球状结构,原生质体囊泡化,菌丝断裂。B8胞外抗菌蛋白对辣椒疫霉菌游动孢子囊产生和游动孢子萌发具有抑制作用,抑制率分别为80%和100%。B8胞外抗菌蛋白对立枯丝核菌菌核产生具有显著的抑制作用,抑制率可达到100%;对菌核萌发速度也具有抑制作用,其处理过的菌核萌发速度缓慢,且萌发产生的菌丝生长量明显减少,菌丝畸形。  相似文献   

7.
生防枯草芽孢杆菌L1特性的初步研究   总被引:9,自引:0,他引:9  
通过对峙培养,测定出枯草芽孢杆菌L1的抑菌谱较宽,特别是对水稻纹枯病菌、大豆菌核病菌、禾谷镰孢菌、辣椒灰霉病菌、玉米小斑病菌抑菌效果明显;枯草芽孢杆菌L1不同发酵时间经湿热灭菌处理后,5 d发酵液中抑菌活性物质含量最高,对水稻纹枯病菌菌丝生长抑制率达83.23%,发酵液随时间延长抑菌效果不再增加;枯草芽孢杆菌L1抑菌活性物质对温度不敏感;枯草芽孢杆菌L1发酵液用硫酸铵梯度沉淀法提取粗蛋白在硫酸铵饱和度达60%~70%(不含60%)沉淀的活性物质抑菌效果最好,对水稻纹枯病菌平均抑菌半径达1.15;枯草芽孢杆菌L1对玉米、大豆、小麦、番茄、菜豆、黄瓜、水稻无致病性,而且还有保鲜和促生作用。  相似文献   

8.
水稻纹枯病的病原菌为立枯丝核菌(Rhizoctonia solani Kǜhn)。用10株弱毒丝核菌提前接种水稻后,再接种纹枯病病原菌,观察其发病症状,并用实时荧光定量RT-PCR方法研究了接种不同处理后的水稻9个抗性基因表达情况,筛选出参与水稻纹枯病抗病过程的基因和能使水稻提前获得系统抗性的弱毒丝核菌菌株。结果显示,参与水稻诱导抗性的抗性基因主要为PR10a、ORK10、NAC4、WRKY53、WRKY71。大部分弱毒双核丝核菌能诱导水稻抗性基因表达,诱导效果最好的弱毒丝核菌菌株是②BS-J-06-8-1、④chd-YT-3-5和⑨DL-YT-06-4-9。  相似文献   

9.
药剂对水稻立枯丝核菌的毒力及形态毒理作用   总被引:8,自引:1,他引:8  
采用室内离体平皿法测定了多菌灵、福美双、甲基立枯磷及混配药剂20%克·福·甲和20%克·多·甲种衣剂对水稻立枯丝核菌(Rhizoctonia solani)的抑菌作用和联合毒力.结果表明,甲基立枯磷对水稻立枯丝核菌具有优异的抑菌效果,其EC50为0.056μg/ml,两个种衣剂对R.solani的共毒系数分别为866.72和597.85,增效倍数分别为7.67和4.98.20%克·福·甲种衣剂(福美双甲基立枯磷为86,w/w)对立枯丝核菌的增效程度优于20%克·多·甲种衣剂(多菌灵甲基立枯磷为55,w/w).借助扫描电镜观察了上述三种杀菌剂和两种混配种衣剂对立枯丝核菌的形态毒理影响.结果表明,杀菌剂及种衣剂低浓度到高浓度处理下可引起立枯丝核菌菌丝不同程度的异常生长,表现为主菌丝上二次分枝频繁发生,菌丝畸形缢缩、膨胀,新分枝处菌丝生长受抑、菌丝顶端呈花絮状或穗状膨大.  相似文献   

10.
丙环唑对水稻纹枯病菌的抑制作用及对纹枯病的防治效果   总被引:5,自引:0,他引:5  
为明确丙环唑对水稻纹枯病的防治作用,通过离体抑菌试验,温室盆钵试验和田间试验研究了丙环唑对水稻纹枯病菌的抑制作用和对纹枯病的防治效果.离体抑菌试验表明,丙环唑能够强烈抑制水稻纹枯病菌(Rhizoctonia solani)的菌丝生长,EC50为0.045 μg/mL,并能够强烈抑制菌核产生,但不能抑制菌核萌发.温室试验表明,纹枯病菌经丙环唑处理后,致病力随药剂浓度提高而显著减弱;丙环唑可以很好地被水稻叶片和根系吸收,并输送到水稻的茎部和叶鞘;丙环唑对水稻纹枯病具有保护和治疗作用,400 μg/mL丙环唑处理水稻,抑制病斑长度分别达到82.16%和76.61%,并随药剂处理浓度的降低而降低;丙环唑对立枯丝核菌有较长的持效期,800 μg/mL处理水稻11 d后再接种的防效为40.10%.田间药效试验表明,25%的丙环唑乳油在有效剂量150 g/hm2下3次喷药后14 d的防效达到89.15%,丙环唑在本试验剂量范围内对水稻安全.表明丙环唑对水稻纹枯病有很好的防治作用,可为生产上防治水稻纹枯病和科学用药提供依据.  相似文献   

11.
[目的] 筛选对板蓝根根腐病有较强拮抗作用的生防菌株。[方法] 采用平板对峙法对137个板蓝根根际土壤样本中分离到的201株拮抗细菌进行测试。[结果] 筛选出1个对板蓝根根腐病菌有强烈抑制作用的菌株Bs-0728。结合显微镜观察确定Bs-0728菌株对板蓝根根腐病的主要致病菌茄腐镰刀菌(Fusarium solani)菌丝生长有较强的抑制作用,导致菌丝生长畸形,弯曲,部分细胞膨大。田间试验结果表明,Bs-0728的发酵液田间防效达72.97%,且增产86.26%。经形态观察、生理生化反应及16S rDNA 序列分析,初步将此拮抗细菌鉴定为枯草芽胞杆菌Bacillus subtilis。[结论] 枯草芽孢杆菌Bs-0728菌株是一株很有应用前景的生防菌株。  相似文献   

12.
枸骨内生真菌抗菌代谢产物的鉴定及活性研究   总被引:2,自引:1,他引:2  
对一株枸骨内生真菌哈茨木霉Trichoderma harzianum抗菌活性成分的分离、鉴定及其抗菌生物活性进行了研究。该真菌发酵液经乙酸乙酯萃取、正相硅胶和ODS-反相色谱分离纯化得到一单端孢霉烯化合物,经红外、质谱和核磁分析,鉴定为:4β-乙酰基-12,13-环氧-9-单端孢霉烯(trichodermin),这是首次从哈茨木霉菌代谢产物中分离出该化合物。Trichodermin对蕃茄早疫病和黄瓜立枯病病原菌的离体抑制活性EC50值分别为3.35和3.59 mg/L;活体测定结果表明,在 100 mg/L的剂量下对两种病的保护效果分别为97.8% 和98.1%,治疗效果为96.7%和97.3%。  相似文献   

13.
Microsphaeropsis sp. strain P130A was evaluated for the control of tuber-borne inoculum of Rhizoctonia solani based on the viability of sclerotia produced in vitro and on both the viability and production of tuber-borne sclerotia. The interactions between the antagonist and the pathogen, as well as the effect of the toxins produced by the antagonist on mycelial growth of R. solani were studied using transmission electron microscopy. On sclerotia produced in vitro, for all incubation periods (1 to 42 days), Microsphaeropsis sp. significantly reduced germination. Percent germination of sclerotia treated with Microsphaeropsis sp. decreased with increasing incubation period from an average of 82.0% after 1 day to stabilize at an average of 5.8% after 35 days. Similarly, percent germination of tuber-borne sclerotia was significantly lower when tubers were treated with Microsphaeropsis sp. Both 2% formaldehyde and Microsphaeropsis sp. treatments significantly reduced sclerotia germination to approximately 10% after 42 days of incubation at 4 degrees C. Furthermore, on tubers treated with the antagonist, the number of sclerotia per square centimeter decreased from 1.6 to 0.5 during the 8 months of storage at 4 degrees C, whereas an increase from 1.2 to 7.8 sclerotia per square centimeter was observed on untreated tubers. Microsphaeropsis sp. (strain P130A) colonized hyphae of R. solani within 4 days after contact on culture media. Transmission electron microscopic observations showed that the antagonist induced a rupture of the pathogen plasma membrane and that a chitin-enriched matrix was deposited at sites of potential antagonist penetration. Host penetration was not associated with pathogen cell wall alterations, which occurred at the time of progress of the antagonist in the pathogen cytoplasm. In the presence of a crude extract of Microsphaeropsis sp., cells of R. solani showed cytoplasm disorganization and breakdown of plasma membranes. Antibiosis and mycoparasitism were involved in the antagonism of R. solani by Microsphaeropsis sp., but the sequence by which these events occur, as well as the significance of wall appositions produced by R. solani, is yet to be established.  相似文献   

14.
木霉对土传病原真菌的拮抗作用   总被引:100,自引:2,他引:100  
 分别在体外及温室测定了筛选菌株哈茨木霉Trichoderma harzianum(T82)和Tricho-derma sp.(NF9)对土传病原真菌的拮抗作用。体外测定表明,木霉菌株T82和NF9对白绢病菌Sclerotium rolfsii,立枯丝核菌Rhizoctonia solani,瓜果腐霉Pythium aphanidermatum刺腐霉P.spinosum和尖镰孢Fusarium oxysporum在对崎培养中的拮抗系数分别为2或2~3和2。温室测定表明,用0、6%(W/W)T82麸皮培养物(107cfu/g)处理土壤。在人工接种白绢病菌,立枯丝核菌及瓜果腐霉20天后,黄瓜发病率分别比未用木霉处理的对照减少46、5%,28.4%和81。2%;用T82和NF9木霉孢子悬浮液(108cfu/ml)处理黄瓜种子,人工接种白绢病菌11天后,黄瓜成苗率分别比未用木霉处理的对照增加14%的20%。分别在光学显微镜和扫描电镜下观察到木霉T82对白绢病菌菌丝和菌核的重寄生以及木霉T82和NF9对立枯丝核菌菌丝的缠绕。穿入及寄生。作者认为重寄生可能是试验木霉菌株T82和NF9对白绢病菌和立枯丝核菌的主要拮抗机制。  相似文献   

15.
北京地区西洋参根腐病病原鉴定及其致病性   总被引:3,自引:0,他引:3  
毕武  陈娟  焦晓林  高微微 《植物保护》2011,37(5):135-138
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 1α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。  相似文献   

16.
ABSTRACT A beta-glucuronidase (GUS) reporter gene and a hygromycin B (hygB) phosphotransferase gene were integrated separately into the Trichoderma harzianum strain 1295-22 genome, using biolistic transformation. The mycelial growth and biocontrol ability of the transformed strains did not differ from that of the original strain. The transformed Gus(+)-kanamycin-resistant (Gus(+)Kan(R)) strains were used to monitor growth and interactions with Rhizoctonia solani on creeping bentgrass plants. The hygB-resistant (hygB(R)) strains were used to selectively recover strain 1295-22 from the rhizosphere soil and phylloplane of creeping bentgrass after spray applications. The population levels of two hygB(R) strains and the original strain were very similar for all treatments. All three strains persisted for the duration of the experiment (28 days) in both the rhizosphere soil and on leaves, although population levels declined somewhat over the course of the experiment in unautoclaved soils. In this study, the results demonstrated that hygB(R) strains remained dominant over time when assayed on Trichoderma-selective medium containing hygB. The hygB(R) strains were not displaced by strains that colonized untreated plants. Microscopic observation showed that the Gus(+)Kan(R) strains colonized the rhizoplane, seed coat, and phylloplane of creeping bentgrass. These results supported our earlier observation that strain 1295-22 was rhizosphere and phyllo-plane competent. Interactions between T. harzianum and R. solani were readily observed in situ and changed over time. Two types of reactions were found in these experiments. In the first type, sections of hyphae of R. solani near the hyphae of T. harzianum appeared damaged, and the pathogen appeared necrotic when viewed with a microscope. The second type, observed less frequently than the first type, was typical of myco-parasitism. The findings in this study provide new insight into the interactions between R. solani and T. harzianum, providing a basis for future research.  相似文献   

17.
ABSTRACT The interaction between the oomycete Pythium oligandrum and various soilborne oomycete and fungal plant pathogens (P. ultimum, P. aphanidermatum, Fusarium oxysporum f. sp. radicis-lycopersici, Verticillium albo-atrum, Rhizoctonia solani, and Phytophthora megasperma) was studied by light and electron microscopy in order to assess the relative contribution of mycoparasitism and antibiosis in the antagonistic process. Scanning electron microscope investigations of the interaction regions showed that structural alterations of all pathogenic fungi and oomycetes (except for Phytophthora megasperma) occurred soon after contact with the antagonist. Light and transmission electron microscope studies of the interaction region between the antagonist and P. ultimum revealed that intimate contact between both partners preceded a sequence of degradation events including aggregation of host cytoplasm and penetration of altered host hyphae. Localization of the host wall cellulose component showed that cellulose was altered at potential penetration sites. A similar scheme of events was observed during the interaction between P. oligandrum and F. oxysporum f. sp. radicis-lycopersici, with the exception that complete loss of host protoplasm was associated with antagonist invasion. The interaction between P. oligandrum and R. solani resulted in an abnormal deposition of a wall-like material at potential penetration sites for the antagonist. However, the antagonist displayed the ability to circumvent this barrier and penetrate host hyphae by locally altering the chitin component of the host hyphal wall. Interestingly, antagonist cells also showed extensive alteration as evidenced by the frequent occurrence of empty hyphal shells. In the case of Phytophthora megasperma, hyphal interactions did not occur, but hyphae of the plant pathogen were damaged severely. At least two distinct mechanisms appear to be involved in the process of oomycete and fungal attack by P. oligandrum: (i) mycoparasitism, mediated by intimate hyphal interactions, and (ii) antibiosis, with alteration of the host hyphae prior to contact with the antagonist. However, the possibility that the antagonistic process may rely on the dual action of antibiotics and hydrolytic enzymes is discussed.  相似文献   

18.
枯草芽孢杆菌Bs-916的抑菌活性及其抑菌物质初探   总被引:7,自引:2,他引:7  
为了揭示从土壤中分离出的拮抗菌—枯草芽孢杆菌Bs-916的抑菌作用和抑菌机理,采用管蝶法、平板涂抹法及孢子盟发法测定了Bs-916及其代谢液对水稻纹枯病菌、蚕豆枯萎病菌等8种病原菌的抑菌活性,结果表明其对供试的大多数病原菌均具有较强的抑菌活性,如Bs-916及其代谢液对水稻纹枯病菌的抑制率分别为95.4%和70.7%,对水稻稻曲病菌的抑制率均为100%。为了探索Bs-916胞外物质的种类及特性,分别采用丙酮沉淀、PEG沉淀、等电点沉淀和超微浓缩等方法从Bs-916代谢液中获得了沉淀物或截留物,它们均具有抑菌活性。沉淀物经蛋白酶K 处理后,活性减弱,说明Bs-916胞外抗菌物质具有蛋白质的性质。  相似文献   

19.
枯草芽孢杆菌微囊剂的制备及其对番茄立枯病的防治效果   总被引:3,自引:0,他引:3  
马新  黄永  程娟  王伟 《农药学学报》2015,17(4):462-468
为开发环境相容性好、贮藏稳定性高的生物农药新剂型,采用喷雾干燥法制备了枯草芽孢杆菌微囊剂。通过单因素试验确定该微囊剂壁材麦芽糊精与芯材枯草芽孢杆菌发酵液(以下简称发酵液)的最佳配比;通过正交试验优化了喷雾干燥条件;通过田间试验验证了该微囊剂对番茄立枯病的防治效果。结果表明:制备枯草芽孢杆菌微囊剂时,壁材与芯材的最佳配比为m(麦芽糊精)∶V(发酵液)=1∶1;喷雾干燥的最优条件为进风温度125℃,进样流量750 m L/h,喷雾压力0.20 M Pa;所制备微囊剂常温贮存360 d后,菌体存活率仍高达91.36%,显著高于对照枯草芽孢杆菌可湿性粉剂。田间药效试验表明,该枯草芽孢杆菌微囊剂用量为300 g/hm2(芽孢浓度为1.5×107cfu/m2)时,对番茄立枯病的防效最高,为72.76%。  相似文献   

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