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1.
来源于佳木斯茄子上的核盘菌菌株多样性的研究 总被引：12，自引：2，他引：12
从我国黑龙江省佳木斯市同一茄子田采集的菌核样品中分离得到21个核盘菌(Sclerotinia sclerotiorum)单菌核分离物。通过比较其菌丝生长速度、菌落形态、菌核产量及菌核在PDA平板上的萌发特性等将其分成3种类型,记为A、B、C,各包含5、7、9个菌株。A型和B型菌株为正常菌株,而C型菌株为异常菌株,生长慢且呈扇形扩展。对代表性菌株转代培养物及菌核后代的培养特性比较结果说明它们的分化特性是稳定的。致病性的测定结果表明参比菌株Cor-6的致病性最强,A型菌株Ep-1PB和B型菌株Ep-1次之,C型菌株Ep-1PD最弱。3类菌株菌核的可溶性蛋白和酯酶同工酶电泳谱带没有明显的差异。 相似文献
2.
栗疫病菌不同毒力菌株生物学特性的研究 总被引：5，自引：0，他引：5
对不同毒力、含或不含dsRNA的菌株的生物学特性进行了研究。含dsRNA的弱毒力菌株的分生孢子后代,可分化出白色和桔黄色两种菌落类型,菌落白色的单孢菌株,可继续分化出白色和桔黄色两种类型的后代,桔黄色的单孢菌株保持稳定,不再发生分化。不含dsRNA的菌株,未见培养性状发生分化。对含dsRNA的弱毒力菌株的第2代两种类型的单孢菌株进行了毒力测定和dsRNA检测,桔黄色的单孢菌株的毒力水平达到或接近强毒力菌株的水平,不含dsRNA;而白色的单孢菌株的毒力很弱,且都含有dsRNA。对不同毒力菌株分生孢子的萌发率进行了比较,结果表明,孵育12h后,即有部分菌株的分生孢子开始萌发,强毒力菌株孢子的萌发最早,含dsRNA的弱毒力菌株的孢子萌发较迟;孵育24h后,各菌株孢子的萌发率均达到90%以上,差异已不太明显,但芽管的分枝程度有较大差异,强毒力菌株的芽管(菌丝)大量分枝,初步形成菌丝丛,而弱毒力菌株,不论是否含有dsRNA,芽管的分枝程度均较低。 相似文献
3.
对采集自我国山东、河南、江苏、安徽4省的21株小麦纹枯病菌菌丝中的dsRNA进行了检测,研究了dsRNA条带与菌株菌落形态、生长速度、对小麦的致病力等生物学特性之间的相关性。结果表明,从16个菌株中检测到dsRNA条带,dsRNA的大小和数量存在丰富的多样性。致病力测定结果表明这21个小麦纹枯病菌菌株的致病力差异显著。目前暂未发现小麦纹枯病菌中dsRNA的类型和数量与菌株的菌落形态、生长速度及致病力等性状存在明显的相关性,但是致病力较弱的菌株中dsRNA条带的多样性更丰富。本研究为今后发掘小麦纹枯病菌中的低毒真菌病毒作了初步的探索。 相似文献
4.
核盘菌对油菜、向日葵和大豆的侵染及其致病性分化研究 总被引：3，自引：0，他引：3
通过对从陕西大荔采集的油菜及其后茬向日葵上的核盘菌和从新疆阿勒泰的向日葵上采集的核盘菌样品进行单菌核分离、培养和纯化,比较其菌丝生长速度、菌丝干重、菌落形态、致病力强弱及菌株的草酸累积等,将两地的核盘菌分成A、B、C三种类型,其中A类来源于陕西大荔的油菜和向日葵,B、C类来源于新疆阿勒泰的向日葵。不同类型核盘菌对于不同寄主的致病力存在着分化现象,A、B类菌株生长正常、菌落均匀旺盛,B类对油菜、向日葵和大豆的致病力较强,草酸产量较高;而A类仅对油菜和向日葵的致病力较强对大豆的致病力很弱,但草酸产量最高。C类菌株生长异常,菌落稀疏不均匀,对3种作物的致病力均弱,草酸产量较低。2001年田问调查亦表明:A类菌株可导致油菜、向日葵菌核病的发生,但未见其使大豆致病,由此提出油菜茬后,不宜种植向日葵,二者应与小麦、玉米等实行较长周期的轮作。本文也同时对各菌株进行了RAPD分析和菌丝体亲和性研究,结果表明,菌株间的遗传多样性表现丰富但未发现与其致病性分化相关。 相似文献
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栗疫病菌的培养性状、毒力与dsRNA的关系 总被引：10，自引：1，他引：10
根据菌落的培养性状将中国东部12个省(市)的429个栗疫病菌(Cryphonectria parasitica)菌株划分为5种培养类型。其中Ⅰ型为桔黄色菌落的野生型正常菌株,占总菌株数的89.3%;Ⅱ~Ⅳ型为培养性状不正常菌株,共有46株,菌落有黄褐色、白色和深褐色等类型。供试菌株间存在明显的毒力分化,可分为强中弱三种类型。培养性状正常的菌株毒力普遍较强,极少菌株检测到dsRNA;培养性状不正常的菌株毒力一般较低,在菌落白色的菌株中都检测到dsRNA。在所测试的70个菌株中含dsRNA的菌株有38个,其中32个属于弱毒力类型,其他6个属中毒力类型;分布于除河南、湖南和广东以外的其他9个省(市)。 相似文献
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一些真菌病毒严重影响寄主生长、产孢量、致病力。本研究对来源于湖北梨轮纹病菌携带真菌病毒情况进行分析,旨在挖掘具有生防潜能的真菌病毒资源。随机采集湖北省梨树发病枝干,分离、鉴定获得13个梨轮纹病菌株,其生长速率、致病性存在差异。提取dsRNA检测,发现12个菌株均携带不同大小的dsRNA片段。观察其dsRNA带型,HBWH-14 dsRNA含有1~7 kb 9条带,其他菌株携带的dsRNA条带位置均位于HBWH-14所含dsRNA带型中的某1条或多条对应的条带位置。RT-PCR检测发现部分菌株携带产黄青霉病毒BdCV1、双分体病毒BdPV1、单分体病毒BdTV1以及未分类的BdRV1。本研究未发现梨轮纹菌株所含病毒种类与致病力存在直接的相关性。HBWH-14原生质体脱毒获得后代100%携带的dsRNAs稳定遗传。 相似文献
7.
内蒙古和黑龙江的核盘菌菌丝融合群分化及致病性研究 总被引：1，自引：0，他引：1
为明确核盘菌的遗传多样性,对采自内蒙古和黑龙江不同地区的44株核盘菌进行了菌丝融合群确定,并比较了不同菌丝融合群间菌丝生长速度、致病力、草酸和总酸产量的差异。结果表明:供试44个菌株分为25个融合群,其中有14个融合群仅由单一菌株组成,所占比例为56.0%。菌丝融合群内和菌丝融合群间菌丝生长速度、致病力、草酸和总酸产量都表现出显著差异(P0.001),并与菌株的地理来源无关。相关分析表明核盘菌菌株的致病力与菌株草酸产量呈正相关(r=0.484,P≤0.01),与pH呈负相关(r=-0.580,P≤0.01),与菌株的生长速度无关;草酸产量与pH高低(表示总酸的分泌量)负相关(r=-0.392,P≤0.01),进一步表明核盘菌菌株产生的总酸中草酸量占了很大的比例。 相似文献
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9.
为明确内蒙古自治区阴山北麓地区向日葵小核盘菌Sclerotinia minor的遗传变异,对自内蒙古自治区乌兰察布市、包头市和呼和浩特市向日葵上分离纯化的110株向日葵小核盘菌菌株进行菌丝亲和组(mycelium compatibility group,MCG)划分,并对5个主要MCG组间和组内各菌株的生物学特性、致病力和交配型进行测定。结果表明,供试的110株菌株被划分为14个亲合组,其中MCG1为主要类型,包含32株菌株,占总菌株的29.1%;MCG2包含来自7个地点的25株菌株;5个MCG仅包含1株菌株;在这14个MCG中,MCG1～MCG5包含92株菌株,占总菌株数的83.6%。MCG1～MCG5组间各菌株在菌落直径和草酸分泌量上存在差异,但在菌核形成量、多聚半乳糖醛酸酶活性和致病力上无显著差异;而MCG1～MCG5组内各菌株在菌落直径、草酸分泌量、菌核形成量、多聚半乳糖醛酸酶活性和致病力上均有一定差异。在MCG1～MCG5各菌株的交配型中,除MCG2中菌株的负反转型与正反转型比例接近1∶1外,其它4个MCG中菌株的负反转型与正反转型比例均偏离1∶1,表明内蒙古自治区向日葵小核盘菌具有较高的遗传变异程度。 相似文献
10.
我国棉花黄萎病菌致病力分化及ISSR指纹分析 总被引：17，自引：0，他引：17
来自我国12个省84个县（市）的棉花黄萎病菌,在PDA培养基上存在5种不同的培养类型,其中,产生微菌核较多的B型菌株为优势类群,占72.9%。长江流域的菌株培养性状变异最大,新疆棉区的变异最小。致病力测定结果和ISSR指纹图谱均将167个单孢菌株划分为强、弱、中3个致病力类型,供试菌株的ISSR指纹图谱与菌株的致病力存在明显的相关性。中等致病力类型菌株在我国占主导地位;强致病力类型的菌株主要分布在河北、河南、湖北等省;弱致病力类型菌株主要分布在新疆和江苏。 相似文献
11.
ABSTRACT Twenty-one strains of Botrytis cinerea isolated from 13 species of plants grown in China were compared for pathogenicity on Brassica napus, mycelial growth on potato dextrose agar, and presence of double-stranded (ds)RNA. The results showed that the strain CanBc-1 was severely debilitated in pathogenicity and mycelial growth, compared with the 20 virulent strains. A dsRNA of approximately 3.0 kb in length was detected in CanBc-1 and 4 hypovirulent single-conidium (SC) isolates of CanBc-1, but was not detected in the 20 virulent strains of B. cinerea and 4 virulent SC isolates of CanBc-1. Results of the horizontal transmission experiment showed that the hypovirulent trait of CanBc-1 was transmissible and the 3.0-kb dsRNA was involved in the transmission of hypovirulence. Analysis of a 920-bp cDNA sequence generated from the 3.0-kb dsRNA of CanBc-1 indicated that the dsRNA element was a mycovirus, designated as B. cinerea debilitation-related virus (BcDRV). Further analyses showed that BcDRV is closely related to Ophiostoma mitovirus 3b infecting O. novo-ulmi, the causal agent of Dutch elm disease. Mitochondria and cytoplasm in hyphal cells of CanBc-1 became degenerated, compared with the virulent isolate CanBc-1c-66 of B cinerea. This is the first report on the occurrence of Mitovirus-associated hypovirulence in B. cinerea. 相似文献
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A single 3 kb segment of double-stranded (dsRNA) was present in three of 30 Brazilian isolates of Cryphonectria cubensis . These dsRNA-containing isolates showed morphological characteristics suggestive of hypovirulence and were significantly less virulent than dsRNA-free isolates. One isolate, however, with morphological characteristics suggestive of hypovirulence, showed reduced virulence, but was free from dsRNA. Conversion of virulent isolates with normal morphology to a morphology associated with hypovirulence was achieved by pairing hypovirulent and virulent isolates of the same vegetative compatibility group (VCG). This suggests that dsRNA can be transmitted to isolates of the same vegetative compatibility group by hyphal anastomosis. Converted isolates exhibited the same hypovirulence-associated traits as those of the original dsRNA-containing hypovirulent isolates. These studies suggest that a single 3 kb segment of dsRNA alters both morphology and virulence by conferring hypovirulence on the pathogen; the first such report for Brazilian isolates of C. cubensis . 相似文献
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N. Mahanti H. Bertrand C. Monteiro-Vitorello D. W. Fulbright 《Physiological and Molecular Plant Pathology》1993,42(6)
In Cryphonectria parasitica, the causal agent of chestnut blight, hypovirulence is commonly associated with the presence of cytoplasmically transmissible, double-stranded RNA (dsRNA). Recently, hypovirulent isolates of C. parasitica that do not have detectable levels of dsRNA have been obtained from healing cankers on chestnut trees. In these isolates, most of the respiratory activity is cyanide-resistant and salicylhydroxamate-sensitive, indicating that the mitochondrial alternative oxidase was induced. In contrast, the respiration of virulent isolates from the same trees and most of the dsRNA-containing hypovirulent isolates from a variety of geographical locations was cyanide sensitive. In all of these isolates, the alternative oxidase could be induced by growing them in the presence of chloramphenicol, an inhibitor of mitochondrial protein synthesis. The attenuated virulence and altered respiratory phenotypes could be transferred from the dsRNA-free hypovirulent isolates to virulent strains through hyphal anastomosis. Some of the dsRNA-free hypovirulent isolates grew more slowly than virulent strains. These results indicate that, in Cryphonectria, cytoplasmically transmitted hypovirulence may have more than one cause, and that mitochondrial mutations sometimes may be involved in the generation of this phenotype. 相似文献
15.
ABSTRACT Two genetically distinct double-stranded RNA (dsRNA) elements were identified in hypovirulent isolates of Sclerotinia homoeocarpa, the causal agent of dollar spot of turfgrass. The large dsRNA (L-dsRNA) was consistently present in all hypovirulent isolates, whereas the small dsRNA (S-dsRNA) was found only in some hypovirulent isolates. Virulence comparisons revealed that there was no significant difference between isolates containing one or both dsRNAs. Therefore, the L-dsRNA appears to be the genetic determinant of hypovirulence, while the S-dsRNA is not essential for hypovirulence in S. homoeocarpa. The L-dsRNA in hypovirulent isolate Sh12B of S. homoeocarpa was previously characterized as a fungal mitochondrial virus and designated Ophiostoma novo-ulmi mitovirus 3a-Sh12B (OnuMV3a-Sh12B) because it was conspecific with O. novo-ulmi mitovirus 3a-Ld from O. novo-ulmi, the causal agent of Dutch elm disease. In the present study, the nucleotide sequences of the S-dsRNAs (738 to 767 nucleotides) in hypovirulent isolates Sh12B, Sh279B, and Sh286B were determined. Nucleotide sequence analysis indicated that the S-dsRNA was not derived from the OnuMV3a dsRNA and it could not encode an RNA-dependent RNA polymerase. These results are consistent with biological data that the S-dsRNA was always associated with the L-dsRNA and was never found independently. Therefore, the S-dsRNA can be regarded as a satellite RNA of OnuMV3a in S. homoeocarpa. Northern blotting analysis indicated that nucleic acid extracts from isolate Sh12B of S. homoeocarpa contained more single (+) stranded RNA than dsRNA for this satellite RNA. The 5'- and 3'-terminal sequences of the positive strand of the S-dsRNA each could be folded into a stem-loop structure and the terminal 21 nucleotides were complementary to each other, potentially forming a panhandle structure. 相似文献
16.
为了从内生菌资源中筛选出对向日葵菌核病有防效的生防菌株,本研究从12个向日葵品种籽粒中分离获得不同菌落形态的33株内生菌株,在此基础上,利用纸杯法进行初筛,从中选出两株对菌核病具有良好防效的菌株,进而采用离体叶片接种试验进行复筛,筛选出一株对菌核病离体防效达100%的内生菌菌株KB3(Bacillus subtilis)。温室盆栽条件下KB3能够显著降低向日葵苗期菌核病的病情指数,防治效果达79.47%。含菌培养基接菌试验表明菌株KB3发酵滤液对核盘菌的抑菌率为68.46%,分皿试验发现KB3能够抑制核盘菌黑色菌核的形成。通过全基因组测序,分析预测到KB3中有7个次级代谢产物合成基因簇。本研究所采取的纸杯法和离体叶片接种相结合的筛菌方法将对菌核病生防菌株的筛选具有参考意义,所获KB3菌株对于向日葵菌核病的防治具有一定的应用前景。 相似文献
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核盘菌(Sclerotinia sclerotiorum)属于世界性分布的植物病原真菌,可以危害油菜等多种经济作物。研究不同地域核盘菌的遗传多样性对了解核盘菌的遗传演化过程和指导病害防控具有重要意义。实验采用序列相关扩增多态性(sequence-related amplified polymorphism,SRAP)标记对四川省17个不同地理来源的66株核盘菌菌株的遗传多样性进行了分析。10对检测引物共获得129个位点,其中123个为多态位点,占95.35%。UPGMA聚类结果显示,在相似性系数为0.7时,66个核盘菌菌株分为5类(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ),分别包含60、2、2、1和1个菌株。在相似性系数为0.74时,第Ⅰ类又可分为3个亚类(Ⅰ-1、Ⅰ-2、Ⅰ-3),分别包含21、37和2个菌株。聚类及组成分分析结果显示,四川省各地区的核盘菌菌株具有较高的遗传多样性,但其遗传变异与菌株地理来源无明显相关性。 相似文献
18.
ABSTRACT One hundred and thirty-two isolates of Sclerotinia homoeocarpa, the causal agent of dollar spot of turfgrass, were evaluated for virulence on swards and detached leaves of creeping bentgrass and for the presence of double-stranded RNA (dsRNA). In at least four isolates, the hypovirulent phenotype was associated with the presence of specific segments of dsRNA. In addition, these hypovirulent isolates often grew slowly on potato dextrose agar (PDA), formed thin colonies with atypical colony margins, and failed to produce typical black stroma. The hypovirulent phenotype and dsRNA were transmitted from hypovirulent isolate Sh12B to virulent isolate Sh48B, and the converted isolate was hypovirulent and contained dsRNA. The hypovirulent phenotype and dsRNA also were transmitted to at least four other isolates of the pathogen, including the fungicide-resistant, dsRNA isolate KY-7. Converted isolates of KY-7 developed the hypovirulent phenotype, grew on fungicide-amended medium, and contained dsRNA. Subcultures of hypovirulent isolate Sh12B that did not contain dsRNA were obtained through curative treatment using cycloheximide-containing medium and heat. Cured subcultures grew faster on PDA, had more typical colony morphologies, were more virulent on bentgrass leaves, and did not contain dsRNA. No cured subcultures were obtained from hypovirulent isolate Sh09B. Isolates regenerated from protoplasts of hypovirulent isolate Sh12B were not cured, remained hypovirulent, and contained dsRNA. Transmission of hypovirulence and dsRNA in S. homoeocarpa has potential as a novel approach to the management of dollar spot of turfgrass. 相似文献
19.
The hyphal tip was isolated from 13 weakly or moderately virulent strains of Helicobasidium mompa to remove double-stranded (ds) RNAs and demonstrate their role as the hypovirulence factor. All of 829 hyphal tip subcultures retained dsRNAs. However, strain v670 containing two large fragments (10kb) and one small fragment (ca. 2.3kb) of dsRNA lost the largest fragment in 3 of 63 subcultures analyzed. One of the three subcultures (v670hti) was used to inoculate carrots to regain virulence compared to the parental strain v670. When isolate v670hti was paired with v670, the largest fragment was reintroduced to v670hti, and its virulence was diminished. Northern blot analysis with two probes hybridizing dsRNA fragments in most H. mompa strains revealed that the largest fragment involved in hypovirulence was different from two other fragments that are common in Japan. These results indicate that the largest dsRNA fragment in strain v670 is associated with hypovirulence in H. mompa. 相似文献