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1.
从荸荠、棉花、西瓜、黄瓜、胡瓜、大豆、花生等12种寄主作物上获得尖孢镰孢(F—usarium oxysporum)菌株20个,已知15个菌株分属于6个专化型。所有20个菌株在含有氯酸盐的培养基上产生抗氯酸盐的突变体,其突变体在以硝酸盐作为氮源的培养基上表现为无气生菌丝生长,即不能利用硝酸盐的突变株(nit),共获得nit突变株181个。同一专化型的nit突变株之间在以硝酸盐为氮源的培养基上配对时,在菌丝接触处可产生互补作用,即营养体亲和性,表现为旺盛气生菌丝生长。不同专化型的nit突变株之间则不能互补产生异核体而表现为非亲和性仍为突变型生长。每个菌株均获得能产生互补作用的nit突变株。根据营养体亲和性反应,20个菌株归入13个营养体亲和群(VCG),并显示出VCGs与菌株专化型之间的相关性。nit突变株在一般条件下是稳定的,而且某些nit株的亲和能力特强。  相似文献   

2.
 从山西运城、临汾、长治、晋中、大同等地保护地黄瓜灰霉病病株上采集、分离的分属于3个不同菌丝融合群的8个灰葡萄孢菌单孢菌株,经氯酸盐诱导处理,共获得了抗氯酸盐的硝酸盐利用缺陷突变体(nit突变体)59株,其中nit1型38株,nit3型10株,nitM型11株。所有nit突变株分别在PDA斜面转管培养3次(21 d)后,除6株恢复成野生菌株外,其余多数nit突变菌株表现稳定。来源于同一野生菌株的不同类型nit突变体间或同一菌丝融合群不同野生菌株的nit突变体间可产生互补反应而形成异核体,其中以nitM型突变株互补性最好,在利用nit突变体测定灰葡萄孢菌营养体亲和性时应作为标准菌株。来源于不同菌丝融合群的nit突变体间不能产生互补反应。  相似文献   

3.
新月弯孢菌营养体亲和群鉴定方法探讨   总被引：4，自引：0，他引：4  
 采用菌株直接配对、显微镜观察菌丝融合和硝酸盐缺陷型(nit)突变体互补测试法,对44个来自不同地区的玉米弯孢菌叶斑病叶中的新月弯孢菌(Curvularia lunata)菌株进行了营养体亲和性分析。在野生型菌株的两两配对中,C.lunata菌株接触产生4种反应类型,但无明显的抗衡反应产生。在菌丝融合显微观察中,光学显微镜下只见大多数菌丝反应为一菌丝向另一菌丝无限靠近,未见融合,但在电子显微镜下,发现两菌丝细胞已不再是独立的。这些结果表明,因两菌落间的抗衡反应和菌丝融合特征都不明显,故不宜采用直接配对和显微观察来划分C.lunata的营养体亲和群。在nit突变体互补测试中,菌株在KClO3浓度1.5%~3.0%的KPS中诱导表明,2.0%~3.0% KClO3适宜于大多数菌株。抗氯酸盐突变体在Czapek培养基中能鉴定出nit突变体,但在MM上却不能。全部3640抗氯酸盐突变体在Czapek中共鉴定出2 40个稳定的nit突变体,其中nit1占59.2%,nit3占39.2%,NitM占0.8%,nit D (3种氮源都不能利用)占0.8%。44个菌株中,24个(55%)获得了nit突变体,20个(45%)还没有,仅2个菌株(124和155)各获得了1个NitM突变体。各菌株突变体类型间只有NitM与nit1或nit3是异核亲和的,其余均不能产生亲和反应。菌株124和155都是营养体自身亲和菌株。用2个NitM作测试菌株,初步划分出2个VCGs,5个归入VCG1,另有5个归入VCG2,其它菌株因未获得NitM或nit突变体还不能鉴定。以上结果表明,硝酸盐缺陷型突变体互补测试法可用于鉴定C.lunata菌株的营养体亲和群。  相似文献   

4.
采集了河南省12个地区的玉米弯孢菌叶斑病标样,分离获得了34个菌株,其中3个是画眉草弯孢(Curvu-laria eragrostidis),其余均为新月弯孢(C.lunata)。利用含KClO3的培养基对其中14个新月弯孢菌株和1个画眉草弯孢菌株(XZ3c)进行诱导,在MM培养基上鉴定均获得了Nit突变体。对获得的190个Nit突变体在MO2和MH培养基上进行了生理表型的划分,并用于菌株内、菌株间的营养体亲和性研究,发现有不少配对组合中均出现了明显的亲和现象,表明Nit突变体技术可以用于玉米弯孢病菌营养体亲和性的研究。根据亲和性测定的结果将这15个菌株初步分为2个营养体亲和群。  相似文献   

5.
瓜类尖孢镰刀菌的营养体亲和群研究   总被引：1，自引：0，他引：1  
 应用营养亲和性方法研究了尖孢镰刀菌菌株抗氯酸盐突变体和nit突变体的诱发规律及分布特性,以及菌株营养体亲和群(VCG)的划分。研究表明,不同寄主(黄瓜、甜瓜和西瓜)分离的尖孢镰刀菌菌株形成的抗氯酸盐突变体数目差异不显著,平均为每个接种点产生0.89~0.98个;但寄主不同部位(根部、茎基部和茎中部)分离的菌株间差异显著,形成的数目分别为1.27、0.75及0.76个。菌株产生的nit1突变体比例(75.40%)显著高于nitM突变体比例(13.17%);nit1突变体数目会因菌株的寄主及菌株寄主部位的不同而有差异,寄主为黄瓜、甜瓜和西瓜的菌株产生的比例依次为67.73%、83.71%和77.50%,根部、茎基部及茎中部分离菌株产生的比例依次为81.82%、78.48%和68.64%,而在致病菌株与非致病菌株间无显著差异,分别为74.43%和79.63%;nitM突变体数目受菌株寄主影响较小,所占比例在11.17%~13.92%之间;而在寄主不同部位分离的菌株及致病菌株与非致病菌株间差异显著,分离自茎基部的菌株所占比例最高为15.97%,茎中部菌株所占比例最低为9.87%,致病菌株与非致病菌株所占比例分别为14.08%和9.26%。供试菌株分为7个VCGs,其特点为来源于不同寄主的尖孢镰刀菌菌株互不亲和,同一寄主的致病菌株与非致病菌株均不亲和,同一寄主不同部位分离的菌株可亲和。  相似文献   

6.
黄瓜枯萎病菌毒力、营养体亲和性及ISSR分析   总被引：2，自引：0，他引：2  
 本研究对来自哈尔滨、长春、沈阳、北京、西宁5个城市的70个尖孢镰刀菌黄瓜专化型菌株进行了毒力、营养体亲和性及ISSR分析。毒力测定结果显示黄瓜枯萎病菌在东农803品种上存在明显的毒力分化。在营养体亲和群的测定中有8个菌株没有产生nit突变体,2个菌株经测定为异核体自身不亲和性菌株,不能进行营养体亲和群的测定;其余60个菌株可分为5个营养体亲和群。利用筛选的7个引物对70个菌株进行了ISSR分子标记,聚类分析可将70个菌株分为3个类群,其中IGⅠ的41个菌株均来自东北三省,IGⅡ的21个菌株均来自北京,IGⅢ的8个菌株全部来自西宁。VCGs和ISSRs与菌株的地理来源及毒力存在一定的相关性。  相似文献   

7.
为评估引起小麦茎基腐病的病原菌假禾谷镰孢Fusarium pseudograminearum对氰烯菌酯的抗性风险,对5株敏感菌株进行了室内药剂驯化,获得33株抗性突变体,突变频率为16.5%,其对氰烯菌酯的抗性水平范围为7.39～1 665.76倍,3株表现低抗,4株表现中抗,26株表现高抗;发现在myosin-5基因上存在11种抗性突变类型,其中217位的丝氨酸突变为亮氨酸(S217L)、420位的谷氨酸突变为赖氨酸(E420K)和135位的丙氨酸突变为苏氨酸(A135T)为主要突变类型,其比例分别为45.5%、15.2%和9.1%。S217L型抗性突变体的产孢量显著下降,菌丝生长速率和致病力与亲本菌株无显著差异。E420K型抗性突变体的菌丝生长速率和致病力显著下降,产孢量与亲本菌株无显著差异。A135T型抗性突变体的菌丝生长速率和产孢量与亲本菌株无显著差异。研究结果表明假禾谷镰孢在药剂选择压力下易形成氰烯菌酯的抗性群体,对氰烯菌酯存在中到高等的潜在抗性风险,其myosin-5的点突变与其对氰烯菌酯的抗性相关。  相似文献   

8.
由多主棒孢Corynespora cassiicola引起的黄瓜棒孢叶斑病是黄瓜上的重要病害。本研究测定了对啶酰菌胺不同抗性类型多主棒孢的生物学特性差异和环境适合度,旨在为探明多主棒孢对啶酰菌胺的抗性变化机制提供生物学研究基础。随机选取不同地区24株对啶酰菌胺具有不同抗性类型的多主棒孢,分析了7种类型抗性突变体对几种不同琥珀酸脱氢酶抑制剂类 (SDHIs) 杀菌剂的交互抗性、不同抗性类型多主棒孢在无药剂选择压力下的抗性遗传稳定性,以及抗性突变体在不同碳源、氮源、温度等环境条件下的生物学特性及适合度。结果表明:除突变类型SdhB-H278Y及SdhB-H278R对啶酰菌胺与氟吡菌酰胺之间存在负交互抗性外,其他突变类型对啶酰菌胺与吡噻菌胺、氟吡菌酰胺及萎锈灵之间均表现为正交互抗性;所有突变类型菌株的抗药性均能稳定遗传;不同突变类型菌株之间致病性存在差异,其中SdhD-D95E突变体的致病力最强;利于所有突变类型菌株生长的碳源是麦芽糖,氮源种类则对突变体的生长影响不显著;各突变类型菌株的最适生长温度范围为25~30 ℃,其中突变体SdhD-D95E在高于30 ℃条件下菌丝生长速率大于其他突变体;耐热性研究中,抗性突变体经65 ℃高温处理45 min后无法存活,同时发现,60 ℃条件下突变体能正常生长,而敏感菌株不能生长;各质量浓度NaCl处理下,SdhD-D95E突变菌株菌丝生长速率快于其他突变菌株,而SdhB-H278Y突变菌株慢于其他突变菌株;葡萄糖对SdhB-H278R突变菌株的生长较为重要。研究表明,对啶酰菌胺不同抗性类型多主棒孢突变菌株的生物学特性及适合度存在差异,SdhD-D95E突变菌株适合度有所提高,表明该突变类型多主棒孢在田间具有较强的竞争力,容易形成优势种群。  相似文献   

9.
稻瘟病菌营养体亲和配对筛选及其亲和能力遗传   总被引：6，自引：2，他引：4  
 在白米玫瑰红培养基上对江苏省的稻瘟病菌Magnaporthe grisea(Hebert) Barr.不同小种间营养体亲和菌株配对组合进行了筛选。当不同小种的菌株对峙接种,在21±1℃、黑暗中培养18 d后,部分配对组合的菌落交界处出现一条肉眼明显可见的菌丝融合带,且具有稳定的重复性。出现菌丝融合带的配对菌株在玻璃纸上对峙微培养2~3 d后,镜检观察到菌丝融合现象普遍存在;未出现明显菌丝融合带的菌株组合经对峙微培养,菌丝融合现象未见或较少。从ZA49、ZG1、ZF1和ZD1 4个小种的12个菌株中筛选出3对营养体亲和性强的小种间菌株配对组合。以所选菌株为亲本建立单分生孢子无性系,测定营养体亲和能力在单孢后代的遗传。结果是,营养体亲和能力在单孢后代遗传不稳定,与另一亲本的单孢株配对产生融合带的百分率为53%~74%之间。进一步研究发现,来自同一个分生孢子不同细胞的单芽管株与配对菌株的营养体亲和能力相同;亲和能力在单芽管株的单孢株后代继续发生分离。  相似文献   

10.
为明确新月弯孢变种的发生和流行规律及有效防治方法,在不同碳源、氮源、温度、pH、光照等培养条件下,测定新月弯孢变种菌株HNWB-131、HNWB-185和模式菌株CX-3的生物学特性,并采用菌丝生长速率法测定这3株菌株对5种药剂的敏感性。结果表明,新月弯孢变种菌株HNWB-131和HNWB-185对碳、氮源的利用更敏感,在大部分碳、氮源培养基上其菌丝均为灰白色至黑色,与新月弯孢模式菌株的墨绿色存在明显区别;2株新月弯孢变种菌株的菌丝生长和产孢最适温度均为30℃,而新月弯孢模式菌株的菌丝生长和产孢最适温度分别为30℃和35℃;新月弯孢变种对光照条件更敏感,且黑暗条件对其分生孢子的产生和萌发有一定刺激作用;新月弯孢变种菌丝生长的最适pH为7~9,比新月弯孢模式菌株的最适pH范围窄（pH为5~11）。苯醚甲环唑对CX-3、HNWB-131、HNWB-185菌株的菌丝生长抑制作用最好,EC50分别为0.39、0.58和0.52 μg/mL;其次为丙环唑,EC50分别为0.79、1.97和1.64 μg/mL,表明2种新月弯孢变种对药剂的敏感性比模式菌株差。  相似文献   

11.
K. Elena 《Phytoparasitica》2000,28(2):115-120
Vegetative compatibility among 17 isolates ofVerticillium dahliae obtained from watermelon, originating from eight regions of Greece, was investigated using complementation tests between nitrate-nonutilizing(nit) mutants. Among 529 chlorate-resistant sectors obtained, only 107 werenit mutants. These mutants were paired with tester strains (from Greece and other countries) of previously described vegetative compatibility groups (VCGs), and also were paired in many combinations among themselves. All isolates were self-compatible. Sixteen isolates were found to belong to VCG2. Only isolate V75 could not be assigned to a VCG, because the threenit mutants obtained from it showed negative reactions with the tester strains of four VCGs and with complementary mutants from other isolates. Based on this sample, we conclude that the population ofV. dahliae from watermelon in Greece is homogeneous in respect to VCG.  相似文献   

12.
Korolev N  Katan T 《Phytopathology》1997,87(10):1067-1070
ABSTRACT Nitrate-nonutilizing (nit) mutants are commonly used to determine vegetative compatibility between isolates of Verticillium dahliae by complementation (heterokaryon) testing. These mutants emerge spontaneously as chlorate-resistant sectors growing out of partially restricted, wild-type colonies on chlorate-amended media. The commonly used chlorate media are based on minimal medium (MMC) or cornmeal agar (CMC), amended with potassium chlorate. nit mutants recovered on these media constituted 10 to 36%(on MMC) and 25 to 45%(on CMC) of the apparently resistant sectors. An improved water agar chlorate medium (WAC) is described that is more effective for selecting chlorate-resistant nit mutants. WAC medium consists of agar (2%), glucose (0.02%), and potassium chlorate (2 to 5%). On WAC, growth of most V. dahliae isolates was strongly inhibited, and 66 to 100%(average >80%) of the chlorate-resistant sectors formed were nit mutants. Most mutants were characterized as nit1, and about 6% as NitM.  相似文献   

13.
Vegetative compatibility groups of a collection of 71 Greek Verticillium dahliae isolates obtained from cotton plants were tested. Nit mutants were generated from single spore wild strains by selecting chlorate-resistant sectors on minimal medium amended with potassium chlorate, 25g/l. These mutants were tested against tester strains from the USA and Greece of the previously described VCGs 1, 2, 3 and 4. Forty-six of 71 isolates belonged to VCG2, because they were able to anastomose with the testers of this group, two isolates belonged to VCG4 and one to VCG1, while the 22 remaining strains could not be assigned to any of the identified VCGs. Our data demonstrated that wilt of cotton is caused only by V. dahliae in Greece, and VCG2 is the most commonly detected VCG. Some strains were found to be more virulent to cotton than other strains from the same VCG. This is the first report of VCG1 of Verticillium in Greece.  相似文献   

14.
Mating behaviour and vegetative compatibility were studied in Spanish populations of Botryotinia fuckeliana. Fifty-seven isolates out of the 61 tested were sexually fertile with one or more of the reference strains of known mating type (MAT1-1 or MAT1-2). Thirty-nine isolates were heterothallic, giving fertile crosses when mated with the MAT1-1 (24 isolates) or the MAT1-2 (15 isolates) reference strain. Eighteen isolates crossed successfully with both MAT1-1 and MAT1-2 reference strains, and were referred to as homothallic or MAT1-1/2. Both mating types were widespread, being represented in isolates from two regions, from the same and different greenhouses, from different hosts, and from different years of isolation. Isolates were paired on Malt Extract Agar + NaCl to evaluate vegetative compatibility. Most of the paired isolates were unable to fuse and showed a different reaction of incompatibility. Nitrate-non-utilising (nit) mutants were selected by growth on a medium amended with 30–50gl–1 potassium chlorate. Over 600 chlorate-resistant sectors were recovered from 40 isolates at a mean frequency of 0.15–2.39 sectors per colony, but only 11% were identified as nit mutants by their thin growth with no aerial mycelium on minimal medium. However, most of these nit mutants reverted to wild type during six months of storage on chlorate-amended medium. Genetic complementation between nit mutants occurred only in two cases between mutants from the same isolate.  相似文献   

15.
Twenty-one strains of Botrytis cinerea isolated from six plant species on ten sites throughout Israel, as well as a strain from France, were tested for vegetative and mycelial incompatibility, pathogenicity, resistance to the fungicides carbendazim and iprodione, and colony morphology. Selenate-resistant mutants were isolated from the strains as spontaneous, fast-growing sectors arising from restricted colonies on medium amended with sodium selenate with a mean frequency of 0.04 sectors/colony; 81% of the sectors were sulphate non-utilizing (sul) mutants. One hundred and four sul mutants were divided into two complementary groups: resistant (66 mutants) and sensitive to chromate. Based on compatibility reactions between chromate-resistant and chromate-sensitive sul mutants, 12 strains were compatible only with themselves and were each classified as belonging to different vegetative compatibility groups (VCGs). Nine strains were each compatible with one to three other strains, and were assembled into three multi-member VCGs. Mycelial incompatibility between wild-type strains (barrage), in the form of a zone of dark pigmentation or sparse mycelium with or without dark pigmentation of the agar along the line of confrontation, was observed for 70% of the inter-strain pairings. There was no correspondence in compatibility between strains revealed by two approaches: strains in different VCGs did not necessarily produce a barrage. However, self-compatibility was observed both as heterokaryon formation between complementary sul mutants and as an absence of barrages between mycelia of wild-type strains; wild-type strains belonging to the same VCG did not exhibit strong barrages, although weak antagonistic reactions were observed. Strains in two multi-member VCGs showed the same patterns of resistance to carbendazim and iprodione; the third multi-member VCG contained isolates with different patterns of resistance. Four morphological types were revealed among wild-type strains: conidial (five strains), sclerotial (six strains), intermediate (ten strains), and mycelial (one strain). On bean leaves, conidial strains were more aggressive than sclerotial strains.  相似文献   

16.
Current status of vegetative compatibility groups in fusarium oxysporum   总被引：1，自引：0，他引：1  
Thirty-eightformae speciales (ff.sp.) ofFusarium oxysporum which have been subjected to vegetative compatibility grouping (VCG) analysis are listed, along with their updated 3-digit numerical codes. The number of VCGs identified within a forma specialis ranges from one (in 11 cases) to 24. Between two and six VCGs were identified in each of 20 ff.spp., whereas seven VCGs or more were identified in the remaining ff.spp. VCGs to which 4-digit numerical codes have been given are listed for 30 ff.spp.  相似文献   

17.
 Fourteen strains of Fusarium oxysporum f. sp. cubense were induced to produce 146 nitrate-nonutilizing(nit) mutants on a chlorate-containing medium. Among them, there were 117 nit1 mutants(80.14%), 17 nit3 mutants(11.64%) and 12 nitM mutants(8.22%). These strains were divided into two vegetative compatibility groups(VCGs) by the vegetative compatibility tests. Twelve strains of F. oxysporum f. sp. cubense from Musa AAA belonged to VCG1, two trains from Musa ABB belonged to VCG2.  相似文献   

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