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1.
常熟地区蚕豆枯萎病病原菌鉴定及其致病力初探   总被引:2,自引:0,他引:2  
2000、2001年在江苏省常熟地区采集了有典型枯萎症状的蚕豆标样各50个,获94个镰刀菌单孢菌株。经鉴定分别属于尖孢镰孢(Fusarium axysporum)、燕麦镰孢(F.avenaceum)、串珠镰孢(F.moniliforme )、木贼镰孢(F.equiseti)、三线镰孢(F.tricinctum)、禾谷镰孢(F.graminearum)和茄镰孢(F.solani),其中尖孢镰孢、燕麦镰孢、串珠镰孢、木贼镰孢为该地区蚕豆镰刀菌枯萎病的主要病原菌。测定了48个镰刀菌菌株对蚕豆的致病力,尖孢镰孢、木贼镰孢、串珠镰孢和燕麦镰孢对蚕豆的致病力都较强。用蚕豆枯萎病菌和棉花枯萎病菌交叉接种棉花和蚕豆,结果表明两者存在着较强的交互侵染能力。  相似文献   

2.
新疆食葵种子健康检测和杀菌剂消毒处理初步研究   总被引:1,自引:1,他引:0  
采用PDA平板法检测了来自新疆自治区的2个品种的食葵种子带菌情况,并测定了9种不同杀菌剂对食葵种子带菌消毒处理效果和对种子发芽及苗期生长的影响。结果表明,食葵种子表面携带的优势菌群主要为镰孢霉属(Fusarium)、链格孢属(Alternaria)和青霉属(Penicillium),种子内部寄藏真菌主要有链格孢属和曲霉属(As-pergillus),其他分离频率较高的真菌还有根霉属(Rhizopus)和枝孢属(Cladosporium)等;2个食葵品种种子表面携带真菌种类有较大差异,种子内部寄藏真菌种类差异不大。杀菌剂苯醚甲环唑、咯菌腈和咪鲜胺具有良好的种子带菌消毒处理效果。  相似文献   

3.
为明确引起福建省大豆炭疽病的病原菌种类,2018—2019年从福建省福州、三明、莆田、泉州和南平市采集具有大豆炭疽病症状的大豆豆荚,采用组织分离法分离病原菌,结合形态学特征和多基因系统发育分析对病原菌进行鉴定。结果表明,从采集的豆荚样本中共分离获得152株炭疽菌菌株,经形态学初步鉴定分属于3种类型,从3种类型的病原菌中分别选取3株代表菌株进行多基因系统发育分析,这9株代表菌株分别与Colletotrichum plurivorum、平头炭疽菌C.truncatum和胶孢炭疽菌C.gloeosporioides聚在一起。形态学和多基因系统发育分析结果表明,引起福建省大豆炭疽病的病原菌有3种,分别为C.plurivorum、平头炭疽菌和胶孢炭疽菌,其占比分别为10.53%、50.00%、39.47%。致病性测定结果表明,C.plurivorum、平头炭疽菌和胶孢炭疽菌对大豆均有致病作用,但不同的菌株致病力存在差异。表明平头炭疽菌是引起福建省大豆炭疽病的主要病原菌,而C.plurivorum为引起我国大豆炭疽病的新纪录种。  相似文献   

4.
肾状线虫属重要种类的鉴定和特征描述   总被引:1,自引:0,他引:1  
杜宇 《植物保护》2008,34(2):101-106
记述了目前世界上认可的肾状线虫属(Rotylenchulus sp.)已知的10个种的重要鉴定特征、世界分布和寄主范围。这10个种包括越南肾状线虫(R.anamictus)、短管肾状线虫(R.brevitubulus)、北方贝肾状线虫(R.borea-lis)、短尾肾状线虫(R.clavicaudatus)、离异肾状线虫(R.leptus)、大囊肾状线虫(R.macrodoratus)、长肾状线虫(R.macrosoma)、微小肾状线虫(R.parvus)、肾形肾状线虫(R.reniformis)和甘蔗肾状线虫(R.sacchari)。并对其最具经济意义的两种线虫的特征进行了描述。  相似文献   

5.
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   

6.
日光温室茄茎腐病病原鉴定   总被引:2,自引:0,他引:2  
1998~2000年连续 3年在甘肃省主要茄子栽培区大量采集茄子茎腐病病株和病土 ,经分离和致病性测定 ,表明引起当地茄茎腐病的主要病原为镰刀菌和疫霉菌。根据病原形态特征、培养性状以及致病性测定 ,确定其为尖镰孢菌 (Fusarium oxysporum)、黄色镰孢菌 (Fusarium culmorum)和寄生疫霉 (Phytophthora nicotianae)。两种镰刀菌生长发育最适温度均为20~30℃ ,最适pH为7.0;在光照条件下菌丝生长缓慢。  相似文献   

7.
五味子茎基腐病发生初报   总被引:3,自引:2,他引:3       下载免费PDF全文
通过对辽宁省多个地区的调查,发现此病害发生普遍,尤其是二年生的五味子茎基腐病发生严重。五味子茎基腐病在5月上旬开始出现,6月初为发生盛期。本文对五味子茎基腐病进行了症状描述,并对不同地点采集的病样分别进行木质部和韧皮部病原物的分离、纯化。对分离得到的菌株按照柯赫氏法则进行致病性测定并对病原菌进行鉴定,结果表明,此病害可由木贼镰刀菌(Fusarium equiseti)、茄腐镰刀菌(F.solani)、尖孢镰刀菌(F.oxysporum)和半裸镰刀菌(F.semitectum)4种镰刀菌属真菌引起。针对此病害的发生特点,提出了相应的防治措施。  相似文献   

8.
玉米地昆虫及捕食性节肢动物群落结构及动态研究   总被引:4,自引:0,他引:4  
南宁市郊玉米地害虫、捕食性昆虫、蜘蛛及中性昆虫由90科315种组成,害虫、蜘蛛及捕食性昆虫是玉米地节肢动物群落组成及功能作用的主要群落。禾谷缢管蚜(Rhopalosiphum padi)、玉米螟(Ostrinia furnacalis)、六斑月瓢虫(Menochilus sexmaculata)、龟纹瓢虫(Propylaea japonica)、食虫沟瘤蛛(Ummeliata insecticeps)、锥腹肖蛸(Tetragnatha maxillosa)、八斑鞘腹蛛(Coleosoma octomaculatum)、类奇异獾蛛(Trochosa ruricoloides)和脉娲蛛(Wadicosa fidelis)等是群落的主体。分析了4个亚群落的时空格局及数量变动规律以及天敌对害虫的控制作用。  相似文献   

9.
昆明市白车轴草上蓟马种群动态调查   总被引:3,自引:0,他引:3       下载免费PDF全文
对昆明市白车轴草上蓟马种类及其周年种群动态进行了调查。白车轴草上蓟马主要有西花蓟马(Fran-kliniella occidentalis)、丽花蓟马(F.intonsa)、八节黄蓟马(Thrips flavidulus)、端大蓟马(Megalurothrips distalis)、稻单管蓟马(Haplothrips aculeatus)和烟蓟马(T.tabaci),有时会出现黄胸蓟马(T.hawaiiensis)、玉米黄呆蓟马(Anaphothrips obscurus)、苏丹呆蓟马(A.sudanensis)和云南纹蓟马(Aeolothrips yunnanensis)。本文分析了前6种蓟马的周年种群动态,重点阐述了外来有害生物西花蓟马,该虫主要在3~6月发生,是此期间白车轴草上的蓟马优势种。  相似文献   

10.
以棉枯萎镰刀菌Fusarium oxysporum f.sp.vasinfectum菌丝体中提取的蛋白质为抗原,制备出3个生理小种、6个菌系的抗血清。琼脂双扩散试验效价1/16—1/32。这些抗血清与串珠(F.moniliforme)、半裸(F.semitectum)、木贼(F.equiseti)和茄病(F.solani)等4种镰刀菌的双扩试验,无肉眼可见或仅有微弱的沉淀线出现,其血清学关系较远;与尖孢种内的黄瓜(F.oxysporum f. sp. cucumerinum)、菜豆(F.oxysporum f. sp. phaseoli)和啤酒花(F. oxysporum f.spp.)等3个专化型的双扩试验,具有明显的沉淀线,其形状、条数及清晰度有差异并出现交叉,血清学关系较为密切;与棉枯萎镰刀菌3个小种14个菌系的双扩试验,具有多条沉淀线,融合多,分枝少,同源反应比异源反应清楚,其血清学关系更为密切。 综合分析镰刀菌的形态,致病性和琼脂双扩散试验结果,表明镰刀菌血清学关系与镰刀菌形态学、致病性有一定程度的一致性和相关性、血清学方法可作为棉枯萎镰刀菌分类的手段之一。  相似文献   

11.
ABSTRACT The causal organism responsible for the recent outbreak of almond and peach anthracnose in California was identified and characterized as Colletotrichum acutatum. Isolates of C. acutatum from almond were found to be similar to California strawberry isolates and South Carolina peach and apple isolates of C. acutatum based on conidial morphology, temperature relationships, fungicide sensitivity, and polymerase chain reaction (PCR) methods using DNA species-specific primers. On almond, blossoms and immature or mature fruit were affected by the disease, causing direct losses of crop. On peach, the disease was observed only on mature fruit. Pathogenicity of almond and peach isolates of C. acutatum was demonstrated on wound- and nonwound-inoculated almond or peach fruit by fulfilling Koch's postulates. Conidial morphology of isolates was variable, depending on the medium or substrate used to culture the isolates. Isolates of C. acutatum from strawberry, almond, and peach were grouped together based on a similar response to temperature, with an optimal growth rate at 25 degrees C (generally less than 10 mm/day), whereas isolates of C. gloeosporioides from citrus and papaya had an optimal growth rate at 30 degrees C (generally greater than 10 mm/day). In fungicide disk assays, isolates of C. acutatum from strawberry, peach, and apple, as well as almond and peach isolates from California, were less sensitive to benomyl at 300, 600, or 1,200 mug/ml. In contrast, C. gloeosporioides isolates from citrus and papaya were very sensitive to benomyl at all concentrations evaluated. All isolates of both species were sensitive to captan (300, 600, or 1,200 mug/ml). Oligonucleotide primers were synthesized for C. acutatum, C. fragariae, or C. gloeosporioides using published DNA sequences from the internal transcribed spacer 1 region of ribosomal DNA. Thirty-two Colletotrichum isolates from almond fruit produced DNA products with a C. acutatum primer (CaInt-2) that matched products and approximate molecular weight of known C. acutatum isolates. No PCR products were produced with primers for C. gloeosporioides or C. fragariae. Isolates from citrus and papaya produced DNA products only with primers from C. gloeosporioides or C. fragariae. Thus, worldwide, anthracnose of almonds may be caused by either C. gloeosporioides, as previously reported, or by C. acutatum, as indicated in this study.  相似文献   

12.
ABSTRACT Colletotrichum crown rot of strawberry in Florida is caused primarily by Colletotrichum gloeosporioides. To determine potential inoculum sources, isolates of Colletotrichum spp. from strawberry and various noncultivated plants growing in the areas adjacent to strawberry fields were collected from different sites. Species-specific internal transcribed spacer primers for C. gloeosporioides and C. acutatum were used to identify isolates to species. Random amplified polymorphic DNA (RAPD) markers were used to determine genetic relationships among isolates recovered from noncultivated hosts and diseased strawberry plants. Selected isolates also were tested for pathogenicity on strawberry plants in the greenhouse. In all, 39 C. gloeosporioides and 3 C. acutatum isolates were recovered from diseased strawberry crowns, and 52 C. gloeosporioides and 1 C. acutatum isolate were recovered from noncultivated hosts. In crown inoculation tests, 18 of the 52 C. gloeosporioides isolates recovered from noncultivated hosts were pathogenic to strawberry. Phylogenetic analysis using RAPD marker data divided isolates of C. gloeosporioides from noncultivated hosts into two separate clusters. One cluster contained 50 of the 52 isolates and a second cluster contained 2 isolates that were homothallic in culture. Isolates from strawberry were interspersed within the cluster containing the 50 isolates that were recovered from noncultivated hosts. The results are not inconsistent with the hypothesis that C. gloeosporioides isolates obtained from strawberry and noncultivated hosts adjacent to strawberry fields are from the same population and that noncultivated hosts can serve as potential inoculum sources for Colletotrichum crown rot of strawberry.  相似文献   

13.
ABSTRACT Isolates of Colletotrichum spp. from diseased strawberry fruit and crowns were evaluated to determine their genetic diversity and the etiology of the diseases. Isolates were identified to species using polymerase chain reaction primers for a ribosomal internal transcribed spacer region and their pathogenicity was evaluated in bioassays. Isolates were scored for variation at 40 putative genetic loci with random amplified polymorphic DNA and microsatellite markers. Only C. acutatum was recovered from diseased fruit. Nearly all isolates from crowns were C. gloeosporioides. In crown bioassays, only isolates of C. gloeosporioides from strawberry caused collapse and death of plants. A dendrogram generated from the genetic analysis identified several primary lineages. One lineage included isolates of C. acutatum from fruit and was characterized by low diversity. Another lineage included isolates of C. gloeosporioides from crowns and was highly polymorphic. The isolates from strawberry formed distinctive clusters separate from citrus isolates. Evaluation of linkage disequilibrium among polymorphic loci in isolates of C. gloeosporioides from crowns revealed a low level of disequilibrium as would be expected in sexually recombining populations. These results suggest that epidemics of crown rot are caused by Glomerella cingulata (anamorph C. gloeosporioides) and that epidemics of fruit rot are caused by C. acutatum.  相似文献   

14.
Molecular analyses of colletotrichum species from almond and other fruits   总被引:1,自引:0,他引:1  
ABSTRACT Isolates of Colletotrichum spp. from almond, avocado, and strawberry from Israel and isolates of the pink subpopulation from almond from the United States were characterized by various molecular methods and compared with morphological identification. Taxon-specific primer analysis grouped the avocado isolates within the species C. gloeosporioides and the U.S. almond and Israeli strawberry isolates within the species C. acutatum. However, the Israeli almond isolates, previously identified morphologically as C. gloeosporioides, reacted with C. acutatum-specific primers. Arbitrarily primed polymerase chain reaction and A+T-rich DNA analyses determined that each population from almond and strawberry was distinct and clonal. Sequence analysis of the complete internal transcribed spacer (ITS) region (ITS 1-5.8S-ITS 2) revealed a similarity of between 97.03 and 98.72% among almond isolates from Israel, C. acutatum almond isolates from the United States, and C. acutatum strawberry isolates from Israel. Similarity of the above populations to that of C. gloeosporioides of avocado was between 92.42 and 92.86%. DNA sequence analysis of the entire ITS region supported the phylogeny inferred from the ITS 1 tree of 14 different Colletotrichum species. Although morphological criteria indicated that the Israeli isolates from almond are unique, this population was grouped within the C. acutatum species according to molecular analyses.  相似文献   

15.
ABSTRACT Ninety-five isolates of Colletotrichum including 81 isolates of C. acutatum (62 from strawberry) and 14 isolates of C. gloeosporioides (13 from strawberry) were characterized by various molecular methods and pathogenicity tests. Results based on random amplified polymorphic DNA (RAPD) polymorphism and internal transcribed spacer (ITS) 2 sequence data provided clear genetic evidence of two subgroups in C. acutatum. The first subgroup, characterized as CA-clonal, included only isolates from strawberry and exhibited identical RAPD patterns and nearly identical ITS2 sequence analysis. A larger genetic group, CA-variable, included isolates from various hosts and exhibited variable RAPD patterns and divergent ITS2 sequence analysis. Within the C. acutatum population isolated from strawberry, the CA-clonal group is prevalent in Europe (54 isolates of 62). A subset of European C. acutatum isolates isolated from strawberry and representing the CA-clonal and CA-variable groups was assigned to two pathogenicity groups. No correlation could be drawn between genetic and pathogenicity groups. On the basis of molecular data, it is proposed that the CA-clonal subgroup contains closely related, highly virulent C. acutatum isolates that may have developed host specialization to strawberry. C. gloeosporioides isolates from Europe, which were rarely observed were either slightly or nonpathogenic on strawberry. The absence of correlation between genetic polymorphism and geographical origin in Colletotrichum spp. suggests a worldwide dissemination of isolates, probably through international plant exchanges.  相似文献   

16.
Fungal isolates from chilli ( Capsicum spp.) fruits in Thailand that showed typical anthracnose symptoms were identified as Colletotrichum acutatum , C . capsici and C . gloeosporioides . Phylogenetic analyses from DNA sequence data of ITS rDNA and β-tubulin ( tub 2) gene regions revealed three major clusters representing these three species. Among the morphological characters examined, colony growth rate and conidium shape in culture were directly correlated with the phylogenetic groupings. Comparison with isolates of C . gloeosporioides from mango and C . acutatum from strawberry showed that host was not important for phylogenetic grouping. Pathogenicity tests validated that all three species isolated from chilli were causal agents for chilli anthracnose when inoculated onto fruits of the susceptible Thai elite cultivar Capsicum annuum cv. Bangchang. Cross-infection potential was shown by C . acutatum isolates originating from strawberry, which produced anthracnose on Bangchang. Interestingly, only C . acutatum isolates from chilli were able to infect and produce anthracnose on PBC 932, a resistant genotype of Capsicum chinense . This result has important implications for Thai chilli breeding programmes in which PBC 932 is being hybridized with Bangchang to incorporate anthracnose resistance into chilli cultivars.  相似文献   

17.
Colletotrichum acutatum and C. gloeosporioides Cause Anthracnose on Olives   总被引:1,自引:0,他引:1  
Morphological and cultural features and restriction fragment length polymorphism analysis of ITS regions, including 5.8S rDNA, from 26 isolates of Colletotrichum species revealed that isolates from olive fruits, previously identified as C. gloeosporioides, belong to two taxa: C. acutatum and C. gloeosporioides. Comparison of both ITS sequence data with reference isolates confirmed the presence of both species in olives affected by anthracnose disease.  相似文献   

18.
ABSTRACT Anthracnose, caused by Colletotrichum sp., is a serious problem of lupins (Lupinus spp.) worldwide. Morphological characters and molecular markers were used to characterize 43 Colletotrichum isolates from lupins, 8 isolates from other hosts, and 18 reference isolates representing related Colletotrichum spp., to assess the pathogen diversity and resolve its taxonomy. All lupin Colletotrichum isolates tested positive with C. acutatum-specific polymerase chain reaction (PCR) and did not test positive with C. gloeosporioides-specific PCR. Spore shape and colony diameter as well as insensitivity to benomyl grouped the lupin anthracnose isolates closer to C. acutatum than to C. gloeosporioides. Analysis of internal transcribed spacer (ITS) sequences of 57 Colletotrichum isolates grouped all lupin isolates with C. acutatum and distinct from C. gloeosporioides. Further, tub2 and his4 sequences revealed groups concordant with ITS, reducing the excessive dependence on the latter. Arbitrarily primed-PCR and amplified fragment length polymorphism analyses revealed intraspecific subgroups, but neither was useful to decipher species level relationships. ITS, tub2, and his4 results strongly support designating lupin anthracnose pathogen as C. acutatum or its subspecies. Most Colletotrichum isolates from lupins from worldwide locations are genetically homogeneous and form a distinct subgroup within C. acutatum. Present results also underline the potential of the C. acutatum-specific PCR for routine pathogen diagnosis.  相似文献   

19.
Four forms of Colletotrichum representing three distinct virulence phenotypes were found associated with foliar anthracnose of yam in Nigeria: the highly virulent (= severity of disease) slow-growing grey (SGG); the moderately virulent fast-growing salmon (FGS); the weakly virulent fast-growing grey (FGG); and the moderately virulent fast-growing olive (FGO) morphotype. Isolates of the four forms were identified as C. gloeosporioides , based on morphology. The reaction of monoconidial cultures on casein hydrolysis medium (CHM), PCR-RFLP and sequence analysis of the internal transcribed spacer region of the ribosomal DNA (ITS1-5·8S-ITS2) were used to establish the identity of the yam anthracnose pathogen(s). All yam isolates were distinguished from C. acutatum by the absence of protease activity on CHM. On ITS PCR and enzymatic digestion of PCR products, all FGS, FGO and SGG isolates produced RFLP patterns identical to those of C. gloeosporioides reference isolates, while FGG isolates revealed unique ITS RFLP banding patterns. Sequence analysis of the ITS1 region and of the entire ITS region revealed that SGG, FGS and FGO isolates were highly similar (98–99% nucleotide identity) and showed 97–100% identity to C. gloeosporioides . Less than 93% similarity of these fungal isolates to reference C. acutatum and C. lindemuthianum isolates was observed. The molecular study confirmed that foliar anthracnose of yam is caused by C. gloeosporioides . While a high similarity was found among most C. gloeosporioides fungi from yam, isolates of the FGG form did not cluster with any previously described Colletotrichum species, and probably represent a distinct species.  相似文献   

20.
ABSTRACT This study was conducted to identify the species of Colletotrichum infecting tamarillo, mango, and passiflora in Colombia and to assess whether cross-infection between host species is occurring. Isolates of Colletotrichum spp. from tamarillo (n = 54), passiflora (n = 26), and mango (n = 15) were characterized by various molecular methods and by morphological criteria. Morphological characterization grouped the tamarillo isolates as C. acutatum and the passiflora and mango isolates as C. gloeosporioides. Species-specific primer analysis was reliable and confirmed grouping of the tamarillo isolates (besides Tom-6) as C. acutatum and the mango isolates (besides Man-76) as C. gloeosporioides. However, DNA of the passiflora isolates was not amplified by either C. acutatum- or C. gloeosporioides-specific primers, but reacted with a new primer, Col1, designed according to the internal transcribed spacer (ITS) 1 region of these isolates. Isolates Tom-6 and Man-76 also reacted positively with the Col1 primer. All the isolates reacting with the C. acutatum- and C. gloeosporioides-specific primers failed to react with primer Col1. Isolate Pass-35 from passiflora did not react with any of the taxon-specific primers. Arbitrarily primed polymerase chain reaction (ap-PCR), random amplified polymerase DNA (RAPD)-PCR, and A+T-rich DNA analyses delineated representative isolates into subgroups within the designated species. Molecular analyses indicated that the C. acutatum tamarillo isolates were uniform or clonal, whereas the C. gloeosporioides mango isolates and Colletotrichum passiflora isolates were heterogeneous. Likewise, sequence analysis of the complete ITS (ITS1-5.8S-ITS2) region identified certain isolates to their respective species: tamarillo isolates as C. acutatum; mango isolates as C. gloeosporioides; passiflora, Tom-6, and Man-76 isolates as a Colletotrichum sp. as yet undefined; and the Pass-35 isolate as an additional undefined Colletot-richum sp. Molecular analyses of the population of Colletotrichum isolates from passiflora, Tom-6 from tamarillo, and Man-76 from mango indicate that this population may not be host specific.  相似文献   

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