首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 859 毫秒
1.
Verticillium dahliae isolates recovered from a new focus of severe Verticillium wilt of cotton in the northeast of Israel were tested for vegetative compatibility using nitrate non-utilizing (nit) mutants and identified as VCG1, which is a new record in Israel. Other cotton isolates of V. dahliae from the northern and southern parts of the country were assigned to VCG2B and VCG4B, respectively. VCG1 isolates induced severe leaf symptoms, stunting and defoliation of cotton cv. Acala SJ-2, and thus were characterized as the cotton-defoliating (D) pathotype, whereas isolates of VCG2B and VCG4B were confirmed as the earlier described defoliating-like (DL) and non-defoliating (ND) pathotypes, respectively. This is the first record of the D-pathotype in Israel. The host range of representative isolates of each VCG-associated pathotype was investigated using a number of cultivated plants. Overall, the D isolates were more virulent than DL isolates on all tested host plants, but the order of hosts (from highly susceptible to resistant) was the same: okra (Hibiscus esculentus local cultivar), cotton (Gossypium hirsutum cv. Acala SJ2), watermelon (Citrullus lanatus cv. Crimson Sweet), safflower (Carthamus tinctorius cv. PI 251264), sunflower (Helianthus annuum cv. 2053), eggplant (Solanum melongena cv. Black Beauty), and tomato (Lycopersicon esculentum cv. Rehovot 13). The pattern of virulence of ND isolates differed from that of D and DL isolates, so that the former were highly virulent on eggplant but mildly virulent on cotton. Tomato was resistant to all cotton V. dahliae isolates tested. RAPD and specific PCR assays confirmed that the D isolates from Israel were similar to those originating from other countries.  相似文献   

2.
Verticillium dahliae is a soilborne fungus that causes Verticillium wilt disease in a plethora of crops. Based on symptoms that develop on cotton, olive and okra, V. dahliae isolates are categorized into two pathotypes, namely defoliating and nondefoliating, with the former showing increased virulence and causing severe defoliation. Reliable differentiation between V. dahliae pathotypes is crucial for the management of Verticillium wilt in cotton and olive. In the present study, a polymorphism was detected among isolates of defoliating and nondefoliating pathotypes in Southern blots using the VdNEP gene as a probe. The regions flanking this gene were isolated by inverse PCR and sequence differences in the 3′ untranslated region (3′-UTR) of the VdNEP gene were detected between the two pathotypes. Based on these sequences, primers were designed and assessed to develop a multiplex PCR detection assay. Using this assay, a collection of cotton and olive V. dahliae isolates from Greece and Cyprus was screened, revealing that the defoliating pathotype is present in several regional units of Greece. Thus, this work presents a new, sensitive molecular marker for the differentiation between V. dahliae pathotypes based on the VdNEP gene. Because the 3′-UTR is involved in the phenotypes displayed by the pathotypes, an expression experiment was conducted under conditions simulating the xylem of a host plant. Expression of the VdNEP gene was elevated at all time points in the defoliating compared to the nondefoliating strain, suggesting a possible involvement of VdNEP expression in the defoliation process.  相似文献   

3.
Genetic diversity and phenotypic diversity in Verticillium dahliae populations on cotton were studied among 62 isolates from Spain and 49 isolates from Israel, using vegetative compatibility grouping (VCG), virulence and molecular assays. In Spain, defoliating V. dahliae isolates (D pathotype) belong to VCG1, and non-defoliating isolates (ND) belong to VCG2A (often associated with tomato) and VCG4B (often associated with potato). The D pathotype was not identified in Israel. The ND pathotype in Israel is comprised of VCG2B and VCG4B. Isolates in VCG2B and VCG4B ranged in virulence from weakly virulent to highly virulent. The highly virulent isolates induced either partial defoliation or no defoliation. Virulence characteristics varied with inoculation method and cotton cultivar. Highly virulent isolates from Israel were as virulent as D isolates from Spain under conditions conducive to severe disease. The D pathotype is pathologically and genetically homogeneous, whereas the ND pathotype is heterogeneous with respect to virulence, VCG, and molecular markers based on single-primer RAPD and on PCR primer pairs.  相似文献   

4.
Severe Verticillium wilt of cotton in southern Spain is associated with the spread of a highly virulent, defoliating (D) pathotype of Verticillium dahliae. Eleven of the D and 15 of a mildly virulent, nondefoliating (ND) pathotype were analyzed by random amplified polymorphic DNA (RAPD) using the polymerase chain reaction (PCR). Six of 21 primers tested generated pathotype-associated RAPD bands. Another 21 V. dahliae isolates were compared in blind trials both by RAPD-PCR using the six selected primers and pathogenicity tests on cotton cultivars. There was a 100% correlation between pathotype characterization by each method. Unweighted paired group method with arithmetic averages cluster analysis was used to divide the 47 V. dahliae isolates into two clusters that correlated with the D or ND pathotypes. There was more diversity among ND isolates than among D isolates, these latter isolates being almost identical. ND- and D-associated RAPD bands of 2.0 and 1.0kb, respectively, were cloned, sequenced, and used to design specific primers for the D and ND pathotypes. These pathotype-associated RAPD bands were present only in the genome of the pathotype from which they were amplified, as shown by Southern hybridization. The specific primers amplified only one DNA band of the expected size, and in the correct pathotype, when used for PCR with high annealing temperature. These specific primers successfully characterized V. dahliae cotton isolates from China and California as to D or ND pathotypes, thus demonstrating the validity and wide applicability of the results.  相似文献   

5.
A total of 101Verticillium dahliae isolates were recovered from cotton plants at 57 sites in the Aegean region of Turkey between 2003 and 2004. Isolates were tested for vegetative compatibility by observing heterokaryon formation among complementary nitrate-nonutilizing (nit) mutants. Forty-six isolates were assigned to VCG 1, 12 to VCG 2A, 33 to VCG 2B and four to VCG 4B. The remaining six isolates could not be tested for vegetative compatibility because of their inability to yieldnit mutants. All isolates recovered were tested for pathogenicity on cotton cultivars Acala SJ-1 and Deltapine 15-21 by the stem-injection method. The isolates of VCG 2 and 4B, irrespective of their origin, induced weak to severe symptoms on cotton and were similar to the previously described cotton non-defoliating pathotype. In contrast, all cotton isolates of VCG1 caused severe foliar symptoms, stunting, defoliation and often death. This is the first report on VCG 1 ofV. dahliae in Turkey. http://www.phytoparasitica.org posting May 4, 2007.  相似文献   

6.
Eighty isolates ofVerticillium dahliae from the southeastern Anatolia region and 20 isolates from the east Mediterranean region from wilted cotton plants were used for vegetative compatibility analysis employing nitrate non-utilizing mutants and reference tester strains of vegetative compatibility groups (VCGs) 1A, 2A, 2B, 3, 4A and 4B. Of the 100V. dahliae isolates, 49 were assigned to VCG1A, 39 to VCG2B, nine to VCG2A and three to VCG4B. Pathogenicity assays were conducted on susceptible cotton cv. Çukurova 1518 in the greenhouse. All VCG1A isolates induced defoliation and all VCG2B isolates caused partial defoliation symptoms. Isolates of VCG2A and VCG4B caused typical symptoms of leaf chlorosis without defoliation. This is the first report on VCGs ofV. dahliae in the southeastern Anatolia region of Turkey, which demonstrates that VCG1A of the cotton-defoliating type and VCG2B of the partially defoliating type are prevalent in this region.  相似文献   

7.
Resistance of 23 important olive cultivars to Verticillium dahliae has been evaluated in four experiments under controlled conditions. Nine-month-old nursery olive plants were inoculated with a cotton non-defoliating (ND) (V4) or a cotton defoliating (D) (V117) isolate of V. dahliae. Resistance was evaluated by assessing symptom severity using a 0–4 rating scale and estimating the area under disease progress curves. The percentage of plants killed and of those which recovered from the disease were used as additional parameters for including a particular cultivar into a defined category. Most of the evaluated cultivars were susceptible, although at different levels, to both isolates of V. dahliae. All cultivars were more susceptible to the D pathotype than to the ND one. A group of 11 cultivars, including several important Spanish cultivars, were susceptible or extremely susceptible to both pathotypes of V. dahliae. A second group showed differences of resistance depending on the pathotype used. They were susceptible or extremely susceptible to the D pathotype but resistant or moderately susceptible to the ND one. Finally, 'Frantoio', 'Oblonga' and 'Empeltre' were moderately susceptible to the D isolate of V. dahliae and resistant to the ND one. The resistance of 'Empeltre' was evident by the plant ability to recover from infection with either isolates. 'Empeltre' is considered to be a valuable cultivar for inclusion in breeding programmes for resistance to Verticillium wilt.  相似文献   

8.
为掌握新疆主要植棉区棉花黄萎病的发生现状及其病原菌大丽轮枝菌Verticillium dahliae的落叶型菌系分布以及遗传变异情况,于2015年对26个新疆主要植棉区棉花黄萎病的发生情况进行了随机调查,统计新疆大丽轮枝菌的培养性状,利用大丽轮枝菌落叶型特异引物D1/D2、INTD2F/INTD2R与非落叶型特异性引物ND1/ND2、INTNDF/INTNDR对新疆大丽轮枝菌菌系进行互补鉴定,并对部分菌系的遗传变异进行简单序列重复区间(inter simple sequence repeat,ISSR)分析。结果表明:2015年新疆棉花黄萎病发病田比例为54.0%,其中病情指数在10.0以上的发病田与2013年持平,而病情指数在20.0以上的严重发病田比例为10.8%,比2013年增加3.8个百分点;新疆大丽轮枝菌的培养性状以菌核型为主,比例为70.1%,菌丝型与中间型比例分别为13.4%和16.5%;新疆大丽轮枝菌落叶型菌系比例为53.2%,26株菌株的来源地全部检出落叶型菌系;聚类分析结果显示,当遗传相似系数为0.66时,新疆大丽轮枝菌落叶型与非落叶型菌系聚为2个谱系,菌系地理来源、培养性状与大丽轮枝菌的遗传分化无明显相关性。  相似文献   

9.
Classification of 32 Verticillium dahliae isolates originating from 19 plant species in eight different botanical families to races and determination of host range pathogenicity were carried out. The physiological races of isolates were identified using the two differential tomato cultivars ??Belladonna?? (susceptible to both races 1 and 2 of V. dahliae) and ??Ace 55VF?? (resistant to race 1, susceptible to race 2 of V. dahliae). Among these isolates, 14 were race 2 (43.8%), 12 race 1 (37.5%) and six nonpathogenic (18.7%) on tomato. The host range pathogenicity of isolates was determined using four differential hosts (eggplant, turnip, tomato (Ve ? ) and sweet pepper). Among isolates, five were pathogenic to both eggplant and turnip (15.6%), 21 to eggplant, turnip and tomato (65.6%), five to eggplant, turnip, tomato and sweet pepper (15.6%) and one was pathogenic to eggplant, turnip and sweet pepper (3.2%). The pathogenicity of isolates on the aforementioned five hosts was investigated on the basis of external symptoms and by calculating the relative areas under disease progress curves (relative AUDPC). Results showed that eggplant was the most susceptible, followed by turnip and tomato cv. Belladonna, while sweet pepper and tomato cv. Ace 55VF were less susceptible to all the isolates used. The pathogenicity of isolates varied from highly to mildly virulent on eggplant and turnip while on Belladonna, Ace 55VF and sweet pepper it varied from highly virulent to nonpathogenic. Belladonna exhibited a similar level of susceptibility to races 1 and 2 of V. dahliae, but was more susceptible than Ace 55VF to race 2. Interestingly, the isolates originating from eggplant were clearly more virulent than those originating from tomato and black nightshade on all solanaceous plants tested.  相似文献   

10.
The chromosome number and electrophoretic karyotype of Japanese isolates of Verticillium dahliae were investigated. In a genomic Southern blot analysis of seven isolates probed with a telomere consensus sequence (TTAGGG)5, 12 or 14 bands were observed. Furthermore, pulsed-field gel electrophoresis (PFGE) of these isolates revealed five or six chromosomal bands. A band (approx. 3.5 Mbp) common to all isolates apparently contained more than two chromosomes. From these results, we concluded that each isolate’s chromosome number is six (an eggplant pathotype isolate) or seven (all isolates of tomato and sweet pepper pathotypes). Although the chromosome sizes differed among isolates, karyotypes were similar within tomato and sweet pepper pathotypes. A small chromosome (approx. 1.8 Mbp) was observed only in the sweet pepper pathotype. Subsequent PFGE-Southern hybridization analyses revealed that the three DNA fragments specific to tomato pathotype are located on the same chromosome. These results suggest that the tomato-pathotype-specific DNA sequences might coexist on one chromosome.  相似文献   

11.
Amplified fragment length polymorphism (AFLP) based genetic diversity was analyzed for 232 Colletotrichum sublineolum isolates collected between 2002 and 2004 from three geographically distinct regions of Texas, and from Arkansas, Georgia, and Puerto Rico. Results revealed significant levels of polymorphism (59%) among the isolates. Even so, genetic similarity between isolates was high, ranging from 0.78 to 1.00. Clustering of similar isolates did not correlate with either geographic origin or year of collection. Pathotypes of 20 of the isolates were determined using 14 sorghum lines previously used in Brazil and the United States and 4 from Sudan. Seventeen new pathotypes were established from the 18 isolates that gave uniform and consistent reactions on all host differentials over 2?years of greenhouse testing. Differentials BTx378 and QL3 were resistant to all isolates while BTx623 and TAM428 were universally susceptible both years. Each of these lines had shown differential responses in prior studies indicating that the pathogen population has sufficient diversity to adapt rapidly to changes in resistant host lines deployed. When the 2-step pathotype classification scheme was used, the 18 isolates examined in this study were placed in four pathotype groups (A, C, D and G), which would further then be separated into ten distinct pathotypes. Common sets of differentials and a standardized nomenclature will allow for comparison to be made among pathotypes of C. sublineolum detected from different regions and also could help direct planting of appropriate sorghum lines and aid in the development of more durable forms of resistance.  相似文献   

12.
Understanding pathogenic variation in plant pathogen populations is key for the development and use of host resistance for managing verticillium wilt diseases. A highly virulent defoliating (D) pathotype in Verticillium dahliae has previously been shown to occur only in one clonal lineage (lineage 1A). By contrast, no clear association has yet been shown for race 1 with clonal lineages. Race 1 carries the effector gene Ave1 and is avirulent on hosts that carry resistance gene Ve1 or its homologues. The hypothesis tested was that race 1 arose once in a single clonal lineage, which might be expected if V. dahliae acquired Ave1 by horizontal gene transfer from plants, as hypothesized previously. In a diverse sample of 195 V. dahliae isolates from nine clonal lineages, all race 1 isolates were present only in lineage 2A. Conversely, all lineage 2A isolates displayed the race 1 phenotype. Moreover, 900‐bp nucleotide sequences from Ave1 were identical among 27 lineage 2A isolates and identical to sequences from other V. dahliae race 1 isolates in GenBank. The finding of race 1 in a single clonal lineage, with identical Ave1 sequences, is consistent with the hypothesis that race 1 arose once in V. dahliae. Molecular markers and virulence assays also confirmed the well‐established finding that the D pathotype is found only in lineage 1A. Pathogenicity assays indicated that cotton and olive isolates of the D pathotype (lineage 1A) were highly virulent on cotton and olive, but had low virulence on tomato.  相似文献   

13.
Verticillium dahliae Klebahn is the causal agent of tomato wilt disease. Isolates of V. dahliae can be classified based on pathogenicity to tomato, but the pathotypes are indistinguishable in morphology. We designed PCR primers for specific detection of isolates pathogenic to tomato (tomato pathotype) from the sequences of a pathotype-specific gene, vdt1. With the primer pair Tg5/Tc3, a PCR product (approximately 3.2 kb) specific to tomato pathotype was amplified from the genomic DNA of isolates. Using the primer pair, a tomato pathotype isolate was specifically detected from hypocotyls of inoculated tomato and eggplant. On the other hand, no amplification was observed from non-tomato pathotype isolates of V. dahliae, some other wilt pathogens of tomato and a healthy host plant. Therefore, the primer pair can be useful for pathotype-specific detection of V. dahliae as well as for diagnosis of wilt disease of tomato plant. Received 7 September 2001/ Accepted in revised form 3 December 2001  相似文献   

14.
Verticillium dahliae isolates from potato on the island of Hokkaido (potato isolates) and those belonging to pathotypes A (eggplant pathotype), B (tomato pathotype) and C (sweet pepper pathotype) were divided into three distinct groups by RAPD and REP-PCR. The three DNA groups I, II, III consisted of pathotypes A and C, pathotype B and potato isolates, respectively. The potato isolates were assigned to pathotype A on the basis of pathogenicity. Another set of potato isolates was further collected from eight potato cropping regions on Hokkaido to further examine the relationships among them in detail. Only one of these isolates was identified as DNA group II, but all the others were classified as DNA group III. Isolates from daikon, eggplant, and melon on Hokkaido also belonged to DNA group III. These results suggest that V. dahliae isolates from Hokkaido are unique at the DNA level and different from other pathotype A isolates in Japan. Received 28 February 2000/ Accepted in revised form 6 November 2000  相似文献   

15.
Clubroot disease caused by Plasmodiophora brassicae is one of the most serious diseases in cruciferous crops. To classify isolates, we developed simple sequence repeat (SSR) markers for P. brassicae. Twenty-four Japanese isolates were used in this study: 12 isolates of an unknown pathotype from the Kyoto Prefecture, as well as 12 isolates of known pathotypes, including three single-spore lines. From the 12 isolates from Kyoto Prefecture, 11 were classified into either pathotype 2 (three isolates) or 4 (eight isolates). We designed 23 SSR markers based on the P. brassicae genome, of which 11 markers from intergenic regions showed polymorphisms in the 24 isolates. Many haploid isolates belonging to pathotypes 2 and 4 were monomorphic, and typical alleles were detected in some isolates not belonging to pathotype 4. Two bands were detected for eight SSR loci in five isolates, indicating that different genotypes were mixed in these isolates. We constructed a phylogram based on the 11 polymorphic SSRs. Pathotypes 2 and 4 formed a cluster, from which pathotypes 3 and 1 were successively placed. These results strongly suggest a close genetic relationship between isolates in pathotypes 2 and 4, consistent with our finding that isolates in these two pathotypes were found at one collection site. In combination with pathotype classification and other marker systems, the SSR markers can be used for more detailed analyses to improve the control of clubroot disease.  相似文献   

16.
Forty-two Brassica rapa and Brassica napus lines were tested for resistance to Turnip mosaic virus (TuMV) isolates representing the three major pathotypes in Europe. Of these lines, 11 were susceptible to all pathotypes; nine were resistant to one pathotype; eight were resistant to two pathotypes; and 14 were resistant to all three pathotypes. Of the lines tested, 23 were either able to, or had the potential to, discriminate between two different pathotype-3 isolates. Genetic models for inheritance of resistance were proposed for four B. rapa lines: Jong Bai No. 2 had dominant resistance to pathotype 1 conferred by a single allele; PI418957C and Jin G 55 had recessive resistance to pathotype 4 where a single allele was required; PI418957C also had recessive resistance to pathotype 3 where a model with one of two epistatic, unlinked loci was proposed. Jong Bai No. 1 also had recessive resistance to pathotype 3, apparently conferred by alleles at three loci, where any two of the three loci were epistatic and required for resistance.  相似文献   

17.
Since 2006, verticillium wilt of olive induced by Verticillium dahliae has caused considerable economic losses in olive orchards in Tunisia. The genetic structure of V. dahliae isolates collected from different olive growing regions was investigated using virulence tests, vegetative compatibility grouping (VCG) and amplified fragment length polymorphism (AFLP) analyses. In total, 42 isolates of V. dahliae from diseased olive trees were tested. Cluster analysis and principal coordinate analysis revealed that geographic origin was the main factor determining the genetic structure of V. dahliae populations and both methods indicated a genetic separation between the central and coastal isolates. Isolates were divided into two major groups: the AFLP‐I group included all isolates from Sidi Bouzid, Kairouan, Kasserine and Sfax (centre of the country) and the AFLP‐II group included isolates from Monastir, Zaghouane, Sousse, Mahdia (coastal region), and two isolates from Sfax. Analysis of the molecular variance (amova ) indicated a significant level of genetic differentiation among (76%) and within (23%) the two populations. Analyses of both the defoliating (D) and non‐defoliating (ND) pathotypes and VCG markers indicated that most of the isolates belong to VCG 2A and 4B/ND pathotype. The disease severity was highly variable among the isolates tested (P < 0·05) with no evidence of association between aggressiveness and geographical origin of the isolates. Overall, results of this study revealed a clear association between the genetic diversity of the isolates and their geographic origin, but not between genetic diversity and virulence patterns.  相似文献   

18.
A comprehensive survey on the prevalence and incidence of Verticillium wilt of olive in Turkey has been conducted over 6 years (2003–2008). Vegetative compatibility group (VCG) assessment and PCR-based molecular pathotyping were used to evaluate the distribution of the defoliating (D) and nondefoliating (ND) pathotypes of Verticillium dahliae in surveyed areas. Pathogen prevalence was 35% of all olive orchards inspected and incidence of the disease reached 3.1%. VCG1A was predominant (29.3%) and infected all major cultivars grown in Turkey. The other two VCGs detected (2A and 4B) were of minor relevance (4.9% and 0.9%, respectively). Disease incidence caused by VCG1A infections was higher (ranging from 1.1% to 6.9%) than that caused by VCG2A and VCG4B in 10 provinces (Manisa, Aydin, Kahramanmaras, Izmir, Mugla, Kilis, Denizli, Gaziantep, Mardin and Balikesir). However, VCG2A and 4B were more prevalent (and responsible for higher disease incidence) than VCG1A in three provinces (Hatay, Osmaniye and Bursa). Finally, VCG1A isolates were found in all provinces except Canakkale, and simultaneous presence of the three VCGs was only verified in Hatay province. An artificial inoculation bioassay (19 representative V. dahliae isolates included) revealed that VCG1A (13) isolates as a group were more aggressive and caused defoliation, whereas VCG2A (5) and VCG4B (1) isolates induced milder symptoms. Within a VCG group, virulence varied among isolates infecting the same olive cultivar and this virulence was also related to the differential susceptibility of the cultivars (‘Manzanilla’, ‘Ayvalik’ and ‘Gemlik’) tested. Molecular pathotyping allowed the identification of D (VCG1A) and ND (VCG2A/4B) pathotypes, which correlated with results from pathogenicity tests. Remarkably, the V. dahliae VCG1A/D pathotype population infecting olive in Turkey was molecularly different from that one previously identified in Spain.  相似文献   

19.
Puccinia triticina reproduces asexually in France and thus individual genotype is the unit of selection. A strong link has been observed between genotype identities (as assessed by microsatellite markers) and pathotypes (pools of individuals with the same combination of qualitative virulence factors). Here, we tested whether differences in quantitative traits of aggressiveness could be detected within those clonal lineages by comparing isolates of identical pathotype and microsatellite profile. Pairs of isolates belonging to different pathotypes were compared for their latent period, lesion size and spore production capacity on adult plants under greenhouse conditions, with a high number of replicates. Isolates of the same pathotype showed remarkably similar values for the measured traits, except in three situations: differences were obtained within two pathotypes for latent period and within one pathotype for sporulation capacity. One of these differences was tested again and confirmed. This indicates that the average aggressiveness level of a leaf rust pathotype may increase without any change in its virulence factors or microsatellite profile.  相似文献   

20.
Korolev N  Katan J  Katan T 《Phytopathology》2000,90(5):529-536
A collection of 565 isolates of Verticillium dahliae, recovered between 1992 and 1997 from 13 host plant species and soil at 47 sites in Israel, was tested for vegetative compatibility using nitrate-nonutilizing (nit) mutants. Three vegetative compatibility groups (VCGs) were found and identified as VCG2A (28 isolates), VCG2B (158 isolates), and VCG4B (378 isolates) by using international reference strains. One isolate was heterokaryon self-incompatible. Of the VCG2B isolates, 92% were recovered from the northern part of Israel and 90% of VCG4B isolates were recovered from the south, with some overlap in the central region. Isolates of the minor group VCG2A were geographically scattered among the two major VCGs. Isolates of the same VCG resembled one another more than isolates from different VCGs based on colony and microsclerotial morphology, temperature responses, and, partially, pathogenicity. Different pathotypes were defined among 60 isolates tested, using cotton (cv. Acala SJ-2) and eggplant (cv. Black Beauty) as differentials. All isolates in VCG2A and 86% of the isolates in VCG4B, irrespective of their origin, induced weak to moderate symptoms on cotton and moderate to severe symptoms on eggplant and were similar to the previously described cotton nondefoliating patho-type. In contrast, all cotton isolates in VCG2B caused severe foliar symptoms, stunting, and often death, but little or no defoliation of inoculated cotton plants. These were defined as a cotton defoliating-like pathotype and induced only weak to moderate symptoms on eggplant. We concluded that vegetative compatibility grouping of V. dahliae in Israel is closely associated with specific pathogenicity and other phenotypic traits.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号