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1.
黄淮海夏玉米主产区穗腐病病原菌的分离鉴定   总被引：6，自引：0，他引：6  
为明确我国黄淮海夏玉米主产区玉米穗腐病的病原菌种类、优势种群及虫害、年度、省份对病原菌的影响,以形态学为基础,结合分子生物学方法对2013、2015年随机采自河南、河北、山东3省的155份玉米穗腐病样品进行分离鉴定。结果表明,引起黄淮海夏玉米主产区玉米穗腐病的主要致病菌为镰孢菌Fusarium spp.,包括拟轮枝镰孢F.verticillioides、禾谷镰孢F.graminearum、层出镰孢F.proliferatum、木贼镰孢F.equiseti及藤仓镰孢F.fujikuroi,分离频率分别为49.7%、28.4%、12.3%、3.9%和1.3%;其次为木霉菌Trichoderma spp.,包括哈茨木霉T.harzianum、绿色木霉T.viride和棘孢木霉T.asperellum,分离频率分别为8.4%、3.2%和5.2%;青霉菌Penicillium spp.分离频率较低,为14.2%;曲霉菌Aspergillus spp.包括黑曲霉A.niger和黄曲霉A.flavus,分离频率分别为2.6%和1.9%。研究表明,黄淮海主产区玉米穗腐病优势病原菌为拟轮枝镰孢、禾谷镰孢和木霉菌,不同省份不同年度间病原菌种类及优势病原菌存在差异,虫害能加重玉米穗腐病的发生。  相似文献   

2.
Eutypa lata is an ascomycete fungus causing a severe dieback in grapevine. The genetic structure of populations of E. lata from seven regions in Australia, France, Italy and Spain was examined using 20 random amplified polymorphic DNA (RAPD) markers. In some regions, populations were subdivided and a total of 14 samples were analysed. A total of 231 RAPD haplotypes were found among the 240 isolates. Vegetative compatibility testing further demonstrated that isolates of the same haplotype were genetically distinct. Gene diversity was the highest in the population from northern Italy and lowest in the Alsace region in France. Linkage disequilibrium between pairs of putative loci was very low and most of the multilocus analyses were consistent with the hypothesis of random association of the loci. This suggests that random mating occurred in every population and that the sexual stage shapes the genetic structure of E. lata populations in the regions sampled. Only 6% of the total variability was attributable to differences between populations. Nevertheless, significant differences in allele frequency appeared with respect to six RAPD markers indicating some genetic differentiation between populations. This differentiation appeared attributable to differences between the Italian and Spanish populations and the other populations. We thus hypothesize that a restriction of gene flow exists within Europe. The population from Australia was genetically closer to the French and Spanish populations than to that from Italy. Genetic diversity is associated with considerable variation in aggressiveness, which was assessed on cuttings in the greenhouse in six populations. All populations included a range of isolates differing in aggressiveness, but the Italian population seemed to have more isolates with low aggressiveness.  相似文献   

3.
Despite being closely related to Fusarium graminearum, which has been extensively characterized in many countries around the world, the population biology of Fusarium pseudograminearum, the main causal agent of crown rot of wheat in Australia and many other wheat‐growing regions, has been comparatively poorly studied to date. A simple sequence repeat analysis of 163 F. pseudograminearum isolates from three field sites in NSW, Australia identified 128 distinct multilocus genotypes. Observed genetic diversity within fields was high, whilst genetic variation between fields was low. Across all fields genetic linkage disequilibrium was detected, but of the three individual fields, only one also displayed linkage disequilibrium. These results indicate that the isolates obtained were part of the same, highly diverse, population. However, this population may not be freely interbreeding. Whilst isolation incidence of F. pseudograminearum was found to be spatially aggregated within fields, spatial aggregation of genotypes within fields was weak. The study suggests that processes influencing population dynamics may operate at a scale larger than the narrow geographical scale covered in the fields sampled.  相似文献   

4.
为明确糖苷水解酶16（glycoside hydrolase,GH16）家族基因在拟轮枝镰孢菌Fusarium verticillioides生长发育和致病过程中的作用,利用生物信息学分析软件对其GH16家族成员进行鉴定,采用转录组分析及实时荧光定量PCR技术对GH16家族成员在不同培养温度下的表达水平进行检测,并通过遗传转化法对家族成员FvGH16-2基因进行敲除及回补,分析其在拟轮枝镰孢菌生长发育及致病过程中的作用。结果显示,在拟轮枝镰孢菌基因组中共鉴定到23个GH16家族基因,其中FvCH16-2、FvCH16-4和FvCH16-12等多个上调表达基因与病菌的生长和抗逆性相关。敲除FvGH16-2基因导致拟轮枝镰孢菌的生长速率及产孢能力降低,细胞壁完整性受损,对H2O2更加敏感,同时对玉米籽粒和茎秆的致病力减弱。表明FvGH16-2基因在拟轮枝镰孢菌生长发育和致病过程中发挥着重要作用,是拟轮枝镰孢菌细胞壁完整性和致病性所必需的。  相似文献   

5.
Rice blast caused by Pyricularia oryzae is a devastating disease worldwide. In Vietnam, rice blast is especially severe in the Red River Delta in the North. The genetic diversity of 114 P. oryzae isolates collected from rice in 2001 in the Red River Delta and nine additional Vietnamese P. oryzae isolates was analysed using Amplified Fragment Length Polymorphism (AFLP). DNA similarity and cluster analysis based on 160 polymorphic AFLP markers showed twelve different AFLP genetic groups among the 123 field isolates. Isolates collected from japonica hosts clustered separately from indica host isolates with at least 60% dissimilarity with little evidence for gene flow between the two populations. In the 2001 population originating from indica hosts, three genetic groups were predominant and represented 99% of the isolates sampled. One predominant clonal lineage represented 59% of the 2001 indica host population and was found in eleven provinces in the Red River Delta of North Vietnam. Significant genotype flow could be demonstrated between the indica population south of Red river and the indica population north of Red river. There was significant linkage disequilibrium between the AFLP loci within the indica population, indicating that this is not a random mating population. Pathogenicity tests of 25 isolates selected from the 12 AFLP groups on a set of 29 differential rice lines revealed two avirulent isolates and 23 pathotypes. Different combinations of known resistance genes were found to have potential for blast resistance breeding for North Vietnam. First two authors contributed equally  相似文献   

6.
Several Fusarium species occurring worldwide on maize as causal agents of ear rot, are capable of producing mycotoxins in infected kernels, some of which have a notable impact on human and animal health. The main groups of Fusarium toxins commonly found are: trichothecenes, zearalenones, fumonisins, and moniliformin. In addition, beauvericin and fusaproliferin have been found in Fusarium-infected maize ears. Zearalenone and deoxynivalenol are commonly found in maize red ear rot, which is essentially caused by species of the Discolour section, particularly F. graminearum. Moreover, nivalenol and fusarenone-X were often found associated with the occasional occurrence of F. cerealis, and diacetoxyscirpenol and T-2 toxin with the occurrence of F. poae and F. sporotrichioides, respectively. In addition, the occurrence of F. avenaceum and F. subglutinans usually led to the accumulation of moniliformin. In maize pink ear rot, which is mainly caused by F. verticillioides, there is increasing evidence of the wide occurrence of fumonisin B1. This carcinogenic toxin is usually found in association with moniliformin, beauvericin, and fusaproliferin, both in central Europe due to the co-occurrence of F. subglutinans, and in southern Europe where the spread of F. verticillioides is reinforced by the widespread presence of F. proliferatum capable of producing fumonisin B1, moniliformin, beauvericin, and fusaproliferin.  相似文献   

7.
Fungal incidence and mycotoxin contamination of farm-stored maize were assessed and compared in grain samples from three villages each in two agroecological zones over time. Maize samples were collected at 2 and 4 months after stocking from 72 farmers’ stores in 1996 and 1997 in the Humid Forest (HF) and Western Highlands (WHL) of Cameroon. Mycological assays of these samples revealed several fungal species.Nigrospora spp. were the most prevalent fungi in HF (32%) and WHL (30%) in 1996,Fusarium verticillioides (22%) andF. graminearum (27%) were also isolated from these samples. In the WHL in 1996, no significant difference in fungal incidence was found among villages for samples collected 2 months after harvest, but at 4 months incidence was significantly higherP<0.05). In 1997 the levels of fungal contamination were lower than in 1996. The incidence ofAspergillus spp. was low in general, ranging from 0.0 to 5.9% infected kernels. Analysis with thin layer chromatography detected low levels of aflatoxins in a few samples.F. verticillioides mycotoxin fumonisin Bi (300-26,000 ng/g) andF. graminearum metabolites deoxynivalenol (<100–l,300 ng/g) and zearalenone (<50–110 ng/g) were determined by means of polyclonal antibody competitive direct enzyme-linked immunosorbent assay. A significant correlation (r=0.72; P=0.0001) was found between the incidence ofF. graminearum and the contamination with deoxynivalenol. Storage time (2vs 4 months after stocking) had a significant positive effect (r=0.39; P=0.013) on the level of fumonisin B1. This is the first report of the natural occurrence of these mycotoxins in maize in Cameroon.  相似文献   

8.
Didymella fabae is a highly destructive fungal pathogen of faba bean (Vicia faba) that represents a significant yield‐limiting biotic constraint in all locations where the crop is grown. However, nothing is known about the population structure of this pathogen anywhere in the world. Population genetic analyses employing 18 sequence‐tagged microsatellite (STMS) markers covering eight genetic linkage groups and a PCR‐based mating type marker were used to elucidate the genetic structure and reproductive mode of the pathogen in three populations in Syria. High gene diversity within populations but low genetic differentiation among populations was observed and the entire collection of isolates was assigned to a single genetic population using a Bayesian clustering algorithm. Independent analyses were performed based on four unlinked sets of STMS markers to infer reproductive mode. A simulation approach was used to estimate which of the repeated multilocus genotypes were probably the result of asexual reproduction and should be clone‐corrected. A 1:1 ratio of mating types could not be rejected in any clone‐corrected population, probably due to small sample sizes. Likewise, frequency of clones and sample size, but not marker linkage, had strong effects on multilocus gametic disequilibrium. The null hypothesis of random mating was rejected in the majority of populations for both non‐clone‐corrected and clone‐corrected samples and with four sets of unlinked markers indicating a predominance of asexual reproduction in these populations. This represents the first detailed screening of clonal and genetic composition of D. fabae populations in Syria.  相似文献   

9.
The occurrence of Fusarium species of Liseola section and related toxins was investigated for two years (1996 and 1998) on maize ear rot samples collected in the most important areas for maize growing in Slovakia. The species most frequently isolated was F. verticillioides, followed by F. proliferatum in 1996 and F. subglutinans in 1998. Most of the strains belonged to mating populations A, D, and E of the teleomorph Gibberella fujikuroi. Fusarium graminearum was also frequently recovered in both the years of investigations. Toxin analysis of maize ears showed that most of the samples (21 out of 22) were contaminated with at least one toxin. In particular, the concentration of fumonisin B1, and fumonisin 2 was up to 26.9 and 5.1gg-1, respectively in 1996, and up to 12.1 and 6.3gg-1, respectively in 1998. Beauvericin was detected only in one sample in 1996. Seven samples in 1996 were contaminated by fusaproliferin up to 8.2gg-1, but just traces of the toxin were found in one sample in 1998. All 29 strains of F. verticillioides, two of three strains of F. proliferatum and none of eight F. subglutinans strains isolated from samples produced fumonisin B1 in culture on whole maize kernels (0.1–5646 and 940–1200ugg-1, respectively). Two strains of F. subglutinans and two of F. proliferatum produced beauvericin (up to 65 and 70gg-1, respectively). Ten strains of F. verticillioides produced beauvericin: 9 strains produced a low amount (up to 3gg-1), while only one of them produced a high level of toxin (375gg-1). Fusaproliferin was produced by two F. proliferatum strains (220 and 370gg-1), by seven F. subglutinans (20–1335gg-1) and by three F. verticillioides (10–35gg-1). This is the first report on fusaproliferin production by F. verticillioides, although at low level.  相似文献   

10.
Fusarium proliferatum can occur on a wide range of economically important vegetable plants but its role in disease is not always well established. In 2000 and 2001, from forty-one field samples of wilting onion and garlic plants in Serbia, F. proliferatum as the predominant fungal species was isolated from root and bulbs. Seventy isolates were firstly characterized for their sexual fertility and were shown to be mostly members of Gibberella intermedia (sixty-seven of seventy isolates, the remaining three isolates were unfertile), the sexual stage of F. proliferatum (syn. mating population D of G. fujikuroi complex). A selected set of eleven F. proliferatum isolates from both hosts were also tested for their pathogenicity and toxigenicity. Although onion and garlic plants were susceptible to all isolates, onion plants showed a significantly higher disease severity index. Six of the eleven isolates of F. proliferatum produced fumonisin B1 from 25 to 3000 μg g−1, and beauvericin from 400 to 550 μg g−1; ten isolates produced fusaric acid from 80 to 950 μg g−1 and moniliformin from 50 to 520 μg g−1. Finally, all isolates produced fusaproliferin up to 400 μg g−1. These results confirm F. proliferatum as an important pathogen of garlic and onion in Europe and that there is a potential mycotoxin accumulation risk in contaminated plants of both garlic and onion.  相似文献   

11.
The development of new maize hybrids with resistance to Fusarium infection is an effective means of minimizing the risk of mycotoxin contamination. Several maize hybrids have been investigated for Fusarium ear rot and accumulation of fumonisin B1 (FB1), fumonisin B2 (FB2), beauvericin (BEA) and fusaproliferin (FP) after artificial inoculation in the field with toxigenic strains of Fusarium verticillioides and Fusarium proliferatum. The year of inoculation had a significant influence on the disease severity and mycotoxin accumulation in maize kernels. Of all the hybrids tested, only Mona exhibited resistance to ear rot caused by F. verticillioides and produced low levels of fumonisins during three years of experiments. In Fusarium-damaged kernels (FDK), fumonisin B1, fumonisin B2, beauvericin and fusaproliferin were detected at concentrations much higher (up to 10–20 times) than in healthy-looking kernels (HLK). Animal and human exposure to these mycotoxins can be drastically reduced by removing mouldy and visibly damaged kernels from the commodity.  相似文献   

12.
The heterothallic ascomycete Fusarium fujikuroi (teleomorph: Gibberella fujikuroi) is the causal agent of bakanae of rice, a disease of increasing economic importance in the major rice‐producing areas in the world and a serious threat for Italian rice cultivation. A few studies have characterized F. fujikuroi isolates in America and the Philippines but no data are available on the genetic structure of Italian pathogen populations. Microsatellite SSRs are useful tools to study the intraspecific diversity at population level. In this study, 19 polymorphic SSRs have been identified and applied to characterize the genetic variation of 334 isolates of F. fujikuroi coming from eight Italian rice‐growing areas. A high degree of diversity at haplotype level has emerged: in the eight populations, 107 unique haplotypes were scored. Analysis of molecular variance (amova ) showed that 98% of genetic variability occurred within F. fujikuroi Italian populations, as confirmed by the allelic Shannon index ranging from 0.56 to 1.06. The presence of a 1:1 ratio of mating type alleles in six out of eight of the Italian fungal populations suggests a potential for sexual reproduction in the field. However, the high fraction of clonality (43%), confirmed by neighbour‐joining clustering analysis, and the high level of linkage disequilibrium observed, indicates that reproduction of F. fujikuroi is mostly clonal in Italy. All data suggest that the observed genetic variability was probably mediated by human activity and transmission by rice seeds.  相似文献   

13.
Fusarium verticillioides(Gibberella moniliformis, G. fujikuroi mating population A) is an important pathogen of maize and produces several mycotoxins, including fumonisins, which cause diseases in humans and animals. The partial sequences of the IGS region (Intergenic Spacer of rDNA units) and the translation elongation factor EF-1α gene of a representative sample (48 strains) of F. verticillioides isolated from diverse hosts, geographical origins and with different levels of fumonisin production were analyzed. A phylogenetic approach by PAUP was used to evaluate the genetic variability in this species and to detect the occurrence of lineages which could be associated with different hosts or produced different toxin profiles within this species. Genetic variability detected by both sequences was high, especially with the IGS sequence which showed a high number of parsimony-informative sites and nucleotide diversity. The results of the phylogenetic analysis indicated that F. verticillioides occurs as (i) a major fumonisin-producing population with a wide geographical distribution, wide host preferences (cereals), showing variability and considerable incidence of sexual reproduction and (ii) a minor fumonisin non-producing population, with restricted host preference (banana), low variability and clonal reproductive strategy.  相似文献   

14.
Bipolaris oryzae causes brown spot in rice (Oryza sativa) inflicting substantial grain yield losses worldwide. Knowledge of the population structure, genetic diversity and sexual recombination of the fungal pathogen can help to implement effective disease management strategies. In this study, B. oryzae isolates sampled from Iran, the Philippines and Japan were analysed with 12 simple‐sequence repeat (SSR) markers, newly developed from the genome sequence of the fungus. Among the 288 B. oryzae isolates genotyped, 278 unique haplotypes were identified. High genotype numbers (richness) with even distribution (evenness) were found within the collection sites. Both mating types, MAT1‐1 and MAT1‐2, were present in each collection area, and the sexual state was induced under controlled conditions with production of viable ascospores. However, the tests of linkage disequilibrium rejected of the hypothesis of random mating. Discriminant analysis of principal components (DAPC) revealed that the B. oryzae collection formed three clusters, each consisting of isolates from different collection sites. Analysis of molecular variance (amova ) showed that genetic variation among clusters was 18.7%, with the rest of the variation distributed within clusters (RST = 0.187, P < 0.001). Statistically significant pairwise genetic differentiation was found between the clusters. These results show that Asian B. oryzae isolates are genetically diverse, and, overall, distributed in three groups. These findings will be helpful in managing the disease and guide the use of representative isolates needed for selection of resistant rice varieties.  相似文献   

15.
We isolated eight polymorphic microsatellite markers for the basidiomycete Armillaria cepistipes and characterised them by analysing 50 isolates representing two geographically distinct populations from Switzerland and the Ukraine. The number of alleles per locus and population varied from one to eight, resulting in 43 alleles over the eight loci and two populations. In both populations, no significant linkage disequilibrium was observed between pairs of loci. Significant (P < 0.05) deviations from Hardy-Weinberg equilibrium were observed at one locus in the Swiss population and at three loci in the Ukrainian population. Of the eight loci developed for A. cepistipes, six were also polymorphic in A. gallica, four in A. ostoyae, two in A. mellea, and one in A. borealis. Beside the potential to be used for population genetic studies on A. cepistipes, these microsatellites thus represent additional molecular markers for three of the four annulated Armillaria species occurring in Europe.  相似文献   

16.
The objective of this study was to assess the genetic diversity and to infer the mode of reproduction of Botrytis elliptica and B. tulipae in the Netherlands. First, three molecular typing methods were compared for their ability to differentiate isolates of B. tulipae, B. elliptica, and B. cinerea. The methods compared were multilocus sequencing, restriction analysis of the ribosomal intergenic spacer (IGS) region, and amplified fragment length polymorphism (AFLP) analysis. AFLP fingerprinting provided the most efficient method to differentiate isolates within each Botrytis species and therefore this method was used for population analyses of B. elliptica and B. tulipae. Isolates of both species were sampled during successive growing seasons in experimental field plots in Lisse and other locations in the Netherlands. Among 174 B. elliptica isolates, 105 genotypes could be discriminated and 87 genotypes were found only once, reflecting high genotypic variation. Clonal genotypes were found only within growing seasons and in one location. Linkage disequilibrium analyses indicated that between 9.4% and 19.3% of the loci in clone-corrected samples were linked. The multilocus association index provided no evidence for random mating. We conclude that sexual recombination occurs in the B. elliptica population. Among the 170 B. tulipae isolates, 25 genotypes could be discriminated and four genotypes were found only once, reflecting a low genotypic variation. Clonal genotypes were frequently found in different growing seasons and different locations. Linkage disequilibrium analyses indicated that between 25.2% and 48.6% of the loci in clone-corrected samples were linked. We conclude that the B. tulipae population is mainly clonal with some recombination.  相似文献   

17.
The phytotoxicity of the Fusarium trichothecene and fumonisin mycotoxins has led to speculation that both toxins are involved in plant pathogenesis. This subject has been addressed by examining virulence of trichothecene and fumonisin-nonproducing mutants of Fusarium in field tests. Mutants were generated by transformation-mediated disruption of genes encoding enzymes that catalyze early steps in the biosynthesis of each toxin. Two economically important species of Fusarium were selected for these studies: the trichothecene-producing species Fusarium graminearum, which causes wheat head blight and maize ear rot, and the fumonisin-producing species F. verticillioides, which causes maize ear rot. Trichothecene-non-producing mutants of F. graminearum caused less disease than the wild-type strain from which they were derived on both wheat and maize, although differences in virulence on maize were not observed under hot and dry environmental conditions. Genetic analyses of the mutants demonstrated that the reduced virulence on wheat was caused by the loss of trichothecene production rather than by a non-target mutation induced by the gene disruption procedure. Although the analyses of virulence of fumonisin-non-producing mutants of F. verticillioides are not complete, to date, the mutants have been as virulent on maize ears as their wild-type progenitor strains. The finding that trichothecene production contributes to the virulence of F. graminearum suggests that it may be possible to generate plants that are resistant to this fungus by increasing their resistance to trichothecenes. As a result, several researchers are trying to identify trichothecene resistance genes and transfer them to crop species.  相似文献   

18.
Spot blotch, caused by Cochliobolus sativus (Ito & Kuribayashi) Drechs. ex Dastur, is one of the important diseases of wheat worldwide. The main objective of this study was to investigate the phenotypic and genotypic variability among C. sativus isolates from the hills and plains in Nepal. A total of 48 monoconidial isolates of C. sativus from the hills (n = 24 isolates) and plains (n = 24 isolates) in Nepal were analyzed for morphology, aggressiveness and genetic structure. C. sativus isolates were grouped into three categories on the basis of their colony texture and mycelia colour. Thirteen isolates from the hills and plains belonging to three morphological groups were randomly selected and evaluated for aggressiveness on eight wheat cultivars (Chirya 1, Chirya 7, Milan/Shanghai 7, SW 89–5422, PBW 343, BL 1473, BL 3036, and RR 21) at the seedling stage. Nonparametric analysis revealed that the isolates from the plains (median disease rating of 5) were significantly (P = 0.0001) more aggressive than the isolates from the hills (median disease rating of 3). A significant (P = 0.0001) isolate by cultivar interaction was demonstrated and the isolates from the same geographic region and morphological group displayed different degrees of aggressiveness on wheat cultivars tested. Combined IS-PCR and rep-PCR analyses revealed moderate gene diversity (H = 0.24 and 0.25 for the hills and plains, respectively). Low linkage disequilibrium (LD) value and non-significant (P = 0.001) population differentiation (G″ST = 0.05) were detected, indicating that isolates of C. sativus from the hills and plains in Nepal were genetically similar. Analysis of molecular variation (AMOVA) revealed low (7%) levels of genetic variation between the hill and plain populations, whereas >93% of genetic variation was found within populations. Overall, C. sativus isolates from Nepal are pathologically and genetically diverse, and such information will be useful in developing wheat cultivars resistant to C. sativus.  相似文献   

19.
为开发可用于拟轮枝镰孢菌Fusarium verticillioides及其近缘种遗传多样性分析的SSR引物,利用生物信息学方法和PCR技术,通过对从NCBI下载的87 086条拟轮枝镰孢菌的EST序列信息进行分析,设计EST-SSR引物,检测其在拟轮枝镰孢菌及其近缘种中的扩增情况,并用筛选出的多态性引物对15株拟轮枝镰孢菌进行SSR遗传多样性分析。结果表明,在EST序列中,共查找到11 952个SSR位点,592种重复基元,SSR出现频率为1.09%,重复基元出现数量最多的为三核苷酸(54.00%),其中(CAA/TTG)n基元出现频率最高。设计的25对EST-SSR引物在拟轮枝镰孢菌种内的有效扩增率和多态率分别为80.00%与32.00%,对5种近缘镰孢菌种的通用率和多态率分别为40.00%和8.00%。遗传多样性分析结果表明,在相似系数为0.664水平下,供试菌株可划分为4个SSR类群,但类群的划分与菌株的地理来源无关;不同菌株间存在明显的遗传分化。表明基于拟轮枝镰孢菌EST序列开发的SSR引物可用于拟轮枝镰孢菌及其近缘种的遗传多样性分析。  相似文献   

20.
The leaf spot form of the barley disease net blotch, caused by the fungus Pyrenophora teres f. maculata (PTM), is an increasingly important foliar disease of barley. Studies of population genetic structure and reproductive mode are necessary to make predictions of the evolutionary potential of the pathogen. Sources of resistance to PTM have been found in Iranian landraces, which may have the potential to improve plant breeding efforts. However, little is known about the population genetic structure of this fungus in Iran. In this study, we analysed the frequency of the mating type genes to assess the potential for sexual mating of PTM collected from four provinces—Khuzestan, Hamadan, Golestan, and East Azerbaijan—and we investigated the population genetic structure using seven simple sequence repeat markers. High genotype diversity, linkage equilibrium, and equal ratios of mating types frequencies in the PTM populations at Khuzestan and Hamadan support the occurrence of sexual reproduction in these populations, while in Golestan and East Azerbaijan populations, significant gametic disequilibrium and relatively low genotype diversity suggest a higher incidence of clonality or different demographic histories. Unequal mating type frequencies in Golestan confirm a predominance of asexual reproduction. Finally, we found significant evidence for strong population structure with most of the genetic variation represented within regional populations (89%). Overall, our study provides evidence for high genetic variation in Iranian PTM populations, which may be the basis for rapid adaptive evolution in this pathosystem. This highlights the need for integrated efforts to control the disease.  相似文献   

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