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1.
Fusarium poae has been considered as a minor species among those that cause Fusarium Head Blight (FHB) disease but in recent years several researchers have documented a high frequency of occurrence of this species. In this study, a total of 173 F. poae isolates from Argentina, Belgium, Canada, England, Finland, France, Germany, Hungary, Italy, Luxembourg, Poland, Switzerland and Uruguay were evaluated by using inter simple sequence repeats (ISSR) and amplified fragment length polymorphism (AFLP) to evaluate genetic variability within F. poae and to amplify MAT idiomorphs as a possible mechanism that could explain part of the variability found in this species. The molecular analysis obtained from both molecular markers showed a high intraspecific variability. However, a partial clustering between F. poae isolates and their geographic origin was obtained by ISSR markers while AFLP showed isolates from different geographic locations distributed throughout the dendrogram. Moreover, ISSR grouped all the F. poae isolates into a different cluster from the F. langsethiae and F. sporotrichioides isolates used as outgroups compared with the dendrogram obtained using AFLP markers. Analysis of molecular variance (AMOVA) indicated a high genetic variability in the F. poae collection, with most of the genetic variability resulting from differences within, rather than between, American and European populations by using both molecular markers. Regarding MAT idiomorphs, for most F. poae isolates both MAT-1 and MAT-2 were present from each isolate.  相似文献   

2.
Moniliophthora perniciosa, causal agent of witches’ broom disease in cacao plantations in South America and the Caribbean Islands, has co‐evolved with its host cacao, but the pathogen has also emerged in many solanaceous hosts in Brazil, including economically important food crops and wild species. This study was carried out to: (i) determine the existence of host subpopulations of M. perniciosa in Brazil; (ii) estimate gene and genotypic diversity of M. perniciosa host subpopulations infecting solanaceous hosts in southeastern Bahia and Minas Gerais states, Brazil; and (iii) estimate the amount and directionality of historical migration of M. perniciosa subpopulations. Up to 203 M. perniciosa isolates collected from solanaceous hosts with symptoms from Bahia and Minas Gerais states in Brazil and from Theobroma spp. (cacao) and Herrania spp. were characterized with 11 microsatellite markers. Factorial correspondence analyses, minimum‐spanning network and Bayesian clustering revealed genetic clusters associated with their host of origin. Significant subpopulation differentiation was evident (ΦST = 0.30,  0.05) among M. perniciosa host subpopulations. Most of the multilocus microsatellite genotypes (MLMGs) were host‐specific, with few MLMGs shared among subpopulations. Pairwise comparisons among M. perniciosa host subpopulations were significant, except between jurubeba (Solanum paniculatum) and cultivated solanaceous subpopulations. The combined analyses rejected the null hypothesis that M. perniciosa in Brazil is a single genetic population not structured by host. These findings support a scenario of introduction and subsequent adaptation to solanaceous hosts that should be taken into consideration to improve mitigation and management of M. perniciosa.  相似文献   

3.
Transposable elements (TEs) are distributed throughout the genome and play an important role in genome variation of the rice blast fungus, Magnaporthe oryzae. TE-associated molecular markers have been developed and used extensively for diversity analysis in natural populations. Here, we investigated the genomic distribution of a selected group of TEs that are dispersed as singletons, and each is of a size feasible for PCR validation, designated as SSTEs, in the genome of the reference laboratory strain, 70-15. The 75 SSTEs identified were distributed evenly on seven chromosomes of the M. oryzae genome. Approximately 40 % of SSTEs were located either in the coding or promoter regions of the predicted genes. The presence or absence of each SSTE at the respective locus was assessed, resolving significant presence/absence polymorphism among 11 rice blast strains collected from different locations worldwide. The presence/absence (P/A) polymorphism of SSTEs in different strains suggests that they may be useful for developing map-based land PATE markers for genetic analysis in M. oryzae.  相似文献   

4.
Random amplified polymorphism DNA (RAPD) and bulk segregant analysis (BSA) approaches were used to characterize the molecular marker linked to the Phytophthora infestans resistance gene Ph-3 in tomato. A total of 800 RAPD primers were screened. One RAPD marker UBC#602 was identified to be tightly linked to the Ph-3 gene. The marker was successfully converted into a co-dominant sequence characterized amplified region (SCAR) marker. The SCAR marker SCU602 was used to analyze 96 F2 progenies and fitted the expected 1:2:1 Mendelian segregation ratio. Forty one tomato inbred lines were screened using the SCAR marker in comparison with a reference marker linked to the Ph-3 gene and both markers gave the same results. SCU602 was further validated for association to resistance and its potential in MAS in 72 tomato lines and cultivars. The marker identified three genotypes harbouring the resistance allele. This SCAR marker can be used in breeding programs for the selection of the Ph-3 gene for Phytophthora infestans resistance.  相似文献   

5.
Kansas and California wheat-growing regions differ dramatically in soils, climate, wheat cultivars, crop rotation patterns, and cultural practices, which could select for different fungal populations of Mycosphaerella graminicola. Our objective in this study was to use amplified fragment length polymorphism (AFLP) loci to assess the genetic diversity of M. graminicola populations within single fields in two widely separated, and geographically isolated sites in Kansas and California. Three primer-pair combinations were used to resolve polymorphism at 177 loci in 67 and 63 isolates from Kansas and California, respectively. Genotypic variability was high, which is consistent with a genetically diverse initial inoculum. There was no evidence of genetic disequilibrium in either population, with only 4.6% of the locus pairs in Kansas, and 5.4% of the locus pairs in California in detectable disequilibrium. The migration rate calculated between the two sites was as low as 1.8 individuals per generation, and significant differences in allele frequencies were observed. Therefore, these two populations do not represent mere subsamples of a larger, randomly mating population. This is a rare report of isolation by distance occurring between two North American populations of M. graminicola, indicating that at least some of these populations may be differentiating. Although genetic isolation by distance may occur, we cannot exclude movement of new gene combinations such as fungicide resistance or virulence between these two locations.  相似文献   

6.
The oomycete Phytophthora colocasiae that causes taro leaf blight is the most devastating disease of taro and is widely distributed worldwide. Molecular and phenotypic techniques were employed for assessing and exploiting the genetic variability among four populations of P. colocasiae obtained from a fine spatial scale (multiple leaf blight lesions on single taro leaf). Phenotypic characters such as virulence, morphology and mating type showed no variation. ITS characterization revealed detectable polymorphism among isolates of P. colocasiae. The mean number of haplotypes (H), haplotype diversity (HD), nucleotide diversity (π), and nucleotide substitution rate (θ) among analyzed sequences were 6.75, 1.00, 0.069, and 0.088 respectively. High levels of inter and intra specific variation were detected by random amplified polymorphic DNA (RAPD) assays. Moderate genetic diversity (H?=?0.2651) was observed among populations of P. colocasiae. Analysis of molecular variance (AMOVA) confirmed that most of the genetic variability was confined to within a population (63.54 %). The coefficient of genetic differentiation among populations (G ST ) was 0.2007 and estimates of gene flow (Nm) among populations was 1.991 migrants per generation. Cluster analysis using UPGMA revealed that individuals from the same population failed to cluster in one distinct group. The results of the study reveal considerable genetic diversity among and within populations of P. colocasiae obtained from fine spatial scale. The possible mechanisms and implications of this genetic variation are discussed.  相似文献   

7.
The objectives of this work were to evaluate the genetic variability of Meloidogyne enterolobii by molecular markers, and develop species‐specific molecular markers for application in detection. Sixteen M. enterolobii isolates from different geographical regions (Brazil and other countries) and hosts were used in this study. The identification and purification of the populations were carried out based on isoenzyme phenotype. The DNA amplification of the intergenic region (IGS) of the rDNA and of the region between the cytochrome oxidase subunit II (COII) and 16S rRNA genes (mtDNA) produced specific fragments of the expected size for this nematode, i.e. 780 and 705 bp, respectively. Intraspecific variability among the isolates was evaluated with three different neutral molecular markers: AFLP, ISSR and RAPD. The results showed a low level of diversity among the isolates tested, indicating that M. enterolobii is a genetically homogeneous root‐knot nematode species. The RAPD method allowed the identification of a species‐specific RAPD fragment for M. enterolobii. This fragment was cloned and sequenced, and from the sequence obtained, a set of primers was designed and tested. The amplification of a 520‐bp‐long fragment occurred only for the 16 isolates of M. enterolobii and not for the 10 other Meloidogyne species tested. In addition, positive detection was achieved in a single individual female, egg‐mass and second stage juvenile of this nematode. This SCAR species‐specific marker for M. enterolobii represents a new molecular tool to be used in the detection of this nematode from field samples and as a routine diagnostic test for quarantine devices .  相似文献   

8.
Crinipellis perniciosa causes a serious disease of cacao known as witches broom (WB). Heritable resistance to witches broom has been used in cacao improvement programs. SCA6 and SCA12 are highly resistant and are the most commonly used parents in the breeding schemes. However, SCA hybrids are not resistant to witches broom in all production areas. Presumably, different populations of C. perniciosa cause these variable responses. Amplified fragment length polymorphism (AFLP) markers were used to assess variation and population structure in this pathogen. We examined 40 isolates of C. perniciosa and one isolate of Melanotus subcuneiformis. Nine of 64 primer pairs produced consistent and informative DNA amplification, and were used to screen all isolates. Fifteen haplotypes (AFLP fingerprints) were detected with 186 polymorphic markers. Cluster analysis grouped isolates of the C biotype (pathogenic on cacao) from Bolivia, Brazil, Ecuador and Trinidad together in a major cluster that was distinct from isolates of the S biotype (pathogenic on solanaceous hosts) and M. subcuneiformis. Isolates of the C biotype were divided further into well supported, country-specific groups. Segregation of AFLP alleles was not observed among basidiospore isolates from the same basidiome, broom, tree or field, supporting previous reports that the fungus did not outcross. The results corroborated prior conclusions that C. perniciosa was probably introduced into the Bahia state of Brazil from the Amazon basin. Representative isolates from the genetically distinct groups that were revealed will be used to examine pathogenic specialization in C. perniciosa and differential responses that have been reported in SCA6-derived germplasm.  相似文献   

9.
利用UP-PCR、ISSR和AFLP标记分析玉米丝黑穗病菌遗传多样性   总被引:3,自引:2,他引:1  
利用UP-PCR、ISSR和AFLP分子标记方法研究了我国主要玉米产区34株玉米丝黑穗病菌的遗传多样性。从供试引物中筛选获得具多态性的UP-PCR引物9个、ISSR引物11个和AFLP引物组合22对,分别扩增出113、72和293条谱带,多态性条带比率分别为91.15%、84.7%和83.27%。聚类分析表明,玉米丝黑穗病菌存在丰富的遗传变异,与地理来源无明显相关性。3种分子标记的遗传相似系数矩阵相关性分析表明,UP-PCR与AFLP具有较高的相关性,相关系数为0.698;UP-PCR与ISSR、ISSR与AFLP的相关系数分别为0.659和0.633。从多态性水平、稳定性和可操作性可以看出,UP-PCR技术更适于分析玉米丝黑穗病菌遗传多样性。此外,UP-PCR、ISSR和AFLP标记划分的类群与鉴别寄主划分的致病类型之间存在一定的相关性,吻合率分别为50.0%、60.0%和47.6%。  相似文献   

10.
Meloidogyne incognita is one of the most polyphagous species of root-knot nematodes occurring in Brazil and worldwide. Eight M. incognita isolates were studied, representing two enzymatic phenotypes (esterase and malate desydrogenase: I1/N1, I2/N1) and four cryptic Meloidogyne sp.1 (S2/N1) isolates, representing one cytological type (3n?=?40–46). Three M. hispanica isolates (Hi3/N1, 2n?=?32–36) and two of an atypical Meloidogyne sp.2 (S2a/N3, 3n?=?40–44) were included in this study for comparison. All isolates were tested with three M. incognita-specific molecular markers. The primer pairs B06F/R, miF/R and incK14F/R amplified three species-specific fragments of 1,200?bp, 955?bp and 399?bp, respectively for M. incognita and Meloidogyne sp.1 isolates. No amplification occurred in the M. hispanica and Meloidogyne sp.2 isolates, except with primers miF/R (1,650?bp). The genetic variability of the Meloidogyne spp. isolates was evaluated, using RAPD and ISSR markers. The phylogenetic analyses revealed two strongly supported monophyletic clades: clade I, consisting of M. hispanica and the atypical Meloidogyne sp.2 isolates, and clade II, clustering together all M. incognita and the Meloidogyne sp.1 isolates. Considering the biometrical, cytological and molecular approaches, it was possible to conclude that the isolates with three enzymatic phenotypes (I1/N1, I2/N1 and S2/N1) presented the characteristics described for M. incognita. Some correlations were detected between the isozymatic phenotypes and the tree topology (S2a/N3, Hi3/N1, I1/N1, S2/N1), but no strict correlation could be observed for the phenotype I2/N1 and one isolate of S2/N1. Morphologically, the Msp.2 isolates differ from M. incognita and M. hispanica by the female stylet features presenting straight cone tip and round pear shaped knobs, posteriorly sloping. The results of this study suggested that the Msp.2 isolates with phenotypes S2aN3 belong to a new or an unidentified species closely related to M. hispanica.  相似文献   

11.
Fusarium oxysporum f. sp. ricini (F. o. ricini) is a ubiquitous soil borne pathogen which causes wilt disease on castor (Ricinus communis L). Rapid and reliable detection of the pathogen is essential for undertaking appropriate and timely disease management measures. Identification based on cultural, morphological characteristics and pathogenicity tests are time-consuming and laborious. Traditional methods are now being increasingly replaced by molecular detection techniques, which are much faster and more specific. In this study we have identified two RAPD markers of 1100?bp and 1350?bp in size which can be amplified by OPJ-14 and OPK-12 primers respectively for detection of F. o. ricini. These two fragments were fully sequenced and two pairs of SCAR primers (For-J14 Fwd/Rev and For-K12 Fwd/Rev) were designed. The specific primer pairs amplified a single band from all F. o. ricini isolates and there was no amplification from another thirteen Fusarium species / subspecies tested. These results clearly demonstrate that the designed SCAR primer pairs can be used consistently to detect F. o. ricini isolates, isolated from the diseased samples or soil samples. To our knowledge this is the first report on generation of SCAR markers for identification of Indian F. o. ricini isolates.  相似文献   

12.
采用菌丝生长速率法测定了7种杀菌剂对蘑菇褐腐病菌Mycogone perniciosa Magn.的室内毒力及其中5种杀菌剂对双孢蘑菇Agaricus bisporus的室内安全性,并通过田间小区试验评价了其中6种杀菌剂对蘑菇褐腐病的药效及对双孢蘑菇的安全性。室内测定结果表明:多菌灵、咪鲜胺、噻菌灵、百菌清、苯醚甲环唑及戊唑醇对蘑菇褐腐病菌的毒力均较强,EC50值分别为0.036 9、0.024 5、0.296、0.136、0.036 0和0.058 1 mg/L,福美双毒力较弱,EC50值为88.0 mg/L;多菌灵和百菌清对双孢蘑菇较安全,苯醚甲环唑、戊唑醇及福美双对其有药害风险。田间试验结果表明:按有效成分质量分数计,50%多菌灵可湿性粉剂(WP)250、500和1 000 mg/kg,50%咪鲜胺锰盐WP 333、266和200 mg/kg,75%百菌清WP 375 mg/kg对蘑菇褐腐病的防效较好,且对双孢蘑菇生长无显著影响;而采用43%戊唑醇悬浮剂(SC)143.3、86.0 mg/kg防治褐腐病时,双孢蘑菇的减产率分别为20.54%和13.19%,采用10%苯醚甲环唑可分散粒剂(WG)33.3 mg/kg时,减产率为4.73%,表明这2种杀菌剂对双孢蘑菇的安全性较差,不宜用于防治蘑菇褐腐病;50%福美双WP 1 000 和 500 mg/kg均会造成蘑菇出菇推迟,而166.7 mg/kg的防效较差,因此也不宜用于防治蘑菇褐腐病。  相似文献   

13.
One hundred and eighty‐two microsatellites or simple‐sequence‐repeat (SSR) markers for Macrophomina phaseolina were developed. These were tested on 24 isolates of M. phaseolina obtained from seven plant species, and the genetic variation of isolates was studied in relation to potential biological processes that could be affected in this fungus. A total of 120 SSR markers were polymorphic, amplifying >90% of the 24 isolates tested. Thirty percent of the markers showed multiple alleles on individual samples. A large number of markers showed unique alleles in isolates collected from pumpkin and snap bean. DNA sequences corresponding to 43 markers had significant hits on blast x and/or blast2go , and the polymorphism of 36 of those markers showed specific allele patterns for one or more plant host origin of the isolates. Additional tests on growth rate and copper resistance of the isolates identified markers that could be related to those traits. In addition, 27 markers were monomorphic and amplified all 24 isolates. Whereas polymorphic markers can be used for population genetics studies of M. phaseolina, the group of 27 monomorphic markers could help in the fast identification of this species in clinical specimens. The SSR markers developed here will enrich the limited molecular marker resource in M. phaseolina and could be used as the basis for more in‐depth studies of the host‐pathogen interactions of M. phaseolina.  相似文献   

14.
Shot hole disease of stone fruits caused by Thyrostroma carpophilum has become a major threat to stone fruit industry of Jammu and Kashmir, India because of the failure in its management with fungicides. To understand the diversity in shot hole pathogen, a combination of conventional (morphological, cultural and pathological) and molecular (ISSR and ITS markers) approaches were employed to discern variability in 25 isolates of T. carpophilum isolated from peach, plum, apricot, almond and cherry leaves collected from Srinagar, Ganderbal, and Baramulla districts of Jammu and Kashmir, India. The studies revealed a high level of variability among the pathogen. Based on the morpho-cultural and pathological studies, the isolates were grouped into different categories based on colony growth, texture, margin and colour besides change in media colour, incubation period, leaf area infected, etc. Using ISSR markers, a high level of polymorphism in different isolates of T. carpophilum was observed which indicated that these markers are suitable for studying the genetic diversity in this pathogen. Based on dendrogram, the isolates were grouped irrespective of their geographical origin or host species. Phylogenetic analysis of the 25 sequences based on ITS region showed maximum similarity with T. carpophilum (Syn. Wilsonomyces carpophilus) sequences retrieved from NCBI and grouped them in a single clade which proved it as a powerful tool for authentic identification. The pathogen was highly variable based on morpho-cultural, pathological and molecular (ISSR) characterisation.  相似文献   

15.
The genetic composition of Melampsora larici-epitea populations on two Salix viminalis varieties in monoculture and in mixed stands of Salix was studied using amplified fragment length polymorphism (AFLP). A total of 88 isolates collected from a large-scale mixture trial in Northern Ireland were analyzed. Genetic analyses were based on polymorphism for 63 AFLP markers. Differences in genetic composition of M. larici-epitea populations between the two S. viminalis varieties were indicated by all population characteristics used. In neighbor-joining analysis and principal component analysis, isolates from the same variety tended to group together. Analysis of molecular variance indicated a substantial differentiation between varieties (ST = 0.20) and differences in genotypic composition was indicated by the non-random distribution of clonal isolates between the two varieties. The detection of host specialization with selectively neutral DNA markers was ascribed to predominant asexual reproduction. No differences in gene or genotypic diversity between M. larici-epitea populations in mixed and monoclonal stands were found for any of the two S. viminalis varieties.  相似文献   

16.
江西省稻区稻瘟病菌遗传宗谱与致病型的关系   总被引:1,自引:1,他引:0  
为了探寻稻瘟病菌无性世代DNA水平的变异,明确江西省稻区稻瘟病菌遗传宗谱与致病型之间的对应关系,利用rep-PCR(repetitive element-based PCR)分子指纹分析技术,对稻区稻瘟病菌的群体结构和遗传多样性进行分析,并用41株代表性菌株对35个水稻品种进行了致病性测定。结果表明,以相似度75%为界,可以将不同稻区采集的99个菌株划分为14个遗传宗谱,其中,宗谱4、1和10为优势宗谱,分别包含37、18和12个菌株,占总数的37.37%、18.18%和12.12%;稻瘟病菌遗传宗谱与致病型间存在复杂的关系,同一宗谱的菌株对应多个致病型,而同一致病型的菌株,分属于不同的遗传宗谱,两者之间不存在简单的对应关系。  相似文献   

17.
W G LI  J J SHEN  & J B WANG 《Weed Research》2005,45(6):424-430
Two molecular genetic screening techniques, RAPD (random amplified polymorphic DNAs) and ISSR (inter-simple sequence repeats), were applied to detect the level and pattern of genetic diversity of Monochoria vaginalis, a common weed of rice fields, in seven populations from southern China. Among these populations, 116 bands were amplified by 18 RAPD primers, of which 34 bands (29.31%) were polymorphic, and 14 ISSR primers produced 111 bands with 87 polymorphic bands (78.38%). Within each population, a relatively low level of genetic diversity was detected by both RAPD and ISSR analyses, with a mean genetic diversity (H) of 0.0348 and 0.0551 respectively. Analysis of molecular variance of the data from the RAPD and ISSR markers detected that the majority of total genetic variation existed among populations (73.50% and 76.70% respectively) and only minor genetic variation within populations (26.50% and 23.30% respectively). Cluster analysis divided the seven populations into two groups, indicating that the genetic relationships among populations have relatively low correlation with their geographical distribution (Mantel test; r = 0.45 and 0.48 respectively). Our results indicated that both RAPD and ISSR markers were effective and reliable for accurately assessing the degree of genetic variation of M. vaginalis. Comparing the two techniques, ISSR markers were more efficient than the RAPD assay. The Mantel test gave r = 0.16, suggesting no correlation between these two molecular markers.  相似文献   

18.
The population structure and genotypic diversity of Mycosphaerella graminicola from six natural field populations in Germany were studied with molecular markers. To reveal the potential effects of plant host resistance on the pathogen population, hierarchical samples were taken from susceptible and resistant cultivars. A total of 203 single spore isolates was subjected to molecular marker analysis using the amplified fragment length polymorphism technique (AFLP). Among the 203 isolates analyzed, 142 different multilocus haplotypes (MLH) were identified revealing a high degree of genotypic diversity of the M. graminicola population. On average, a F ST value of 0.04 was found, indicating a low genetic differentiation with only 4% of the genetic variation between the local populations but leaving 96% of the genetic variation within the populations. According to the low F ST value, a high migration rate of Nm 12 was found. The observed high within-population diversity, and the significant migration between populations, prevented genetic isolation and differentiation of putative geographically separated populations. Furthermore, plant host resistance had no obvious effect on the population structure and diversity of M. graminicola. Genotypic variability can be attributed to sexual recombination which appears to have a considerably larger influence on the population structure. Gene flow on this scale could have significant implications for plant breeding and fungicide spraying programmes.  相似文献   

19.
Phytopthora root rot in pepper (C. annuum) is caused by Phytophthora capsici L., which exhibits a high level of pathogenic diversity. Resistance to this disease is conditioned by a number of quantitative trait loci. Pyramiding resistance alleles is desirable and could be simplified by the use of molecular markers tightly linked to the resistance genes. The purpose of this study was development of molecular markers linked to Phytophthora root rot resistance. An F8 recombinant inbred line (RIL) population derived from a cross between YCM334 and a susceptible cultivar ‘Tean’ was used in combination with bulk segregant analysis utilizing RAPD and conversion of AFLP markers linked to Phytophtora root rot resistance into sequence-characterized amplified region (SCAR) markers. In conversion: one marker was successfully converted into a co-dominant SCAR marker SA133_4 linked to the trait. In bulked segregant analysis (BSA): three RAPD primers (UBC484, 504, and 553) produced polymorphisms between DNA pools among 400 primers screened. Genetic linkage analysis showed that the SCAR and RAPD markers were located on chromosome 5 of pepper. Quantitative trait locus (QTL) analysis showed that the SA133_4 and UBC553 were linked to Phytophtora root rot resistance. These markers were correctly identified as resistant or susceptible in nine promising commercial pepper varieties. These markers will be beneficial for marker-assisted selection in pepper breeding.  相似文献   

20.
Seven root-knot nematodes (RKN), including Meloidogyne exigua, M. incognita, M. paranaensis, M. enterolobii, M. arabicida, M. izalcoensis and M. arenaria are major pathogens of coffee crop in the Americas. Species-specific primers for their identification have been developed for five of them and constitute a fast and reliable method of identification. Here we report a PCR-based assay for specific detection of M. arabicida and M. izalcoensis. Random Amplified Polymorphic DNA fragments specific for these two species were converted into sequence characterized amplified region (SCAR) markers. PCR amplification using the SCAR primers produced a specific fragment of 300 bp and 670 bp for M. arabicida and M. izalcoensis, respectively, which were absent in other coffee-associated Meloidogyne spp. tested. SCAR primers also allowed successful amplification of DNA from single second-stage juveniles (J2), males and females. In addition, these primers were able to unambiguously detect the target species in nematode suspensions extracted from soil and roots samples, in different isolates of the same species or when used in multiplex PCR reactions containing mixtures of species. These results demonstrated the effectiveness of these SCAR markers and their multiplex use with those previously developed for M. exigua, M. incognita, M. paranaensis, M. enterolobii and M. arenaria constitute an essential detection tool. This diagnostic kit will contribute for specific J2 identification of the major RKN infecting coffee from field samples in the Americas.  相似文献   

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