Diversity of Meloidogyne arenaria using morphological, cytological and molecular approaches

Nematology ◽  
2008 ◽  
Vol 10 (6) ◽  
pp. 819-834 ◽  
Author(s):  
Maria Ritta Almeida ◽  
Regina Carneiro ◽  
Marcilene dos Santos ◽  
Myrian Tigano ◽  
Ana Cristina Gomes ◽  
...  
Keyword(s):  
Bootstrap Support ◽  
Meloidogyne Arenaria ◽  
Molecular Approaches ◽  
Morphological Studies ◽  
Race 1 ◽  
Unidentified Species ◽  
High Bootstrap ◽  
Race 2 ◽  
Species Specific ◽  
High Level

AbstractThirteen Meloidogyne arenaria isolates representing two cytological types (3n = 51-56, 2n = 42-48) and four enzymatic phenotypes (esterase and malate dehydrogenase: A3N1, A2N1, A1N1, A2N3) were studied using different approaches. The analysis of molecular markers showed a high level of polymorphism among the isolates. The trees obtained with RAPD or ISSR polymorphisms showed concordant results and agree with morphological studies. By considering morphometrical and morphological features, it was possible to conclude that the isolate with enzymatic phenotype A2N3 race 1 was the M. arenaria described in 1949 by Chitwood and appearing clearly separated in the trees, as well as in the outgroups. The seven isolates with phenotype A2N1 from different localities and isolate A1N1 can be considered morphometrically typical of M. arenaria race 2 and they were apparently clustered by geographical origin. Morphologically, they differed from isolate A2N3 race 1. The two isolates with phenotype A3N1 appeared to be closely related to the isolate of M. morocciensis and, considering all of the features described for this species, were identified as such. The two isolates A2N3 race 2 were identified either as an atypical M. arenaria or an unidentified species (females and males having atypical stylets), and clustered together and separated from other M. arenaria isolates with high bootstrap support. The same M. arenaria isolates were tested with the species-specific molecular marker, type SCAR. A fragment of 420 bp was obtained for ten isolates of M. arenaria, including the atypical A2N3 race 2 and M. morocciensis. This fragment was not amplified for three typical A2N1 isolates of M. arenaria.

scholarly journals Characterization of Resistance Conferred by the N gene to Meloidogyne arenaria Races 1 and 2, M. hapla, and M. javanica in Two Sets of Isogenic Lines of Capsicum annuum L.

2000 ◽  
Vol 125 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Judy A. Thies ◽  
Richard L. Fery
Keyword(s):  
Capsicum Annuum ◽  
Nematode Resistance ◽  
N Gene ◽  
Recurrent Parent ◽  
Resistance Locus ◽  
Meloidogyne Arenaria ◽  
Meloidogyne Hapla ◽  
Root Knot Nematode ◽  
Race 1 ◽  
Race 2

Two isogenic sets of bell pepper (Capsicum annuum L.) lines (differing at the N root-knot nematode resistance locus) were characterized for resistance to Meloidogyne arenaria (Neal) Chitwood races 1 and 2, M. hapla Chitwood, and M. javanica (Treub) Chitwood in greenhouse and growth chamber tests. The isogenic sets of C. annuum were `Charleston Belle' (NN) and `Keystone Resistant Giant' (nn-recurrent parent), and `Carolina Wonder' (NN) and `Yolo Wonder B' (nn-recurrent parent). Meloidogyne arenaria race 1 is pathogenic to C. annuum. `Charleston Belle' and `Carolina Wonder' exhibited high resistance to M. arenaria race 1. Their respective recurrent backcross parents, `Keystone Resistant Giant' and `Yolo Wonder B', were susceptible to M. arenaria. Meloidogyne arenaria race 2 and M. javanica are not highly pathogenic to pepper. However, `Charleston Belle' and `Carolina Wonder' both exhibited higher (P≤0.05) resistance to M. arenaria race 2 and M. javanica than `Keystone Resistant Giant' and `Yolo Wonder B'. Meloidogyne hapla is pathogenic to pepper. Both `Charleston Belle' and `Carolina Wonder' and their respective recurrent parents, `Keystone Resistant Giant' and `Yolo Wonder B', were susceptible to M. hapla. We concluded that the N gene confers resistance to M. arenaria races 1 and 2, and M. javanica in C. annuum, but the N gene does not condition resistance to M. hapla.

scholarly journals New Host Races of Meloidogyne arenaria, M. incognita, and M. javanica from Horticultural Regions of Spain

Plant Disease ◽  
2009 ◽  
Vol 93 (2) ◽  
pp. 180-184 ◽  
Author(s):  
L. Robertson ◽  
M. A. Díez-Rojo ◽  
J. A. López-Pérez ◽  
A. Piedra Buena ◽  
M. Escuer ◽  
...  
Keyword(s):  
North Carolina ◽  
Meloidogyne Arenaria ◽  
Specific Primers ◽  
New Host ◽  
Differential Host ◽  
Race 1 ◽  
Polymerase Chain ◽  
New Races ◽  
Species Specific ◽  
Susceptible Tomato

In total, 140 populations of the genus Meloidogyne collected from representative horticultural regions of Spain and maintained at the Department of Agroecology, Institute of Agrarian Sciences, Madrid were characterized using perineal morphology, sequenced characterized amplified region polymerase chain reaction with species-specific primers, and bioassay. Using a modified North Carolina differential host test as a basis, 13 Meloidogyne populations did not fit into the published race scheme. These populations had very limited host ranges, reproducing only on susceptible tomato cv. Marmande and sometimes also on tobacco cv. NC95 and the pepper cv. Sonar in the case of Meloidogyne arenaria. They did not reproduce on cotton or peanut. The species and new races were identified as M. incognita races 5 (6 populations) and 6 (2 populations) and M. javanica race 5 (2 populations), with new records of M. arenaria race 3 (2 populations) and M. javanica race 1 (23 populations) for Spain.

Characterization of the mitochondrial genome and phylogeny of the black arowana (Osteoglossum ferreirai)

Biologia ◽  
2014 ◽  
Vol 69 (9) ◽  
Author(s):  
Xidong Mu ◽  
Yi Liu ◽  
Xuejie Wang ◽  
Chao Liu ◽  
Hongmei Song ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Nucleotide Composition ◽  
Gene Arrangement ◽  
Bootstrap Support ◽  
Radiation Process ◽  
Molecular Approaches ◽  
The Family ◽  
High Bootstrap ◽  
Relationship Of

AbstractIn this study, we sequenced and assembled the mitochondrial (mt) genome of Osteoglossum ferreirai to re-assess the phylogenetic relationship of the family Osteoglossidae. We determined that the mitogenome of O. ferreirai contains the entire set of 37 mt genes, and the nucleotide composition and gene arrangement were similar to those of other bonytongues. Our phylogenetic analyses exhibited monophyly of the family Osteoglossidae with high bootstrap support, which is in agreement with the currently accepted phylogenetic viewpoint that is based on both morphological and molecular approaches. These findings provide additional informative data for the further study of phylogenetic relationships and help to elucidate a key component of the species radiation process within the family Osteoglossidae.

scholarly journals An Assessment of the Genetic Diversity in a Field Population of Phytophthora nicotianae with a Changing Race Structure

Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 455-460 ◽  
Author(s):  
M. J. Sullivan ◽  
E. J. Parks ◽  
M. A. Cubeta ◽  
C. A. Gallup ◽  
T. A. Melton ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Single Gene ◽  
Phytophthora Nicotianae ◽  
Bootstrap Support ◽  
Resistant Variety ◽  
Aflp Analysis ◽  
Pathogen Population ◽  
Independent Events ◽  
Race 1 ◽  
High Level

One hundred fifty-three isolates of Phytophthora nicotianae that were collected over a 4-year period from a single field were subjected to amplified fragment length polymorphism (AFLP) analysis to investigate the effect of different types of resistance in tobacco (Nicotiana tabacum) on genetic diversity in the pathogen population. No race 1 isolates were detected in the field prior to initiating the study, but the race was present in multiple plots by the end of the 4-year period. There were 102 race 0 isolates and 51 race 1 isolates characterized. Seventy-six of the 153 isolates had a unique AFLP profile, whereas the remaining 77 isolates were represented by 27 AFLP profiles shared by at least two isolates. Isolates of both races were found in both the unique and shared AFLP profile groups. Twenty-three of the AFLP profiles were detected in multiple years, indicating a clonal component to the pathogen population. Race 1 isolates that were detected over multiple years were always obtained from the same plot. No race 1 profile was found in more than one plot, confirming the hypothesis that the multiple occurrences of the race throughout the field were the result of independent events and not pathogen spread. Three identical race 0 AFLP profiles occurred in noncontiguous plots, and in each case, the plots contained the same partially resistant variety. Cluster analysis provided a high level of bootstrap support for 41 isolates in 19 clusters that grouped primarily by race and rotation treatment. Estimates of genetic diversity ranged from 0.365 to 0.831 and varied depending on tobacco cultivar planted and race. When averaged over all treatments, diversity in race 1 isolates was lower than in race 0 isolates at the end of each season. Deployment of single-gene resistance initially decreased genetic diversity of the population, but the diversity increased each year, indicating the pathogen was adapting to the host genotypes deployed in the field.

scholarly journals First Report of the Root-Knot Nematode Meloidogyne arenaria Race 2 from Several Vegetable Crops in Jordan

Plant Disease ◽  
2005 ◽  
Vol 89 (2) ◽  
pp. 206-206 ◽  
Author(s):  
M. Karajeh ◽  
W. Abu-Gharbieh ◽  
S. Masoud
Keyword(s):  
North Carolina ◽  
Meloidogyne Arenaria ◽  
Vegetable Crops ◽  
Root Knot Nematode ◽  
Lateral Field ◽  
Differential Host ◽  
First Report ◽  
Race 1 ◽  
Meloidogyne Spp ◽  
Race 2

Meloidogyne arenaria (Neal) Chitwood (race 2) is reported for the first time in Jordan. The nematode populations were recovered from several vegetable crops, including tomato (Lycopersicon esulentum Mill), squash (Cucurbita pepo L.), cucumber (Cucumis sativus L.), and bean (Phaseolus vulgaris L.), at Dier Alla in the northern area of the Jordan Valley. Symptoms included root galling, leaf chlorosis, and stunting. Galled plant root samples were collected during a survey conducted from May 2002 to August 2003 covering most of the irrigated agricultural areas of Jordan. Eighty-three Meloidogyne spp. populations were collected from various vegetable crops and fruit trees. Identification to species and race levels of the nematode populations was based on combination of currently available methods including nematode morphology, host preference based on the North Carolina (NC) differential host test (1), and cytogenetics and DNA-fingerprinting. Seventy of the eighty-three collected populations were identified as M. javanica, five as M. incognita (race 1), three as M. incognita (race 2), and five as M. arenaria (race 2). The perineal patterns of M. arenaria were characterized by a low, round to indented dorsal arch near the lateral field with irregular forks in the lateral field, fine smooth striae, and a distinct whorl. Race 2 was identified with the NC differential host test. Cytogenetic studies indicated that M. arenaria populations were triploid with an average of 52.2 chromosomes, while the populations of M. incognita (race 1), M. incognita (race 2), and M. javanica were hypotriploid with an average of 45.2, 46.1, and 46.7 chromosomes, respectively. Two polymerase chain reaction (PCR)-based assays were used to confirm species identification and to study genetic variability of the Meloidogyne spp. populations including sequence characterized amplified regions (SCAR) and random amplified polymorphic DNA (RAPD). In the SCAR-PCR-based assay (2), typical DNA products of 420, 670, or 1,200 bp in size were amplified by using extracted DNA of M. arenaria (race 2), M. javanica, or M. incognita (race 1 or 2), respectively, as template DNA. The RAPD-PCR primer, OPA-01, produced DNA patterns with bands that clearly distinguished M. arenaria from the other two Meloidogyne spp. To our knowledge, this is the first report of the root-knot nematode, M. arenaria race 2, in Jordan. References: (1) A. Taylor and J. Sasser, North Carolina State University Graphics, Raleigh, NC, 1978. (2) C. Zijlstra et al. Nematology 2:847, 2000.

scholarly journals Comparative Sequence Analysis of TRI1 of Fusarium

Toxins ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 689 ◽  
Author(s):  
Amanda C. Ramdass ◽  
Ria T. Villafana ◽  
Sephra N. Rampersad
Keyword(s):  
Amino Acid ◽  
Fusarium Species ◽  
Phylogenetic Analyses ◽  
Comparative Sequence Analysis ◽  
Bootstrap Support ◽  
Functional Difference ◽  
Functional Variation ◽  
Systematic Analysis ◽  
High Bootstrap ◽  
Species Specific

Trichothecene mycotoxins are a class of secondary metabolites produced by multiple genera of fungi, including certain plant pathogenic Fusarium species. Functional variation in the TRI1 gene produces a novel Type A trichothecene called NX-2 in strains of F. graminearum. Using a bioinformatics approach, a systematic analysis of 52 translated TRI1 sequences of Fusarium species, including five F. graminearum NX-2 producers and four F. graminearum non-NX-2 producers, was conducted to explain the functional difference of TRI1p of FGNX-2. An assessment of several signature motifs of fungal P450s revealed amino acid substitutions in addition to the post-translational N-X-S/T sequons motif, which is indicative of N-linked glycosylation of this TRI1-encoded protein characteristic of NX-2 producers. There was evidence of selection bias, where TRI1 gene sequences were found to be under positive selection and, therefore, under functional constraints. The cumulative amino acid changes in the TRI1p sequences were reflected in the phylogenetic analyses which revealed species-specific clustering with a distinct separation of FGNX-2 from FG-non-NX-2 producers with high bootstrap support. Together, our findings provide insight into the amino acid sequence features responsible for the functional diversification of this TRI1p.

scholarly journals DISTRIBUTION AND RACE COMPOSITION OF DOWNY MILDEW (Plasmopara halstedii (Farl.) Berl. and de Toni) IN BULGARIA / EXTENSION Y RAZAS DEL MILDIU (Plasmopara halstedii (Farl.) Berl. y de Toni) EN BULGARIA / ÉTENDUE ET RACES DE LA ROUILLE (Plasmopara halstedii (Farl.) Berl. and de Toni) EN BULGARIE

Helia ◽  
2000 ◽  
Vol 23 (33) ◽  
pp. 25-32
Author(s):  
P.S. Shindrova
Keyword(s):  
Downy Mildew ◽  
Resistance Gene ◽  
The Other ◽  
Plasmopara Halstedii ◽  
North West ◽  
North East ◽  
Race 1 ◽  
Race 2 ◽  
Production Areas ◽  
Number Of Authors

SUMMARY Downy mildew caused by the fungus Plasmopara halstedii is the main disease on sunflower in Bulgaria. In recent years a number of authors have reported the occurrence of new more virulent races of the pathogen. According to other authors these races demonstrate resistance to the fungicides used up to now. This fact is rather alarming and imposes the necessity of annual researches with the aim of following the changes in the downy mildew race variability. In the period 1995-1997 downy mildew isolates were collected from the following locations: Bourgas, Boyanovo, Karnobat, Ognyanovo, Selanovtsi, Kroushari, Lovech, Koubrat, Brashlyan, Sitovo, Tervel, Targovishte, IWS “Dobroudja” and Dobrich. The samples were assessed for virulence on a set of sunflower differential - lines under greenhouse conditions. The obtained results do not reveal a great race variability of downy mildew population in Bulgaria. In the period of study two races of the pathogen were identified: race 1 which infects the differential lines without genes for resistance to the pathogen. It is distributed in all sunflower production areas of the country. The other one is race 2. It is of limited distribution and has been registered in individual fields of north-east and north-west Bulgaria. It attacks the differential lines carrying the resistance gene Pl-1.

scholarly journals Effect of continuous growing of resistant soybean genotypes on Meloidogyne arenaria race 1 reproduction

2001 ◽  
Vol 26 (1) ◽  
pp. 93-94 ◽  
Author(s):  
ELVIRA M.R. PEDROSA ◽  
ROMERO M. MOURA
Keyword(s):  
Glycine Max ◽  
Continuous Culture ◽  
Reproduction Rate ◽  
Meloidogyne Arenaria ◽  
Root Knot Nematode ◽  
Resistant Plant ◽  
Nematode Management ◽  
Soybean Genotypes ◽  
Race 1

Even though resistance is the most promising tactic for root-knot nematode management on soybean (Glycine max), virulent biotypes may occur and be selected on specific resistant plant genotypes. In the present study, reproduction rate of Meloidogyne arenaria race 1 increased after four sequences of continuous culture of the parasite on resistant soybean genotypes.

scholarly journals Species in section Peltidea (aphthosa group) of the genus Peltigera remain cryptic after molecular phylogenetic revision

2018 ◽  
Vol 63 (2) ◽  
pp. 45-64 ◽  
Author(s):  
Jolanta Miadlikowska ◽  
Nicolas Magain ◽  
Carlos J. Pardo-De la Hoz ◽  
Dongling Niu ◽  
Trevor Goward ◽  
...  
Keyword(s):  
High Specificity ◽  
Molecular Data ◽  
Fungal Species ◽  
Bootstrap Support ◽  
Phenotypic Traits ◽  
Phylogenetic Structure ◽  
Putative Species ◽  
Molecular Phylogenetic ◽  
High Bootstrap ◽  
Phylogenetic Revision

AbstractClosely related lichen-forming fungal species circumscribed using phenotypic traits (morphospecies) do not always align well with phylogenetic inferences based on molecular data. Using multilocus data obtained from a worldwide sampling, we inferred phylogenetic relationships among five currently accepted morphospecies of Peltigera section Peltidea (P. aphthosa group). Monophyletic circumscription of all currently recognized morphospecies (P. britannica, P. chionophila, P. frippii and P. malacea) except P. aphthosa, which contained P. britannica, was confirmed with high bootstrap support. Following their re-delimitation using bGMYC and Structurama, BPP validated 14 putative species including nine previously unrecognized potential species (five within P. malacea, five within P. aphthosa, and two within P. britannica). Because none of the undescribed potential species are corroborated morphologically, chemically, geographically or ecologically, we concluded that these monophyletic entities represent intraspecific phylogenetic structure, and, therefore, should not be recognized as new species. Cyanobionts associated with Peltidea mycobionts (51 individuals) represented 22 unique rbcLX haplotypes from five phylogroups in Clade II subclades 2 and 3. With rare exceptions, Nostoc taxa involved in trimembered and bimembered associations are phylogenetically closely related (subclade 2) or identical, suggesting a mostly shared cyanobiont pool with infrequent switches. Based on a broad geographical sampling, we confirm a high specificity of Nostoc subclade 2 with their mycobionts, including a mutualistically exclusive association between phylogroup III and specific lineages of P. malacea.

scholarly journals Revision of moles in the genus Scapanus

Therya ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 275-281
Author(s):  
Sergio Ticul Alvarez Castañeda ◽  
Patricia Cortés-Calva
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Genetic Distances ◽  
Valid Species ◽  
Bootstrap Support ◽  
Oxidase Subunit ◽  
Morphological Studies ◽  
Subspecies Level ◽  
Taxonomic Changes ◽  
Morphological Differences

Scapanus latimanus is a species with many morphological differences among its populations.  This variation is associated with multiple taxonomic changes at the species or subspecies level.  This study incorporates genetic analyses and comparisons with previous morphological studies to propose a better understanding of the latimanus complex.  Mitochondrial markers (cytochrome b; cytochrome c oxidase subunit I; and cytochrome c oxidase subunit III) were sequenced to construct a phylogeny for the subfamily Scalopinae in North America.  Genetic distances ranged from 2.49 to 10.50 % among geographic areas.  Results identified three monophyletic clades with high bootstrap support values.  Based on our phylogenetic analysis and previous morphological analyses, we confirm S. anthonyi from San Pedro Mártir as a valid species and propose that S. occultus from southern California and northern Baja California peninsula be considered as a species

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