Differential disease reactions on lucerne genotypes inoculated with Phytophthora medicaginis isolates from lucerne and chickpea

1997 ◽  
Vol 48 (5) ◽  
pp. 545 ◽  
Author(s):  
E. C. Y. Liew ◽  
J. A. G. Irwin
Keyword(s):  
Host Species ◽  
Quantitative Assessment ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Breeding For Resistance ◽  
Significant Difference ◽  
First Time

Stem inoculation of clonally propagated lucerne genotypes was used to assess levels of host species and genotype specialisation in Phytophthora medicaginis. A quantitative assessment of pathogenic aggressiveness of 29 P. medicaginis isolates (from lucerne and chickpea) on 9 different clonally propagated lucerne genotypes revealed no significant difference in aggressiveness between isolates from lucerne and those from chickpea on all of the lucerne genotypes. This supported previous studies which showed that P. medicaginis isolates from lucerne and chickpea were indistinguishable using random amplified polymorphic DNA (RAPD) analysis. Analysis of pathogenic aggressiveness towards individual lucerne genotypes revealed, for the first time, specificity of individual P. medicaginis isolates. This has implications for breeding for resistance to P. medicaginis in lucerne, where screening should be done using the widest range of pathogen specificity obtainable.

scholarly journals Molecular Detection and Phylogeny of Anaplasmaphagocytophilum and Related Variants in Small Ruminants from Turkey

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 814
Author(s):  
Münir Aktaş ◽  
Sezayi Özübek ◽  
Mehmet Can Uluçeşme
Keyword(s):  
16S Rrna ◽  
Small Ruminants ◽  
Rrna Gene ◽  
Infection Rates ◽  
Sheep And Goats ◽  
Significant Difference ◽  
Pcr Rflp ◽  
First Time ◽  
Japan And China ◽  
Apparently Healthy

Anaplasma phagocytophilum causes tick-borne fever in small ruminants. Recently, novel Anaplasma variants related to A. phagocytophilum have been reported in ruminants from Tunisia, Italy, South Korea, Japan, and China. Based on 16S rRNA and groEL genes and sequencing, we screened the frequency of A. phagocytophilum and related variants in 433 apparently healthy small ruminants in Turkey. Anaplasma spp. overall infection rates were 27.9% (121/433 analyzed samples). The frequency of A. phagocytophilum and A. phagocytophilum-like 1 infections was 1.4% and 26.5%, respectively. No A. phagocytophilum-like 2 was detected in the tested animals. The prevalence of Anaplasma spp. was comparable in species, and no significant difference was detected between sheep and goats, whereas the prevalence significantly increased with tick infestation. Sequencing confirmed PCR-RFLP data and showed the presence of A. phagocytophilum and A. phagocytophilum-like-1 variant in the sampled animals. Phylogeny-based on 16S rRNA gene revealed the A. phagocytophilum-like 1 in a separate clade together with the previous isolates detected in small ruminants and ticks. In this work, A. phagocytophilum-like 1 has been detected for the first time in sheep and goats from Turkey. This finding revealed that the variant should be considered in the diagnosis of caprine and ovine anaplasmosis.

Patients Who Attend Alone at a First Memory Consultation: Are They a Specific Population,or Is It an Instance of Confounding Bias?

2019 ◽  
Vol 81 (1-2) ◽  
pp. 81-86
Author(s):  
Pierre Koskas ◽  
Mouna Romdhani ◽  
Olivier Drunat
Keyword(s):  
Selection Bias ◽  
Confounding Bias ◽  
Significant Difference ◽  
Comparison Groups ◽  
Methodological Problems ◽  
Group 2 ◽  
The Impact ◽  
First Time ◽  
State Examination ◽  
Group 1

As commonly happens in epidemiological research, none of the reported studies were totally free of methodological problems. Studies have considered the influence of social relationships on dementia, but the mechanisms underlying these associations are not perfectly understood. We look at the possible impact of selection bias. For their first memory consultation, patients may come alone or accompanied by a relative. Our objective is to better understand the impact of this factor by retrospective follow-up of geriatric memory outpatients over several years. All patients over 70 who were referred to Bretonneau Memory Clinic for the first time, between January 2006 and 2018, were included in the study. The patients who came alone formed group 1, the others, whatever type of relative accompanied them, formed group 2. We compared the Mini-Mental State Examination (MMSE) scores of patients; and for all patients who came twice for consultation with at least a 60-day interval, we compared their first MMSE with the MMSE performed at the second consultation. In total, 2,935 patients were included, aged 79.7 ± 8.4 years. Six hundred and twenty-five formed group 1 and 2,310 group 2. We found a significant difference in MMSE scores between the 2 groups of patients; and upon second consultation in group 2, but that difference was minor in group 1. Our finding of a possible confounding factor underlines the complexity of choosing comparison groups in order to minimize selection bias while maintaining clinical relevance.

scholarly journals Host density predicts the probability of parasitism by avian brood parasites

2019 ◽  
Vol 374 (1769) ◽  
pp. 20180204 ◽  
Author(s):  
Iliana Medina ◽  
Naomi E. Langmore
Keyword(s):  
Spatial Distribution ◽  
Reproductive Success ◽  
Host Species ◽  
Field Data ◽  
Host Density ◽  
Brood Parasites ◽  
Parasitism Rates ◽  
Analyse Data ◽  
First Time ◽  
Determining Factor

The spatial distribution of hosts can be a determining factor in the reproductive success of parasites. Highly aggregated hosts may offer more opportunities for reproduction but can have better defences than isolated hosts. Here we connect macro- and micro-evolutionary processes to understand the link between host density and parasitism, using avian brood parasites as a model system. We analyse data across more than 200 host species using phylogenetic comparative analyses and quantify parasitism rate and host reproductive success in relation to spatial distribution using field data collected on one host species over 6 years. Our comparative analysis reveals that hosts occurring at intermediate densities are more likely to be parasitized than colonial or widely dispersed hosts. Correspondingly, our intraspecific field data show that individuals living at moderate densities experience higher parasitism rates than individuals at either low or high densities. Moreover, we show for the first time that the effect of host density on host reproductive success varies according to the intensity of parasitism; hosts have greater reproductive success when living at high densities if parasitism rates are high, but fare better at low densities when parasitism rates are low. We provide the first evidence of the trade-off between host density and parasitism at both macro- and micro-evolutionary scales in brood parasites. This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.

scholarly journals SNP and SCAR Markers for Specific Discrimination of Antler-Shaped Ganoderma lucidum

2019 ◽  
Vol 7 (1) ◽  
pp. 12 ◽  
Author(s):  
O-Chul Kwon ◽  
Chang-Soo Lee ◽  
Young-Jin Park
Keyword(s):  
Ganoderma Lucidum ◽  
Gene Sequence ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Morphological Characteristics ◽  
Pcr Analysis ◽  
Scar Markers ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Specific Fragment

In this study we identified single nucleotide polymorphism (SNP) and sequence characteristic amplification region (SCAR) markers for specific identification of antler-shaped Ganoderma lucidum strains. When the partial mitochondrial SSU rDNA gene sequence of various antler- and kidney-shaped G. lucidum strains were analyzed and aligned, an SNP was found only in the antler-shaped G. lucidum strain at position 456 bp. In addition, this SNP of antler-shaped strains was digested by HinfI restriction enzyme. We further analyzed the polymorphism of various G. lucidum strains by random amplified polymorphic DNA (RAPD) analysis. In RAPD analysis, we isolated and sequenced a fragment, specific for antler-shaped G. lucidum strains. Based on this specific fragment sequence, two sets of specific primer pairs for antler-shaped G. lucidum strains were designed. PCR analysis revealed that two specific bands were observed only from antler-shaped strains. These two molecular markers will be helpful for identification of morphological characteristics of G. lucidum.

Random amplified polymorphic DNA (RAPD) analysis for the verification of hybridity in interspecific crosses of Alstroemeria

2000 ◽  
Vol 119 (5) ◽  
pp. 443-445 ◽  
Author(s):  
L. de Benedetti ◽  
G. Burchi ◽  
A. Mercuri ◽  
N. Pecchioni ◽  
P. Faccioli ◽  
...  
Keyword(s):  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Interspecific Crosses

scholarly journals Isolates of Uromyces appendiculatus with Specific Virulence to Landraces of Phaseolus vulgaris of Andean Origin

Plant Disease ◽  
1999 ◽  
Vol 83 (2) ◽  
pp. 108-113 ◽  
Author(s):  
Craig M. Sandlin ◽  
James R. Steadman ◽  
Carlos M. Araya ◽  
Dermot P. Coyne
Keyword(s):  
Phaseolus Vulgaris ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Rust Fungus ◽  
Distinct Group ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Banding Patterns ◽  
Highly Virulent ◽  
Specific Virulence

Five isolates of the bean rust fungus Uromyces appendiculatus were shown to be specifically virulent on bean genotypes of Andean origin. This specificity was demonstrated by the virulence of five pairs of isolates on a differential set of 30 Phaseolus vulgaris landraces. Each isolate pair was from a different country in the Americas and consisted of one Andean-specific isolate and one nonspecific isolate. Of the differential P. vulgaris landraces, 15 were of Middle American origin and 15 were of Andean origin. The Andean-specific rust isolates were highly virulent on Andean landraces but not on landraces of Middle American origin. Rust isolates with virulence to Middle American landraces were also generally virulent on Andean material; no truly Middle American-specific isolates were found. Random amplified polymorphic DNA (RAPD) analysis of the rust isolates also distinguished the two groups. Four of the Andean-specific rust isolates formed a distinct group compared to four of the nonspecific isolates. Two of the isolates, one from each of the two virulence groups, had intermediate RAPD banding patterns, suggesting that plasmagomy but not karyogamy occurred between isolates of the two groups.

scholarly journals The genetic structure of Pandalus borealis in the Northeast Atlantic determined by RAPD analysis

2006 ◽  
Vol 63 (5) ◽  
pp. 840-850 ◽  
Author(s):  
Iciar Martinez ◽  
Michaela Aschan ◽  
Taran Skjerdal ◽  
Salah M. Aljanabi
Keyword(s):  
Genetic Structure ◽  
Barents Sea ◽  
Rapd Analysis ◽  
Rapd Marker ◽  
Arbitrary Primers ◽  
Pandalus Borealis ◽  
Northeast Atlantic ◽  
The Barents Sea ◽  
Local Selection ◽  
Significant Difference

Abstract The genetic structure of shrimp (Pandalus borealis) in the Northeast Atlantic was examined by RAPD analysis on specimens caught at eight stations in the Barents Sea, three off Svalbard, two off Jan Mayen, and in two northern Norwegian fjords (19 < n > 31 per station). A total of 34 polymorphic markers generated by seven 10-mer arbitrary primers was used to assess the genetic population structure using analysis of molecular variance (AMOVA). There was considerable RAPD diversity (>90%) among shrimp at all stations. The two Norwegian fjords and the Jan Mayen stations were different from all the others, and the Jan Mayen stations also differed from each other. More than 98% of the genetic variation between Barents Sea and Svalbard was ascribed to individual diversity, and there was no significant difference between the two areas, although there seemed to be a subpopulation structure in the Barents Sea. Principal component analysis on the frequency of each RAPD marker on each sampled station confirmed the presence of three populations: Barents Sea and Svalbard, northern Norwegian fjords, and Jan Mayen. We postulate that the large genetic variability found at an individual level may provide the total population with a diverse genetic pool from which traits can be selected to respond to variations in local environmental conditions, and that this local selection may be the cause of the subpopulation structure observed.

Phylogenetic relationships of five morphological groups of hexaploid wheat (Triticum aestivum L. em Thell.) based on RAPD analysis

Genome ◽  
2000 ◽  
Vol 43 (4) ◽  
pp. 724-727 ◽  
Author(s):  
Wenguang Cao ◽  
G Scoles ◽  
P Hucl ◽  
R N Chibbar
Keyword(s):  
Hexaploid Wheat ◽  
Phylogenetic Relationships ◽  
Genetic Similarity ◽  
Rapd Analysis ◽  
Genetic Relationships ◽  
Random Amplified Polymorphic Dna ◽  
Triticum Aestivum L ◽  
Similarity Coefficients ◽  
Morphological Classification ◽  
Wild Wheat

The genetic relationships among the five groups of hexaploid wheat: common, spelta, macha, vavilovii, and semi-wild wheat (SWW) are not clear. Random amplified polymorphic DNA (RAPD) analysis was used to assess phylogenetic relationships among these five morphological groups of hexaploid wheat. RAPD data were analyzed using the NTSYS-PC computer program to generate Jaccard genetic similarity coefficients. A dendrogram based on RAPD analysis grouped 15 accessions into five distinct clusters. These results are in agreement with those based on morphological classification, suggesting that common wheat is most closely related to SWW, followed by spelta, vavilovii, and macha.Key words: RAPD, macha, spelta, vavilovii, semi-wild wheat, phylogenetic relationships.

scholarly journals Characterization of Fusarium oxysporum Isolates Obtained from Cucumber in China by Pathogenicity, VCG, and RAPD

Plant Disease ◽  
2004 ◽  
Vol 88 (6) ◽  
pp. 645-649 ◽  
Author(s):  
D. J. Vakalounakis ◽  
Z. Wang ◽  
G. A. Fragkiadakis ◽  
G. N. Skaracis ◽  
D.-B. Li
Keyword(s):  
Fusarium Oxysporum ◽  
Random Amplified Polymorphic Dna ◽  
Vegetative Compatibility ◽  
Stem Rot ◽  
Chinese Isolate ◽  
Vegetative Compatibility Group ◽  
Group I ◽  
Compatibility Group ◽  
First Time

Thirty-four isolates of Fusarium oxysporum, obtained in China from cucumber plants showing either Fusarium wilt (F. oxysporum f. sp. cucumerinum) or root and stem rot (F. oxysporum f. sp. radicis-cucumerinum) symptoms, were characterized by pathogenicity, vegetative compatibility, and random amplified polymorphic DNA (RAPD). Of these, 23 isolates were identified by pathogenicity as F. oxysporum f. sp. cucumerinum, and one as F. oxysporum f. sp. radicis-cucumerinum, while 10 isolates were avirulent on cucumber, melon, sponge gourd, and pumpkin. The Chinese isolates of F. oxysporum f. sp. cucumerinum were assigned to RAPD groups III and XXI and to vegetative compatibility group (VCG) 0183, four new VCGs, 0184 to 0187, and a single-member VCG included in the artificial VCG 018-. The Chinese isolate of F. oxysporum f. sp. radicis-cucumerinum was assigned to RAPD group I and bridging VCG 0260/0261. The occurrence of F. oxysporum f. sp. radicis-cucumerinum on cucumber is reported for the first time in China.

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