Population structure of Sclerotinia sclerotiorum in an Australian canola field at flowering and stem-infection stages of the disease cycle

Genome ◽  
2006 ◽  
Vol 49 (11) ◽  
pp. 1408-1415 ◽  
Author(s):  
Adrienne C. Sexton ◽  
Athol R. Whitten ◽  
Barbara J. Howlett
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Gene Diversity ◽  
Genotypic Diversity ◽  
Population Subdivision ◽  
Analysis Of Molecular Variance ◽  
Molecular Variance ◽  
Stem Infection ◽  
Fixation Indices ◽  
Stem Lesions ◽  
Genotypic Disequilibrium

Populations of the ascomycete pathogen Sclerotinia sclerotiorum sampled from a canola field were analysed using microsatellite markers. Fifty isolates were collected from ascospore-infested canola petals and, later in the season, another 55 isolates were obtained from stem lesions; these isolates were used to compare inoculum and disease-causing populations. Fifty-five unique haplotypes were identified, with gene diversity ranging from 0.40 to 0.71. Genotypic diversity was higher in the inoculum population than it had been in the previous year, but analysis of molecular variance (AMOVA) showed that less than 10% of the variation was attributable to differences between the 2 years. Genotypic disequilibrium measures were consistent with the occurrence of both clonal reproduction and out-crossing. There was no significant population subdivision between the ascospore and stem-lesion populations, as measured with fixation indices (RST = 0.015, p = 0.90) and AMOVA, suggesting that there are no genetically defined subgroups of isolates more likely to proceed from petal colonization to cause stem infection. This might be because S. sclerotiorum possesses wide-ranging pathogenicity mechanisms that account for the lack of host specificity observed to date.

scholarly journals Genetic Divergence and Diversity in Himalayan Puccinia striiformis Populations from Bhutan, Nepal, and Pakistan

2019 ◽  
Vol 109 (10) ◽  
pp. 1793-1800 ◽  
Author(s):  
Muhammad Rameez Khan ◽  
Zia-ur Rehman ◽  
Sidra Noreen Nazir ◽  
Sangay Tshewang ◽  
Suraj Baidya ◽  
...  
Keyword(s):  
Puccinia Striiformis ◽  
Gene Diversity ◽  
Genotypic Diversity ◽  
Himalayan Region ◽  
Population Subdivision ◽  
Aerial Dispersal ◽  
Western Himalayan Region ◽  
Nonsignificant Difference ◽  
Limited Gene Flow ◽  
High Level

The western Himalayan region in Pakistan has been shown to be the center of diversity of Puccinia striiformis; however, little is known about its genetic relations with the eastern part of the Himalayas. We studied the genetic structure of P. striiformis from Nepal (35 isolates) and Bhutan (31 isolates) in comparison with 81 Pakistani samples collected during 2015 and 2016, through microsatellite genotyping. Genetic analyses revealed a recombinant and highly diverse population structure in Pakistan, Bhutan, and Nepal. A high level of genotypic diversity (>0.90) was observed for the three countries of Pakistan (0.96), Bhutan (0.96), and Nepal (0.91) with the detection of 108 distinct multilocus genotypes (MLGs) in the overall population; 59 for Pakistan, 27 for Bhutan, and 26 for Nepal. Mean number of alleles per locus and gene diversity were higher in Nepal (3.19 and 0.458, respectively) than Bhutan (3.12 and 0.458, respectively). A nonsignificant difference between the observed and the expected heterozygosity in all populations further confirmed the recombinant structure. A clear population subdivision between the Himalayan region of Nepal, Bhutan, and Pakistan was evident, as revealed by FST values (ranging between 0.111 to 0.198), discriminant analysis of principal components, and resampling of MLGs. Limited gene flow could be present between Nepal and Bhutan, while the population from Pakistan was clearly distinct, and no divergence was present between two populations from Pakistan (Bajaur and Malakand). The overall high diversity and recombination signature suggested the potential role of recombination in the eastern Himalayan region (Nepal and Bhutan), which needs to be considered during host resistance deployment and in the context of aerial dispersal of the pathogen. Further surveillance should be made in the Himalayan region for disease management in the region and in the context of worldwide invasions. [Formula: see text] Copyright © 2019 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

Gene flow in symbionts of Cladonia arbuscula

2006 ◽  
Vol 39 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Jason ROBERTSON ◽  
Michele D. PIERCEY-NORMORE
Keyword(s):  
Internal Transcribed Spacer ◽  
Fragment Length Polymorphism ◽  
Small Subunit ◽  
Geographic Range ◽  
Population Subdivision ◽  
Analysis Of Molecular Variance ◽  
Molecular Variance ◽  
Symbiont Transmission ◽  
High Level ◽  
Restriction Fragment Length

Genetic diversity in symbionts of the lichen Cladonia arbuscula was investigated. Forty-eight specimens of Cladonia arbuscula located within a 2 km range at Payuk Lake in Manitoba were collected. Population structure and method of symbiont transmission in C. arbuscula were inferred by examining the presence or absence of introns in the nuclear small subunit (SSU) ribosomal DNA (rDNA) of the mycobiont and restriction fragment length polymorphism (RFLP) of the internal transcribed spacer (ITS) rDNA in the photobiont. The mycobiont showed a high level of genetic variation and the photobiont a low level of variation within the small geographic range studied. An analysis of molecular variance of fungal genotypes showed significant population subdivision for the mycobiont when the data were analysed at P=0·05. No population subdivision was detected when P=0·001. The photobiont also showed no population subdivision. Photobiont genotypes did not correlate with mycobiont genotypes suggesting the symbionts were not transmitted together in the same propagule. Multiple fungal genotypes were also detected in C. arbuscula and possible explanations were discussed.

scholarly journals Genetic variability of three natural populations of Maytenus aquifolium (Celesteraceae) from Telêmaco Borba, Paraná, Brazil

2010 ◽  
Vol 53 (5) ◽  
pp. 1037-1042 ◽  
Author(s):  
Sandra Aparecida Sahyun ◽  
Eduardo Augusto Ruas ◽  
Claudete de Fátima Ruas ◽  
Cristiano Medri ◽  
José Roberto Pinto de Souza ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genetic Variability ◽  
Bayesian Analysis ◽  
Rapd Markers ◽  
Gene Diversity ◽  
Natural Populations ◽  
Soil Types ◽  
Number Of Clusters ◽  
Analysis Of Molecular Variance ◽  
Molecular Variance

Three populations of Maytenus aquifolium from Monte Alegre farm, Telemaco Borba county, Paraná, Brazil were analyzed by RAPD markers. A total of 13 primers were applied wich yielded 283 well amplified markers in all the studied populations (Mortandade, Vila Preta and Trinita), producing different values of gene diversity and polymorphic loci. The analysis of molecular variance (AMOVA) indicated that 21.77% of the genetic variation was among the population. Pairwise F ST analysis showed that the most divergent populations were closer geographically, demonstrating that other factors such as different soil types could explain this variation. Bayesian analysis for K number of clusters and the Principal Coordinate indicated that these three populations were highly structured, corroborating the high values found for the F ST and indicating that for conservation purposes all populations should be maintained.

scholarly journals Population Genetic Analysis Corroborates Dispersal of Fusarium oxysporum f. sp. radicis-lycopersici from Florida to Europe

1999 ◽  
Vol 89 (8) ◽  
pp. 623-630 ◽  
Author(s):  
U. Liane Rosewich ◽  
R. E. Pettway ◽  
Talma Katan ◽  
H. C. Kistler
Keyword(s):  
Fusarium Oxysporum ◽  
Gene Diversity ◽  
Population Subdivision ◽  
Founder Population ◽  
Palm Beach County ◽  
Population Genetic Analysis ◽  
Low Frequencies ◽  
The United Kingdom ◽  
Crown And Root Rot ◽  
Southern Florida

Fusarium oxysporum isolates from tomato plants displaying crown and root rot symptoms were collected in central and southern Florida and analyzed using vegetative compatibility grouping (VCG) and nuclear restriction fragment length polymorphism (RFLP) data. VCG 0094 of F. oxysporum f. sp. radicis-lycopersici, previously known only from northwestern Europe, was predominant among 387 isolates assessed. In addition, two newly described VCGs (0098 and 0099) were detected at low frequencies. Floridian VCG 0094 isolates displayed a continuum of compatibilities, which is in contrast to the three distinct subgroups previously identified among European VCG 0094 isolates. RFLP haplotypes were constructed using one repetitive and three low-copy probes. Population subdivision of VCG 0094 from various Floridian counties and from northwestern Europe (Belgium, the Netherlands, and the United Kingdom) was evaluated by analysis of molecular variance. A “natural” population structure was revealed, differentiating populations from the east and west coasts of Florida. In addition, isolates from Europe were statistically indistinguishable from the Palm Beach County, FL, population. Furthermore, gene diversity among Palm Beach County VCG 0094 isolates was more than five times greater than among European isolates. Results from both VCG and RFLP analyses strongly support the inference that the European VCG 0094 constitutes a founder population that resulted from intercontinental migration of a few isolates from Palm Beach County, FL.

Prevalence of sclerotinia stem rot of canola in New South Wales

2003 ◽  
Vol 43 (2) ◽  
pp. 163 ◽  
Author(s):  
T. L. Hind ◽  
G. J. Ash ◽  
G. M. Murray
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
New South ◽  
New South Wales ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Mean Values ◽  
Stem Infection ◽  
South Wales

Surveys of petal infestation and stem infection conducted in 1998, 1999 and 2000 indicated that Sclerotinia sclerotiorum poses a threat to the Australian canola industry. Inoculum was present throughout all canola-growing regions of New South Wales and the stem disease was widespread throughout southern New South Wales. Percentage petal infestation increased over the 3 years surveyed with values ranging from 0 to 99.4%. The highest petal infestation values were observed in 2000 (maximum of 99.4%, mean of 82.2%), with lower mean values in 1998 (38.4%) and 1999 (49.6%). Stem infection ranged from 0 to 37.5% and most fields had less than 10% stem infection. Stem rot incidence before harvest did not relate to percentage petal infestation determined during flowering. This indicated that factors other than percentage petal infestation were important in influencing stem rot incidence. While there was no relationship between percentage petal infestation and stem rot incidence, stem infection never occurred without prior petal infestation.

Analysis of molecular variance and population structure in southern Indian finger millet genotypes using three different molecular markers

2016 ◽  
Vol 19 (4) ◽  
pp. 275-283 ◽  
Author(s):  
Host Antony David Rajendran ◽  
Ramakrishnan Muthusamy ◽  
Antony Caesar Stanislaus ◽  
Thirugnanasambantham Krishnaraj ◽  
Sivasankaran Kuppusamy ◽  
...  
Keyword(s):  
Population Structure ◽  
Molecular Markers ◽  
Finger Millet ◽  
Analysis Of Molecular Variance ◽  
Molecular Variance

scholarly journals Genetic diversity in natural populations of Buriti (Mauritia flexuosa L. f.)

2011 ◽  
Vol 11 (3) ◽  
pp. 216-223 ◽  
Author(s):  
Liene Rocha Picanço Gomes ◽  
Maria Teresa Gomes Lopes ◽  
Jania Lilia da Silva Bentes ◽  
Willian Silva Barros ◽  
Pedro de Queiroz Costa Neto ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Length Polymorphism ◽  
Fragment Length Polymorphism ◽  
Natural Populations ◽  
Analysis Of Molecular Variance ◽  
Molecular Variance ◽  
Polymorphic Loci ◽  
Mauritia Flexuosa ◽  
Geographical Distances ◽  
Traditional Communities

This study aimed to characterize the genetic diversity of buriti populations by AFLP (Amplified Fragment Length Polymorphism) markers. The analysis was performed in four populations used by traditional communities in the state of Amazonia (Bom Jesus do Anamã, Lauro Sodré, Santa Luzia do Buiçuzinho, and Esperança II). From each population 30 plants were randomly selected. To obtain the markers four primer combinations were used. The percentage of polymorphic loci was estimated, the molecular variance among and within populations analyzed and a dendrogram constructed. The primers detected 339 polymorphic loci ranging from 81.1 % to 91.1 % among populations. Analysis of molecular variance attributed 77.18 % to variation within and 22.8 % to variation between populations. The dendrogram indicated the formation of two groups, showing that the populations of Bom Jesus do Anamã and Lauro Sodré are genetically most similar and thet the genetic and geographical distances are not correlated.

scholarly journals Assessment of relationships among and within Helichrysum Mill. (Asteraceae) species by using ISSR markers and morphological traits

Hacquetia ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 105-118 ◽  
Author(s):  
Narjes Azizi ◽  
Masoud Sheidai ◽  
Valiollah Mozaffarian ◽  
Mitra Arman ◽  
Zahra Noormohammadi
Keyword(s):  
Genetic Similarity ◽  
Morphological Traits ◽  
Morphological Analysis ◽  
Gene Diversity ◽  
Molecular Data ◽  
Issr Markers ◽  
Diagnostic Features ◽  
Analysis Of Molecular Variance ◽  
Information Index ◽  
Expected Heterozygosity

Abstract This study conducted to determine relationship among and within Iranian Helichrysum species (Asteraceae). In this study based on ISSR markers, the highest percentage of ISSR loci polymorphism (54.7%) occurred in H. armenium. The highest gene diversity over loci (1.224), Shannon’s Information Index (0.224%) and Expected Heterozygosity (0.142%) occurred in H. armenium (0.18) and the lowest of these parameters (0%) were observed in H. araxinum, H. graveolens, H. persicum and H. psychrophilum. The highest genetic similarity occurred between H. armenium and H. rubicundum (0.989), while the lowest was between H. polyphyllum and H. graveolens (0.213). The analysis of molecular variance (AMOVA), showed significant genetic variation among (24%) and within (76%) species. In morphological analysis traits such as indumentum, resting bud, achene length, achenial papillae, dimension of receptacle and form and apex of phyllaries were main diagnostic features. Results obtained from the morphological cluster were greatly consistent with the molecular data, to elucidating taxonomic relationships, as well as both attributed the higher diversity in H. armenium and H. rubicundum in comparison with other species and also indicated that H. persicum is a member of H. oocephalum species. Totally we confirmed the presence of 18 species in Iran.

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