scholarly journals Induction of sexual reproduction and genetic diversity in the cheese fungus P enicillium roqueforti

2014 ◽  
Vol 7 (4) ◽  
pp. 433-441 ◽  
Author(s):  
Jeanne Ropars ◽  
Manuela López‐Villavicencio ◽  
Joëlle Dupont ◽  
Alodie Snirc ◽  
Guillaume Gillot ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sexual Reproduction

Microsatellite markers provide evidence for sexual reproduction of Mycosphaerella graminicola in Saskatchewan

Genome ◽  
2004 ◽  
Vol 47 (5) ◽  
pp. 789-794 ◽  
Author(s):  
M Razavi ◽  
G R Hughes
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Sexual Reproduction ◽  
Primary Source ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Allelic Series ◽  
Evolutionary Potential ◽  
Wheat Field

This study examined the genetic structure of a Saskatchewan population of Mycosphaerella graminicola, cause of the foliar disease Septoria tritici blotch of wheat. Such knowledge is valuable for understanding the evolutionary potential of this pathogen and for developing control strategies based on host resistance. Nine pairs of single-locus microsatellite primers were used to analyze the genomic DNA of 90 isolates of M. graminicola that were collected using a hierarchical sampling procedure from different locations, leaves, and lesions within a wheat field near Saskatoon. Allelic series at eight different loci were detected. The number of alleles per locus ranged from one to five with an average of three alleles per locus. Genetic diversity values ranged from 0.04 to 0.67. Partitioning the total genetic variability into within- and among-location components revealed that 88% of the genetic variability occurred within locations, i.e., within areas of 1 m2, but relatively little variability occurred among locations. Low variability among locations and a high degree of variability within locations would result if the primary source of inoculum was airborne ascospores, which would be dispersed uniformly within the field. This finding was confirmed by gametic disequilibrium analysis and suggests that the sexual reproduction of M. graminicola occurs in Saskatchewan.Key words: Mycosphaerella graminicola, SSR markers, sexual reproduction, genetic diversity.

scholarly journals Influence of breeding strategy on genetic diversity of individuals

2021 ◽  
pp. 1168-1174
Author(s):  
A.A. Poroshina ◽  
◽  
D.Yu. Sherbakov ◽  
Keyword(s):  
Genetic Diversity ◽  
Computer Simulation ◽  
Molecular Evolution ◽  
Microsatellite Markers ◽  
Simulation Model ◽  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Reproductive Strategy ◽  
Breeding Strategy ◽  
Computer Simulation Model

Abstract. Using a computer simulation model, we tried to investigate how the transition from sexual reproduction to asexual reproduction will affect the population of diploid organisms with a neutral character of molecular evolution. At the same time, special attention was paid to the specificity of microsatellite markers. In this paper, we develop fast and inexpensive methods for assessing the changes in populations that occur with a change in reproductive strategy.

scholarly journals Global Biodiversity Patterns of the Photobionts Associated with the Genus Cladonia (Lecanorales, Ascomycota)

2020 ◽  
Author(s):  
Raquel Pino-Bodas ◽  
Soili Stenroos
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Sexual Reproduction ◽  
Geographical Distribution ◽  
Type I ◽  
Generalist Species ◽  
Climatic Regions ◽  
The World ◽  
Global Biodiversity ◽  
High Diversity

Abstract The diversity of lichen photobionts is not fully known. We studied here the diversity of the photobionts associated with Cladonia, a sub-cosmopolitan genus ecologically important, whose photobionts belong to the green algae genus Asterochloris. The genetic diversity of Asterochloris was screened by using the ITS rDNA and actin type I regions in 223 specimens and 135 species of Cladonia collected all over the world. These data, added to those available in GenBank, were compiled in a dataset of altogether 545 Asterochloris sequences occurring in 172 species of Cladonia. A high diversity of Asterochloris associated with Cladonia was found. The commonest photobiont lineages associated with this genus are A. glomerata, A. italiana, and A. mediterranea. Analyses of partitioned variation were carried out in order to elucidate the relative influence on the photobiont genetic variation of the following factors: mycobiont identity, geographic distribution, climate, and mycobiont phylogeny. The mycobiont identity and climate were found to be the main drivers for the genetic variation of Asterochloris. The geographical distribution of the different Asterochloris lineages was described. Some lineages showed a clear dominance in one or several climatic regions. In addition, the specificity and the selectivity were studied for 18 species of Cladonia. Potentially specialist and generalist species of Cladonia were identified. A correlation was found between the sexual reproduction frequency of the host and the frequency of certain Asterochloris OTUs. Some Asterochloris lineages co-occur with higher frequency than randomly expected in the Cladonia species.

Active sexual reproduction but no sign of genetic diversity in range-edge populations of Vanilla roscheri Rchb. f. (Orchidaceae) in South Africa

2014 ◽  
Vol 15 (6) ◽  
pp. 1403-1415 ◽  
Author(s):  
Rodolphe L. Gigant ◽  
Alexandre De Bruyn ◽  
Brigitte Church ◽  
Laurence Humeau ◽  
Anne Gauvin-Bialecki ◽  
...  
Keyword(s):  
South Africa ◽  
Genetic Diversity ◽  
Sexual Reproduction ◽  
Range Edge ◽  
Edge Populations

scholarly journals Genetic diversity and clonal vs. sexual reproduction in Fallopia spp. (Polygonaceae)

2007 ◽  
Vol 94 (6) ◽  
pp. 957-964 ◽  
Author(s):  
J. L. Grimsby ◽  
D. Tsirelson ◽  
M. A. Gammon ◽  
R. Kesseli
Keyword(s):  
Genetic Diversity ◽  
Sexual Reproduction

Epidemiology and genetics in the coevolution of parasites and hosts

1983 ◽  
Vol 219 (1216) ◽  
pp. 281-313 ◽  
Keyword(s):  
Genetic Diversity ◽  
Sexual Reproduction ◽  
Empirical Evidence ◽  
Population Biology ◽  
Natural Populations ◽  
Numerical Magnitude ◽  
Parasitic Infections ◽  
Genetic Studies ◽  
New Ideas ◽  
Host Parasite

Recent studies suggest that parasites (interpreted broadly to include viruses, bacteria, protozoans and helminths) may influence the numerical magnitude or geographical distribution of their host populations; most of such studies focus on the population biology and epidemiology of the host-parasite association, taking no explicit account of the genetics. Other researchers have explored the possibility that the coevolution of hosts and parasites may be responsible for much of the genetic diversity found in natural populations, and may even be the main reason for sexual reproduction; such genetic studies rarely take accurate account of the density- and frequency-dependent effects associated with the transmission and maintenance of parasitic infections. This paper aims to combine epidemiology and genetics, reviewing the way in which earlier studies fit into a wider scheme and offering some new ideas about host-parasite coevolution. One central conclusion is that ‘successful’ parasites need not necessarily evolve to be harmless: both theory and some empirical evidence (particularly from the myxoma-rabbit system) indicate that many coevolutionary paths are possible, depending on the relation between virulence and transmissibility of the parasite or pathogen.

Genetic diversity of an introduced pest, the green spruce aphid Elatobium abietinum (Hemiptera: Aphididae) in New Zealand and the United Kingdom

1998 ◽  
Vol 88 (5) ◽  
pp. 537-543 ◽  
Author(s):  
D. Nicol ◽  
K.F. Armstrong ◽  
S.D. Wratten ◽  
P.J. Walsh ◽  
N.A. Straw ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
United Kingdom ◽  
New Zealand ◽  
Sexual Reproduction ◽  
Control Strategies ◽  
The United Kingdom ◽  
Introduced Pest ◽  
Elatobium Abietinum ◽  
The Uk

AbstractThe green spruce aphid Elatobium abietinum (Walker) is an introduced pest in the United Kingdom and more recently in New Zealand. In outbreak years this aphid can cause severe defoliation and sometimes death of spruce trees (Picea spp.). As chemical control is not financially viable, other options including host-plant resistance and biological control are currently being investigated. An understanding of the genetic variation of this pest is imperative in fully utilizing these control strategies. To examine this, E. abietinum was collected from Sitka spruce Picea sitchensis from four locations in the UK that were up to 240 km apart. Of these, 40 aphids were analysed via two alternative polymerase chain reaction (PCR) analyses using primer pairs. The first analysis used 10-mer random primers, whilst the second analysis used primers designed to amplify across the intergenic spacer region of rDNA. Combining results from the two analyses allowed the 40 UK aphids to be separated into 28 different genotypes. The genetic variation was also high within each UK site, with 77 to 89% of the aphids sampled being of a different genotype. The two PCR analyses were subsequently used to examine 40 aphids across six sites in New Zealand up to 1200 km apart. No genetic variation was identified. Further analysis of several of these New Zealand aphids with 87 individual 10-mer primers and two polymerase enzymes, still did not detect any genetic variation. The high degree of genotypic diversity in the UK populations was presumably due to a longer period of establishment, multiple introductions and/or sexual reproduction. The contrasting lack of genetic variation in New Zealand populations was probably due to a very limited founder population, continued isolation and lack of sexual reproduction. Reduced genetic diversity can seriously decrease the ability of a population to adapt to control strategies. Therefore the durability of certain control methods may be more readily maintained in such an isolated population in New Zealand.

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