scholarly journals Genetic Diversity and Population Differentiation ofGuignardia mangiferaefrom “Tahiti” Acid Lime

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Ester Wickert ◽  
Eliana Gertrudes de Macedo Lemos ◽  
Luciano Takeshi Kishi ◽  
Andressa de Souza ◽  
Antonio de Goes
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Population Differentiation ◽  
Black Spot ◽  
The Other ◽  
Presenting Symptoms ◽  
Citrus Black Spot ◽  
Panmictic Population ◽  
Acid Lime

Among the citrus plants, “Tahiti” acid lime is known as a host ofG. mangiferaefungi. This species is considered endophytic for citrus plants and is easily isolated from asymptomatic fruits and leaves.G. mangiferaeis genetically related and sometimes confused withG. citricarpawhich causes Citrus Black Spot (CBS). “Tahiti” acid lime is one of the few species that means to be resistant to this disease because it does not present symptoms. Despite the fact that it is commonly found in citric plants, little is known about the populations ofG. mangiferaeassociated with these plants. Hence, the objective of this work was to gain insights about the genetic diversity of theG. mangiferaepopulations that colonize “Tahiti” acid limes by sequencing cistron ITS1-5.8S-ITS2. It was verified that “Tahiti” acid lime plants are hosts ofG. mangiferaeand also ofG. citricarpa, without presenting symptoms of CBS. Populations ofG. mangiferaepresent low-to-moderate genetic diversity and show little-to-moderate levels of population differentiation. As gene flow was detected among the studied populations and they share haplotypes, it is possible that all populations, from citrus plants and also from the other known hosts of this fungus, belong to one great panmictic population.

scholarly journals Genetic Diversity and Population Differentiation of the Causal Agent of Citrus Black Spot in Brazil

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Ester Wickert ◽  
Antonio de Goes ◽  
Andressa de Souza ◽  
Eliana Gertrudes de Macedo Lemos
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Differentiation ◽  
Sweet Orange ◽  
Black Spot ◽  
Pathogenic Fungi ◽  
Its2 Region ◽  
Citrus Black Spot ◽  
Different Populations ◽  
Different Origins

One of the most important diseases that affect sweet orange orchards in Brazil is the Citrus Black Spot that is caused by the fungusGuignardia citricarpa. This disease causes irreparable losses due to the premature falling of fruit, as well as its severe effects on the epidermis of ripe fruit that renders them unacceptable at the fresh fruit markets. Despite the fact that the fungus and the disease are well studied, little is known about the genetic diversity and the structure of the fungi populations in Brazilian orchards. The objective of this work was study the genetic diversity and population differentiation ofG. citricarpaassociated with four sweet orange varieties in two geographic locations using DNA sequence of ITS1-5.8S-ITS2 region from fungi isolates. We observed that different populations are closely related and present little genetic structure according to varieties and geographic places with the highest genetic diversity distributed among isolates of the same populations. The same haplotypes were sampled in different populations from the same and different orange varieties and from similar and different origins. If new and pathogenic fungi would become resistant to fungicides, the observed genetic structure could rapidly spread this new form from one population to others.

scholarly journals Study of genetic differences among Slovak Tsigai populations using microsatellite markers

2009 ◽  
Vol 54 (No. 10) ◽  
pp. 468-474 ◽  
Author(s):  
S. Kusza ◽  
E. Gyarmathy ◽  
J. Dubravska ◽  
I. Nagy ◽  
A. Jávor ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Distance ◽  
Microsatellite Markers ◽  
Mating System ◽  
Population Differentiation ◽  
Genetic Relationships ◽  
The Other ◽  
Potential Risks ◽  
Substantial Degree

In this study genetic diversity, population structure and genetic relationships of Tsigai populations in Slovakia were investigated using microsatellite markers. Altogether 195 animals from 12 populations were genotyped for 16 microsatellites. 212 alleles were detected on the loci. The number of identified alleles per locus ranged from 11 to 35. In the majority of the populations heterozygosity deficiency and potential risks of inbreeding could be determined. High values of <I>F</I><sub>ST</sub> (0.133) across all the loci revealed a substantial degree of population differentiation. The estimation of genetic distance value showed that the Slovak Vojin population was the most different from the other populations. The 12 examined populations were able to group into 4 clusters. With this result our aim is to help the Slovak sheep breeders to establish their own mating system, to avoid genetic loss and to prevent diversity of Tsigai breed in Slovakia.

scholarly journals Rind Stippling on Valencia Oranges by Copper Fungicides Used for Control of Citrus Black Spot in South Africa

Plant Disease ◽  
1997 ◽  
Vol 81 (8) ◽  
pp. 851-854 ◽  
Author(s):  
G. C. Schutte ◽  
K. V. Beeton ◽  
J. M. Kotzé
Keyword(s):  
South Africa ◽  
Black Spot ◽  
The Other ◽  
Copper Oxychloride ◽  
Copper Fungicides ◽  
Citrus Black Spot ◽  
Other Hand ◽  
Wettable Powder ◽  
Cupric Hydroxide ◽  
Protection Period

Four copper sprays and copper mixtures with dithiocarbamates aggravated stippling of the fruit rind of Valencia oranges if sprayed in succession at registered rates during the recommended protection period from October to January for control of citrus black spot in South Africa. Copper stippling was more severe on treatments in which copper oxychloride was sprayed in succession, individually, or in combination with mancozeb or maneb/ZnO. On the other hand, less copper stippling was observed on treatments in which three mancozeb applications were altered with a single copper oxychloride as tank mixtures with or without mancozeb, which was sprayed during midsummer (December and January). Cupric hydroxide resulted in more general copper stippling lesions than any other copper oxychloride spray program. Four successive applications of the wettable powder copper oxychloride formulation resulted in more copper stippling when compared with the suspension concentrate formulation. Stippling was calculated to be more severe with late applications of copper fungicides during December and January. In another experiment, all contact fungicides tested were effective in controlling citrus black spot.

scholarly journals Genetic Diversity and Structure of the Apiosporina morbosa Populations on Prunus spp.

2005 ◽  
Vol 95 (8) ◽  
pp. 859-866 ◽  
Author(s):  
Jinxiu Zhang ◽  
W. G. Dilantha Fernando ◽  
William. R. Remphrey
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Gene Flow ◽  
Host Species ◽  
Population Differentiation ◽  
The United States ◽  
Flow Rates ◽  
Geographic Locations ◽  
Genetic Diversity And Structure ◽  
Geographic Populations

Populations of Apiosporina morbosa collected from 15 geographic locations in Canada and the United States and three host species, Prunus virginiana, P. pensylvanica, and P. padus, were evaluated using the sequence-related amplified polymorphism (SRAP) technique to determine their genetic diversity and population differentiation. Extensive diversity was detected in the A. morbosa populations, including 134 isolates from Canada and the United States, regardless of the origin of the population. The number of polymorphic loci varied from 6.9 to 82.8% in the geographic populations, and from 41.4 to 79.3% in the populations from four host genotypes based on 58 polymorphic fragments. In all, 44 to 100% of isolates in the geographic populations and 43.6 to 76.2% in populations from four host genotypes represented unique genotypes. Values of heterozygosity (H) varied from 2.8 to 28.3% in the geographic populations and 10.2 to 26.1% in the populations from four host genotypes. In general, the A. morbosa populations sampled from wild chokecherry showed a higher genetic diversity than those populations collected from other host species, whereas the populations isolated from cultivated chokecherry, P. virginiana ‘Shubert Select’, showed a reduction of genetic diversity compared with populations from wild P. virginiana. Significant population differentiation was found among both the geographic populations (P < 0.05) and populations from different host genotypes (P < 0.02). In the geographic populations, most of populations from cultivated and wild P. virginiana were closely clustered, and no population differentiation was detected except for the populations from Morris, Morden, and Winnipeg, Manitoba, Canada. Furthermore, the populations from P. virginiana in the same geographic locations had higher genetic identity and closer genetic distance to each other compared with those from different locations. Four populations from P. virginiana, P. pensylvanica, and P. padus, were significantly differentiated from each other (P < 0.02), except there was no differentiation between the Shubert Select and wild chokecherry populations (>P> = 0.334). Indirect estimation of gene flow showed that significant restricted gene flow existed between populations from different regions and host species. Gene flow rates (Nm) varied from <1 to 12.5, with higher gene flow rates among population pairs from the same host species (P = 1.000). The analysis of molecular variance revealed that a major genetic variance source came from the genetic variation among isolates within populations regardless of the origin and host genotype of the population. Although some locations had a limited number of isolates, the results of this study clearly showed that the genetic diversity and population differentiation of A. morbosa were closely associated with host genotypes and geographic locations, but mostly with the former.

scholarly journals Landscape and climatic features drive genetic differentiation processes in a South American coastal plant

2020 ◽  
Author(s):  
Gustavo A. Silva-Arias ◽  
Lina Caballero-Villalobos ◽  
Giovanna C. Giudicelli ◽  
Loreta B. Freitas
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Coastal Plain ◽  
Population Differentiation ◽  
Water Bodies ◽  
Marginal Populations ◽  
Landscape Features ◽  
Precipitation Seasonality ◽  
Isolation By Environment

ABSTRACTBackground and aimsHistorical and ecological processes shaped the patterns of genetic diversity in plant species; among these, colonization to new environments such as coastal regions generate multiple signals of interest to understand the influence of landscape features on the population differentiation.MethodsWe analysed the genetic diversity and population structure of Calibrachoa heterophylla to infer the influence of abiotic landscape features on this coastal species’ gene flow in the South Atlantic Coastal Plain (SACP). We used ten microsatellite loci to genotype 253 individuals from 15 populations, covering the species’ entire geographical range. We applied population genetics analyses to determine population diversity and structure along the SACP, migration model inference and correlative analyses to disentangle the most likely drivers of gene flow in the SACP.Key ResultsThe C. heterophylla populations located more distantly from the seashore showed higher genetic diversity than those closer to the sea. The genetic differentiation had a consistent signal of isolation-by-distance. Landscape features, such as water bodies and wind corridors, and raw geographical distances equally explained the genetic differentiation, whereas the precipitation seasonality showed a strong signal for isolation-by-environment in marginal populations. The estimated gene flow suggested that marginal populations had restricted immigration rates, which could enhance the genetic differentiation.ConclusionsThe influence of topographical features in population differentiation in C. heterophylla is related with the history of the coastal plain deposition. Gene flow is mainly restricted to nearby populations and facilitated by wind fields but with no apparent influence of large water bodies. Furthermore, differential rainfall regimes in marginal populations can promote local genetic differentiation.

scholarly journals Genetic Diversity and Gene Flow of Quercus crispula in a Semi-Fragmented Forest Together With Neighboring Forests

2006 ◽  
Vol 55 (1-6) ◽  
pp. 160-169 ◽  
Author(s):  
Takafumi Ohsawa ◽  
Y. Tsuda ◽  
Y. Saito ◽  
H. Sawada ◽  
Y. Ide
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Population Differentiation ◽  
Pollen Dispersal ◽  
Parentage Analysis ◽  
Natural Forest ◽  
Central Japan ◽  
Quercus Crispula ◽  
Fragmented Forest ◽  
Fragmented Forests

Abstract The genetic diversity and differentiation in Quercus crispula populations in the Chichibu Mountains, central Japan, were evaluated using six microsatellite markers. Gene flow into a 2500-m2 semi-fragment of a natural forest from the neighboring natural forest at a distance of more than 50m was also evaluated using parentage analysis. All five populations in the mountains had similar levels of genetic diversity (He = 0.752-0.792), and the level of population differentiation was low (FST = 0.016). The semi-fragmented stand showed similar genetic diversity with the neighboring unfragmented forests, and Hardy-Weinberg disequilibrium was not found (FIS = 0.083 in adults, 0.025 in seedlings). In the semifragment, 70 seedlings were examined; according to the parentage analysis, eight of the 70 seedlings (ca. 11%) had neither of the parent trees in this fragment. These seeds must have been transported from a distance of more than 50 m; therefore, there could be a possibility that the seeds were dispersed by birds. A similar trend of seed flow into the fragment was also confirmed by genotyping endocarps of hypogeal cotyledons, while more frequent seed flow was found in the neighboring unfragmented forest. Of the remaining 62 seedlings, the maternal trees (but not the paternal trees) of 29 seedlings and both parent trees of 33 seedlings were detected in the semi-fragment. These results indicate that the gene flow among the populations occurs frequently via pollen dispersal and occasionally via seed dispersal and that, at least the current levels of genetic diversity have been maintained in such fragmented forests.

scholarly journals Erratum to “Genetic Diversity and Population Differentiation ofGuignardia mangiferaefrom “Tahiti” Acid Lime”

2012 ◽  
Vol 2012 ◽  
pp. 1-1
Author(s):  
Ester Wickert ◽  
Eliana Gertrudes de Macedo Lemos ◽  
Luciano Takeshi Kishi ◽  
Andressa de Souza ◽  
Antonio de Goes
Keyword(s):  
Genetic Diversity ◽  
Population Differentiation ◽  
Acid Lime

Interspecific gene flow and an intermediate molecular profile of Dyckia julianae (Bromeliaceae), an endemic species from southern Brazil

2019 ◽  
Vol 192 (4) ◽  
pp. 675-690 ◽  
Author(s):  
Luiza D Hirsch ◽  
Camila M Zanella ◽  
Camila Aguiar-Melo ◽  
Laís M S Costa ◽  
Fernanda Bered
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
The Other ◽  
Hybrid Origin ◽  
Molecular Profile ◽  
Southern Brazil ◽  
Sympatric Populations ◽  
Interspecific Gene Flow ◽  
Viable Seeds ◽  
Origin Hypothesis

Abstract When related species are distributed in sympatric populations, hybridization may occur. Likewise, one or more of these species may have arisen through historical hybridization between taxa. Here, we aim to elucidate the occurrence of hybridization among three Dyckia spp. (Bromeliaceae) from southern Brazil. We used seven nuclear and six plastid microsatellite loci to assess patterns of genetic diversity, population structure and hybridization in the three species. Furthermore, we performed manual crosses between species to test compatibility and fertility. The results showed that Dyckia julianae has an intermediate molecular profile, low gene flow occurs between Dyckia hebdingii and Dyckia choristaminea and higher gene flow occurs between D. julianae and the other two species. Plastid microsatellites identified 12 haplotypes that are shared among the species. The manual crosses between D. julianae and the other two species produced viable seeds, but no crosses between D. hebdingii and D. choristaminea generated fruits. Our data suggest that the reproductive barrier between D. julianae and the other two species is permeable. Further investigation into the hybrid origin hypothesis of D. julianae should be undertaken, as well as the mechanisms involved in reproductive isolation between D. hebdingii and D. choristaminea.

scholarly journals Gene flow on ice: the role of sea ice and whaling in shaping Holarctic genetic diversity and population differentiation in bowhead whales (Balaena mysticetus)

2012 ◽  
Vol 2 (11) ◽  
pp. 2895-2911 ◽  
Author(s):  
S. Elizabeth Alter ◽  
Howard C. Rosenbaum ◽  
Lianne D. Postma ◽  
Peter Whitridge ◽  
Cork Gaines ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Sea Ice ◽  
Population Differentiation ◽  
Balaena Mysticetus ◽  
Bowhead Whales

Genetic rescue by augmenting gene flow

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Inbreeding Coefficient ◽  
Outbreeding Depression ◽  
Genetic Rescue ◽  
Evolutionary Potential ◽  
Beneficial Effects ◽  
The Difference ◽  
Inbred Populations ◽  
Harmful Effects

Inbreeding is reduced and genetic diversity enhanced when a small isolated inbred population is crossed to another unrelated population. Crossing can have beneficial or harmful effects on fitness, but beneficial effects predominate, and the risks of harmful ones (outbreeding depression) can be predicted and avoided. For crosses with a low risk of outbreeding depression, there are large and consistent benefits on fitness that persist across generations in outbreeding species. Benefits are greater in species that naturally outbreed than those that inbreed, and increase with the difference in inbreeding coefficient between crossed and inbred populations in mothers and zygotes. However, benefits are similar across invertebrates, vertebrates and plants. There are also important benefits for evolutionary potential of crossing between populations.

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