Genetic Structure of <i>Cronartium ribicola</i> Populations in Eastern Canada

Et-touil, Khalid; Bernier, Louis; Beaulieu, Jean; Bérubé, Jean A.; Hopkin, A. A.; Hamelin, Richard

doi:10.1094/phyto.1999.89.10.915

Cited by 34 publications

(35 citation statements)

References 23 publications

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“…Therefore, differentiation among local populations within regions could not be distinguished from variation among individual galls within populations. Similar observations of large withinpopulation variability have been reported for eastern Canadian populations of white pine blister rust fungus, C. ribicola (Hamelin, 1996;Hamelin et al, 1998;Et-touil et al, 1999). As a general conclusion, C. quercuum fusiforme exists as a highly variable formae speciales, with a large proportion of its genetic variability occurring within populations.…”

Section: Tl Kubisiak Et Alsupporting

confidence: 82%

“…Furthermore, within the eastern and western metapopulations, associations between genetic and geographic distance have not been observed in C. ribicola. Although genetic variability in C. ribicola follows a pattern consistent with a hypothesis of subpopulations within metapopulations where genetic drift or founder effects play major evolutionary roles (Kinloch et al, 1998;Et-touil et al, 1999), in C. quercuum fusiforme the distribution of genetic variability is consistent with a hypothesis of at least four metapopulations with gene flow occurring less among regions than among populations within regions, and where overall levels of gene migration are related to the geographic distance between populations. Asterisk ¼ probability random value is greater than observed value based on a total of 16 000 permutations; *ao0.01, **ao0.001, ***ao0.0001.…”

Section: Tl Kubisiak Et Alsupporting

confidence: 63%

“…This pattern of genetic differentiation is different from that reported for C. ribicola in eastern Canada. Et-touil et al (1999) found variation among provinces to be several orders of magnitude smaller than differentiation among populations within regions. Furthermore, within the eastern and western metapopulations, associations between genetic and geographic distance have not been observed in C. ribicola.…”

Section: Tl Kubisiak Et Almentioning

confidence: 90%

“…Unlike C. quercuum fusiforme, C. ribicola is an exotic pathogen in North America, having been separately introduced to both eastern and western portions of this continent early in the 20th century (Maloy, 1997). Investigations in eastern Canada and in western North America based on neutral genetic markers indicate that most genetic diversity in this fungus is found among individual infections within local populations, but that modest differentiation also occurs among populations within geographic regions (Hamelin et al, 1995(Hamelin et al, , 1998Kinloch et al, 1998;Et-touil et al, 1999). Furthermore, there is no evidence for genetic variability among population composites representing different regions within either eastern or western areas.…”

Section: Introductionmentioning

confidence: 99%

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Microsatellite DNA suggests regional structure in the fusiform rust fungus Cronartium quercuum f. sp fusiforme

et al. 2003

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This paper reports results obtained from microsatellite DNA analysis of genetic structure for populations of the native fungus Cronartium quercuum f. sp fusiforme infecting loblolly pine (Pinus taeda L.) over much of this host's natural range. Mostly all fusiform rust galls formed under field conditions are produced as a result of infection and colonization by haploid mycelium originating from a single basidiospore of C. quercuum fusiforme. If multiple infections do occur, then only a single haplotype must ultimately dominate and be responsible for gall formation. High levels of microsatellite variability exist in C. quercuum fusiforme and most of this variation occurs within local populations (average 88.4%). A statistically significant proportion, however, is found among populations, and the magnitude of this differentiation is closely associated with geographic distance between populations. Unweighted pair-group mean analysis and principal components analysis both indicate that at least four genetically distinct regional groups of C. quercuum fusiforme exist in the south Atlantic and Gulf coastal plains. In summary, the distribution of genetic variability in C. quercuum fusiforme is consistent with a hypothesis of at least four metapopulations with gene flow occurring less among regions than among populations within regions, and where overall levels of gene migration are related to geographic distance between populations.

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Section: Tl Kubisiak Et Alsupporting

confidence: 82%

Section: Tl Kubisiak Et Alsupporting

confidence: 63%

Section: Tl Kubisiak Et Almentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

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Microsatellite DNA suggests regional structure in the fusiform rust fungus Cronartium quercuum f. sp fusiforme

et al. 2003

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“…At the global scale, some patterns of isolation were also detected, for example in M. graminicola (Linde et al, 2002) and in Rhynchosporium secalis (Zaffarano et al, 2006), causing a scald disease on various Poaceae species. In contrast, in Cronartium ribicola, causing the white pine blister rust, no IBD pattern was detected among nine populations separated by a maximum distance of 2,000 km in Canada (Et-touil et al, 1999). The authors interpreted this latter result as the signature of long distance migration with frequent extinction-recolonization events creating high differentiation among close populations.…”

Section: Dispersal and Gene Flowmentioning

confidence: 93%

Population genetics of fungal diseases of plants

et al. 2008

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Summary :Although parasitism is one of the most common lifestyles among eukaryotes, population genetics on parasites lag far behind those on free-living organisms. Yet, the advent of molecular markers offers great tools for studying important processes, such as dispersal, mating systems, adaptation to host and speciation. Here we highlight some studies that used molecular markers to address questions about the population genetics of fungal (including oomycetes) plant pathogens. We conclude that population genetics approaches have provided tremendous insights into the biology of a few fungal parasites and warrant more wide use in phytopathology. However, theoretical advances are badly needed to best apply the existing methods. Fungi are of prime interest not only because they are major parasites of plants and animals, but they also constitute tractable and highly useful models for understanding evolutionary processes. We hope that the emerging field of fungal evolution will attract more evolutionary biologists in the near future. (0)1 69 15 73 53. E-mail: Tatiana.Giraud@u-psud.fr genetics studies have also valuable practical applications, for instance for studying the evolution of drug resistance or new virulence. Another reason to study parasites is that they display a huge diversity of life cycles and lifestyles, thus providing great opportunity for comparative studies to test pathogen-specific questions or general issues about evolution. Nevertheless, the field of parasitology has yet to attract more evolutionary biologists. This is even truer for the field of phytopathology, despite the importance of crop diseases for human activities. Furthermore, there are few connections so far between scientists in the fields of parasitology and phytopathology despite their obvious common interests. Here we highlight some studies that used molecular markers to address questions about the population genetics of fungal plant pathogens, fungi being taken sensus lato, i.e. including oomycetes. We do not aim providing an exhaustive review, but instead we use selected examples, mainly from our own works, to illustrate peculiarities of the phytopathogenic lifestyle. We focus on the study of mating systems (i.e. selfing, outcrossing, clonality), between and within population dispersal and population structure due to host adaptation.

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