Evolution of the population structure ofVenturia inaequalis, the apple scab fungus, associated with the domestication of its host

Abstract

Evaluating the impact of plant domestication on the population structure of the associated pathogens provides an opportunity to increase our understanding of how and why diseases emerge. Here, we investigated the evolution of the population structure of the apple scab fungus Venturia inaequalis in response to the domestication of its host. Inferences were drawn from multilocus microsatellite data obtained from samples collected on (i) the Central Asian Malus sieversii, the main progenitor of apple, (ii) the European crabapple, Malus sylvestris, a secondary progenitor of apple, and (iii) the cultivated apple, Malus x domestica, in orchards from Europe and Central Asia. Using clustering methods, we identified three distinct populations: (i) a large European population on domesticated and wild apples, (ii) a large Central Asian population on domesticated and wild apples in urban and agricultural areas, and (iii) a more geographically restricted population in M. sieversii forests growing in the eastern mountains of Kazakhstan. Unique allele richness and divergence time estimates supported a host-tracking co-evolutionary scenario in which this latter population represents a relict of the ancestral populations from which current populations found in human-managed habitats were derived. Our analyses indicated that the domestication of apple induced a significant change in the genetic differentiation of populations of V. inaequalis in its centre of origin, but had little impact on its population dynamics and mating system. We discuss how the structure of the apple-based agrosystem may have restricted changes in the population structure of the fungus in response to the domestication of its host.

Genetic Diversity and Population Structure of Fusicladium effusum on Pecan in the United States

“…Preliminary studies of genetic diversity in the apple scab pathogen (Venturia inaequalis) using dominant markers (random amplified polymorphic DNA [RAPD]) and internal transcribed spacer (ITS) region sequences demonstrated a high degree of genetic diversity (58,59). More recent studies using codominant markers have allowed a more in-depth analysis of populations worldwide (21), providing new insights into the epidemiology and possible management of the disease (64). Overall, the coevolution of V. inaequalis and Mcdus species (domestic and natural) is characterized by a high level of genetic diversity and relatively low population differentiation; interpreted as showing the importance of human transport and the existence of sexual spores that are dispersed moderate distances (21).…”

“…More recent studies using codominant markers have allowed a more in-depth analysis of populations worldwide (21), providing new insights into the epidemiology and possible management of the disease (64). Overall, the coevolution of V. inaequalis and Mcdus species (domestic and natural) is characterized by a high level of genetic diversity and relatively low population differentiation; interpreted as showing the importance of human transport and the existence of sexual spores that are dispersed moderate distances (21). A population with this mafing and dispersal behavior ensures genetic recombinafion, gene flow, and genetic equilibrium.…”

Evolutionary history and variation in host range of three Stagonosporopsis species causing gummy stem blight of cucurbits

“…Host-plant domestication is considered to be one type of force driving divergence and speciation of numerous plant pathogens (Couch et al 2005;Stukenbrock et al 2007;Frenkel et al 2009;Gladieux et al 2010;Silva et al 2012). Domestication and cultivation of crops have been documented to not only drive divergence and speciation in the crop species but can influence pathogens associated with the domesticated crop leading to the formation of species complexes (Couch et al 2005;Stukenbrock et al 2007).…”

Avaliação da diversidade genética e associação com patogenicidade de isolados de Moniliophthora perniciosa oriundos da Amazônia Brasileira

“…Estudos com locos de microssatélites foram realizados visando avaliar a evolução da estrutura de populações de V. inaequalis e o impacto associado com a domesticação de seu hospedeiro (GLADIEUX et al, 2010). Essas análises indicaram que a domesticação da maçã induziu uma mudança significativa na diferenciação genética de populações de V. inaequalis em seu centro de origem, mas teve pouco impacto na dinâmica de populações e no sistema de acasalamento (GLADIEUX et al, 2010).…”

“…Essas análises indicaram que a domesticação da maçã induziu uma mudança significativa na diferenciação genética de populações de V. inaequalis em seu centro de origem, mas teve pouco impacto na dinâmica de populações e no sistema de acasalamento (GLADIEUX et al, 2010).…”