Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2009
Publication Date: 1/15/2010
Citation: Travadon, R., Baumgartner, K., Rolshausen, P.E., Trouillas, F.P., Gubler, W.D., Sosnowski, M.R., Lecomte, P., Halleen, F., Peros, J. 2010. Intercontinental genetic structure of the fungal grapevine pathogen Eutypa lata. Phytopathologia Mediterranea. 49:108. Interpretive Summary:
Technical Abstract: The ascomycete fungus Eutypa lata, causal agent of Eutypa dieback of grapevine (Vitis vinifera), impacts all vineyard production systems worldwide. Our objectives were to characterize the population structure of E. lata at different geographical scales to identify migration patterns through ascospore dispersal, centers of diversity and new introductions areas. We genotyped 145 isolates from four vineyards, in each of two locations (California, South Australia), using nine polymorphic microsatellite loci. Results showed high levels of gene (H=0.56 to 0.62) and genotypic (G=0.85 to 1) diversity among the eight vineyards. There was no significant linkage disequilibrium among loci (P<0.01). We found that 93% of genetic variance was found within vineyards (P<0.01) and 3% of variance could be attributed to differences between California and South Australia (P<0.05). Three pair-wise comparisons revealed significant genetic differentiation between populations from these two continental regions (FST=0.03-0.10, P<0.05). When isolates were pooled by continental regions, genetic differentiation between the two populations was low, but significant (FST=0.03; P<0.05). These preliminary findings suggest that gene flow prevents genetic differentiation at the regional scale within continents, spanning distances up to 410 km, whereas continental populations are somewhat isolated. An additional collection of 156 isolates from Europe and South Africa, representing 12 vineyards populations, was recently obtained, and are currently being genotyped using the same nine microsatellite loci.