RT Journal Article SR Electronic T1 Genetic Diversity of Grape Phylloxera Leaf Galling Populations on Vitis species in Uruguay JF American Journal of Enology and Viticulture JO Am. J. Enol. Vitic. FD American Society for Enology and Viticulture SP ajev.2014.14026 DO 10.5344/ajev.2014.14026 A1 Leticia V. Bao A1 Iris B. Scatoni A1 Carina Gaggero A1 Lucía Gutiérrez A1 Jorge Monza A1 M. Andrew Walker YR 2014 UL http://www.ajevonline.org/content/early/2014/09/24/ajev.2014.14026.abstract AB Grape phylloxera (Daktulosphaira vitifoliae) feeds exclusively on Vitis species preferentially on leaves of American Vitis species and roots of European V. vinifera. Recently, extensive feeding and galling on V. vinifera leaves has been observed in Italy, Brazil and Peru. In Uruguay D. vitifoliae infestations on V. vinifera leaves were recently detected in very high densities. The cause of this unexpected insect behavior is unknown, but could be due to selection pressure for more aggressive native strains in the new context of vigorous plants replacing old vineyards, loss of resistance in plants from improvement programs, or importation of exotic strains. The aims of this research were to evaluate genetic diversity of leaf galling populations of Uruguayan phylloxera; estimate genetic distances among them, and compare Uruguayan and foreign phylloxera populations (Brazilian, Peruvian and European). Genetic distances between root and leaf samples from the same plant individual were also estimated. Four polymorphic microsatellite primers were used. In the analysis of leaf and root insect populations from the same plant individuals, different insect genotypes were found on grafted vines, with one genotype on the rootstock and one on the V. vinifera (cultivar scion). For Uruguayan leaf galling insect populations the average number of alleles per locus was 4.25. Genetic variance found among individuals within populations was 88% (SE=2,298, p< 0,001), and 12% between populations (SE=0,319, p< 0,001). An FST of 0.211(p<0.001) suggests limited genetic flow among populations. Significant deviation from Hardy Weinberg equilibrium detected for the loci analyzed and negative FIS values suggest that parthenogenesis could be the reproductive mode. Genetic diversity found in this work shows a considerable potential for host adaptation to environmental variability.