|Walker, M. Andrew|
Submitted to: Vitis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2014
Publication Date: 6/1/2014
Citation: Riaz, S., Lund, K., Lin, H., Walker, M. 2014. Development and characterization of a large set of microsatellite markers for grape phylloxera (Daktulosphaira vitifoliae Fitch). Vitis. 53:95-101. Interpretive Summary: Grape phylloxera (Daktulosphaira vitifoliae) is one of the most devastating pests in many grape production regions worldwide. Currently, information regarding genetic diversity and genetic relationships among phylloxera strains in various viticultural environments is unclear. This study describes development of a new set of molecular markers from the phylloxera genome. A total of 130 markers were designed and validated from 10 phylloxera strains chosen for their behavioral and geographic diversity. Eighty-nine markers showing reliable detection were selected for genetic analysis. The new molecular markers developed in this study are easily used for large-scale genetic analyses and for differentiation of host specific phylloxera strains in natural populations.
Technical Abstract: This study describes novel simple sequence repeat (SSR) primers designed from a genomic DNA sequence of phylloxera. A total of 130 SSR primers were designed from 145 unique sequences with di, tri, tetra, and penta simple sequence repeats. The SSR primers were tested on DNA from 10 phylloxera strains chosen for behavioral and geographic diversity. Eighty-nine primers generated easy to score alleles with standardized conditions of amplification. Twenty-eight new and four previously published markers were selected to genotype 32 root and leaf phylloxera samples to validate markers. SSR data from these samples also was used to determine frequency of null alleles, locus specific estimates of population differentiation, and genotype clustering. Up to six alleles were detected with a mean expected heterozygosity (He) of 0.51. The observed heterozygosity (Ho) was 0.73, and the majority of markers had higher Ho values. Null alleles for four markers were considered to be the result of homozygous genotypes. The 89 SSR loci developed in this study represent a new and informative set of markers that are easy to combine for multi-loading and suitable for large-scale genetic analyses of population structure, genetic diversity, and origin of host specific strains in grape phylloxera.