ANALYSIS OF GENETIC DIVERSITY AND STRUCTURE OF SOME HISTORIC OLIVE (OLEA EUROPAEA L.) GERMPLASM IN THE UNITED STATES USING MICROSATELLITE MARKERS

Fifteen microsatellite simple-sequence repeat (SSR) loci were used to genotype 58 accessions of cultivated olive, Olea europaea L. ssp. europaea var. europaea, from two collections of 19^th to 20^th century plantings in Arizona and California, in order to examine genetic diversity and structure within and among collections.
These collections are Lotusland Gardens in Santa Barbara, CA, and the Arboretum of the University of Arizona, Tucson.
Genotypes in the olive collection at the USDA-ARS National Clonal Germplasm Repository for Fruit & Nut Crops (NCGR) in Davis, California were compared with the historic collections to potentially establish cultivar identity.
Mean number of alleles per locus was 5.0 for Lotusland and 3.5 for the University of Arizona.
Mean observed heterozygosity per collection was 0.650 for Lotusland and 0.598 for the University of Arizona.
Up to 90% of the samples per collection were found to be synonymous with named, primarily Spanish or Italian, cultivars, yet these historic collections also contain significant genetic diversity, including genotypes and alleles not present in the NCGR germplasm collection.
The cluster analysis placed the unknown genotypes within clades containing cultivars from the Eastern Mediterranean or from throughout the Mediterranean region, and in some cases produced relatively distinct branches.

I International Symposium on Wild Relatives of Subtropical and Temperate Fruit and Nut Crops

A.M. Koehmstedt, M.K. Aradhya, D. Soleri, J.L. Smith, V.S. Polito

SSRs, cluster analysis, genetic resources management, California, Arizona

https://doi.org/10.17660/ActaHortic.2012.948.17