Objective:
1) Quantify and apportion genetic diversity in collections of wild relatives of Malus 2) Identify a group of individuals that represents the overall genetic diversity of wild Malus collections with the fewest number of individuals.

Approach:
Plant exploration trips to Kazakhstan, China, and Turkey have brought valuable Malus germplasm into the US that is maintained in the National Plant Germplasm System. Genotypic data from 15 to 20 unlinked microsatellite loci for each individual will be analyzed to calculate a set of descriptive genetic diversity parameters such as observed and expected heterozygosity, number of private alleles, number of group specific alleles as well as hierarchical and pairwise F statistic. AMOVA will be performed using Arlequin to estimate variance components within and among accessions. We will explore the relationship between divergence (Fst) and diversity (allelic richness) and make estimates, where appropriate, of past genetic bottlenecks. We will graphically represent diversity and structure using network, ordination and Bayesian methods. Core collections will also be identified.