Does hybridization between native Red Mulberry and invasive White Mulberry threaten the native species?

Methods

Challenges

Microsatellite markers consist of a short (2-6 bp) tandemly-repeated nucleotide distributed throughout the genome in high abundance. These markers can provide information about recent evolutionary change because they are hypervariable, codominant and highly reproducible. Microsatellites for Morus have recently been developed and tested for number of Morus species including M. alba. Microstaellites for M. rubra have not been developed yet. It is possible that the primers working for most of the Morus species will work for M. rubra. I propose to use the requested fund for assessing hybridization using 15 microsatellite markers from Zhao et al. (2005).

Pre Analysis Plan

Fifteen polymorphic microsatellite loci will be amplified for ca. 500 samples. The microsatellite fragments will be genotyped using ABI 3700 capillary sequencer (Applied Biosystems, Foster City, CA). A model-based genetic admixture analysis, which clusters individuals to species and putative hybrid groups, will be performed in the program Structure (Pritchard et al. 2000). Genetic diversity within each cluster will be assessed by calculating allele frequencies, expected heterozygosity and population differentiation (F_st values) as implemented by Arlequin 3.0 (Excoffier et al., 2005).