Population genetic studies in wild olive (Olea cuspidata) by molecular barcodes and SRAP molecular markers

Abstract

Olive is an important horticultural plant having both cultivated and wild forms. The aim of the present study was investigating genetic diversity of 13 wild olive trees belonging four geographical populations in IRAN using SRAP neutral molecular markers as well as cp-DNA rpl intergenic sequences and ITS region. Genetic diversity parameters determined for 76 SRAP loci within the studied olive populations identified the most variable loci. Population differentiation parameters determined for SRAP loci, identified 13 SRAP loci with Gst value of 1, that means they differentiate the studied trees. PCoA analysis based on SRAP data separated olive trees from each other due to genetic difference. Distribution of the samples in PCoA plot indicated that the population 1 are more spread due to population genetic variability. However, the SRAP result reveals that these molecular markers can be used in population genetic investigations and germ plasm analysis. AMOVA showed significant genetic difference among the studied olive populations. Cp-DNA analysis produced 366 bp long sequences, out of which 224 sites were segregating among the studied plants. The mean nucleotide diversity was 0.32. TCS network based on cp-DNA separated most of the studied populations. Therefore, it seems that cp-DNA rpl sequences is a suitable barcode molecular marker for population genetic studies. Phylogenetic tree of ITS data could partially differentiate wild olive population. In conclusion, a combined use of SRAPs and cp-DNA sequences are suggested for wild olive population genetic investigation.