Date Palm (Phoenix dactylifera L.) Cultivar Relationships Based on Chloroplast Genotyping

Date palm (Phoenix dactylifera L.) is a member of the genus Phoenix in Arecaceae family. It is the cultivated species in this genus with great economical and social importance in our country. We used three chloroplast regions of rbcL, matK, and trnH-psbA with the following aims: 1. To illustrate the cultivars phylogeny, 2. to identify nucleotide variations and identify the molecular events leading to these variations, and finally, 3. to provide DNA barcode for the studied cultivars. ILD (incongruence length difference test) heterogeneity test revealed that the genes used are not homogenous and produce different evolutionary signals, and the phylogenetic trees constructed by each of these genes differ in topology. A combined data were used to produce phylogenetic tree by SVDQuartets method, to consider evolutionary signals of all three genes together. The SVDQuartets tree and Bayesian-based phylogenetic tree obtained from BEAST were utilized to construct a condensed tree and produce divergence time by RASP program. Date palm cultivars were separated in two distinct major clades corresponding to their geographical distribution, Khuzestan province and Sistan and Baluchestan province. The present study produced some new information with regard to potential DNA barcodes for commercial date palms cultivation and threw light on the date of cultivar divergence in this area.