Gender Discrimination of Date Palm (Phoenix dactylifera L.) Using High-Resolution Melting Analysis

Abstract

Date palm (Phoenix dactylifera L.) is dioecious plant, having separate male and female flowers with late initial reproductive age. In order to produce dates, it is important for the agriculturalist to know the gender of the date palm because the date can only be collected from females. High-Resolution Melting (HRM) analysis is a powerful molecular technique for identifying species, cultivars, and gender of living organisms. Therefore, this study aims to use the HRM analysis for sex discrimination of the date palm cultivar Deglet Nour. This research is divided into three main parts, including (i) collecting the nucleotide sequences of the 12th chromosome, which are the single nucleotide polymorphisms (SNPs) region and the gene region, as markers for gender identification; (ii) selecting candidate primers for sex identification requires designing primers and performing simulation HRM analysis using uMELT software; and (iii) conducting in vitro HRM analysis with the candidate primers to differentiate the gender of the date palm. The difference in melting curve profile and melting temperatures (Tm) between the genders were used to determine the sex of date palms. It is found that the most suitable primer for gender identification of the date palm by HRM analysis is the TIF2 primers (gene region). Male and female melting curves generated from TIF2 primers can be clearly separated. In addition, melting temperature of male and female date palm were also different. The results demonstrate that the HRM coupled with TIF2 primers is a powerful molecular technique for sex discrimination of the date palm cultivar Deglet Nour.