Date Palm Genome Sequence and Gender-Linkage Analysis

Date palm is one of the most economically important woody crops cultivated in the Middle East and North Africa and is a good candidate for improving agricultural yields in arid environments. Nonetheless, long generation times (5-8 years) and dioecy have complicated its cultivation and genetic analysis. Based on a next-generation sequencing draft genome we assembled, we sequenced 8 date palm cultivars including Khalas, Medjool and Deglet Noor for comparative analysis. We discuss polymorphism differences among these important varieties that yielded results critical to fruit differences and most importantly allowed us to identify a region strongly linked to sex. This region was validated in over 60 date palm trees from numerous commercial and non-commercial varieties. Our findings support the theory that date palm employs an XY system of gender inheritance and indicates that the male is the heterogamete. Future studies will also be discussed.