Genetic and Breeding Applications of Microsatellite Markers in Date Palm (Phoenix dactylifera L.)

Date palm (Phoenix dactylifera L.) is a dioecious perennial of significant agricultural and socio-economic value in arid regions, yet its genetic improvement is constrained by a long juvenile phase and separate male and female plants. Microsatellite markers have emerged as key tools to overcome these limitations. They aid in assessing genetic diversity, cultivar identification, population structure analysis, somaclonal variation detection, and early sex determination using male-specific markers, enhancing breeding and plantation management. The advent of genome sequencing has enabled detailed identification and characterization of microsatellite motifs. The P. dactylifera genome contains approximately 105,183 microsatellite motifs, with a higher frequency of simple/imperfect repeats than perfect ones. Dinucleotide repeats are most abundant, particularly AG/TC, AT/TA, and AC/TG, while TAA and GAA dominate among trinucleotide motifs, jointly accounting for 52% of all trinucleotide types. To date, 87 functionally validated, polymorphic microsatellite primer pairs have been developed for polymerase chain reaction-based amplification in P. dactylifera.