Molecular Identification of Sex in Phoenix dactylifera Using Inter Simple Sequence Repeat Markers

Early sex identification of Date Palm (Phoenix dactylifera L.) at seedling stage is an economically desirable objective, which will significantly increase the profits of seed based cultivation. The utilization of molecular markers at this stage for early and rapid identification of sex is important due to the lack of morphological markers. In this study, a total of two hundred Inter Simple Sequence Repeat (ISSR) primers were screened among male and female Date palm plants to identify putative sex-specific marker, out of which only two primers (IS_A02 and IS_A71) were found to be associated with sex. The primer IS_A02 produced a unique band of size 390 bp and was found clearly in all female plants, while it was absent in all male plants. Contrary to this, the primer IS_A71 produced a unique band of size 380 bp and was clearly found in all male plants, whereas it was absent in all the female plants. Subsequently, these specific fragments were excised, purified, and sequenced for the development of sequence specific markers further in future for the implementation on dioecious Date Palm for sex determination. These markers are efficient, highly reliable, and reproducible for sex identification at the early stage of seedling.