Validation of PCR-based Markers Associated with Sex Determination in Date Palm (Phoenix dactylifera L.)

Phoenix dactylifera (Date palm) is one of the essential commercial and economical fruit crops which mainly grows in hot arid areas. A good source of food, shelter, and energy, date palm is widely known due to its unique characteristics. The dioecious nature of date palm made it challenging to prognosticate its sex until they flower almost 5 to 8 years after plantation. Researchers have developed many strategies to determine sex, including morphological study, biochemical studies, molecular-based studies as sequence characterized amplified regions (SCAR), randomly amplified polymorphic DNA (RAPD) marker, and polymerase chain reaction (PCR) assays, but still more endeavours are integral. To foretell sex at the seedling stage, specific PCR primers were employed in this study. These primers were designed on sex-linked regions that determine their gender. Date palm DNA was extracted through the CTAB method. The DNA was then amplified through PCR using sex-linked specific primers. PCR products have run on gel electrophoresis using 1.2% agarose to score the bands for sex determination. Four primers were employed in this study to determine sex. Two primers were SCAR markers, and one was a sex-linked tetra primer. Tetra-primer amplified the double band fragment of 430 and 320bp respectively in male plants, while a band of 430bp was amplified in female plants. The other primer named ALAMER1 was amplified by the single band fragment of 186bp in males with no band in females. The fourth primer, named as SCARdp, amplified the band fragment of 354bp fragment in males. These SCAR markers were established to be male-specific. Sex-linked markers provide a platform for robust, efficient, and accurate determination of sex in date palms.