This study aimed to assess the genotypic and phenotypic diversity of Plantago ciliata samples collected from two distinct locations in the Ha’il Region of Saudi Arabia. The two species of P. ciliata were collected from local rangelands in the spring of 2016. Phenotypic variation was assessed by measuring various traits including the primary root length, number of stems (spikes), longest stem length, number of leaves, longest leaf length, and the fresh weight of the entire plant. The RAPD (Random Amplified Polymorphic DNA) method was used to assess genotypic variation. Phenotypic data were analyzed using analysis of variance (ANOVA), while cluster analysis and similarity matrices were applied to the data, utilizing the unweighted pair group method with arithmetic mean (UPGMA) to construct a dendrogram. The results indicated significant differences (P ≤ 0.05) in the phenotypic characteristics of P. ciliata between and within the two studied populations. The data showed that the plant population from location I showed the highest number of measurements, while the population from location II showed the lowest. Regarding the RAPD markers, two primers successfully amplified both populations, while 3 primers failed to produce any amplification. Out of the five primers used, two primers exhibited polymorphism and showed variation in band patterns. In summary, these findings are valuable for plant breeding programs and biodiversity conservation efforts in the Ha’il Region of Saudi Arabia.
