Integrative Analysis of Morphological, Phytochemical, and Genetic Variability in Aloe Species From the Taif Highlands of Saudi Arabia

Background: The genus Aloe comprises ecologically and pharmacologically important plants; however, the diversity of these taxa in the Arabian Peninsula remains incompletely characterized, particularly using integrative, multi-evidence frameworks. Methods: To our knowledge, this study provides, for the first time, a concurrent morphological, phytochemical, and molecular characterization of nine Aloe species collected from different locations in the Kingdom of Saudi Arabia (Taif, Al-Baha, Abha and Jazan), an ecologically significant yet under-researched region. Thus, this study aimed to elucidate interspecific diversity, establish chemotaxonomic relationships, and provide a robust foundation for conservation and pharmacological applications. Results: Comprehensive quantitative assessments of vegetative and reproductive morphological traits were recorded for all nine taxa. High-performance liquid chromatography (HPLC) was employed to detect and compare the accumulation profiles of seven major flavonoids, apigenin, luteolin, naringin, quercetin, rutin, kaempferol, and hesperetin, demonstrating species-specific phytochemical signatures with significant chemotaxonomic relevance. Molecular diversity was assessed using Random Amplified Polymorphic DNA (RAPD-PCR) with four decamer primers, which yielded 22 scorable bands and an overall polymorphism of 64.16%, indicating significant genetic differences among the species studied. Independent cluster and ordination analyses of morphological, phytochemical, and molecular datasets produced consistent species groupings, demonstrating that phenotypic, chemical, and genetic differentiation are mutually supportive and indicative of both evolutionary divergence and ecological adaptation to the environmental gradients of the Taif Highlands. Conclusion: The primary innovation of this study lies in the convergence of three distinct lines of evidence, creating a comprehensive reference framework for the taxonomy, conservation, and sustainable use of Aloe genetic and phytochemical resources in Saudi Arabia.