Agromorphological and phytochemical variations of Orthosiphon aristatus (Blume) Miq. morphotypes in the Philippines

Orthosiphon aristatus (Blume) Miq. is a medicinal plant valued for its diuretic properties and potential benefits in treating kidney and urinary diseases in the Philippines. Similar to other plants, intraspecific variation exists in O. aristatus, which often leads to ambiguity in the genotype utilized and hinders its effective utilization. Hence, we characterized and evaluated the agromorphological and phytochemical properties of three Philippine accessions of O. aristatus with different inflorescence colors through a field trial conducted in a completely randomized design, to select promising accessions that could serve as genetically stable reference materials. Differences were observed in 22 out of 31 quantitative traits, while variation occurred in 12 out of 18 qualitative traits. Phytochemical traits were negatively correlated with biomass. Philippine Biorepository Network (PBN) 2019-119 (white morphotype) exhibited the highest leaf count of 2,001.75 ± 311.40 per plant, shoot number of 53.25 ± 6.65 g/plant, and dry leaf yield of 25.16 ± 3.99 g/plant. However, PBN 2018-073 (purple morphotype) had the highest total flavonoid content of 31.05 ± 1.83 mg QE/g extract and rosmarinic acid content of 2.957 ± 0.22 mg/200 g sample. Based on both agronomic and phytochemical traits, PBN 2019-119 was identified as the most promising genotype, with a high agronomic yield and intermediate phytochemical content. This is the first study to evaluate O. aristatus accessions in the Philippines. It highlights the importance of understanding infraspecific variation in O. aristatus to improve its utilization and conservation.