S25 - Session P2 - Morphological characterization of Origanum vulgare spp. virens from spontaneous populations in Alentejo (Portugal)

Authors: Orlanda Viamonte Póvoa, Mariana Paulo *, Noémia Farinha

Origanum vulgare spp. virens Hoffmanns. et Link is used as an aromatic, flavouring and medicinal plant in Alentejo. Its sustainable cultivation, should contribute to reduce genetic erosion caused by harvesting in nature. This study was based on 14 accessions of Oregano propagated from stem terminal herbaceous cuttings during spring 2021, collected from previously identified places throughout Alentejo region. The rooted plants were transferred to the field essay on April 2021, with drip irrigation system, using weed control fabric and was constituted by 3 randomized blocks (15 plants; 5 plants/block, 25 cm spacing between plants in row and 50 cm between rows). Observations were carried using the 2011 ECPGR Working Group on Medicinal and Aromatic Plants Draft Descriptor List for Origanum vulgare L. A total of 52 descriptors were considered; 7 descriptors for plant (growth habit, height) and stem (number of stems, branching density, pubescence, color, number of internodes), 13 descriptors for basal leaf (density of foliage, color, shape of blade, shape of leaf base, leaf margin, pubescence, ratio length/width, shape of apex), 12 descriptors for the leaf below inflorescence (color, shape of blade, shape of leaf base, leaf margin, pubescence, ratio length/width, shape of apex), 17 descriptors for inflorescence: length and width of inflorescence, date of beginning of flowering; density of flowers; calyx and corolla- color, ratio length of petals/length of calyx tube, shape of calyx tube, pubescence; bracts: number of bracts pairs per spike, length, ratio length of bracts/length of calyx, shape, color, pubescence; 3 descriptors for seed: color, seed productivity, 1000-seed weight and inflorescence biomass. A multivariate statistical analysis (Principal component analysis and Cluster Analysis) was done with the obtained data. High variably within and between accessions was observed in the essay field. Further studies should be carried out for agronomic characterization of the species.