Evaluation of the morphological variability in Iberian Salvia lavandulifolia Vahl accessions

Salvia lavandulifolia Vahl grows in the West-Mediterranean area in a wide range of altitudes and environmental conditions, showing great ecological plasticity. As a result, high morphological variability has been described constituting a very polymorphic taxon. Despite its cultivation potential for essential oil production, the lack of standardized and well-characterized plant material has hindered its agronomical production. In our study, 12 wild populations previously selected by their essential oil yield and general appearance have been propagated and cultivated during three years (2013–2015) in two different experimental fields. 13 morphological traits regarding leaves, inflorescences, bracts and flowers were yearly measured in the same individual specimens. The cultivated material has shown phenotypic stability in the two different environments and during the three years of testing. However, intra-population and, above all, inter-population variability have been detected. The studied populations were clustered in four groups by mean of multivariate statistical analysis. Clusters were distinguished by leaf size, inflorescence shape, number of flowers in the second verticillaster from the top and bracts dehiscence or not, and presented a consistent geographical distribution since geographically-closer populations were grouped into the same cluster. Population P5 (Guixers) stood out by its remarkable leaf size under cultivation conditions (6.8–9.7 cm length, 2.1–3.0 cm width), much higher than that previously reported for S. lavandulifolia in literature. It is considered as the most suitable population among the studied to provide specimens to be used as base material for breeding and selection programmes.