Morphological, ecological and genetic variability of Lavandula luisieri (Rozeira) Rivas-Martínez in central eastern Portugal

The morphological characterisation and data analysis of germplasm accessions of wild Portuguese Lavandula luisieri (Rozeira) Rivas-Martínez from the southern Beira Interior region of central eastern Portugal are described. The study, based on seeds and cultivated plants, was conducted in 2005, 2006 and 2008 among populations selected from four sites (I, II, III and IV). Quantitative and qualitative phenotypic data relating to a set of 35 morphological traits were analysed using canonical discriminant analysis. Genetic similarity among accessions was assessed using amplified fragment length polymorphism molecular markers. The traits contributing most to the variability among studied populations were related to plant density, leaf colour, seed weight and various spike and flower characteristics. Plant populations from each of the four test sites were statistically distinct, exhibiting unique characteristics when compared with one another; however, populations from Sites II, III and IV showed greater genetic similarity and differed substantially from the population of Site I. Altitude and temperature were found to be the most significant environmental variables influencing plant traits, yet the morphological variability of L. luisieri was also influenced by soil pH levels, suggesting that the expressed variability is not only a result of genetic characteristics but also of existing ecological conditions.