Variability of morphological features of Dracocephalum multicaule (Lamiaceae) in natural populations of Dagestan

Abstract

The structure of intra- and inter-population variability of Dracocephalum multicaule Montbr. et Auch. ex Benth. along the altitude gradient was studied on the basis of a complex of morphological features of plants. Two populations of D. multicaule were collected from different altitude levels (800 and 1130 m above sea level). Differences between populations by place of growth (microclimatic conditions), communities in which the species grows, age composition, as well as morphological features were revealed. A decrease in the average values of quantitative and dimensional traits with the increase in altitude has been recorded, with the exception of two (the length of the inflorescence and the number of verticils). Intra- and inter-population variability of traits are at medium and high levels. Variability of the number of flowers in the inflorescence (43.5–51.5) and weight characteristics (36.1–50.0) are high. The interpopulation variability of species traits is the result of the influence of a complex of factors of the altitude gradient and the population age. The areas differ in ecological habitat conditions and the degree of anthropogenic load. The increasing anthropogenic impact in the places where the species grows disrupts the stability of natural populations and affects plant reproduction. In order to preserve the species of D. multicaule in natural habitats, it is necessary to reduce anthropogenic pressure, as well as to introduce the species into culture.