The Content of Endogenous Hormones in Explants and Calluses of Lavandula angustifolia Mill. at the Initial Stages of an In Vitro Culture

The content of endogenous hormones (auxin IAA, cytokinines, ABA) in explants of various types (segments of the leaf, bud, and stem), primary calluses induced from them, and morphogenic and nonmorphogenic calluses at the initial stages of in vitro culture by the immunoassay method was studied for the first time for Lavandula angustifolia Mill. The maximum value of the hormone levels in explants such as segments of a bud was shown. An increase in the content of hormones in primary calluses was revealed in comparison with similar characteristics in all types of explants. The higher level of the active form of cytokinin (trans-zeatin) and ABA, as well as the lower level of the inactive form of cytokinin (zeatin-nucleotide) and auxin IAA, were identified in the morphogenic callus compared with the nonmorphogenic one. It is suggested that the content of endogenous hormones in explants and calluses of L. angustifolia is due to their histological status. A conclusion is made about the unified histophysiological mechanisms of callusogenesis and morphogenesis in vitro in the studied plant.