Study on colchicine treatment effects on some morphological and physiological characteristics and active substances in Salvia leriifolia Benth

Salvia leriifolia Bent., belonging to Lamiaceae family, is a perennial herbaceous plant, which is endemic to Khorasan and Semnan provinces of Iran. Different pharmacological activities of this plant have been evaluated in recent years. Induction of polyploidy is an important technique for breeding of medicinal and aromatic plants. In the present study, we studied the effects of colchicine on morphological and physiological characteristics and chemical compositions of Salvia leriifolia. Polyploidy induction was carried out in the four-leaf stage. Apical meristem was treated by colchicine at concentrations of 0, 0.05, 0.1, 0.2, and 0.5%, and three different time levels of 24, 48 and 72 hours. Morphological, microscopic (light and electron), flow cytometric analysis and chromos counting were used for ploidy induction analysis and selection of induced tetraploids. Identification of essential oil compounds was carried out by gas chromatograph and gas chromatography mass spectrometry methods. According to the results, colchicines at a concentration of 0.05% for 48 hours at four-true-leave stage was the best treatment for induction of autotetraploidy (23.3%) in Salvia leriifolia. Tetraploid induction in Salvia leriifolia caused significant changes in morphological, cytological, physiological and physiochemical characteristics such as increased dry and fresh weight, chlorophyll content, photosynthesis, and decreased plant height. In addition, an increase in ploidy level caused significant changes in essential oil composition.