The effect of polyploid induction on morphophysiological changes and essential oil yield of Lavandula stricta

In this study, to investigate the effect of ploidy level changing on morphological and physiological traits and the amount of essential oil  of Lavandula stricta as a Iranian  native medicinal plant. In this experiment, gel containing colchicine at five concentrations (0, 0.05, 0.1, 0.2, and 0.4 %) and four times (8, 16, 24 and 48 h) in the final meristem in the four-leaf growth stage of the potted plant under greenhouse conditions. The results of flow cytometry showed that the genome size in all diploid and treated plants with colchicine were in the same range (0.55 and 0.57 pg, respectively), but, it was obtained 0.73 pg for treated plant with 0.4% colchicine in 48 hours and SEM images showed an increase in the density of glandular trichomes and stomata size in them. Also, the results showed that the concentration of colchicine and the time of treatment had no significant effect on chlorophyll and carotenoid, but increasing the concentration of colchicine and the application time increased the weight of 1000-seed, weight of seed with cover, peroxidase, polyphenol oxidase, catalase and percentage and yield of essential oil. According to the obtained results, it can be stated that the application of colchicine at 0.4% for 48 hours has the ability to increase ploidy level of Lavandula stricta plant and increase medicinal value of this plant.