THE EFFECTS OF COLCHICINEINDUCED AUTOTETRAPLOIDY ON SELECTED CHARACTERISTICS OF NURUOZAK (SALVIA LERIIFOLIA).

Nuruozak (Salvia leriifolia Benth), is a perennial herbaceous plant that is endemic to Iran and has recently been introduced as a medicinal plant. Artificial polyploidy is an efficient method to increase the production of secondary metabolites and can result in a whole spectrum of genetic, molecular and physiological modifications. In order to produce an autotetraploid population of nuruozak, various concentrations of colchicine (0.00, 0.05, 0.10, 0.20 or 0.50 % w/v) were applied to the seeds and shoot apical meristems of young seedlings at the fourth leaf-stage. Microscopic studies, flow cytometry analysis and chromosome counting were conducted to select tetraploid nuruozak plants. Furthermore, the effects of ploidy level on the essential oil content and composition and biomass production of nuruozak plants, as well as selected structural and physiological characteristics were studied. Based on the number of the obtained tetraploids, treatment of shoot apical meristems was more efficient than seed treatment. Structural and phytochemical characteristics, chlorophyll content and photosynthetic rate were affected by the increase in ploidy level. In addition to the higher potential in biomass production, tetraploid plants produced eight new compounds which were absent in diploids.

In vitro regeneration ability of diploid and autotetraploid plants of Cichorium intybus L.

Polyploidy has played a significant role in the evolutionary history of plants and is a valuable tool for obtaining useful characteristics. Because of the novelty of polyploids, comparison of their in vitro culture response with diploids would be notable. In this study, leaf explants from diploid, autotetraploid and mixoploid plants of Cichorium intybus L. were cultured in vitro on the similar media and under same conditions. The ploidy level of the obtained calluses and regenerants were determined by flow cytometry analysis. The callogenic response of leaf explants cultured on the callus induction medium did not depend on the ploidy level of their parental plants. According to the flow cytometry analysis, the increased ploidy levels (4x) and (8x) were observed in the callus cultures with diploid and tetraploid origin, respectively. A considerable difference was observed between the ploidy level of mixoploid plants and their calluses, indicating the dominance of diploid cells in the callus tissue. The results showed that polyploidy led to the loss of organogenic potential as the tetraploid origin calluses failed to regenerate, while the diploid origin calluses successfully regenerated to whole plants.