Investigation of stress response caused by the different type and concentration of salt of karacadag rice in in vitro

In this study, the physiology and biochemical changes were investigated in in vitro culture medium which arose in the stres conditions by applying different salt type and salt concentration in Karacadag's traditional type of rice (Siverek population) which is produced in the Southeastern Anatolia region and commenly prefered by local community. The optimum surface sterilization medium and the power of Murashige&Skoog culture medium were investigated in order to determine optimum in vitro growing condition after rice seeds were waited in the sodium hypochlorite (%5) at different times (10-15-20-25-30-35-40-45-50-55-60 minutes) before conducting the salinity tests Following 3 weeks after the culture peroid optimum sterilization time was determined to be 60 minutes in the sodium hypochlorite (%5) among the tested parameters. When the germination affects of MS culture medium were investigated, there was only slight differences in terms of germination percentage, on the other hand, the highest germination percentage was obtained from seeds which were cultured in 1/4 MS culture medium (%95). The affect of the salinity stres to Karacadag rice was examined differents seperately in the phases of germination and seedling. Hence, the rice seeds were taken to the 1/4 MS medium including 5 different concentrations (25, 50, 75, 150, 300 mM) of NaCI, CaCI2, MgCI2. In the 3 types of salt that were tested, it was found out that germination percentage is not affected from low concentrations however, germination percentage dramatically decrease in the high concentrations. Besides, there was no germination in the 300 mM MgCl2 and CaCl2 salt concentration and the MgCl2 is salt type affects germination most. At the seedling growing phase, the seedlings that were obtained from 1 week culture periodwas at the different concentrations of NaCI, CaCI2, MgCI2 to investigate the salt stres effects. After three-week culture period, responses to the salt stress of Karacadag rice were analyzed in terms of some physiological and biochemical analysis such as plant and root length, shoot and root wet/dry weight, %RWC of shoot and root, content of photosynthetic pigments and lipid peroxidation degree. When the analysis values of in vitro seedlings which are exposed to different type and concentration of salt stress, plant and root length, green components and root wet/dry weight, %RWC of shoot and root were observed to decreased at all of salt types as long as salt concentration increases. When the general morphological growing of plants were evaluated, the plant growth was very poor at high concentrations (150 mM), and the plants did not grow at 300 mM concentration. After stres exposure, the salt mostly adversely affected the photosynthetic pigment (chlorophyll a, chlorophyll b, total chlorophyllandcarotenoid) contents of plants, besides there were differences among values according to salt concentrations rather than in salt type. Among the salt varieties only NaCI was found to have a less adverse effecton photosynthetic pigment contents. MDA is an important stres parameter which is the last product of lipid peroxidation and is formed as e result of the cell membrane destruction in plants. In our study, thecontent of MDA generally increased as long as salt concentration in all salt type increased proportionally. When applied salt types were compared, MDA content was determined to have a higher ratio in CaCl2 than another salt type (NaCl, MgCl2) and the most membrane injury was determined in 75 mM CaCl2 with the highest MDA content (4.1820 µmol/g). In conclusion, traditional rice Karacadag's growth and development were affected adversely both in the germination and seedling phases which were tested in in vitro medium especially in high concentration salt types (NaCl, CaCl2 ve MgCl2).