The effects of pretreatment and different culture media İn vitro androgenesis on Stevia rebaudiana Bertoni

In this study, Stevia rebaudiana Bertoni plant which is known as a "sweet herb", determination of the appropriate bud stage and looked in vitro androgenesis effects on different hormone concentrations with different pre-treatment in MS basic nutrient medium. In the study used different size of Stevia buds which are staining with various staining methods. The most successful staining methods is ethidium bromide and suitable bud stage (uninucleate) was determined. Anter with uninucleate stage should be classified with bud opening period and there is established a relationship between the development of anthers and bud opening period. The study was carried out for two years. First year trial was set up and second-year trial started in light of data obtained from the first year trial. For this purpose, in the first year trial, anters are taken directly to culture media (without pre-treatment). In the second year, trial was expanded and anthers were exposed to two different pre-treatment and one control groups. Totally second-year trial was carried out with three different applications. First-year trial was conducted in 11 different culture media and 3 medium gives reaction to androgenesis. In this three medium; callus, embryos and embryogenic calli was obtained. Embryos was obtained from MS 2.0 NAA+0.5 BAP medium with a rate of 13,33% and MS 0.5 2,4-D+0.5 BAP medium and MS 1.0 NAA+0.5 BAP medium has followed respectively with a rate of callus forming 10% and 3,33%.Obtained at the end of the first year of the callus did not occur any differentiation. Second-year trial, anters directly taken to culture and exposed to hot temperature (+35 °C) and cold shock (+4 °C). There was no significant difference between the hot and cold pre-treatments. MS 2.0 NAA + 0.5 Kinetin hot application were the most successful medium with 37.5% embryos ratio obtained from two callus. MS 2.0 NAA + 0.5 BAP cold application and control group, MS 1.0 NAA+0.5 BAP medium both of them callus forming ratio is 7.5%. Only cold application results organogenesis via callus. The obtained plants were duplicated in vitro condition and stoma counting was done with control plant. There is no difference has been observed in the control group and obtained plants so this plants are also diploid character.