In vitro micropropagation of selected rootstock genotypes of pistachio

Pistachio is a dioecious, woody plant species generally propagated vegetatively by grafting. Seeds obtained by foreign pollination have different characteristics than the parent plant. Since there are problems in propagating pistachios by grafting and this method is slow, the in vitro propagation method, which allows mass production in a short time, is an alternative method to produce clonal plants. This thesis investigated the propagation possibilities of UCB1 rootstock used as rootstock for pistachio and 12 selected rootstock candidate genotypes under in vitro conditions. For this purpose, for surface sterilization, different chemicals (NaOCl, HgCl2, H2O2, ClO2) are used for different periods from minimum of 5 minutes to maximum of 20 minutes and at different times (May, June, July, August, September, and October), different nutrient media (MS, DKW, WPM, POM and DKW modification), in vitro optimization was investigated by applying different concentrations between different GA3 concentrations and cytokinin groups (BAP, 2IP, Zeatin and Kinetin). In addition, the effect of explant sources taken at different times under in vitro conditions from explants of 12 rootstock candidate genotypes on the total phenolic substance contents was also investigated. The best result in surface sterilization was obtained by applying 20% NaOCl for 10 minutes (35±3.06%), and the explants taken in October (genotypes 7, 6, 8, and 3) were healthy and showed the best development. % sterile plant yield, growth rate of explants, and amount of total phenolics were higher in genotype seven than in other genotypes (51.33±5.98, 28.5±2.83, 655.86±61.88). The number of shoots was same (1±0) in all genotypes in the first and second subculture, and an increase in the average number of shoots obtained in the 3rd subculture was observed in genotypes 7 (3.0±0.44) and 8 (3.11±0.11). As a result of these observations, shoot tip necrosis continued after the fifth subculture, to solve this experiment was set up with different pH levels (5.8, 6.0, 6.5, 7.0, and 7.5). DKW medium supplemented with 0.25 mg/l GA3, 0.1 mg/l IBA, 200 mg/l Fe EDDHA along with 1.0 mg/l Zeatin, and modified DKW pH was adjusted to 7.5, and the percentage of necrosis decreased with increasing pH in some genotypes. However, it was determined that genotypes 5, 6, 7, and 8 did not respond to DKW modification.