In vitro shoot tip grafting in Pistacia species

ABSTRACT IN VITRO SHOOT TIP GRAFTING IN Pistacia SPECIES TÖREMEN, Hakan M.Sc. in Biology Supervisor: Asst. Prof. Dr. Canan Can December 2004, 49 pages Pistacia vera L. (Pistachio), a member of the Anacardiaceae family, is a semitropical tree. Pistachio has a great commercial importance which is widely cultivated in the Mediterranean regions of Europe and North Africa, the Middle East, China and California. Since pistachio is difficult to propagate by cuttings, clonal propagation is achieved by either germination from seeds or grafting buds from elite clones onto heterozygous rootstocks. Wild-type (WT) rootstocks belonging to genus Pistacia are used more than P. vera for micrografting because their root structure is highly susceptible to some parasites. However, in vivo grafting onto Pistacia species has some problems. The leading problem is phenolic compounds which prevent grafting. For this reason, developing methods on in vitro shoot tip grafting is seen as secondary alternative. In this study, the usage possibilities of P. mutica, P. terebinthus, P. atlantica and P. khinjuk were investigated by in vitro shoot tip grafting to propagate pistachio. Because WT seeds were highly contaminated, different sterilization techniques, fungicide treatments, and embryo culture technique were investigated. The compatibility and growing activity of the shoot tip explants of the variety Uzun and Siirt of P. vera, taken from different seasons, onto P. mutica, P. terebinthus, P. atlantica and P. khinjuk rootstocks were investigated. No compatibility and growing between scion and rootstock were observed at the end of 22 in vitro shoot tip grafts within 2004 cultivation period. Key Words: Pistachio, in vitro, shoot tip, grafting, rootstocks