Optimization of in vitro micropropagation protocol for some vigorous rootstocks of pear

In order to micropropagate of four vigorous rootstocks of pear, including Pyrus betulifolia, Konjuni, Dargazi and Gh1, effects of basic plant culture media (MS, QL and modified QL), cytokinins and auxins on productivity, proliferation and rooting were studied in Seed and Plant Improvement Institute, Karaj. The highest amount of productivity for all rootstocks was observed in QL medium. Among pear rootstocks, Gh1 rootstock in both QL and modified QL mediums showed proper growth. Results of proliferation (BAP with 1 and 2 mg/l and 2ip at 0, 1 and 2 mg/l) illustrated that the highest amount of proliferation was achieved with 1 mg/l BAP, while adding 2ip into medium had no significant influence on proliferation rate. In addition, maximum rooting percentage was obtained by IBA at 1 mg/l. Also, evaluation of rooting percentage in both culture media containing agar and perlite proved that the highest rooting of all rootstocks (except P. betulifolia) was achieved in culture medium containing perlite. In general, to succeed micropropagation of aforementioned rootstocks, utilizing QL culture medium containing BAP (1 mg/l) is recommended for optimal proliferation and treatment of IBA (1 mg/l) in perlite is suitable for proper rooting.