نگهداری درازمدت ژرم­پلاسم شمشاد خزری (Buxus hyrcana Pojark.)، یک درختچه­ی زینتی در حال انقراض، در شرایط فراسرد با کپسوله­کردن-آب­برداری و باززایی آن توسط هورمون­های گیاهی

Abstract Box tree (Buxus sempervirens L. or Buxus hyrcana Pojark.), is an ornamental shrub species that has application in various industries such as handmade and ornamental industeries. This species is under danger of extinction. Conservation of plants germplasm especially the plants under danger of extinction is one of the purposes of researchers and parlements members all of the worlds. Thus, the aim of this research was long-term conservation of germplasm in liquid nitrogen with sucrose and encapsulation-dehydration pre-treatments. Used germplasms or explants were seed and apical bud which were prepared from mother plants grown in greenhouse. This research presents a suitable method for sterilization of explants especially apical bud. Concentrations of 0, 0.5, 1, 1.5 and 2 mg l-1 of three plant growth regulators BAP, IBA and NAA were used in germplasm regeneration medium after conservation in liquid nitrogen. The experiment was carried out as factorial based on a randomized complete block design in four replications. The results of the research showed that encapsulation as a pre-treatment had effective role on the survival and germination of apical bud. Around 50% of encapsulated apical buds were attained their germination capacity. The highest germination percentage of encapsulated apical buds (60%) was obtained in culture medium containing 0.5 mg l-1 BAP along with 1.5 mg l-1 NAA. Medium containing 0.5 mg l-1 BAP without NAA with the content of 48% germination induction of apical buds was a suitable medium, too. None of non-encapsulated apical buds and encapsulated and non-encapsulated seeds had survival after conservation in liquid nitrogen and cultivation in regeneration medium.