Seeds conservation of dracocephalum kotschyi with vitrification and encapsulation-dehydration methods in cryopreservation condition

Today, preservation of diversity the species of medicine-rangeland and preventing of genetic erosion is importance. Dracocephalum kotschyi Boiss is one of the most important plants that exposed to extinction because of the irregular removal and climate changes. Hence, in the present study, the effects of encapsulation-dehydration and vitrification with hydration solutions (PVS2 and PVS3) in the technique of protection cryopreservation on Dracocephalum kotschyi Boiss seeds were studied. Then the seeds were kept for 20 hours in nitrogen liquid tank with temperature of -196 C˚. After spending the period of freezing, the seeds were placed in Bain Mari at 40˚C to make melting and thermal shock. The seeds were cultured in laboratory and greenhouse conditions. The percentage and rate of germination, seed vigor index, root length, stem length and fresh and dry weight of the plants were evaluated. Treatment of encapsulation-dehydration decreased, significantly and dramatically, the percentage and speed of germination index and seed vigor index. Minimum and maximum of seedling length was obtained in treatments of encapsulation-dehydration and vitrification with dehydration solution of PVS3, respectively. Root dry weight was not influence by different treatments of cryopreservation, but encapsulation-dehydration treatment reduced the dry weight of shoot significantly. The results showed that the treatment of vitrification with a dehydration solution of PVS3 can decrease the stresses of the transition to the conditions of cryopreservation and improve the quality of the seeds the plants that are exposed to extinction and destruction.