Studies Of Prolonged Preservation Time Of Potato Plantlets In Vitro Treated By Sorbitol

The study about the preservation of potato plantlets has developed slowly due to the short subculture time and immature key technologies of cryopreservation. Our study further investigated the effect of preservation under 4℃ using potato varieties Fw and Chuanyu 117, the preservation time, physiological changes and genetic stability of regenerated plants after preservation were studied. Intended to prolong the preservation time of potato plantlets and improve cryopreservation system, reduced the preservation cost and provide theoretical basis to promote the preservation quality. Main research results are as follows:Add different levels of Chlormequat chloride,Sorbitol and mannitol into MS culture media, and preservation is under 4℃, the results showed that 20g·L-1 in MS culture media with 4℃ treatment obviously prolonged preservation time from 100d to 300d and this materials can be soon restored in new MS culture media.Use normal temperature and no treatment as control, preliminary study of physiology changes of potato plantlets cultured in the MS media with 20g·L-1 Sorbitol and under low temperature discovered that plantlet ageing happened and content of chlorophyll and free proline reduced as incubation time passed. But the add of Sorbitol with preservation under 4℃ can slow the decline rate of this physiological indexes obviously. The content of malondialdehyde rolls up as the preservation time passed and. this can be relieved by the culture media with 20g·L-1 Sorbitol and under 4℃ temperature.The RAPD system of potato DNA was improved by the study of potato plantlets under low temperature use RAPD technology. The genetic background of potato plantlets treated by sorbitol under 4℃ is stable and have no genetic material found changed after using RAPD technology to screen 200 random primers.