低温保存技术在顽拗性种子种质保存中的利用

Cryopreservation of recalcitrant seed germplasm

关键词:  顽拗性种子  (超)低温保存  玻璃化法  两步法  种子含水量  脱水方式

Key words:  recalcitrant seed  cryopreservation  vitrification  two- step freezing  seed water content  drying method

摘要:

由于顽拗性种子不耐脱水且对低温敏感,常规保存方法难以达到长期保存的目的。因此,(超)低温保存顽拗性种子种质是最理想的方法。顽拗性种子的低温保存,应用较多的是玻璃化法和两步法。诸多因素影响着低温保存的成败,如种子或胚的含水量水平、溶液低温保护剂效应、降温冰冻与解冻方式、水合过程以及后培养等,这些需深入探索与解决。除顽拗性种子脱水耐性和低温敏感性机理外,植物细胞的冻害和抗冻机理也亟需探明,以便找到最佳冷冻方法,制定长期保存种质基因的最佳方案。

Abstract:

Being sensitive to desiccation and low temperature,the recalcitrant seeds can not be stored with conventional methods. However,cryopreservation has been considered as the most effective means. As far as cryostorage of recalcitrant seeds is concerned,vitrification and two-step freezing have been applied in many studies. Unfortunately,there are some factors,including water content of seeds or embryonic axes,effects of cryopretectants in solutions,cooling rate and thawing,rehydration and after-thawing culture that influence succeeding in cryopreservation. To produce normal plants after cryopreservation of recalcitrant seeds or embryonic axes,a carefully defined sequence of manipulations is needed to be solved. Besides the mechanisms of desiccation tolerance and sensitivity to low temperatures,the freezing and antifreezing mechanisms of plant cells are also ascertained imminently in order to dig out the most effective long-term storage method through seed-gene bank.