Study on preservation of functions of biological consortia responsible for maintenance of sound balance of global environment.

微藻和植物是维持全球生态环境良好平衡的生物联盟的主要成员。但是最近，温室效应、酸雨等环境问题日益严重。在这种情况下，许多种类的藻类和植物濒临灭绝。本研究旨在建立一种通用、简便、长期的冷冻保存方法。本研究采用包封脱水法，将材料包封在海藻酸钙微球中并干燥，因为在低温保存过程中可以保持组份之间的功能和结构相互作用。7株海洋微藻中的6株、6株淡水绿藻中的1株和7株淡水蓝藻中的4株在添加0.5 M蔗糖诱导脱水耐性的液氮中成功低温保存。这些结果表明，该方法特别适用于海洋微藻的低温保存。本文首次采用包封脱水法对微藻进行低温保存研究。将该方法应用于辣根毛状根培养物诱导的茎原，存活率约为50%。1.0 M的甘油和0.5 M的蔗糖可使其存活率提高到90%以上。用0.5 M甘油和0.3 M蔗糖对毛状根培养物的根尖进行低温保存，成活率约为60%。这也是用这种方法对植物根系进行低温保存的首次研究。结果表明，该方法是一种实用的植物资源低温保存方法。

Microalgae and plants are the main members of biological consortia responsible for maintenance of sound balance of global environment. Recently, however, environmental problems, such as greenhouse effect and acid rain are becoming serious. Under those conditions, many species of those algae and plants are on the point of extermination. The aim of this research is to establish a general, simple, and long term cryopreservation method of them.Encapsulation-dehydration method in which materials were encapsulated in Ca-alginate beads and desiccated, was employed in this study, because functional and structural interactions among constituents of the consortia could be maintained during cryopreservation process.Six of the 7 marine microalgal strains, 1 of the 6 freshwater green algae, and 4 of the 7 freshwater cyanobacteria were successfully cryopreserved in liquid nitrogen by using 0.5 M sucrose as an additives for induction of desiccation tolerance. These results suggest that this method is specifically useful for cryopreservation of marine microalgae. This is the first research about the cryopreservation of microalgae by the encapsulation-dehydration method.When the method was applied to shoot primordia induced from hairy root cultures of horseradish, about 50% of survival was obtained. Furthermore, the survival was increased to more than 90% by addition of 1.0 M glycerol combined with 0.5 M sucrose. Root tips of the hairy root cultures also successfully cryopreserved by using 0.5 M glycerol and 0.3 M sucrose, and the survival was about 60%. This is also the first research about the cryopreservation of plant roots by this method.It is indicated that the method presented here is promising as a practical procedure for cryopreservation of useful plant resources.