Analysis on mechanism of polysomaty and its application for cellular breeding

用流式细胞仪分析了几种植物在不同组织、幼苗生长过程和不同光照条件下的多体状态。在大葱和菠菜中，种子的胚中没有发现多倍体，但在萌发过程中诱导了多体。与光照条件相比，黑暗条件下甘蓝的多倍体水平增加。芦笋组织培养过程中也观察到多体水平的变化。在含有NAA的培养基上，愈伤组织形成初期倍性水平较高，倍性水平越高的外植体愈伤组织越容易产生倍性水平较高的愈伤组织。将与多体有关的CCS基因导入非多体植物矮牵牛，未观察到多体诱导。在针叶石竹这一非多体体植物的悬浮细胞培养中，阐明了细胞的多倍化与植株再生能力的丧失密切相关，并且可以直观地选择和保持高再生能力的细胞。本研究通过阐明多体体状态与几个内部和环境因素的关系，提出了控制组织培养倍性水平的重要细胞育种策略。

Flow cytometric analysis was carried out to clarify the polysomaty status of several plant species in different tissues, during the growth of seedling, and under different light conditions. In Welsh onion and spinach, polysomaty was not found in embryo of the seeds but induced during germination. In cabbage, polysomaty level increased under dark condition compared with light condition. Change in polysomaty level was also observed in tissue culture of asparagus. On medium containing NAA, ploidy level increased during the early stage of callus formation, and the explants with higher ploidy levels tended to produce the calli with higher ploidy levels. When ccs gene, which is expected to relate polysomaty, was introduced into petunia, which is a non-polysomatic species, no polysomaty induction was observed. In cell suspension culture of Dianthus acicularis, which is a non-polysomatic species, it was clarified that polyploidization of the cells was closely related to the loss of plant regeneration ability, and that it was possible to select visually and to maintain the cells with high plant regeneration ability.In conclusion, this study proposed important cellular breeding strategies for controlling ploidy level of the tissue cultures through clarifying the relationship between polysomaty status and several internal and environmental factors.