条斑紫菜叶状体细胞的发育与分化

条斑紫菜壳孢子经室内10～80d培养后长成的叶状体分别被酶解成单个细胞，后者在液体培养基中发育成正常叶状体、畸形叶状体、细胞团、性细胞囊等10种不同类型的再生体，它们的形态与结构、细胞排列与大小，放散单孢子难易程度及最终发育结果等均不同。来自日龄不同的种藻的细胞，其再生体类型的数目和各类再生体的百分数不同。当种藻日龄为10～30d时，在它们的单离细胞再生体中出现了极少的细胞团，正常叶状体和具假根畸形叶状体的百分数随着种藻日龄的增加，急剧减少，但不具假根．的畸形叶状体百分数却随着种藻日龄的增加而增加。当种藻日龄大于40d以后，它们的单离细胞就几乎不能直接再生成正常叶状体。随着种藻日龄的增加，细胞再生体中不具假根的畸形叶状体百分数也显著减少，而细胞团的百分数急剧上升，精子囊和果胞子囊的数量也逐渐上升。来自同一藻体不同部位的细胞，在它们的再生体中，随着细胞所处藻体部位的上移，正常叶状体和畸形叶状体的百分数急剧减少，而细胞团百分数却不断增加。上述结果说明，在离体条件下，条斑紫菜叶状体的单离细胞发育成不同类型的再生体，是由于它们在种藻里处于不同分化阶段的缘故；同时，初步得出在条斑紫菜叶状体的发育过程中，从壳孢子细胞分化成性原细胞的过程可分为8个不同的分化阶段。

Development and differentiation of gametophytic blade cells in Porphyra yezoensis Ueda

From the gametophytic blades of Porphyra yezoensis Ueda which developed from conchospores and aged 10 to 80 days by culturing in the laboratory, the single cell were enzymatically isolated and regenerated into plants showing ten developmental types, such as normal blades, abnormal blades, cell2masses, sexual cell2masses and others. They did not only have the different morphological and structural features, but also were different in cell size and cell arrangement, monospore2release and their final developmental results. When the single cell were isolated from the mother blades in different ages, the numbers and the percentages of their developmental types were different, respectively. When the age of the mother blades increased from 10 to 30 days, among the plants regenerated from the single cell, only a few of cell2masses appeared, and the percentages of the normal blades and abnormal blades with rhizoids sharply decreased, but the percentage of the abnormal blades without rhizoids increased. When the mother blades aged more than 40 days, among the plants regenerated from the single cells, the normal blades did not appear, and the percentages of the abnormal blades without rhizoids also sharply decreased in addition to the significant increase of cell2masses, and the percentages of both spermatangia and caposporangia gradually increased with the increase of the ages of mother blades. When the single cells were isolated from different parts of a long blade, among the regenerated plants from them, the percentages of both normal and abnormal blades significantly decreased, but with increasing of percentage of the cell2masses. These results suggested that the single cell isolated from the gametophytic blade of P. yezoensis regenerated into different types of plants in vitro are attributed to the difference of the differentiation stages of the cells in vivo. The differentiation period of the gametophytic blade cells from the conchospore cell to sexual cell, can at least be divided into eight differentiation stages.