紫菜种内原生质体的融合和融合体再生(英文)

Intrageneric fusion of protoplasts from gametophytic blades and development of fusion products in Porphyra spp.(Rhodophyta)

利用酶解法分离出野生型叶状体和红色突变体的坛紫菜原生质体以及条斑紫菜野生型叶状体的原生质体 ,再用聚乙二醇 (PEG)法进行种内原生质体融合。当加入原生质体液内的PEG被稀释除去时 ,原生质体发生融合并形成许多杂合体。种内原生质体融合率坛紫菜为 9.7%～ 12 .4% ,条斑紫菜为 10 %～ 11.5 %。PEG分子量在 15 40～ 6 0 0 0之间 ,随着分子量的提高 ,原生质体融合率增高。原生质体融合体被挑出来进行单个培养。经过 30天培养坛紫菜的一个杂合体 (含一个红色原生质体和一个野生型原生质体 )再生成一个呈红色和野生色的相嵌叶状体。而一个含两个红色原生质体的融合体再生成一个在基部和头部均长假根的叶状体。但来自这个再生体的原生质体只长成具一个假根的叶状体。从原生质体融合体的再生体以及它们无性繁殖体的结果来看 ,坛紫菜的种内原生质体融合体可能只发生了细胞质融合 ,而真正的核融合并没有发生。培养 15～ 2 0天 ,条斑紫菜的原生质体融合体先再生成细胞团 ,然后由细胞团释放出许多胞子并萌发成正常野生型叶状体。

The protoplasts were isolated enzymatically from the gametophytic blades of the wild type and red mutant of Porphyra haitanensis and from the wild type blades of Porphyra yezoensis, respectively. Protoplast fusions were made by treatment with polyethylene glycol (PEG) solution. Many heterokaryocytes formed after the PEG solution was diluted out. The rate of intrageneric fusion was 9.7%-12.4% for P.haitanensis, and 10%-11.5% for P.yezoensis. The fusion rate became higher as the molecular weight of PEG increased from 1 540 to 6 000. Fusion products that involved one red and one wild type protoplasts in P.haitanensis were picked out and individually cultured. After 30 days of culture, one of them developed into a chimeral blade composed of two sectors showing red and wild type color. While, a fusion product involving two red protoplasts developed into a red blade that has two rhizoids at the top and basal ends of the blade. However, protoplasts isolated from the blade, regenerated into red blades, which only have one rhizoid at the basal end of the blade. After culture of 15-20 days, intrageneric fusion products of P.yezoensis developed into cell masses, which released many spores to germinate into normal wild type blades.