Production of Chimeral Thalli by Protoplast Fusion in Porphyra yezoensis and P.tenera

细胞融合是提高植物品质的优良技术。在本研究中，我们尝试用细胞融合的方法从一种红海藻类卟啉中产生嵌合菌体。为了进行细胞融合，必须产生大量的原生质体。我们从自然生境中寻找能降解藻类细胞壁的细菌，分离出3株能产生大量细胞壁降解酶（-1,4-甘露聚糖酶、-1,3-木聚糖酶和卟啉酶）的细菌。从野生型中也获得了一个绿色的突变体。野生型植物菌体的原生质体。用-1,4-甘露聚糖酶、-1,3-木聚糖酶和卟啉酶处理叶藻和绿型突变体。将这些原生质体暴露在聚乙二醇（PEG）中诱导其融合。经peg处理的原生质体发育成形状不规则的愈伤组织，并形成大量的植株。这些植株生长成部分杂色嵌合体菌体（嵌合体i），除了棕色或绿色菌体外，还由棕色和绿色菌体组成。显微镜观察发现，嵌合体- 1的绿色部分变成了棕色的成熟细胞。嵌合体i释放出的一些单孢子长成由棕色和绿色组成的嵌合体菌体，另一些长成褐色或绿色的菌体。由嵌合体- 1的单孢子发育而成的嵌合体菌体释放出了碳孢子。这些壳孢子长成螺孢子并产生螺孢子。38.4%的贝壳孢子长成由棕色和绿色组成的嵌合菌体。因此，嵌合体- 1应该是由叶藻（p.e yezoensis）与拟南芥（p.e tenera）的融合细胞发育而来的菌体。

Cell fusion is the superior technique to improve the quality of plants. In this study was tried to produce chimeral thallus from a red sea algae, Porphyra, by cell fusion. For carrying out cell fusion it is necessary to produce a number of protoplasts. We searched bacteria capable of degrading the cell wall of algae from natural habitats, and isolated 3 strains of bacteria which could produce a lot of cell wall-degrading enzymes ( -1,4-mannanase, -1,3-xylanase, and porphyranase). A green thallus of the spontaneous mutant was also obtained from the wild type of P.tenera. A number of protoplasts from thalli of the wild type of . Yezoensis and the green type mutant of P.tenera by the treatment with -1,4-mannanase, -1,3-xylanase, and porphyranase. These protoplasts were induced to fuse by exposing them to polyethylene glycol (PEG). The PEG-treated protoplasts developed into calli of irregular shapes, and a large nummber of plantlets were formed from the calli. These plantlets grew into sectorially variegated chimeral thalli (chimera-I) composed of brown and green sectors, in addition to brown or green thalli. Microscopical observation revealed that green sector of chimera-I turned into brown mature cells. Some monospores released from chimera-I grew into chimeral thalli composed of brown and green, and others bedame brown or green thalli. A chimeral thallus developed from monospores of chimera-I released carpospores. These carpospores grew into conchocelis and produced conchospores. A 38.4 % of the conchospores grew into chimeral thalli composed of brown and green. Therefore, chimera-I was supposed to be a thallus developed from fusion cell of P.yezoensis and P.tenera.