Algae. 1989; 4(2): 207-211.
Crossbreeding in Cultivars of Porphyra yezoensis (Bangiales, Rhodophyta) - Preliminary Report
Akio Miura, Jong-Ahm Shin
Laboratory of Algae Cultivation, Tokyo University of Fisheries Konan 4-5-7
Lustrous deep pigmentation and crisp texture in dried sheets of nori as well as high yield are desired characteristics in cultivars of Porphyra and required by nori growers. The genetic improvement of yields in foliose thalli (gametophytes) and in pigmentation and texture of dried sheets of nori made of them are objectives of this study. The green-type (C-0 giant) and red-type (H-25) mutants of P. yezoensis were used as parental lines for crossbreeding. Green- and red-type mutants are monogenic, recessive to the wild-type, and belong to the same linkage group, with each gene situate on different loci on a homologous chromosome. Crossbred conchocelis thalli (sporophytes) were produced by crossbreeding green- and red-type mutants, then recombinant wild-type foliose thalli produced from their conchospores. The fixation of the recombinant wild-type was performed by successive self-fertilization in vitro. Using fixed recombinant wild-type conchocelis thalli, the same type foliose thalli were experimentally cultivated in the sea. They expressed excellent yield and quality characteristics in comparison to growers' cultivars.
Keywords : crossbreeding, fixation, pigmentation mutant, prophyra yezoensis, recombinant wild-type