Algae. 1999; 14(1): 73-77.

Crossing between Porphyra yezoensis and P. Tenera

Jong-Ahm Shin

Department of Aquaculture, Yosu National University

Crossing between Porphyra yezoensis and P. tenera was performed using their color mutant types as genetic markers. In all cross combinations, phenotypes of F sub(1) gametothalli developed from conchospores released from homozygous F sub(1) sporothalli were the same as their respective parental types; phenotypes of F sub(1)gametothalli from heterozygous F sub(1)sporothalli presenting the wild-type were segregated. Most of F sub(1) gametothalli from conchospores released from the heterozygous wild-type F sub(1) sporothallus became extinct at the two-to six-cell stage. A few uniformly-colored gametothalli might be hybrid breakdown and that the survivors breakthroughs. These results show that incomplete mechanism of reproductive isolation exists between P. yezoensis and P.tenera; this suggests the reality of biological species in the genus Porphyra.

Keywords : breakthrough, hybrid breakdown, interspecific crossing, Porphyra tenera, Parphyra yezoensis