Identification of cross-fertilized conchocelis using cleaved amplified polymorphic sequence markers in cross-experiments of Porphyra yezoensis (Bangiales, Rhodophyta)

As a part of the construction of a Porphyra yezoensis Ueda genetic linkage map, we conducted intraspecific cross-experiments and subsequent screening of cross-fertilized conchocelis by cleaved amplified polymorphic sequence (CAPS) analysis. The cross-experiments were carried out between males of the wildtype (KGJ) and females of the recessive green mutant (TU-2) using two methods, controlled and random crosses. A total of 42 and 186 wildtype-colored conchocelis colonies were obtained from the former and latter experiments, respectively. Among those, 49 DNA samples (14% and 23% obtained from the former and latter crosses, respectively) showed biparental CAPS patterns in the two gene regions (EF-1 alpha open reading frame [ORF] region and V-ATPase). This study represents the first report in which the cross-fertilized conchocelis of P. yezoensis has been directly confirmed by molecular marker. The combination of the simple DNA extraction and CAPS analysis may be applicable in genetic studies of other macroalgae that are monoecious and/or grow slowly in laboratory culture.