Characterization and Genetic Analysis of the Violet Type Pigmentation Mutant of Porphyra yezoensis Ueda (Bangiales, Rhodophyta)

Algae > Volume 8(2); 1993 > Article

Algae 1993;8(2): 217-230.

Kyosuke Niwa, Akio Miuea, Jong-Ahm Shin, Yusho Aruga

Laboratory of Phycology, Tokyo University of Fisheries, Laboratory of Marine Biotechnology, Aomori University

ABSTRACT

To characterize the violet type pigmentation mutant of Porphyra yezoensis Ueda (Bangiales, Rhodophyta), the in vivo absorption spectrum and the contents of photosynthetic pigments were compared with those of the wild type and other type pigmentation mutants of the species. In vivo absorbance of the violet type was lower in the wavelength ranges in which chlorophyll α mainly takes part as compared with the wild type and other type mutants. The content of chlorophyll α per unit area of foliose thallus was also lower in the violet type than in the wild type and other type mutants. These results suggest that the violet type is mainly due to the quantitative variation of chlorophyll α. For genetic analysis of the violet type of P. yezoensis, the violet type was crossed with the wild type or the green type of the species. The inheritance mode of the violet type was studied and the tetrad analysis was carried out. The cross between the violet type and the wild type produced the wild type heterozygous F sub(1) conchocelis, from which appeared a lot of sectorially variegated chimeric F sub(1) foliose thalli composed of the violet and wild type and the wild type produced the wild type heterozygous F sub(1) conchocelis, from which appeared a lot of sectorially variegated chimeric F sub(1) foliose thalli composed of the violet and wild appeared a lot of sectorially variegated chimeric F sub(1) foliose thalli composed of the violet and wild type sectors. This suggests that the violet type is governed by a single recessive gene. The recombination value between the violet type gene and the centromere was estimated by tetrad analysis to be 7.8 when the wild type was a maternal parent and 9.8 when the violet type was a maternal parent. The cross between the violet type and the green type produced also the wild type heterozygous F sub(1) conchocelis, the dihybrid possibly resulted from complementation of the violet type gene and the green type gene. In this cross also appeared a lot of sectorially variegated chimeric F sub(1) foliose thalli composed of the violet, green, wild and a new color type sectors. From the tetrad analysis, it is suggested that the violet type gene and the green type gene belong different linkage groups. The wild type and a new color type thalli in this cross are considered to be produced by chromosome recombination.

Key words: culture, genetics, in vivo absorption spectrum, mutant, pigmentation, Porphyra yezoensis, Rhodophyta