An improved method for karyotype analyses of marine algae

Modified carbol fuchsin staining method was successfully introduced into the karyotype analyses of marine algae, including Porphyra, Undaria pinnatifida and Laminaria japonica. Haploid chromosomes were numbered clearly in the vegetative, spermatangial and conchosporangial cells of P. haitanensis and P. yezoensis. Diploid chromosomes were observed and numbered in immature conchosporangial cells of P. haitanensis and P. yezoensis. Pit-connections of Porphyra were also clearly demonstrated. Prophase chromosomes of conchocelis cells were also clearly stained with modified carbol fuchsin. One molar per liter hydrochloric hydrolysis at 60°C for 7–8 min is necessary for getting transparent cytoplasm for conchosporangial karyotype analysis of Porphyra. Staining effects of the three methods using iron alum acetocarmine, aceto-iron-haematoxylin-chloral hydrate and modified carbol fuchsin were compared on the vegetative, spermatangial and conchosporangial cells of Porphyra and the gametophytes of U. pinnatifida and L. japonica. Among the three methods, the modified carbol fuchsin method gave the best result of deep staining and good contrast between nucleus and cytoplasm.