KARYOMORPHOLOGY OF THE GENUS LYCOPODIUM-SENSU-STRICTO AND RELATIONSHIPS AMONG SPECIES

Karyomorphological comparisons were made of six species of Japanese Lycopodium sensu stricto. There were no marked differences at interphase and prophase among the six species. Lycopodium annotinum had 2n = 68 and the formula of its metaphase karyotype was 18m(median centromeric chromosomes) + 12sm(submedian) + 12st(subterminal) + 26t(terminal). Lycopodium casuarinoides had 2n = 68 = 16m + 10sm + 18st + 24t, L. clavatum 2n = 68 = 22m + 12sm + 18st + 16t, and L. obscurum 2n = 68 = 10m + 22sm + 20st + 16t. Each of these species, which belong to different sections, displayed several karyomorphological differences. Among them L. casuarinoides differs largely from the others in its mean chromosome length, ratio of the longest chromosome to the shortest, and frequency of m + sm chromosomes. Both Lycopodium complanatum and L. nikoense, belonging to section Complanata, had a common karyotype 2n = 46 = 10m + 12sm + 18st + 6t. This section displayed a low differentiation in its karyotype. In the whole Lycopodium s.s., the ratios of m + sm in a complement varied from 38 to 50%, being higher among pteridophytes.