Allozyme variability within and divergence among populations of the liverwortConocephalum conicum (Marchantiales: Hepaticae) in Japan

Genetic variation within, and divergence among, populations of the liverwortConocephalum conicum were estimated from the study of 17 populations and 23 putative gene loci. Two additional multilocus genotypes (“T” and “FS”) were detected in Japan, along with the previously reported “J” type. These three multilocus genotypes differed both morphologically and ecologically. All eight populations from western Japan included only the J-type and exhibited low genetic variation within populations: Nei's (1973) average gene diversity (Ĥ)=0.080±0.029. In contrast, co-occurrence of several multilocus genotypes in each population from the Kanto District resulted in much higher levels of genetic variation (Ĥ=0.218±0.037). If the three genotypes are distinguished,Ĥ values are 0.113±0.030 for T-type, 0.107±0.033 for FS-type, and 0.083±0.018 for J-type. UsingC. japonicum, which showed low genetic variation (0.014±0.010) as an outgroup, each genotype formed a monophyletic clade, and the J- and FS-types were more closely related to each other than to the T-type. Populations of western Japan and the Kanto District also differed in the degree of gene diversity among populations, but the reasons for these differences are obscure.