Genetic Variation of Alnus trabeculosaPopulations in Japan

Alnus trabeculosaHand.-Mazz. is classed as “near threatened,” and efforts should be made to conserve the species, but effective action would require understanding of its genetic variation and structure. Therefore, the genetic variation at 12 isozyme loci was examined in seven populations of the species in Japan. The expected heterozygosity within species (Hes=0.222) and the expected heterozygosity within populations (Hep=0.199) were found to be slightly higher than in most other woody species. The coefficient of genetic differentiation (GST=0.146) was also high. The northernmost population had the lowest values for almost all measures of genetic variation, and populations in southern Japan tended to show greater within-population variation than those in northern Japan. The level and distribution of genetic variation in this species might be related to its life history and ecological traits, and distribution history.