Abstract
The past vegetation has been clarified by identifying taxa based on morphological characteristics of fossil plant remains such as fossil pollen grains found in sediments. The identification of taxa from pollen grains is, however, generally at the genus level, and the species level identification from pollen grains has been difficult. To identify species from fossil pollen grains, we amplified DNA from fossil pollen grains using PCR methods. Fossil pollen samples were collected from the sediments of ca. 20,000 years ago at the Tomizawa site, Sendai. Two intergenic chloroplast DNA regions, trnT-trnL and trnW-trnP (160 and 158 bp long, respectively), were amplified from pollen grains that had been identified as Abies or Picea spp. morphologically. The PCR amplification was successful for two of the 61 pollen samples. The trnT-trnL sequence of one pollen sample differed from five Abies species occurring in Japan by at least one substitution. The other pollen sample had the same trnW-trnP sequence as A. homolepis and A. veitchii. The current northern limit of distributiion of these species is in Fukushima Prefecture to the south. Thus, the results unexpectedly showed a northward distribution of Abies species growing in the south during the last glacial period.
