ESTIMATE FOR HISTORICAL CHANGE OF ANCIENT ECOSYSTEMS BASED ON DNA ANALYSIS OF PLANT REMAINS EXCAVATED

对出土植物遗骸进行DNA分析是研究古生态系统的有效工具。为了追溯古代生态系统的历史变迁，我们分析了静冈等地区考古遗址出土的植物遗存。研究结果如下：1.据我们所知，出土的稻谷都是粳稻。杂草和树种的叶子是从Magarikane-kita遗址的古代稻田中获得的。从数量上的均匀性来看，古代稻作是在异质条件下进行的.根据角江遗址出土的树尖估算了树木的种类。绳文时代末期的树种与现在的树种基本相同.此外，还对青森县三内丸山遗址出土的栗子粒进行了分析。根据PCR产物的异质性，推测其遗传多样性较低，为原始栽培板栗的产物，推测其栽培板栗的历史可追溯到绳文时代。同时也表明，日本古代农业生态系统中保存了较高的遗传多样性和物种多样性。

DNA analysis for plant remains excavated is useful tool for estimation of the ancient ecosystem. For the aims at tracing the historical change of ancient ecosystem, we analyzed plant remains excavated from some archaeological sites in Shizuoka and other areas. The results obtained are as follows.1. Rice grains excavated were japonica, as far as we observed.2. Weed and leaves of tree-species were obtained from ancient paddy fields at Magarikane-kita relics. Judging from the low uniformity in terms of numbers, ancient rice cultivation was done under heterogeneous conditions.3. Species of trees were estimted based on tips of tree excavated at Kakue relics. Tree species grown at the late Jomon period was almost same as the present ones.4. Chestnut grains excavated at Sannai-Maruyama relics of Aomori prefecture were also analyzed. Judging by low genetic diversity based on the heterogeneity of PCR-product, primitive cultivation would be suggested for their chestnut production.From these results, we suggest that cultivation was practiced till Jomon period. It was also suggested that high genetic diversity as well as species diversity was preserved in agroecosystem in the ancient Japan.