I found the following blog article today.
http://app.blog.livedoor.jp/archaeoring/tb.cgi/50462635 (Japanese only)
Root plants as archaebotanical materials are very rare at sites in ancient Japan. Ancient starch researches I described (see Feb. 2006) are a very new field in Japanese archaeology, but these studies may contribute to the big results.
Although it still be problematic to apply research methods in other countries to Japanese archaeological methods, if ancient starch analysis can present new evidence which is only conjecture, its academic value would be great in Japan.