Collaborative exploration between Japan and Vietnam was conducted in the Mekong Delta area of Southern Vietnam from November 17 to December 16, 1998. A total of 124 landraces and 12 wild relatives, including Oryza rufipogon and O. officinalis were collected. Land races which are adapted to deep water conditions, acid sulfurate soils, aluminum soil, or salinity were found in various locations. Some land races were grown for their high quality as aromatic rice and glutinous rice. Twelve accessions of wild relatives of rice, which include Oryza rufipogon and O. officinalis, were also collected near former fields. Oryza officinalis was collected in Ca Mau province, which is the first accession of that species from that province
