Sustainability of Populations of Wild Rice Species in Natural in situ Conservation Sites of South and West Sulawesi

Abstract

Exploration and identification of wild rice species (Oryza spp.) was carried out in South and West Sulawesi area of the Sulawesi Island in Indonesia. We collected several accessions of wild rice in these surveys and identified species of accessions through DNA analysis. Two accessions of wild rice were collected in Palopo (IS-03) and Malangke (IS-20) of South Sulawesi and one accession was collected in Mamuju of West Sulawesi (IS-23). Total DNA was isolated from leaves of each accession using a modified CTAB method. Then, DNA fragment containing intron 19 sequence of PolA1 gene was amplified by PCR using a pairs of primers, 19ex5P and 20ex3P. DNA sequence of the amplified PCR product was determined by direct sequencing method. The result showed that these three wild rice accessions collected in South and West Sulawesi were identified as Oryza officinalis. Sequence analysis also showed that there were two types of the intron 19 sequences in O. officinalis. Two accessions from Palopo and Mamuju had the intron 19 sequence (298 bp) that was identical to that of O. officinalis accession (W0614) from Prome in Burma. In contrast, the accession from Malangke had the sequence (283 bp) that was shared with W0002 accession from Bangkok in Thailand. The habitats of O. officinalis were swamp or a temporary flooded plain, for example at the edge of the ditch and the rivers that are flooded in the rainy season. Sustainability of populations of this wild rice species in natural in situ conservation sites is now dangerously threatened by suburbia town expansions during the last five years.