Summary of final report on the Australian Flora Foundation funded project:
Brian Atwell and Margaret Morgan
Departments of Biological Sciences & Chemistry and Biomolecular Sciences, Macquarie University, NSW 2109
Australian Flora Foundation Final Report November 2010
Oryza meridionalis is a wild relative of cultivated rice (Oryza sativa) and is endemic to tropical Australia. As a vigorous summer-growing plant, it has potential for agriculture. We report a number of novel findings relating to the reproductive development of wild rice. The photoperiod requirement of three O. meridionalis accessions from tropical Australia were compared, based on observations that flowering times differed under natural daylengths. While panicles initiated in the accession from Western Australia after just 53 d, even with a 13-h daylength, accessions from the Northern Territory and Queensland required a 12-h day or less to initiate and took three weeks longer to do so. That is, plants from the driest region (Western Australia) were photoperiod-insensitive, maybe as an adaptive phenomenon. Grain yield was compromised in the wild rice by small individual grains and a harvest index of about 10%. The grain of O. meridionalis had high inorganic nutrient levels, particularly copper and zinc. Nitrogen levels were also high, suggesting a protein-rich grain in wild rice. Amino acid composition was not remarkable except for a higher methionine level in the wild rice relative compared to O. sativa and wheat.