Can the phenology of Australian wild relatives of cultivated
rice be modified for human use?
Brian Atwell and Margaret Morgan
Departments of Biological Sciences & Chemistry and Biomolecular Sciences,
Macquarie University, NSW 2109
Australian Flora Foundation Final Report November 2010 Grant details Final report
Abstract . 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.