1Centre for Plant Conservation Genetics, Southern Cross University, Lismore, Australia,
2School of Environmental Science and Management, Southern Cross University, Lismore, Australia
The endosperm morphology of eight representatives across the breadth of the Australian Native Grass Subfamilies were compared to their nearest commercial relatives using Scanning Electron Microscopy (SEM). Mature caryopses were critical-point dried and then snap fractured transversely through the grain. Comparison at high and low magnification showed a wide variation in shape, size, distribution and surface structures of the starch granules. The presence or absence of protein bodies and their arrangement in the protein matrix varied, as did the degree to which they were embedded into the starch granules.
The Australian native species showed strong homology to their respective commercial relatives and members of the same Tribe, however, in each case distinguishing novel starch, protein or cell wall characteristics were observed. Previous SEM studies of commercial varieties identified correlations between endosperm structure and functional traits including digestibility. This study suggests that our native grasses may provide new sources of genetic diversity for future grain improvement programs.