Free aminoacid pattern and species relationship in genus Oryza.

Using the two-dimensional paper-chromatographic technique, free-aminoacid analysis was made on nine diploids and five allotetraploid species of Oryza, to study the biochemical and physiological bases of species relationships. The relationship between different species was inferred on the basis of similarity or differences in polygon patterns of aminoacids, drawn using Ellison's paired affinity values. Among the diploid species, O. sativa, O. perennis subsp. balunga, O. glaberrima and O. breviligulata showed similar polygon patterns, suggesting close relationships. The other diploid species differed in their polygon pattern, reflecting species differences. In the tetraploid species, O. alta and O. latifolia, and O. minuta, O. schweinfurthiana and O. malampuzhaensis, showed similar polygon patterns. Polygon maps of O. punctata failed to show any similarity with O. officinalis, but some similarity was observed between O. punctata and O. schweinfurthiana.