Abstract:
Abstract: The study assessed the variations in morphologically,
physiologically and anatomically distinct traits of wild rice
species in Sri Lanka; O. nivara, O. rufipogon, O. eichingeri,
O. rhizomatis and O. granulata, which could be useful in rice
breeding. The wild rice species were grown in a common
garden, and the morphological traits were measured soon
after heading. The results showed qualitative parameters such
as the panicle type, awning, stigma colour, lemma and palea
pubescence, seed coat colour, blade pubescence and ligule
shape, are distinctive among the five species and are promising
characters in their field identification. ANOVA revealed that the
quantitative traits, such as flag leaf length, flag leaf width, culm
length, culm diameter, panicle length, 100 grain weight and
plant height are useful for further confirmation of species. The
highest net photosynthetic rate (5.86 µmol m-2 s-1), high cluster
width of the base (61.4 µm), and trichome density (184.33 per
25 mm2
area) were observed in O. rufipogon compared to the
rest, and such desirable traits are effective in rice breeding.
Moreover, transpiration rates, stomatal conductance and sub stomatal CO2
concentration are ideal physiological traits to be
considered in super rice breeding. Significant correlations were
observed between transpiration and photosynthesis processes.
Thus, our study provides a clear picture on habitat preferences,
life cycle, distinctive morphologies and diverse functional traits
to be effectively used in field identification and future utilisation
of wild relatives of rice in the plant breeding programmes.
