Abstract:
Wild species of rice (Oryza) have superior agronomic
characteristics to be incorporated in rice breeding programs
worldwide. Population studies of wild relatives of rice in Sri Lanka
have not been well documented despite a few attempts. In the
present study, phenotypic diversity of Oryza rufipogon populations
exist in Sri Lanka were characterized based on nine quantitative
morphological traits. Populations (P1, P2, P3, P4 and P5) were
established in a common-garden and were characterized. The
results revealed moderate phenotypic diversity among O. rufipogon
populations studied. However, flag leaf length and awn length
were the most variable traits while plant height, flag leaf angle, flag
leaf panicle neck length and spikelet angle were the least variable
traits. O. rufipogon can be simply distinguished using flag leaf length
and width, panicle branching type and distance from panicle base
to lowest spikelet insertion. The dendrogram results indicated that
four main clusters are at a similarity level of 98.73, showing the
diversely related populations with a high identity based on higher
similarity values. P1 and P2 populations grouped together by
forming the first cluster. The second, third and fourth clusters
consisted of P3, P5 and P4 populations, respectively. One
population from the first cluster and P3, P5 and P4 populations can
be used for conservation. This study highlights the phenotypic
diversity of O. rufipogon populations existing in Sri Lanka across the
geographic locations and Knowledge on such morphological
diversity provides opportunities to design conservation strategies
and the potentials of using particular population based on breeding
objectives.
