Abstract:
Rice (Oryza sativa L.) has been cultivated as a major crop for about thousands of years, and it currently
sustains nearly one-half of the world population. Wild relatives of rice are an invaluable resource for rice
upgrading by widening genetic diversity and incorporating useful traits to modern cultivars. In this
context, phenotypic variations of O.nivara accessions exist in Sri Lanka were studied, based on thirteen
quantitative morphological traits. The results revealed high phenotypic diversity among O.nivara
accessions tested. Among the vegetative traits studied, a huge variability was observed for the plant height
(138.70±6.1-93.00±3.Ocm) and seedling height (55.50±3.8-27.10±1.8cm). Among the reproductive traits
observed, panicle length (31.5±0.3-12.2±0.3cm), panicle-bearing tillers/plant (25.3±1.2-11.7±2.5),
number of spikelets/ panicle (123±5.3-47±3.6), filled grains/panicle (98.7±3.1-24.3±4.0) and shattered
seeds/panicle (105.33±7.6-44±1.7) showed remarkable variability among accessions. This study
highlights the phenotypic diversity of 0. nivara accessions exist in Sri Lanka and the potential of using
them in rice improvement program in future.