Abstract:
Oryza rhizomatis is a wild rice species endemic to Sri Lanka and is reported to have
tolerance to biotic and abiotic stresses prevailing in the dry zone of the country. Several
morphological differences have been observed in O. rhizomatis grown under different agroecological
conditions of Sri Lanka. Therefore, these rice species (accessions) may have genetic
differences to consider them as ‘ecotypes’. Morphological and genetic diversity of O.rhizomatis
accessions collected from different locations were carried out to observe genetic differences
among them. Scattered diagram of PCoA of O. rhizomatis accessions, based on morphological
data showed that there were no significant differences among them. According to molecular
analysis by AFLP, all the accessions were genetically similar and Jaccard genetic similarity
coefficient varied with a very narrow range between the accessions (0.915 to 1.000). According to
the results, the O. rhizomatis accessions tested did not show significant morphological and genetic
differences. In this study representative samples from different locations were grown in the green
house, exposing them to the same environmental conditions. This may have contributed to results
obtained with no observable morphological differences. Further studies have to be carried out with
insitu collections from different locations when extreme weather conditions are prevailing to see
the morphological characters are changed as an adaptation and to assess any genetic diversity.
