The CC genome of Oryza is found in nine species of Oryza that are distributed on all continents having a tropical climate. Three diploid Oryza species with CC genome are found in Africa and Asia to Papua New Guinea. In southern South Asia these three CC genome diploid species can be found, O. eichingeri and O. rhizomatis in Sri Lanka and O. officinalis in India. AA genome wild relatives of rice are also found in the same geographic region. Germplasm of both diploid CC and AA genome Oryza germplasm has recently been collected from Sri Lanka. AFLP analysis was used to compare the genetic diversity of the two Oryza genomes from a similar geographic region in southern South Asia. In addition, the diploid CC Oryza germplasm was also analyzed by RAPD and SSR methodologies and the combined results were analyzed. The results show that in southern South Asia the diploid CC genome species have a high level of genetic diversity compared to the diploid AA genome species. Molecular marker analysis revealed that populations of O. rhizomatis from northern and southeastern Sri Lanka are genetically differentiated. One accession of O. rhizomatis was aligned with O. eichingeri. This accession was collected from the site of O. rhizomatis that is the closest to a population of O. eichingeri. O. eichingeri showed lower genetic diversity than the other two diploid Oryza CC genome species. O. officinalis accessions from Assam, India, and China were genetically less diverged from O. eichingeri and O. rhizomatis than two accessions of O. officinalis from Kerala state, India.

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Recent analyses confirm that urgent attempts to catalogue the distribution of biological diversity may be facilitated by focusing at the level of genera or families rather than species. However, questions remain over the application of higher-taxon surveys to identify networks of priority areas for conservation action. Is the close spatial match between species and higher-taxon richness at global and regional scales re iterated when sites are locally distributed? How much money is saved by the higher-taxon approach? And how does using genus or family information affect the efficiency with which spatial priorities for conservation are identified? We examined these issues using data on the diversity of woody plants in Sri Lankan forests. We found that at this local scale, the family and particularly generic richness of sites was closely linked to their species richness, independently of variation in site size. Moreover, fieldwork in an additional forest showed that targeting woody plant genera and families rather than species reduced survey costs by a minimum of 60 % and 85 % respectively. Most importantly, while using family data in site-selection algorithms led to the loss from reserve networks of around 7-10% of woody plant species, using genera rather than species had virtually no effect on the representation of species in priority sites. These results thus confirm that judicious use of the higher-taxon approach is indeed a valuable technique for improving the cost effectiveness of field surveys for local conservation planning in the tropics.

Stemonoporus Thw. (Dipterocarpaceae), a genus endemic to Sri Lanka, contains as many as 26 species, all but one confined to the perhumid forests of the island. Several species reach 1800 m, the highest altitude recorded for any dipterocarp species in Sri Lanka. We report the first quantitative data on Stemonoporus-domirated stands in the montane zone (1500–1700 m). Stemonoporus cordifolius and 5. rigidus show clear single-species dominance of their respective stands. Stemonoporus gardneri is a co-dominant with Palaquium rubiginosum in its two stands. All Stemonoporus species appear to have a unique geographical and ecological range and no two Stemonoporus species co-exist in our stands.

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