Abstract
Sri Lankan traditional rice is an important breeding resource for development of rice for ecological adaptation during the era of climate change. There are around 2000 accessions belonging to more than 500 varieties comprised of one to several accessions in each with wider morphological differences, flowering times and yield variations. Genetic identity of Sri Lankan traditional rice accessions belonging to each rice variety is not established at molecular level. Variety Sudu wee comprises of around 30 accessions at PGRC. Sudu wee could be useful in re-introduction programmes of traditional rice due to relatively shorter crop duration. The objective of the present study was to evaluate the diversity of 29 Sudu wee accessions from PGRC, based on days to flowering, (DF), 12 morphological and 2 physiological characters during non-inductive photoperiod season. DF varied from 62 to 106 days while accession 4193 did not flower during the experimental period of nearly 7 months. Leaf temperature at heading (LeT) and Leaf temperature difference at heading (LeTD), vegetative morphological characters and yield components varied among Sudu wee accessions. Seventy nine percent of total observed variation among accessions was explained through Principal Component Analysis. In the dendogram of accessions, 10 clusters were formed at the rescale distance of 5. Seed morphology indicated the genetic similarity among accessions while significantly different DF could be an indication of flowering time gene variation among similar genotypes. Increased DF reduced the grain yield increasing the vegetative growth among accessions of Sudu wee. Our results would be useful in future breeding for manipulating flowering time and yield within similar genetic backgrounds.