Morphological and Molecular Characterization of Ex-situ Conserved Kaluheenati (Oryza sativa L.) Traditional Rice Accessions in Sri Lanka

This research focused on characterizing 30 Kaluheenati rice accessions, conserved at the Plant Genetic Resources Centre (PGRC), Sri Lanka, using morphological traits and molecular markers. The study aimed to assess the extent of diversity within the Kaluheenati collection, to identify accessions suitable for quality seed production, and identify duplications in the PGRC seed collection. The trial was conducted in 2022 Yala and 2022/23 Maha seasons at the PGRC. The study recorded 44 morphological traits and used 30 Simple Sequence Repeat markers, and significant morphological diversity was observed in the tested traits except for variety group, ligule shape, collar color, flag leaf angle, lemma and palea pubescence and panicle threshability. Principal component analysis and cluster analysis grouped the accessions into seven clusters highlighting the variations. SSR analysis detected 147 alleles, indicating a diverse gene pool. Polymorphic Information Content ranged from 0.31 to 0.75, indicating moderate to high levels of polymorphism. The phylogenetic tree revealed five distinct clusters, indicating genetic variations within the Kaluheenati accessions. Ten accessions (AC 016955, AC 016944, AC 012926, AC 004091, AC 006713, AC 004089, AC 004087, AC 005191, AC 005385, and AC 007802), including pure lines from the RRDI and conserved accession at International Rice Research Institute clustered together, demonstrating genetic similarities. Despite name similarities, no exact genetic duplications were observed. These findings emphasize the genetic diversity present within the conserved Kaluheenati accessions, highlighting the importance of correct identification and utilization for future breeding programs.