ABSTRACT
Aims: To study the diversity of flowering time locus RM248 in some traditional rice cultivars in Sri Lanka and compare it with days to flowering of studied rice cultivars. Study Design: A field experiment was carried out to evaluate the days to flowering of the studied traditional rice cultivars. Rice plants were transplanted according to randomized complete block design with four replications and 20 plants per plot with 15 cm X 20 cm plant spacing. Diversity of flowering time locus RM 248 was analyzed by performing PCR using SSR marker RM 248 with genomic DNA of different eighty-nine rice genotypes. Gel electrophoresis was carried out in vertical gel electrophoresis unit for three hours. Gel plates were Silver stained and banding pattern was scored. Place and Duration of Study: Field data were collected in Sri Lanka. The experiment was carried out during 2011/2012 Maha season and 2012 Yala season at the Faculty of Agriculture, University of Ruhuna, Sri Lanka. In Sri Lanka Yala is referred as dry season while Maha is referred as wet season. Laboratory data were collected at the Laboratory of Genetics, Graduate school of Science and Technology, Kobe University, Japan from October 2012 – December 2012. Methodology: Days-to-flowering of traditional rice cultivars was studied in a field experiment and diversity of flowering time locus, RM 248 was studied by PCR amplification of SSR marker RM 248. SSR marker was amplified using the Gene Amp PCR System 9700 thermocycler. Amplified products were fractionated by electrophoresis through 6% denaturing Polyacrylamide gels and stained using Silver sequence DNA sequencing system staining regents (Promega, USA). Results: Silver stained Polyacrylamide gel showed six different allele types in traditional rice accessions in RM 248 locus. Conclusion: There is a great diversity in the RM248 locus among the traditional rice cultivars in Sri Lanka.
ABSTRACT
Aims: To study the diversity of traditional rice genotypes in Sri Lanka using cluster analysis and principle component analysis. Study Design: The experiment was carried out using one hundred rice genotypes with six modern rice cultivars and ninety four traditional rice cultivars. Rice genotypes were planted according to a randomized complete block design with four replications and 20 plants per plot with 15 cm X 20 cm spacing. Place and Duration of Study: A field experiment was carried out during 2011/2012 Maha season and 2012 Yala season at Faculty of Agriculture, University of Ruhuna, Sri Lanka. Methodology: Plant height (cm), number of tillers/plant and number of productive tillers/plant were measured before harvesting. Panicle length (cm), panicle weight (g), number of spikelets/panicle, number of fertile spikelets/panicle, 100 grain weight (g) and yield/plant (g) were measured after harvesting and drying of grains for 14% moisture content. Principal component analysis (PCA) and cluster analysis were performed using SPSS statistical software. Results: Among nine studied variables three principal components exhibited more than one Eigen value and showed about 89.6 % variability. The principal components (PC) 1, 2 and 3 had 51.07%, 22.08% and 16.46% variability among the genotypes for the evaluated traits respectively. The first PC was more related to panicle weight, number of spikelets/panicle, number of fertile spikelets/panicle, spikelet fertility percentage and yield (g/plant). Number of tillers/plant, number of productive tillers/plant and yield (g/plant) were more related traits in the second principal component. The highest contribution in third principal component was from the panicle weight, 100 grain weight and yield (g/plant). Based on the nine yield and yield attributing characters, the genotypes were grouped in to seven clusters in cluster analysis. The genotypes under cluster V recorded the highest divergence among them as it exhibited the highest intra-cluster distance. The lowest intracluster distance was recorded in the cluster VI. The modern rice cultivar BG 379/2 was fallen in to the cluster VI with 3 traditional rice cultivars namely Karayal I, Bathkiri el and Hondarawala. Conclusion: One hundred rice genotypes were grouped in to divergent groups by principle component analysis and cluster analysis. This clustering pattern can be used for the selection of parental materials with diverse characters.