Assessment of Genetic Diversity across differentially adopted rice ecotypes

Rice is an important staple food and a rich source of carbohydrates for 90% of South and Southeast Asians. Genetic diversity of naturally adopted upland lines along with few germplasm collections in Karnataka were studied based on 13 SSR loci on chromosome 1. A total of 24 individuals belonging to 3 differentially adopted groups [Upland (8), landraces (8) and cultivated varieties (8)] had a moderate to high level of genetic variability at groups level with number of alleles ranging from 5 to 23 (average 11.5) and PIC from 0.51 to 0.94 (average 0.79). The heterozygosity varied from 0.39 to as high as 0.70. Over all genetic diversity of 0.81 was revealed indicating a high level of genetic variation among these individuals. At the similarity coefficient of 7, all the lines were clearly grouped in 3 clusters. All cultivated types grouped in one cluster (cluster 1) except Rasi and CTH 1 which were included in cluster 2 and cluster 3 respectively. Cluster 1 contained 9 cultivated genotypes, where as cluster 2 contained 11 land races and cluster 3 had 4 upland lines. Out of 4 upland lines one line (AC35341) intermixed, with C1 and three lines (PS229, JBT37/4 and AC35310) with C3. The study of SSR markers on chromosome 1 facilitated the classification of these lines according to their adaptability. The information about the genetics of these populations will be for specific chromosomes and will be very useful for rice breeding programs, especially for gene mapping and ultimately for marker assisted selection programs.