Assessing the Genetic Diversity and Population Structure of World Germplasm Collection of Erianthus arundinaceus (Retz.) Jeswiet Using Sequence-Related Amplified Polymorphic Markers

Genetic diversity of world collection of E. arundinaceus germplasm clones was analyzed using SRAP marker polymorphic survey. The marker survey with thirty combinations of SRAP marker generated distinct DNA profiles with fragments ranging in size from 120 to 1000 bp in all the germplasm lines. The selected primer pairs yielded a total of 306 scorable bands and 237 polymorphic bands. The mean percentage of polymorphic bands (PPB) among all the population was 75.9%. The maximum genetic distance (0.49) was measured between the Indonesian and Indian collections, and the minimum distance of 0.040 was measured between the population of Fiji and Philippines, and within the population of Philippines. The phylogenetic tree derived based on the dissimilarity index clustered 208 accessions into ten groups, and the clusters correlated with geographical origin of the clones. From the structure output using the SRAP data set, the best K value or the uppermost level of structure obtained was nine. The Mean Fixation Index (Fst) was 0.79 with a range from 0.88 to 0.70. Cluster 9 showed the highest Fst of 0.88, and cluster 1 showed the lowest Fst of 0.70, respectively. The structure analysis with high Fst and low gene flow (Nm) values indicated a lower gene flow and significant genetic differentiation among the populations. Proportion of individuals sharing > 60% membership within cluster ranged from 50 to 95.7. Blast analysis of selected fragment sequences showed homology to functional genes indicating the amplification of coding regions by the SRAP markers.