Title: Evaluation of genetic Diversity of the M3 Mutant population originated from Hashemi rice cultivar
Author: Leila Khazaie
Abstract: Mutagenesis has been one of the important sources of genetic diversity and plant mutants can be important bio-resources for crop breeding and functional genomics studies. The purpose of this study was mutation induction in Hashemi local rice variety using chemical mutagen ethyl methane sulfonate (EMS) to create genetic variation and evaluating genetic variation at M2 generation. So, the genetic diversity of M3 selected genotypes (95 genotypes out of 17 populations) was studied by means of 13 ISSR (inter-simple sequence repeats) primers. The results of the molecular analysis showed that all used ISSR markers were polymorphic, among them the ISSR9 marker had the highest polymorphism and Nei gene diversity index. The highest gene diversity was observed in HM2 (0.19) and HM5 (0.16) mutant populations. Genetic diversity assessed by molecular markers showed that the total number of fragments amplified per primer raised from 4 (pr1-7) to 11 (ISSR-7, ISSR11). In general, a total number of 99 fragments were generated by the 13 primers of which 50 were polymorphic (52.92 %). The average number of loci and polymorphic loci generated per primer were 7.62 and 3.85 respectively. The genetic variation created by ISSR markers within the 17 populations were varied from 11.11 % in HM9 (HM for Hashemi Mutant line number 9) to 45.45 % in HM2. Cluster analysis using the UPGMA method placed the original cultivar alone in one cluster from the grouping of the selected mutant populations. The average value of molecular polymorphism content was 0.16. Based on the analysis of molecular variance, intra-population variance was higher than inter-population variance and the minimum and maximum genetic distance were between improved and HM2 and HM5 (0/03) and HM8 and HM9 with Hashemi parent, respectively. Therefore, it can be stated that the ISSR markers used in this study to evaluate the genetic diversity among the mutant populations were highly effective and this mutant population is expected to serve as a genetic resource for understanding rice biology as well as for use in genetic improvement of quantitative traits.
Keywords: EMS, genetical diversity, ISSR marker, Mutation, Rice