Study of genetic diversity and association analysis of agronomic traits with ISSR and EST-SSR markers in tall fescue (Festuca arundinacea)

Tall fescue (Festuca arundinacea) from Poaceae family is an aloehexaploid (2n= 6x= 42) and cross pollinated plant that is used throughout the world as a forage plant. Most of economically important morphological traits have quantitative (polygenic) inheritance, and the expression of genes controlling these traits are widely influencedby the environment. So improving these traits with classical breeding methods is difficult and time consuming. In the last 40 years, the development of molecular markerstechnology and its integration with biometric methods has made possible identificationof QTL and developing marker assisted selection. This research was aimed to study the genetic control and identification of genomic regions controlling agro-morphological traits in tall fescue germplasm using association analysis approach. In the molecular experiment, the genetic diversity of ninety tall fescue populations was assessed by 10 EST-SSR and 39 ISSR primers. In the phenotypic assessment, the phenotypic variability of ninety tall fescue populations for 10 agro-biological traits was assessed using randomized complete block design with three replications. Among studied agro-biological traits, the highest variation was observed for plant heightanddate to pollination. In principal component analysis based on agro-biological traits the studied tallfescue population subdivided into two main groups and four subgroups. In grouping population based on all studied molecular markers via UPGMA and Bayesian methods, the population divided into two main groups including grass and forage groups. The results showed that based on both morphological and molecularmarkers there are valuable genetic diversity among studied population. In association analysis with both GLM and MLM methods the highest number of markers was identified for data to pollination trait. In the GLM method, some common markers were identified for date to pollination and flowering date traits that could be used to study both traits simultaneously