Evaluation of genetic variation of endophytic fungi isolated from Iranian grasses and grouping them based on SSR marker

Fungal endophytes of the genus Neotyphodium are common in main cool-season grass species and confer both beneficial and deleterious agronomic characteristics to their hosts. The aim of this study was to understand the genetic diversity of Iranian grass endophytes using 20 EST-SSR primer pairs. After optimization of their PCR amplifications, 18 primer sets were used to assay the polymorphism of 19 fungi endophytes which were isolated from two plant genus referred to eight different regions of Iran. The amplification patterns of the fragments on denaturing sequencing gel were analyzed using, NTSys Ver 2.02, PowerMarker V3.25 and MEGA4 softwares. The number of observed polymorphic loci was 46 and varied from one to four for each primer pairs. Polymorphic Information Contents (PIC) of polymorphic loci was varied from 0.171 to 0.374 with mean of 0.204. Cluster analysis using molecular data, separated studied endophytes into five groups. The first group represented endophytes from perennial rye grass. All the remaining endophytes were isolated from tall fescue and were clustered into more four groups. The first containing isolates from Fariman region. The second represents endophytes from Kamyaran and two latter groups were from Abyaneh and Isfahan (Keshe, Padena, Honejan) respectively. Studied SSR markers detected high levels of polymorphism between Neotyphodium and Epichloe species, and low levels of polymorphism within these genuses. Genetic distances between endophyte isolates showed that there is a positive relationship between genetic and geographical distance of resulted groups. Data of this investigation demonstrated that the SSR markers were informative for the assessment of genetic variation between endophyte species. These markers may be used to identify endophyte taxa and to evaluate genetic diversity among endophyte populations, which may be correlated with variation for endophyte-derived agronomic traits.