Tall Fescue Morphotype Differentiation Using Chloroplast DNA Sequence Variation and SSR Diversity.

Tall fescue (Festuca arundinacea Schreb.) is an important cool-season perennial grass species used as turf, forage and in conservation plantings. Differentiation of tall fescue morphotypes and their relationships with other species within the Festuca genus were conducted using chloroplast sequence from hyper-variable regions and 145 nuclear SSR markers. Hyper-variable regions of chloroplast sequences were retrieved using 33 specially designed primers. Phylogenetic relationships were analyzed using Geneious Pro 5.1, NTSYSpc 2, and FreeTree software’s. Chloroplast sequences showed close association between Rhizomatous and Continental tall fescue morphotypes, while Mediterranean morphotype was positioned in a distant clade. F. pratensis and F. glaucescens, the P and G1G2 genome donors, respectively, were grouped with the Continental clade but F. mairei (M1M2 genome) grouped with the Mediterranean clade. Almost similar relationship was displayed using SSR markers, except individual distant groups formation by F. pratensis and F. mairei. Four chloroplast (NFTCHL17, NFTCHL43, NFTCHL45 and NFTCHL48) and four nuclear SSR (nffa 090, nffa 204, nffa 338 and nffg 37) primer sets were selected, which found highly useful in screening tall fescue morphotypes identification by PCR amplification. Morphotype classification of tall fescue collections from Greece (n=85) with the four chloroplast primers perfectly matched with a previously reported classification. NFTCHL45 has 49 bp deletions between the Mediterranean and Continental morphotypes and is routinely used by the Noble Foundation core facility for the classification of the tall fescue morphotypes. The findings of this study will enhance tall fescue breeding by manipulating Mediterranean tall fescue for summer dormancy.