Influence of Epichloë coenophiala, a seed-borne endophyte, on the micropropagation of tall fescue

REGALADO GONZÁLEZ, J. J.; BERDION, V.; TOSSI, V. E.; IANNONE, L. J.; PITTA-ALVAREZ, S. I.; NOVAS, M. V.

MYCOLOGICAL PROGRESS

SPRINGER HEIDELBERG

Año: 2020 vol. 19 p. 1301 - 1308

1617-416X

Improving micropropagation success rate is important since this technique allows the development of other biotechnologicaltools, such as genetic transformation, in vitro polyploidization, or endophyte inoculation. This is particularlyrelevant for grasses, as they are traditionally considered recalcitrant to plant tissue culture. Grasses of thesubfamily Pooideae establish mutualistic associations with grass endophyte fungi of the genus Epichloë. Theseassociations are specific, as each host species is associated with one or few Epichloë species. Lolium arundinaceum(Schreb.) Darbysh. is a perennial C3 species, native to Europe, which has become an important cool season foragecrop worldwide. This grass usually establishes beneficial symbioses with E. coenophiala, but these benefits dependon both plant and fungal genetics and environmental conditions. Micropropagation protocols have been published forL. arundinaceum, but the influence of Epichloë endophytes was never examined. The aim of this manuscript was tostudy the effect of E. coenophiala on different micropropagation stages of L. arundinaceum and growth of theregenerated plantlets. Association with E. coenophiala (E+) increased callus induction, enhanced their proliferation,and increased shoot regeneration in L. arundinaceum. However, the biomass of plantlets regenerated from E+ seedswas lower than from non-associated seeds, both in vitro and ex vitro, and the in vitro multiplication rate alsodecreased. Contrary to other endophyte Epichloë-host associations with Lolium multiflorum and Bromus auleticus,the association with E. coenophiala did not improve tall fescue micropropagation. We can conclude that the effectsof Epichloë endophytes on micropropagation and growth of their host differ for each endophyte-host association.