The Effect of Seed-Borne Fungi and Epichloë Endophyte on Seed Germination and Biomass of Elymus sibiricus

Abstract

The interactive effects of asexual <i>Epichloë</i> (formerly known as <i>Neotyphodium</i>) endophytes isolated from <i>Hordeum brevisubulatum, Elymus tangutorum</i> and <i>Achnatherum inebrians</i>, and seed-borne fungi on <i>Elymus sibiricus</i> seeds, were determined by an <i>in vitro</i> study using supernatants from liquid cultures of the endophyte strains. In an 8 week greenhouse study, the effects on the seedlings growth was measured. The <i>in vitro</i> study was carried out with the seed-borne fungi <i>Alternaria alternata, Bipolaris sorokiniana, Fusarium avenaceum</i>, and a <i>Fusarium</i> sp. isolated from <i>E. sibiricus</i>. Different concentrations and combinations of the liquid cultures of endophytic fungi enhanced the interim germination, germination rate, length of coleoptile and radicle, and seedling dry weight of <i>E. sibiricus</i> under stress from seed-borne fungi. In the greenhouse study, different concentrations of the supernatant of the endophytes from <i>H. brevisubulatum</i> and <i>E. tangutorum</i> but not <i>A</i>. <i>inebrians</i>, signficantly (<i>P</i> < 0.05) enhanced <i>E. sibiricus</i> seed germination. There was no significant (<i>P</i> > 0.05) increase of the tiller numbers after 2 weeks. However, later on, there were significant (<i>P</i> < 0.05) increases in tiller number (4-8 weeks), seedling height (2-8 weeks) and dry weight (2-8 weeks). The application of <i>Epichloë</i> endophyte culture supernatants was an effective strategy to improve seed germination and growth under greenhouse conditions.