Effects of interaction of Epichloë gansuensis and Bacillus strains on the seed germination and seedling growth in Achnatherum inebrians plants

Abstract

Abstract Previous studies have confirmed that Bacillus and also Epichloë fungal endophytes can promote seed germination of grasses and induce stress resistance. However, the effects of interactions between Bacillusand endophyte on seed germination and seedling growth of grasses have not been well studied. In this study, Epichloë gansuensis endophyte-infected and endophyte-free Achnatherum inebrians seeds, and two month old seedlings, were inoculated with 12 Bacillus strains, and then effects of the treatments on four germination indicators and eight growth parameters were determined. The results showed that the interaction between E. gansuensis and Bacillus strains significantly (P<0.05) increased seed germination and the growth of A. inebrians. Interestingly, Bacillus strain inoculation, except for strain B96, provided a greater increase in growth on the 2-3 month old seedlings than the increase of growth with young seedlings. The germination rate of A. inebriansinoculated with the 12 strains ranged from 93.7% to 99%. Compared with other strains, B18 and B419 showed greater increases in growth of 2-3 months old plants. Moreover, the study employed a membership function value to assess the growth-promoting ability of the 12 Bacillusstrains on A. inebrians as an integrative tool for screening strains. Among the 12 strains, the B419 strain showed the best growth-promoting ability, while B106 was the worst strain. These results indicate that the B419 strain has potential value in agricultural production, and mechanisms of plant growth promotion will be further studied.