Effects of Epichloë endophyte on the growth and nutritional quality of different geographic populations of Festuca sinensis

To investigate the effects of Epichloë endophyte on the growth and nutritional quality of different ecotypes of Festuca sinensis, six ecotypes of endophyte-infected (E+) and endophyte-free (E−) Festuca sinensis were established. The plant seeds were obtained from Qinghai and Sichuan provinces and compared for their growth (tiller, stem diameter, leaf width, plant height, fresh weight, and dry weight) and nutritional quality (crude fat, crude protein, crude ash, and moisture content) under pot cultures in a greenhouse. The results are as follows: 1) Epichloë endophyte had a significant impact on the height, tiller, stem diameter, fresh weight, crude fat, crude protein, and moisture content of ecotypes (P < 0.05), and these effects were different for different ecotypes. The height of ecotype 84 E+ was significantly higher than that of E− plants (P < 0.05), while the crude fat content of ecotypes 41 E+, 57 E+, and 141 E+ was significantly higher than that of the corresponding E− plants (P < 0.05). The crude protein content of ecotypes 41 E+, 99 E+, and 141 E+ plant was significantly higher than that of the corresponding E− plants (P < 0.05), and the moisture content of the ecotype 99 E+ was significantly higher than that of E− plants (P < 0.05). Moreover, tillering number was significantly lower for ecotype 57 E+ than that for E− plants (P < 0.05), while the stem diameter of ecotype 99 E+ was significantly lower than that of E− plants (P < 0.05). The height of ecotypes 57 E+ and 99 E+ was significantly lower than that of the corresponding E− plants (P < 0.05), and the crude protein content of ecotype 57 E+ was significantly lower than that of E− plant (P < 0.05). 2) Significant differences were reported in tiller, stem diameter, plant height, fresh weight, crude fat, and crude protein content among different geographical populations, while the performance of various groups was different (P < 0.05). Among the six endophyte-free (E−) F. sinensis populations, the tiller number of ecotype 57 was significantly higher than that of the ecotypes 84 and 99 (P < 0.05), and the crude protein content was significantly higher for ecotype 57 than that for the other five ecotypes (P < 0.05). The height of ecotype 111 was significantly higher than that of ecotypes 84 and 99 (P < 0.05), and the crude fat content of ecotype 111 was significantly higher than that of the ecotypes 41 and 99 (P < 0.05). Among the six endophyte-infected (E+) F. sinensis populations, ecotype 111 had significantly higher tiller number and stem diameter than the other five ecotypes (P < 0.05). Both fresh weight and dry weight of ecotype 141 were significantly higher than those of ecotypes 41 and 84 (P < 0.05), while the crude fat content of ecotypes 111 and 141 was significantly higher than that of ecotypes 41, 84, and 99 (P < 0.05). Comprehensive analysis of growth and nutrition indicators showed that ecotypes 57 and 111 were the best among the six endophyte-free (E−) F. sinensis populations, while ecotypes 111 and 141 were the best among the six endophyte-infected (E+) F. sinensis populations. In summary, the endophytic fungi promoted growth (84) and improved nutritional quality (41 and 141) or restrained growth (99) and reduced nutritional quality (57). Thus, the host genotype had a significant impact on the growth and nutritional quality of Epichloë endophyte-F. sinensis symbiont (P < 0.05).