Effects of fungal endophytes on agronomic characteristics and yield of wild barley forage under different water gradients

The purpose of this study was to explore the effects of different water conditions and endophytic fungal interactions on the growth, development, and yield of the forage grass Hordeum brevisubulatum (wild barley). The maximum field capacity, expressed as field water content (FWC), was simulated by greenhouse pot planting. Six water gradients (50%, 60%, 70%, 80%, 90%, and 100% FWC) were established to treat Hexi wild barley with endophytic fungi (E+) and without endophytic fungi (E–), and with Saertu wild barley (SA). Agronomic indices of wild barley, including plant height, number of tillers, leaf length, stem diameter, leaf area, chlorophyll content, root length, and dry weight, initially increased and then decreased with increasing water content. The maximum value of each material was obtained with 80% FWC treatment. No significant differences were evident between 70% FWC and 80% FWC. Analyses of different materials using the same water treatment revealed that forage indices, such as stem diameter, number of tillers, plant height, leaf length, leaf area, and aboveground dry weight of Hexi wild barley, were better than those of the control group SA. The aboveground dry weight of E+ wild barley was 8.90% and 38.38% higher than that of E– and SA, respectively. Interactions between different water treatments and endophytic fungi significantly influenced the growth of wild barley materials (P < 0.01). The collective findings reveal that 70% and 80% FWC was a suitable water content range for the growth of wild barley; 80% FWC was best in agronomic indices, whereas 70% FWC was water-saving and efficient. Wild barley displayed some tolerance to waterlogging in the process of growth and development. Hexi wild barley with endophytic fungi was a more dominant forage variety in this study.