Effects of mycorrhizae on sorghum growth, photosynthesis, and stomatal conductance under drought conditions

In this study, we determined whether inoculating sorghum (Sorghum bicolor(L.) Moench cv NK‐367) seedlings with a vesicular arbuscular mycorrhizal (VAM) fungus (Glomus intraradices Schenck and Smith) would enhance plant yield under drought conditions. Seven‐day‐old seedlings were inoculated with the fungus and irrigated to field capacity for an additional 7 days. Daily irrigation treatments of I1 (dry, ‐0.56 to ‐1.4 MPa), I2 (moderately dry, ‐0.15 to ‐0.48 MPa), and I3 (wet, ‐0.03 to ‐0.06 MPa) were then imposed with a line‐source sprinkler. Under moderately dry soil conditions, growth, photosynthetic rate, and stomatal conductance of G. intraradices‐colonized sorghum plants were significantly greater than in uncolonized plants. Results indicate that the VAM fungus enhanced yield of sorghum plants under drought conditions.