Arbuscular mycorrhizal fungi alter the response of growth and nutrient uptake of snap bean (Phaseolus vulgaris L.) to O_3

摘要

The effects of arbuscular mycorrhizal fungi (AMF) Glomus mosseae on the responses to elevated O_3 in growth and nutrition of snap bean (Phaseolus vulgaris L. cv Guangzhouyuan) were investigated. Exposure was conducted in growth chambers by using three O_3 concentrations (20 (CF), 80 (CFO1) and 120 nL/L (CFO2); 8 hr/day for 75 days). Results showed that elevated O_3 slightly impacted overall mycorrhizal colonization, but significantly decreased the proportional frequency of hypha and increased the proportional frequency of spores and vesicles, suggesting that O_3 had significant effects on mycorrhizal structure. Elevated O_3 significantly decreased yield, dry mass and nutrient contents (N, P, K, Ca and Mg) in both non-mycorrhizal and mycorrhizal plants. However, significant interactive effects were found in most variables due to that the reduction by O_3 in the mycorrhizal plants was less than that in the non-mycorrhizal plants. Additionally, AMF increased the concentrations of N, P, Ca, and Mg in shoot and root. It can be concluded that AMF alleviated detrimental effects of increasing O_3 on host plant through improving plant nutrition and growth.