Arbuscular mycorrhizal fungi promote early flowering and prolong flowering in Antirrhinum majus L. by regulating endogenous hormone balance under field-planting conditions

Abstract

It is well documented that arbuscular mycorrhizal fungi (AMF) affect growth and nutrient absorption in host plants under pot conditions. However, their effects on reproductive growth in ornamental plants under field conditions are unknown. Our study evaluated the effects of AMF on flowering and physiological traits in snapdragon (Antirrhinum majus) under greenhouse field conditions. Seedlings were inoculated with Funneliformis mosseae (Nicolson & Gerd.) and without as controls. Results showed that AMF inoculation significantly increased plant height, stem diameter, phosphorus, and soluble protein; decreased soluble sugar; and had no effect on total nitrogen, carbon, and potassium. AMF colonization increased concentrations of abscisic acid (ABA), indol-3-acetic acid (IAA), gibberellin (GA3), and zeatin riboside (ZR); increased the ZR/IAA ratio; and reduced ABA/GA3 and ABA/IAA+GA3+ZR ratios. AMF advanced flowering by five days and prolonged flowering by 13 days. Our study showed that AMF can promote flowering and prolong flowering in snapdragon, which may be due to the improvement of endogenous hormone equilibrium.