Abstract: To elucidate the root phosphorus (P) acquisition strategies of Phyllostachys edulis to maintain high productivity under P deficiency, we conducted an in situ P addition experiment (0, 50, 100 kg P·hm^-2·a^-1 defined as CK, low-P (LP), and high-P (HP) addition). We investigated the regulatory effects of P addition on morphological and physiological traits of rhizome root, root exudates, and mycorrhizal symbiosis characteristics. The results showed that P addition significantly increased specific root surface area (LP:19.1%; HP:23.4%), root nitrogen (LP:42.6%; HP:37.7%) and P contents (LP:83.8%; HP:115.3%), but significantly decreased phosphatase activity (LP:22.2%; HP:30.4%) and arbuscular mycorrhizal fungi (AMF) infection rate (LP:24.1%; HP:25.3%). There were no significant differences between low-P and high-P treatments for these impacts. P addition significantly increased rhizosphere soil pH, citrate-P, enzyme-P, HCl-P and microbial biomass carbon, nitrogen and P in the rhizosphere soil. Notably, citrate-P, enzyme-P, and HCl-P contents in HP treatment were significantly higher than those in LP treatment. There were significant correlations between rhizosphere soil P fractions and specific root surface area, phosphatase activity, as well as AMF infection rate, indicating that rhizosphere soil P fractions were important drivers of P acquisition pathways in rhizome roots. Under P addition, rhizome roots shifted from a conservative pathway relying on “root exudation and mycorrhizal symbiosis” to an acquisitive pathway characte-rized by “high surface area”.

Key words: Moso bamboo, root morphological trait, arbuscular mycorrhizal fungi, root exudate, phosphorus fraction