Arbuscular mycorrhizal fungi (AMF) are widespread and specialized soil symbiotic fungi, and the establishment of their symbiotic system is of great importance for adversity adaptation. To reveal the growth and photosynthetic characteristics of AMF–crop symbionts in response to heavy metal stress, this experiment investigated the effects of Rhizophagus irregularis (Ri) inoculation on the growth, photosynthetic gas exchange parameters, and chlorophyll fluorescence characteristics of hemp (Cannabis sativa L.) at a Cd concentration of 80 mg/kg. The results showed that (1) under Cd stress, the biomass of each plant structure in the Ri treatment was significantly higher than that in the noninoculation treatment (P < 0.05); (2) under Cd stress, the transpiration rate, stomatal conductance, net photosynthetic rate, PSII efficiency, apparent electron transport rate and photochemical quenching coefficient of the Ri inoculation group reached a maximum, with increases ranging from 1% to 28%; (3) inoculation of Ri significantly reduced Cd enrichment in leaves, which in turn significantly increased the transpiration rate, stomatal conductance, electron transfer rate, net photosynthetic rate and photosynthetic intensity, protecting PSII (P < 0.05); and (4) by measuring the light response curves of different treatments, the light saturation points of hemp inoculated with the Ri treatment reached 1448.4 μmol/m²/s, and the optical compensation point reached 24.0 μmol/m²/s under Cd stress. The Ri–hemp symbiont demonstrated high adaptability to weak light and high utilization efficiency of strong light under Cd stress. Our study showed that Ri–hemp symbiosis improves adaptation to Cd stress and promotes plant growth by regulating the photosynthetic gas exchange parameters and chlorophyll fluorescence parameters of plants. The Ri–hemp symbiosis is a promising technology for improving the productivity of Cd-contaminated soil.

丛枝菌根真菌(AMF)是一种分布广泛、特化的土壤共生真菌,其共生系统的建立对逆境适应具有重要意义。为揭示AMF-作物共生体在重金属胁迫下的生长和光合特性，本试验研究了接种不规则根霉(Ri)对大麻( Cannabis sativa L ) 生长、光合气体交换参数和叶绿素荧光特性的影响。.) Cd 浓度为 80 mg/kg。结果表明：（1）在Cd胁迫下，Ri处理各植物结构的生物量显着高于未接种处理（P < 0.05); (2)在Cd胁迫下，Ri接种组的蒸腾速率、气孔导度、净光合速率、PSII效率、表观电子传递速率和光化学猝灭系数达到最大值，增加幅度为1%~28%；(3) 接种Ri显着降低了叶片中Cd的富集，进而显着提高了蒸腾速率、气孔导度、电子传递速率、净光合速率和光合强度，保护了PSII ( P  < 0.05)；(4)通过测量不同处理的光响应曲线，接种Ri处理的大麻光饱和点达到1448.4 μmol/m ² /s，光学补偿点达到24.0 μmol/m ²/s 在 Cd 应力下。Ri-hemp共生体在Cd胁迫下表现出对弱光的高度适应性和强光的高利用效率。我们的研究表明，Ri-hemp 共生通过调节植物的光合气体交换参数和叶绿素荧光参数来提高对 Cd 胁迫的适应并促进植物生长。Ri-hemp 共生是一种很有前途的技术，可以提高 Cd 污染土壤的生产力。