Effects of two AMF combinations on leaf growth and photosynthetic efficiency of <italic>Lycoris radiata</italic>

<bold>Objective</bold> This study aims to examine the impact of inoculating <italic>Lycoris radiata</italic> with arbuscular mycorrhizal fungi（AMF）on its growth and photosynthetic efficiency，in order to screen good strains suitable for the cultivation of <italic>L. radiata</italic>. <bold>Method</bold> The Potted <italic>L. radiata</italic> was cultivated in an artificial climate chamber（25/20 ℃）.Two types of AMF，<italic>Funneliformis mossea</italic>e（FM）and <italic>Rhizophagus intraradices</italic>（RI），were used as test inoculants，and three AMF inoculation treatments（FM，RI，and FM+RI）were adopted，with no inoculation treatment as the control（CK）.The root infection rate，leaf growth and photosynthetic physiological indexes were measured respectively. <bold>Result</bold> The results showed that：（1）AMF can form a beneficial symbiotic relationship with <italic>Lycoris radiata</italic>.The average root infestation rate of the three AMF treatments was 83.55%，with the mixed double inoculation treatment（FM+RI）having the highest root infestation rate（up to 87%）.（2）Different AMF inoculation treatments had a significant promoting effect on the leaf growth of <italic>L. radiata</italic>.Compared with the control group（CK），the average maximum leaf length in the FM，RI，and FM+RI groups increased by 5.04%，6.85%，and 18.89%，respectively.（3）Under the conditions of 25/20 ℃，the leaves of the four treatments were always in a “constantly renewing” state.（4）All three AMF inoculation treatments were effective in increasing the relative chlorophyll content，light energy utilisation and leaf stomatal exchange capacity of <italic>L. radiata</italic>，and reducing energy loss.Among them，FM+RI was the most effective，which increased the relative chlorophyll content，the actual photosynthetic efficiency of PSΠ，the photochemical quenching coefficient，the photosynthetic electron transfer rate，the net photosynthetic rate，the stomatal conductance，and the water utilisation by 9.89%，42.5%，25.91%，37.93%，50.00%，22.33%，and 75.53%，respectively，compared with that of CK.It also significantly reduced the non-photochemical quenching coefficient（54.68%）and intercellular CO₂ concentration（30.03%）.（5）The effects of different inoculation treatments on leaf growth and photosynthetic efficiency of <italic>L. radiata</italic> were in the order of FM + RI &gt; FM &gt; RI &gt; CK. <bold>Conclusion</bold> The three AMF treatments were effective in infesting the root system of <italic>L. radiata</italic>，and they also significantly promoted the elongation growth of the leaves and the improvement of the photosynthetic efficiency of <italic>L. radiata</italic>.Among them，the mixed treatment group（FM+RI）showed the best combined effect，which can be considered to be applied in the production and cultivation of <italic>L. radiata</italic> in the future.