RESUMO
Objective: To study the effect of the inoculation time of arbuscular mycorrhizal (AM) fungi on endogenous hormone content in Paris polyphylla var. yunnanensis seedlings. Methods: The indoor pot test was applied. The seeds, one-year-old seedlings, and two-year-old seedlings of P. polyphylla var. yunnanensis were inoculated by different mixed AM fungi and cultivated in the sterilized soil matrix respectively. The contents of endogenous hormone zeatin riboside (ZR), gibberellin (GA), indole acetic acid (IAA) and abscisic acid (ABA) were determined by HPLC. Results: The results showed that the endogenous hormone (ZR, GA, IAA and ABA) contents in rhizome and fibrous roots of P. polyphylla var. yunnanensis from different regions or different time inoculated by mixed AM fungi were various. As a whole, the contents of endogenous hormone ZR and GA increased obviously in the rhizome and fibrous roots of the wild and cultivated P. polyphylla var. yunnanensis compared with the control group (CK), while the content of ABA reduced. The IAA/ABA value, GA/ABA value and ZR/ABA value increased obviously in the rhizome and fibrous roots of P. polyphylla var. yunnanensis. Conclusion: The one-year-old of P. polyphylla var. yunnanensis inoculated with S2 and S6 mixed AM fungi showed the best comprehensive effect for promoting growth of the rhizome and fibrous roots of P. polyphylla var. yunnanensis seedlings.