AM Fungi and Piriformospora indica Improve Plant Growth of Pinus elliottii Seedlings

Pinus elliottii is an exotic afforestation pine extensively distributed insouthern parts of China. In order to understand whether endophytic fungi canaffect seedling growth of P. elliottii, Piriformospora indica (Pi), Funnelifcrmismosseae (Fm), and Diversispora tortuosa (Dt) were inoculated respectively,and the non-inoculated group was set as control. The growth indexes, the contentsof soluble sugar and soluble protein, and plant endogenous hormone levels in theleaves of P. elliottii, were analyzed. The results showed that Fm, Dt and Pi colonizedthe P. elliottii roots to form mycorrhizal structure and chlamydosporesarranged in beads respectively. Three fungal inoculants exhibited the stimulatedgrowth responses, whilst Dt illustrated the most positive effect on plant height, singlefresh weight, trunk diameter and root system structure, compared with the control.On the other hand, the soluble sugar and soluble protein contents wereincreased distinctively in mycorrhizal plants. The endogenous IAA, GA3, ZR contentswere increased, while the ABA contents were reduced in mycorrhizal plantsversus non-mycorrhizal plants. The fungi-induced endogenous hormone changestriggered plant growth improvement of P. elliottii seedlings. This research unraveledthe positive effect of AM fungi and P. indica on growth of pine seedlings, while,more application of endophytic fungi to fields needs to be explored.