Promoting Effects of Piriformospora indica on Plant Growth and Development of Tissue-Cultured Cerasus humilis Seedlings

Piriformospora indica is a beneficial endophytic fungus that promotes plant growth and root development by colonizing plant roots. In order to investigate whether P. indica could promote the growth of tissue-cultured Cerasus humilis seedlings, in this study, we co-cultivated P. indica colony segments (P+) and P. indica spore suspensions (P++) in the rooting medium, and plant biomass as well as chlorophyll and root hormone contents of ‘3-19-3’ tissue-cultured C. humilis seedlings were determined under P+, P++, and CK (without fungus inoculation) treatments. The results showed that above-ground biomass and chlorophyll content of P+-and P++-treated tissue-cultured seedlings were significantly increased, and root peroxidase (POD), indole-3-acetic-acid (IAA) content, and root activities were significantly enhanced, while jasmonic acid (JA) and 1-aminocyclopropane-1-carboxylic acid (ACC) contents were reduced. Moreover, the growth-promoting effects of P++ treatment were found to be stronger than those of P+ treatment. Our results confirmed that P. indica was able to promote the growth of tissue-cultured C. humilis seedlings and effectively promoted root development by regulating hormone content. Therefore, the application of P. indica in the production of C. humilis is promising, especially in the cultivation of elite varieties.