Effects of Piriformospora indica on rooting and growth of tissue-cultured banana (Musa acuminata cv. Tianbaojiao) seedlings

Piriformospora indica is a plant growth- and disease resistance-promoting fungus in the Sebacinales family. In this study, the effect of this symbiotic fungus on the growth of tissue-cultured banana seedlings was investigated to explore its potential applications in the banana tissue culture industry. P. indica plugs (P-1) and a P. indica chlamydospore suspension (P-2) were co-cultured with banana seedlings in rooting medium to investigate their growth-promoting efficiency. Both the P-1 and P-2 treatments improved the plant biomass and chlorophyll contents of banana seedlings. The P-2 treatment had stronger promoting effects than the P-1 treatment, especially on plant height and root length in the first 3 weeks. At 4 weeks after inoculation, seedlings in the P-1 and P-2 treatments showed increased plant height, more and longer roots, increased shoot fresh weight, leaf width and length, and stem circumference compared with controls. The P. indica treatments also significantly enhanced the chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid contents in banana leaves. The results of this study verified that the fungus can facilitate the growth of banana seedlings in vitro and shorten the rooting time of tissue-cultured banana seedlings. Therefore, it has the potential to improve the growth and quality of tissue-cultured banana plants.