Effects of Native Arbuscular Mycorrhizae Isolated on Root Biomass and Secondary Metabolites of Salvia miltiorrhiza Bge

Abstract

Arbuscular mycorrhiza fungi (AMFs) are a group of soil-dwelling fungi that form symbiotic associations with plants, to mediate the secondary metabolism and production of active ingredients in aromatic and medicinal plants. Currently, there is little research on <i>Salvia miltiorrhiza</i> Bge. inoculation with native AMFs and the concomitant effects on growth and secondary metabolites. In this study, <i>S. miltiorrhiza</i> was treated with eight AMFs, i.e., <i>Glomus formosanum</i>; <i>Gl. tenebrosum</i>; <i>Septoglomus constrictum</i>; <i>Funneliformis geosporum</i>; <i>Rhizophagus manihotis</i>; <i>Ambispora gerdemanii</i>; <i>Acaulospora laevis</i>; <i>Ac. tuberculata</i>, to investigate the influence of AMF inoculation on biomass and secondary production under greenhouse conditions in <i>S. miltiorrhiza</i> roots. The results showed that mycorrhiza formation rates were between 54.83 and 86.10%. Apart from <i>Ac. laevis</i> and <i>Gl. tenebrosum</i> treatment, the roots biomass of the other treatment groups was effectively increased, and the fresh and dry weight of the plant inoculated with <i>Fu. geosporum</i> were increased by 86.76 and 86.95%, respectively. Specifically, AMF treatments also impacted on phenolic acids production; inoculation with both <i>Fu. geosporum</i> or <i>Ac. laevis</i> significantly reduced total phenolic acids, whereas the other treatments effectively increased these levels, of which <i>Gl. formosanum</i> generated significant levels. Most AMF-plant symbiotic experiments facilitated phenolic acid accumulation in the secondary metabolites of <i>S. miltiorrhiza</i> (except <i>Ac. laevis</i>). This study showed that most native AMFs inoculation with <i>S. miltiorrhiza</i> promoted roots growth and increased secondary metabolites production (especially phenolic acids). Going forward, inoculation of native AMF is a promising method to improve the quality and yield of <i>S. miltiorrhiza</i> and should be considered during production.