Effect of soil pH on efficiency of mycorrhizal symbiosis on Salvia miltiorrhiza

Abstract

By comparing the effects of soil pH on the efficiency of mycorrhizal symbiosis on Salvia miltiorrhiza， the study is aimed to provide guidance for the use of mycorrhiza in the cultivation of S. miltiorrhiza. In this experiment, the inoculant treated and the non-inoculant treated control were grown in different soil pH. The data was collected after 60 days of cultivation including rate of mycorrhizal infection, biomass, and three chemical constituents with known medicinal action. The results showed that Glomus versiforme was more apt to infect S. miltiorrhiza (F>94.00%; M>69.45%; m>73.66%) and promote the growth of S. miltiorrhiza under pH 5-9 soil. The mycorrhizal contribution to the growth of S. miltiorrhiza was the highest when grown in pH 8 soil. Plants grown with mycorrhiza in pH 8 soil had above-ground biomass more than 2 times and root biomass more than 5 times. The uninoculated plants grew better under acidic and neutral conditions, but the inoculated plants grew better under alkaline (pH 8) conditions. This result showed mycorrhiza can play a role in the adaptability of S. miltiorrhiza to the environment. Inoculation of mycorrhiza significantly increased the accumulation of rosmarinic acid, salvianolic acid B, and dihydrotanshinone by 6.59,5.03 and 2.20-folds. Based on our results alkaline soil (pH 8) is most suitable for the cultivation of S. miltiorrhiza by inoculation with the mycorrhiza G. versiforme.