Allochthonous Isolates Boost Herb Quality at the Cost of Rhizome Growth.

is a perennial herb whose rhizome (AR) is a valuable traditional Chinese medicine with immense market demand. The cultivation of faces outbreaks of root rot and deterioration in herb quality due to complex causes. Here, we investigated the effects of spp., well-known biocontrol agents and plant-growth-promoters, on ARs. We isolated strains from healthy ARs collected in different habitats and selected three . strains (Th2, Th3 and Th4) with the strongest antagonizing effects on root rot pathogens ( spp.). We inoculated geo-authentic . plantlets with Th2, Th3 and Th4 and measured the biomass and quality of 70-day-old ARs. Th2 and Th3 promoted root rot resistance of . . Th2, Th3 and Th4 all boosted AR quality: the concentration of the four major medicinal compounds in ARs (atractylon, atractylodin, hinesol and β-eudesmol) each increased 1.6- to 18.2-fold. Meanwhile, however, the yield of ARs decreased by 0.58- to 0.27-fold. Overall, Th3 dramatically increased the quality of ARs at a relatively low cost, namely lower yield, showing great potential for practical application. Our results showed selectivity between and allochthonous isolates, indicating the importance of selecting specific microbial patches for herb cultivation.