Alleviatory effect of spent Pleurotus eryngii Quel substrate on replant problem of Rehmannia glutinosa Libosch

ABSTRACT

Rehmannia glutinosa Libosch. is a medicinal plant cultivated at a commercial scale in China. However, replanting problems result in a severe decline in both the biomass and quality of its roots, which are of greatest medicinal value. This study attempted to remediate the replant soil using spent Pleurotus eryngii Quel substrate for alleviating this issue, and to investigate the underlying mechanisms. Results showed that R. glutinosa grew successfully in fresh soil and remedial replant soil, while no roots were harvested in the unremedied replant soil. Overall, the nutritional status in the remedial soil was higher than that of the unremedied and fresh soil, while the concentration of allelopathic phenolic acids was lower. When planted in unremedied soil, the growth of five plant pathogens was induced and one beneficial fungus was suppressed. When planted in remedied soil, four out of the five pathogens were suppressed, while two beneficial fungi were identified in the remedial soil. This study suggests that the spent P. eryngii substrate significantly alleviates the replant problem of R. glutinosa, and that the alleviatory function reflects a synergetic effect, including the supplementation of soil nutrition, the degradation of allelochemicals, and the remediation of unbalanced microbial community.

KEYWORDS:

• Rehmannia glutinosa Libosch
• spent Pleurotus eryngii Quel substrate
• alleviatory effect
• replant problem

Conflicts of interest

The authors have guaranteed that there are no conflicts of interest.

Additional information

Funding

This work was supported by grants from the National Science Foundation of China under grants 30772729 and 81274022 and the Scientific Research Foundation of Graduate School of Fujian Agriculture and Forestry University under grant 324-1122yb028.