Phosphorus and iron in soil play dominating roles in regulating bioactive compounds of Glechoma longituba (Nakai) Kupr

Soil is the natural medium for plant growth, and its chemical property is one of the most important factors for metabolic process of phytochemicals. Therefore, revealing the soil chemical property-crop effects will strongly improve the cultivation technology for higher yield and quality. Glechoma (G.) longituba has been long treated as a dedicated edible and medicinal herb. Here, the relationships between soil chemical properties and bioactive compounds of G. longituba were analyzed, and the effects of the most two related soil indicators on the plant were investigated and evaluated. The soil from thirty G. longituba provenances with different chemical properties were selected to test their effects on G. longituba. Based twelve soil indicators, the elements of phosphorus (P) and iron (Fe) were screened out as the most primary influential factors attributing to the high fluctuations of the contents of bioactive compounds. Through a factorial design of P and Fe by five different levels, significant influences of P, Fe, and their interaction on the bioactive compounds and biomass of G. longituba were validated. All the contents of the bioactive compounds in G. longituba expressed the same trend, which increased firstly and then decreased with the growing additions of P or Fe, but were slightly different in the peak levels. In all, the optimum extra addition was the combination of 0.9 g kg(-1) P and 00.24 g kg(-1) Fe. These findings could theoretically elucidate the connections between soil chemicals and bioactive compounds, and provide targeted cultivated strategies for improving the biological yield and medicinal quality of G. longituba.