Variation in bioactive compounds of Glechoma longituba and its influential factors: Implication for advanced cultivation strategies

Glechoma longituba is a widespread crop in China. With high concentrations of many bioactive compounds, it has long been treated as a health beneficial ingredient for human diet and even some medicine. In order to gain comprehensive understandings of current resources of Glechoma longituba, samples from seventeen geographical origins in fifteen Chinese provinces were collected to reveal the connections between different influence factors and certain bioactive compounds. Firstly, high variations in the contents of ethanol-soluble extracts, total flavonoid, chlorogenic acid, caffeic acid, rosmarinic acid, oleanolic acid and ursolic acid were proved among different Glechoma longituba populations. Totally four parameters of soil physical properties, twelve parameters of soil chemical properties, thirty years’ climate records and genetic diversity among different Glechoma longituba populations were thoroughly investigated. As a result, soil chemical property and climate condition with significant correlation between each other were both indicated to have the strongest positive correlations with bioactive compounds of Glechoma longituba, among which soil phosphorus, soil iron, temperature and moisture were showed to act as key factors. Neither the genetic variation nor the soil physical property was significantly related to the concentrations of bioactive compounds. These results laid the first theoretical foundation for further study of how to improve the quality of Glechoma longituba resources, as well as provided guidance for breeders to focus more on choosing planting areas with ideal climate conditions and modulating the optimum soil chemical properties for better Glechoma longituba cultivation.