Correlations of polysaccharide and flavonoid contents in Prunella vulgaris L. with main environmental factors and high-quality provenance screen

Objective  To explore the quality differences of wild Prunella vulgaris L. from different geographical provenances, reveal the main environmental factors that affect the medicinal ingredient contents of P. vulgaris, and provide a theoretical support for the rational development and effective protection of P. vulgaris germplasm resources.

Method  Taking ten geographical provenances of P. vulgaris distributed in different regions as the research object, the differences of polysaccharide and flavonoid contents were compared and analyzed, and the correlations of polysaccharide and flavonoid contents with environmental factors were studied by Pearson correlation analysis. The cluster analysis and membership function evaluation method were used to select high-quality geographical provenance.

Result  The polysaccharide and flavonoid contents of P. vulgaris from different geographical provenances were significantly different. The polysaccharide content ranged from 70.45 to 120.39 mg·g⁻¹, and the flavonoid content ranged from 34.40 to 59.04 mg·g⁻¹. The polysaccharide content of the provenance in Yichang of Hubei and the flavonoid content of the provenance in Guilin of Guangxi were the highest, with the content reaching 120.39 and 59.04 mg·g⁻¹, respectively. The polysaccharide content in P. vulgaris showed a highly significant negative correlation with the flavonoid content. The main environmental factors affecting the polysaccharide content of P. vulgaris were latitude, longitude and altitude; And the main environmental factors affecting the flavonoid content were longitude, altitude, annual average air temperature, annual sunshine hour and annual precipitation. The clustering results divided the ten geographical provenances into three categories. The provenance in Guilin of Guangxi had the largest average membership function value and the best comprehensive quality among all the provenances.

Conclusion  There were significant differences in the contents of medicinal ingredients in P. vulgaris from different geographical provenances. Different environmental factors have inconsistent effects on the major medicinal ingredients. The better-quality geographical provenances and ranking of different geographical provenances can provide a basis for the selection, development and utilization of P. vulgaris germplasm resources.