Effects of environmental factors on anthocyanin accumulation in the fruits of Lycium ruthenicum Murray across different desert grasslands

Abstract

Anthocyanins can help plants adapt and resist adverse environments and have important nutritional and medicinal effects on human beings. However, how environmental factors affect the anthocyanins accumulation of plants and how to improve the anthocyanins content of plants in different soils needs further exploration. Hence, this study aimed to investigate the effects of environmental factors on the accumulation of cyanidin, petunidin, malvidin, and delphinidin in the fruits of Lycium ruthenicum in sandy desert grassland (SS), gravel desert grassland (GD), and saline-alkali desert grassland (SD) in the lower reaches of the Shiyang River Basin. The variable importance screened the key environmental factors affecting anthocyanin accumulation in projection (VIP) and multiple stepwise regressions. The structural equation model (SEM) was established to understand how the climate and soil factors affect the total anthocyanin accumulation. For establishing soil nutrient optimization schemes by partial least squares regression (PLS) and the simplex algorithm used to improve the anthocyanin content in different types of desert grassland. In SS, electrical conductivity (EC) and microbial biomass carbon (SMBC) showed highly significant and positive effects on the content of total anthocyanin, cyanidin, and petunidin. In GD, soil moisture and microbial biomass nitrogen (SNBN) significantly negatively affected total anthocyanin content. In SD, catalase (CAT), phosphatase (PHO), and total potassium (TK) had the greatest impact on total anthocyanin content. It is indicated that the targeted improvement measures are necessary to increase anthocyanin content in the fruit of Lycium ruthenicum.

Keywords: Climate and soil factors; Desert grassland; Endemic desert plant; Partial least squares regression; Soil nutrient optimization scheme.