Effects of Potassium-Solubilizing Bacteria on Growth, Antioxidant Activity and Expression of Related Genes in Fritillaria taipaiensis P. Y. Li

This study aimed to examine the effects of inoculating Fritillaria taipaiensis P.Y.Li leaves with different strains of potassium-solubilizing bacteria (KSB), or combinations thereof, focusing on aspects of photosynthesis and physiological and biochemical characteristics. At present, some studies have only studied the rhizosphere microbial community characteristics of F. taipaiensis and have not discussed the effects of different microbial species on the growth promotion of F. taipaiensis. This paper will start from the perspective of potassium-solubilizing bacteria to conduct an in-depth study. Seed cultivation commenced at the base with three different KSBs in early October 2022. The growth of F. taipaiensis leaves was observed after different treatments. Both single-plant and compound inoculations were executed. A total of eight treatment groups were established, with aseptic fertilizer and sterilized soil functioning as the control group. The results reveal that intercellular CO₂ concentration (Ci), stomatal conductance (Gs), and transpiration rate (Tr) were at their apex in the S7 group. Most treatment groups exhibited an increase in leaf area, photosynthetic pigment content, soluble sugar, soluble protein, Superoxide Dismutase (SOD), Peroxidase (POD), Catalase (CAT) activities, and proline content. The expression levels of POD, SOD, and CAT genes were evaluated, following inoculation with different KSB. The highest was the S7 group. The inoculation with various KSB, or combinations thereof, appears to bolster the growth and development of F. taipaiensis. The composite inoculation group S7, comprising Bacillus cereus, Burkholderia cepacia, and Bacillus subtilis, manifested the most favorable impact on the diverse indices of F. taipaiensis, thereby furnishing valuable insights for the selection of bacterial fertilizer in the artificial cultivation of F. taipaiensis.