The effect of different doses of potassium solubilizing bacteria on the growth and development of Dianzhonglou
Paris polyphylla var. yunnanensis has attracted attention from all walks of life for its anti-inflammatory, analgesic, heat clearing, detoxifying, and liver cooling effects. As one of the main production areas for cultivating Paris polyphylla var. yunnanensis, its artificial cultivation has become a unique biological resource and economic pillar industry in the southwestern region of China. Due to the increasing demand in the pharmaceutical industry, wild Paris polyphylla var. yunnanensis resources have been decreasing year by year and are increasingly on the brink of depletion. In order to alleviate the supply-demand contradiction in the market, the planting area of Paris polyphylla var. yunnanensis has been increasing year by year. In order to avoid serious pests and diseases, low yield, and quality degradation in the cultivation of Paris polyphylla var. yunnanensis, and to maintain the sustainable development of the planting area, growers have improved the yield and quality of Paris polyphylla var. yunnanensis through various agricultural biotechnology methods.
Potassium is one of the essential nutrients for plant growth, which has a significant impact on energy and material metabolism in plants. The available potassium in soil that can be utilized by plants is 2% of the total potassium content. Improving the effectiveness of potassium in soil is one of the effective ways to increase plant yield. Potassium in soil mostly exists in the form of fixed potassium and mineral potassium, which cannot be directly absorbed by plant roots, becoming a major obstacle to the potassium nutrition required for plant growth. Potassium solubilizing bacteria, also known as potassium bacteria, are a common type of plant rhizosphere growth promoting bacteria that can convert and decompose mineralized potassium in soil into soluble potassium substances, improve the microecological environment of rhizosphere soil, increase the content of available potassium in soil, promote plant growth, yield and quality improvement, enhance plant disease resistance, etc. This is because potassium solubilizing bacteria in plant rhizosphere can produce secretions that promote soil microbial activity. Previous studies on the regulation of potassium solubilizing bacteria on the growth and development of tobacco have shown that moderate application of potassium solubilizing bacteria can effectively increase agronomic traits such as plant height, stem circumference, effective leaf number, maximum leaf length, and maximum leaf width of tobacco, resulting in varying degrees of increase in total nitrogen and potassium content in plant leaves, significantly improving the yield and economic value of tobacco, and enhancing its quality. Therefore, potassium solubilizing bacteria can be used as microbial fertilizers to promote plant growth, increase plant potassium absorption, reduce fertilizer usage, and promote sustainable agricultural development.
So far, the decomposition effect of potassium solubilizing bacteria on mineralized potassium in soil has gradually attracted the attention of scholars. Using the interaction between plants and potassium solubilizing bacteria to regulate the effectiveness of potassium in plant rhizosphere and convert mineralized potassium into available potassium has become a current research hotspot. However, research on the promoting effect of potassium solubilizing bacteria on plants is mainly focused on potassium loving crops such as potatoes and tobacco, and there are few studies on the impact of potassium solubilizing bacteria on the growth and development of medicinal plants. There are few reports on the growth and development of Dianzhong Lou medicinal materials by potassium solubilizing bacteria. This study used Dianzhong Lou seedlings as indicator plants and applied potassium solubilizing bacteria as experimental subjects to investigate the effects of different doses of potassium solubilizing bacteria on the growth, development, and medicinal quality of Dianzhong Lou seedlings. The optimal inoculation amount of potassium solubilizing bacteria was found to provide a theoretical basis for the application of potassium solubilizing bacteria in Dianzhong Lou cultivation and production.

Compared with CK, inoculation of potassium solubilizing bacteria during the seedling stage of Dianzhong lou can significantly improve its root vitality, promote the increase of Chl, Car, soluble protein and soluble sugar content in leaves, reduce the activity of protective enzymes (SOD, POD and CAT) and MDA content in leaves. It can be seen that inoculation of potassium solubilizing bacteria during the seedling stage of Dianzhong lou can effectively maintain the stability of the cell membrane system, thereby promoting the growth and development of Dianzhong lou plants. Among them, inoculation with 35.00g of potassium solubilizing bacteria had the best promoting effect on the growth of Dianzhong Lou seedlings, followed by the regulating effect of 17.50g of potassium solubilizing bacteria. Vaccination with potassium solubilizing bacteria during the seedling stage of Dianzhong Lou can significantly increase the potassium content in both old and new rhizomes, promote the increase of nutrient elements Mn, Mg, and Zn content in both rhizomes, while the content of heavy metals Pb, Cu, As, and Cd generally decreases. This indicates that inoculation with potassium solubilizing bacteria during the seedling stage of Dianzhong Lou can promote the accumulation of beneficial nutrients in its rhizomes, reduce heavy metal content, and enhance the medicinal value of Dianzhong Lou rhizomes.