绿色高效青霉菌PQxj3菌剂的促生优势与广谱性分析OA

[Objective]This study was designed to evaluate the application potential of the plant growth-promoting rhizosphere fungus Penicillium PQxj3(hereinafter referred to as the growth-promoting strain PQxj3),thereby providing technical support for the development of efficient and green agricultural biological agents.[Method]Using the viable count as the indicator,single-factor experiments were designed with the liquid-to-solid ratio[V(H₂O/mL)∶m(bran/g)],temperature,incubation time,and inoculation mass fraction as influencing factors.Based on these results,the fer-mentation conditions of strain PQxj3 were further optimized using response surface methodology(RSM).A tobacco pot experiment was conducted to compare the PQxj3 agent along with three com-mercial microbial agents(a compound microbial agent,a Trichoderma harzianum agent,and a Delong PeiGen agent)by measuring fresh weight and root weight,thereby demonstrating its growth-promoting advantage.Furthermore,pot experiments on nine different crops(spinach,Shanghai pak choi,cucum-ber,mustard,cabbage,sesame,endive,onion,and fast-growing Chinese cabbage)were conducted to systematically analyze the broad-spectrum growth-promoting capability of the PQxj3 agent.[Result]The optimal solid-state fermentation conditions for strain PQxj3 were determined as follows:liquid-to-solid ratio of 92.9∶100.0,temperature of 22.8℃,incubation time of 15 days,and inoculation mass fraction of 2.5%.Under these conditions,the viable count reached 2.6×10⁹ cfu·g-1.The PQxj3 agent prepared under these optimized conditions increased the fresh weight and root weight of tobacco by 2.17 times and 4.29 times compared to the blank control group,respectively,significantly outperform-ing the commercial agents.The PQxj3 agent also significantly promoted the growth of spinach,Shang-hai pak choi,cucumber,mustard,cabbage,sesame,endive,onion,and fast-growing Chinese cab-bage,with the fresh weight of each treatment group increasing by 100.94%,138.45%,71.53%,178.53%,115.33%,140.90%,257.75%,46.23%,and 170.30%,respectively,compared with the blank control group.[Conclusion]After optimization of the fermentation process,the PQxj3 agent exhibits significant advantages in plant growth promotion and broad-spectrum applicability.