Objective In this study, the biocontrol potential of Trichoderma koningiopsis T222 was analyzed, which provide basic materials for the development and utilization of high-efficiency biological fertilizer.

Method T. koningiopsis T222 strain was isolated and identified by plate method, and its antagonistic ability against different pathogens were analyzed by confrontation experiment. The sporulation ability under different culture conditions were analyzed by cross method. The growth promoting and disease resistance ability of T222 to poplar seedlings were analyzed by root application of its conidia suspension. The expression patterns of resistance and growth related genes in poplars that induced by T222 strain were analyzed by fluorescent quantitative PCR.

Result (1) A T. koningiopsis T222 strain was isolated in this study and it was shown a high inhibition rate against six pathogens by the confrontation test. (2) T222 strain exhibits strong adaptability and high spore yield, capable of growth and sporulation across temperatures ranging from 5 to 30 ℃ and on five carbon source media. It produces the highest spores on PDA medium, reaching approximately 2.51 × 10¹⁰ (piece/dish) after cultvation at 30 ℃ for 6 days. (3) Root application of different spore concentrations of T222 conidia suspension improved the resistance of poplar to Alternaria alternate, the lesion area of poplar leaves which treated with 1.5 × 10⁹ cfu/mL T222 conidia suspension, were decreased by 84.11%, compared with the control. (4) Root application of different concentrations of T222 conidia suspension could effectively improve the growth of poplar seedlings and significantly increased the root numbers of poplar seedlings (p < 0.05). (5) Fluorescent quantitative PCR showed that root application of T222 spore suspension induced the expressions of genes related to disease resistance and auxin signal pathway in poplar.

Conclusion T. koningiopsis T222 exhibits strong adaptability and high spore yield, with high inhibition rates against various pathogens, possesses goodth promoting and disease resistant functions for poplars, which holds application potential for biological control in forest disease prevention.