The invention provides a
penicillium oxalicum strain K3R2 and a preparation method and application of a
biological agent of the
penicillium oxalicum strain K3R2. The biocontrol bacterium
Penicillium oxalicum strain K3R2 screened by the invention is preserved in the China General
Microbiological Culture Collection Center on September 25, 2025, the preservation number is CGMCC NO.42219, and the preservation address is Institute of
Microbiology, Chinese Academy of Sciences, No. 3, No.1
yard, Beichen West Road, Chaoyang District, Beijing; the ITS sequence of the
Penicillium oxalicum strain K3R2 is as shown in SEQ ID NO: 1, and the
CaM sequence is as shown in SEQ ID NO: 2. The
penicillium oxalicum strain K3R2 provided by the invention can inhibit
hypha growth and
spore germination of beet neocam spores, the
hypha inhibition rate is 83.60%, the
spore inhibition rate is 65.31%, and the
penicillium oxalicum strain K3R2 has the effect of preventing and treating quinoa stem
blight. Meanwhile, the
penicillium oxalicum strain K3R2 has the capabilities of
salt resistance, alkali resistance,
phosphate solubilization,
potassium solubilization,
cellulose solubilization and
nitrogen fixation; the strain K3R2 remarkably promotes the growth of quinoa plants, so that the
chlorophyll content is increased by 20.22%, and the accumulation of
nutrient substances is accelerated; the
fresh weight, the
dry weight and the stem
diameter of quinoa plants are increased, and the lodging resistance is enhanced.