Effects Of Paecilomyces Variotii Extract On Yield,Nitrogen Metabolism And Photosynthetic Characteristics Of Maize

The fermentation,wall breaking and extrusion of Paecilomyces Variotii had strong growth promoting stress tolerance,but the Paecilomyces Variotii extract（ZNC）on maize growth and nitrogen metabolism were rarely reported.In order to investigate the effects of extracts from the endophytic fungus Paecilomyces on crop yield and nitrogen use efficiency（NUE）of wild seabuckthorn roots,a pot experiment was conducted on maize（Zea Mays L.）for two consecutive years.To investigate the effects of farmers’ customary fertilization combined with Paecilomyces Variotii extract root irrigation on maize yield,nitrogen use efficiency,soil nutrients,enzymes related to crop nitrogen metabolism,endogenous hormone levels and photosynthetic characteristics.Nitrogen blank（CK）,farmers’ customary fertilization（U）,farmers’ customary fertilization combined with Paecilomyces Variotii extract root irrigation（U+ZNC）were set as three treatments.The main research results are as follows:（1）ZNC could significantly improve nitrogen use efficiency and soil nutrient supply intensity,and its yield increase effect was significant.Compared with the conventional fertilization treatment,maize yield under U+ZNC treatment was significantly increased by6.75% and 8.22%,and nitrogen use efficiency was significantly increased by 13.05 and 21.08 percentage points,respectively.Compared with the traditional fertilization treatment,the soil nitrate nitrogen content under U+ZNC treatment was significantly increased by 21.03% at the silking period of maize.At the jointing period of maize,soil ammonium nitrogen content increased by 104.63% and available phosphorus content increased by 13.18%.The content of available potassium was significantly increased by 68.23% at the silking period of maize.（2）ZNC significantly increased endogenous hormone levels and nitrogen metabolization-related enzyme contents,and increased nitrogen accumulation.Maize in the12-leaf collar period,compared with the U treatment,The concentrations of auxin（IAA）,nitrate reductase（NR）,glutamine synthase（GS）,glutamate synthase（GOGAT）and glutamate dehydrogenase（GLDH）were increased by 60.42%,68.38%,17.49%,22.51% and 31.18%under U+ZNC treatment,respectively.The concentration of nitrogen metabolizing enzymes NR,nitrite reductase（Ni R）,GS and GLDH in maize leaves was significantly increased by46.27%、56.66%、70.89% and 32.29%,respectively.At jointing period,the concentration of Ni R,GOGAT and GLDH in leaves increased by 79.97%,33.98% and 46.34% under U+ZNC treatment.（3）ZNC could significantly improve the content of photosynthesis and photosynthetic characteristics of maize.At the silking period,maize plant height under U+ZNC treatment was significantly increased by 6.03% compared with U treatment.Urea combined with ZNC root irrigation could significantly improve the photosynthesis of maize leaves.The concentration of photosynthetic enzymes phosphoenolpyruvate carboxylase and pyruvate phosphate dikinase in maize leaves significantly increased by 31.44% and 71.07% during 12-leaf collar period.Compared with U treatment,net photosynthetic rate,stomatal conductance and transpiration rate of leaves under U+ZNC treatment were significantly increased by62.37%,23.13% and 14.64%,respectively,which promoted dry matter accumulation.Under the conditions of this study,farmers’ customary fertilization combined with Paecilomyces Variotii extract could significantly enhance soil nutrient supply intensity,increase the activities of nitrogen metabolism-related enzymes in roots and leaves,enhance the activities of photosynthesis-related enzymes,increase photosynthetic rate,and significantly increase yield and nitrogen use efficiency.To investigate the effects of ZNC root irrigation on maize yield,nitrogen metabolism and photosynthetic characteristics,and to provide a basis for the application and promotion of ZNC root irrigation in maize production.