Effect of Exogenous Bacillus velezensis on Seed Germination and Seedling Growth and Photosynthetic System of Maize
To investigate the regulatory effects of exogenous Bacillus velezensis(B.v.)on seed germination,seedling growth and photosynthetic system of maize,Zhengdan 958 and Jingnongke 728 were used as test materials for inoculation with B.v..the results showed that:Compared with CK,exogenous application of B.v.significantly promoted maize seed shoot germination and effectively increased seedling height,leaf are-a,fresh weight,dry weight and root to crown ratio.Compared with Bacillus bacteria agent,B.v.treatment had a significant advantage in pro-moting maize seed germination,and the indexes related to agronomic traits such as plant height,leaf area,dry weight and fresh weight were also not significantly different from those of Bacillus bacteria agent.Compared to CK,maize seedlings under exogenous B.v.treatment showed significantly higher Pn,Tr,Gs and WUE and significantly lower Ci compared to CK.Pn,Tr and Gs under B.v.treatment were not significantly different from Bacillus bacteria agent treatment,but significantly weaker than Bacillus mycoflora in terms of Ci utilization efficiency.Compared with CK,exogenous application of B.v.helped to enhance chlorophyll content and improve fluorescence characteristics in maize seedling leav-es:significantly enhanced chlorophyll a,chlorophyll b,chlorophyll a/b,the total chlorophyll content,Fm,Fv/Fm,Fv/Fo and qP,and signifi-cantly reduced Fo and NPQ.The chlorophyll content and total content of leaves under B.v.treatment were significantly higher than those under Bacillus bacteria agent treatment,and the fluorescence parameters were not significantly different from Bacillus bacteria agent treatment over-all,and some indexes were even better than Bacillus bacteria agent treatment.Therefore,Bacillus velezensis has a good development prospect and application value on corn,and has the potential to be further developed into a new type of bacterial agent.