Identification and Biocontrol Evaluation of Marine Bacteria 221-11 on Tomato Early Blight
In order to identify the marine bacteria antagonistic to tomato early blight(Alternaria solani)and evaluate its biocontrol effect,in this experiment,the species of the antagonistic bac-terium 221-11 for tomato early blight screened in previous work was used as research object.Based on the morphological characteristics,physiological and biochemical properties,and 16S rDNA sequence analysis,the species of antagonistic bacterium was identified.Then,an indoor pot test was used to detect the growth-promoting effects of marine biocontrol bacteria on tomato plants and preventive,therapeutic effect on tomato early blight.Finally,the effects of antago-nistic bacteria on the activities of plant defense enzymes(SOD,POD,CAT)were determined by using the aziridinium blue tetrazolium method,the guaiacol method,and the UV-absorbance method.The results showed that the marine antagonistic bacterium 221-11 was Bacillus velezen-sis.It produced an inhibition zone of 61.2±0.3 mm in diameter with 77.2％of inhibition rate a-gainst tomato early blight pathogen,and inhibited the spore germination and teratogenesis.Af-ter potting root inoculation for 35 d,it was found that 5.75 × 102-5.75 × 108 CFU/mL of ma-rine bacterium 221-11 fermentation solution were able to promote the growth of tomato plants.Among them,the plant height,fresh weight and dry weight of the plants treated with 5.75 × 108 CFU/mL solution was the highest,which increased by 15.23％,64.23％and 118.97％,re-spectively.The preventive and therapeutic effects of the fermentation solution were 63.45％and 45.74％.Compared with the control group,the activities of SOD,POD and CAT after inocula-tion with biocontrol bacterium 221-11 increased with the increase of fermentation liquid concen-tration,and the highest increase was 139.82％.In summary,the biocontrol bacterium 221-11 has good control effect on tomato early blight and promotion potential to tomato plants,and is a potential strain for biological control of tomato early blight.
tomato early blightantibacterialBacillus velezensiscontrol efficiencydefensive enzyme
万方数据
维普
