Isolation And Screening Of Antagonistic Yeast 3-110 And Its Preservation Mechanism On Mango

The stalk rot is one of the main diseases of postharvest storage of mango,At present,there is no effective control method control it.Kloechera apiculata strain 34-9 plays a positive role in inhibiting blue and green Mold of Citrus.In our laboratory,we improve the yeast gene and establish a transformation library by ATMT system.The experiment,the transformation library was used as the material and the strain 3-110 was selected to inhibit mango stalk rot In vitro and in vivo.the stalk rot pathogen was identified too.After that,the antibacterial mechanism of strain 3-110 was studied by measuring the enzyme activity and the expression of related genes.The main results are as follows:1.Formed obvious inhibition zone around yeast 3-110 to inhibit the growth of stalk rot in vitro;and the incidence rate of inoculated strain 3-110,chemical agent carbendazim and sterile water were respectively 45.84%?59.89%?79.63%,as well as the disease spot diameter were 17.76 mm?28.25 mm?22.70 mm,which the incidence rate and disease spot diameter with strain 3-110 both significantly lower than sterile water.2.According to morphological observation and isolation and identification of the strain,the pathogen in this study was identified as Lasiodiplodia theobromae.3.By measuring the enzyme activity of mango peel and the expression of related genes,it was found that inoculating strain 3-110 could induce the change of enzyme activity of mango peel:the activities of SOD and PPO were increased compared with the control group,while the activities of PG and ?-GAL was lower than that of control group.In addition,the POD increased first and then decreased and the content of MDA was significantly lower at the 5th day.The microstructure of mango peel was observed.SEM showed that a large number of mycelium appeared in the peel of the control group at the 4th day,but no mycelium was found in the peel inoculated with 3-110.TEM also showed that the cell walls of the control group became loose and porous at 4d,whereas the cell walls of the treatment group remained relatively intact.The experimental results showed that strain 3-110 could inhibit the invasion of Lasiodiplodia theobromae by scavenging the reactive oxygen species and protecting the cell wall structure,to prevent the root rot of mango.