Optimization Of ATMT For Biocontrol Yeast 34-9 And Preliminary Research On Transformations In Biocontrol Effect

Kloechera apiculata strain 34-9 is a biocontrol yeast,which plays a positive role in inhibiting postharvest diseases including Penicillium italicum and Penicillium digitatum Sacc in citrus.However,the yeast exists some problems such as unstable effect of control and the less species of pathogenic bacteria due to the change of environment and the single biocotrol effect.Through the improvement of yeast genes,yeast can improve the control effect of bio-control bacteria 34-9.In the work,we optimized the methods for yeast 34-9 through Agrobacterium tumefaciens-mediated transformation system and establishing the yeast mutant library eventually.At the same time,transformations had been studies the biocontrol effect for Geotrichum citri-aurantii and Colletotrichum gloeosporides Penz preliminarily.The pivotal results are as follows:1.Optimizing the conditions for yeast of Agrobacterium tumefaciens-mediated transformation system:when the concentration of AGL-1 was OD₆₀₀00 0.6,as well as34-9 suspension at 10⁷ CFU/mL,adding reagent is in the pre-culture stage,it can odtain the stabie transformations.Then it can successfully transformed 34-9 while culturing the strains for 48h at 25°C in the dark.The number of obtained transformations has reached to one thousand.2.The transformation for inhibiting Geotrichum citri-aurantii,named 3-138,was obtained,which can delay the time for pathogenic of AY-1.3.The transformation,named 3-2,can delay the time for pathogenic of AISH.