Agrobacterium tumefaciens-mediated Transformation of Fusarium oxysporum f. sp. niveumis and Screening of Mutants with Special Traits

In this study,Fusarium oxysporum f.sp.niveumis FO-11-06 was successfully transformed mediated by Agrobacterium tumefaciens,and T-DNA insertion mutants were further screened.The effects of pH and cultivation media on genetic transformation were studied under the condition of 25 ℃,1×106 spores/mL,A.tumefaciens(AGL1) OD600=0.15,200 μmol/L of acetosyringone and 48 h of co-cultivation in the presence of induction medium.The results showed that the transformants could be obtained in specific pH value range from 5.1 to 5.8 and the transformation efficiency reached the highest level at pH 5.3,with about 553 transformants per 106 spores.It also revealed that transformation efficiency was higher on cellophane(551 transformants per 106 spores) and NC millipore filter(549 transformants per 106 spores) compared to filter paper.Hygromycin resistance and PCR assay of the transformants showed that the T-DNA had been successfully integrated into the genome of F.oxysporum f.sp.niveumis FO-11-06.Forty six mutants with specific traits were identified from 1 989 transformants by assay of colony growth,colony color,and conidia output.The transformation system and mutants provided a basis for the study of development,pathogenicity mechanism and functional gene of the fungus.