Abstract: In order to reveal the pathogenic molecular mechanism of Leptosphaeria biglobosa, 16 mutants were randomly selected based on the established Leptosphaeria biglobosa mutant library and their pathogenicity was detected, and 12 mutants with reduced pathogenicity were screened.Six of these mutants with significantly reduced pathogenicity were carried out the characteristics of colony growth, growth rate and spore production quantity.The results showed that T1, T3, T4 and T7 mutants had no obvious difference in colony morphology compared with wild type nm-1, while T9 and T11 had the characteristics of the dense hyphae, but no sporulation compared with wild type nm-1;The growth rate of T1, T3, T4, T7 and T9 mutants were faster than nm-1, while T11 was significantly lower than wild type nm-1;The sporulation ability of six mutants significantly decreased compared with wild type nm-1.The Southern Blot assay revealed T-DNA insert was single copy of six mutants.Finally, the right flank sequences of six mutants were amplified by Hi TAIL-PCR, the position of T-DNA inserted into L.biglobosa genome was preliminarily identified by Blast analysis.The right flanking sequence of the six mutants might be part of the pathogenic gene sequence.This study provides the references for further screening the pathogenic genes and functions of L.biglobosa, and provides a theoretical basis for the pathogenesis of L. biglobosa.

Key words: Brassica napus, Leptosphaeria biglobosa, T-DNA, Pathogenicity, Flanking sequence

CLC Number: 

• S432.4