POLYMORPHISM OF TEN NEW MINISATELLITE MARKERS IN SUBPOPULATIONS OF PHYTOPATHOGENIC FUNGUS LEPTOSPHAERIA MACULANS DIFFERING WITH METCONAZOLE TREATMENT

摘要

Stem canker of brassicas is one of the most damaging diseases of oilseed rape worldwide. The disease is caused by two related Leptosphaeria species, and L. maculans is regarded as the more damaging one. Being an ascomycete, the pathogen is able to quickly create new variants that can overcome new resistance genes introduced by researchers and breeding companies. The aim of this work was to study polymorphism of L. manikins populations using 10 recently developed minisatellite markers. The studied subpopulations differed with metconazole treatment.Seven minisatellite markers showed polymorphisms and formed alleles varying from 2 to 10 different core motifs, with 5 alleles on average. In total 36 alleles were found. The majority of alleles (72%) were found in both studied subpopulations of L. maculans. There were 28 alleles in the group of L. maculans isolates originating from plants not treated with any fungicide and 32 in the subpopulation treated with metconazole. Ten unique alleles and imbalanced ratios between some alleles contributed to differences between L. maculans subpopulations. The minisatellites MinLm555, MinLm935-2, MinLm939, MinLm1139 and MinLm2451 showed 6 new variants as compared to the isolates described so far.