Genetic diversity and occurrence of Leptosphaeria spp. on brassica oleracea and b. Napus in Lithuania

Abstract

Blackleg, caused by the Leptosphaeria maculans/L. biglobosa, is one of the most damaging diseases of Brassica spp. Isolates of L. maculans and L. biglobosa were recoveed from oilseed rape, cabbage and broccoli in Lithuania. All isolates from cabbage were identified as L. biglobosa, while both fungal species were detected on broccoli and oilseed rape. Amplified fragment length polymorphism (AFLP) analysis was used to assess the genetic diversity among 68 isolates of L. maculans and L. biglobosa. Cluster analysis divided isolates into two groups of L. maculans and L. biglobosa species. Analysis of molecular variance attributed 57.9% of molecular variance to differences among isolates within the population of L. maculans and 26.6% within the population of L. biglobosa. This is the first study that demonstrates the coexistence of both Leptosphaeria species on B. oleracea in Lithuania. Analysis of molecular variance showed that the populations of Leptosphaeria spp from different host plants were genetically differentiated.