Effects of Fusarium culmorum head blight on mycotoxin accumulation and yield traits in barley doubled haploids

The susceptibility of barley doubled haploids (DH) to Fusarium head blight (FHB) was investigated. Heads of 24 DH lines (11 two-rowed and 13 six-rowed ) derived from F-1 Maresi (two-rowed) x Pomo (six-rowed) hybrids were inocu lated with a conidial suspension of the single isolate IPO348-01 of Fusariu m culmorum. The experiment was carried out in three consecutive years (1996 -98) in one location. The number of kernels per ear, 1000-kernel weight and kernel weight per ear were recorded in inoculated and control plots. In th e infected kernels nivalenol (NIV) content and deoxynivalenol (DON) content were determined. The effects of genotype, year and genotype-year interacti on on reduction of yield traits were significant. For mycotoxin content onl y genotype and year effects were found to be important. The average NIV con centration in kernels of inoculated lines ranged from 0.15 mg/kg in the two -rowed line MP7 to 6.36 mg/kg in the six-rowed line MP113. A low accumulati on of DON was observed in the studied population (from 0.01 to 0.20 mg/kg). Generally, no significant differences in mycotoxin content were found betw een two-rowed and six-rowed genotypes. The line MP7 was found to be superio r - with the lowest mycotoxin accumulation, and reduction in yield traits, Environmental conditions (years) affected DON and NIV level in kernels; how ever, the tendency to a lower or higher accumulation of mycotoxin in indivi dual lines was stable over the years.