Chromosomal location of Fusarium head blight resistance genes and analysisof the relationship between resistance to head blight and brown foot rot

In order to identify chromosomes involved in resistance to Fusarium head bl ight, a set of 21 substitution lines of Triticum macha (resistant) chromoso mes into 'Hobbit' 'sib' (susceptible) were evaluated in trials over 2 years . For the first year's trial, all plants were inoculated on the same day wi th a conidial suspension of F. culmorum. For the second trial, individual p lants were inoculated precisely at mid anthesis of each plant over a period of 2 weeks. The disease level was assessed by visual scoring, relative ear weight and F. culmorum-specific quantitative polymerase chain reaction. Th e results showed that T. macha chromosomes 1B, 4A and 7A conferred good ove rall resistance, suggesting that they carry important genes for resistance. In two additional trials, T. macha and 'Hobbit' 'sib' were evaluated for r esistance to brown foot rot. The results showed that T. macha was more susc eptible than 'Hobbit' 'sib', indicating that stem base disease response is not correlated with head blight resistance in these cultivars.