Resistance to Septoria nodorum in a durum wheat cultivar as determined by stage of host development

Abstract

Seedlings of the spring durum wheat cv. Giorgio 396 (CI 15111), show a high level of resistance to S. nodorum while the mature plants are very susceptible. Tests under greenhouse conditions showed seedlings of this cultivar to have a significantly higher level of resistance to isolates of S. nodorum than seedlings of a susceptible cultivar in its seedling stage; but field and greenhouse inoculations of the mature plant showed it to be susceptible in terms of both disease symptoms expressed and reduction in weight of the kernels produced. This seedling resistance may be of potential value if it can be incorporated into cultivars grown in environments where seedling resistance is essential, or incorporated along with other genes for resistance to produce cultivars with a high level of resistance to S. nodorum over several growth stages.