Genetic analysis of resistance to loose smut and an associated DNA marker in durum wheat doubled haploids

Abstract

Knowledge of the inheritance of loose smut [Ustilago tritici] resistance in durum wheat (Triticum turgidum var. durum) is useful in assisting the development of DNA markers for resistance. Application of inheritance information and marker technology can improve the efficiency of selection in a breeding program. This study was carried out to determine the inheritance of resistance to loose smut in durum wheat and to develop a DNA marker linked to resistance. A doubled haploid population was developed from a cross of the resistant line DT676 with the susceptible line W9260-BK03. The population was found to segregate for resistance to race T33, which cosegregated for resistance to T32. No segregation for resistance occurred with race T26. The simplest explanation is that DT676 and W9260-BK03 share one resistance gene and differ by one resistance gene. No loose smut infection of the F₁ indicated resistance was completely dominant. Amplified fragment length polymorphism (AFLP) analysis generated a DNA polymorphism that was associated with loose smut resistance. The AFLP was converted to a sequence characterized amplified region (SCAR), which cosegregated with resistance to race T33.

Keywords:

• genetic resistance
• DNA marker
• maize pollen