Breeding Hard Red Spring Wheat for Fusarium Head Blight Resistance

Abstract

Fusarium head blight (FHB) or scab (caused by Fusarium graminearum Schwabe [telomorph Gibberella zeae (Schwein.) Petch]) is one of the most destructive diseases of wheat (Triticum aestivum L.) worldwide, causing significant reductions in grain yield and quality. In the USA, since the 1993 FHB epidemic, tremendous research efforts have been undertaken to address this major problem that causes substantial economic losses for the wheat growers, industry, and export market. The deployment of resistant varieties is the only effective, economical and environmentally safe way to control FHB in wheat. More than a decade of classical breeding efforts to develop scab resistant hard red spring wheat (HRSW) cultivars at North Dakota State University (NDSU) resulted in releasing several HRSW cultivars with varying levels of FHB resistance. Since 2000, three major HRSW cultivars with FHB resistance were released and grown on large scale in the Northern-Central plains of the USA. These are ‘Alsen’ (2000), ‘Steele-ND’ (2004), and ‘Glenn’ (2005). Alsen has been grown, in average, on more than one million hectares in the last 3 years. However, Alsen and most FHB resistant wheat cultivars released by other wheat programs in the USA, trace back to the Chinese line ‘Sumai-3’ (PI481542) or its derivatives. The HRSW breeding program at NDSU has invested substantial breeding efforts to identify, introgress novel resistance genes from other sources to enhance genetic diversity, and facilitate pyramiding these resistance genes. The ultimate objective is developing HRSW cultivars with effective and durable FHB resistance. Our efforts have yielded in releasing the HRSW cultivars ‘‘Steele-ND’’ in 2004 and ‘‘Glenn’’ in 2005. Steele-ND traces its resistance to the wheat relative species Triticum dicoccoides and Glenn combines both Alsen and Steele-ND resistances. This paper addresses the breeding efforts at NDSU to release FHB resistant HRSW cultivars and elite germplasm as parental material for many breeding programs worldwide; and the future challenges to keep our research efforts ahead of the FHB disease