Evaluation of Fusarium Head Blight Resistance in Wheat and the Development of a New Variety by Integrating Type I and II Resistance

Fusarium head blight (FHB), which is caused by Fusarium graminearum Schwabe [teleomorph: Gibberella zeae (Schwein.) Petch], is a devastating disease affecting wheat (Triticum aestivum L.) spikes, which considerably reduces grain yield and quality and produces mycotoxins that are harmful to humans and animals, especially in warm and humid climates, such as that of west Japan. Therefore, an important target of breeding programs is to improve FHB resistance in wheat. In general, wheat cultivars bred in west Japan exhibit high resistance to FHB worldwide. FHB resistance in wheat can be divided into resistance to initial infection (type I) and resistance to spread within the spike (type II). To improve FHB resistance in west Japanese wheat, we first improved the methods used to evaluate type I and II resistance separately. We then analyzed factors related to type I and II resistance using diverse materials. Finally, we selected a wheat line, ‘Norin PL-9,’ into which we integrated type I and II resistance, and applied for registration as the wheat parental line. The knowledge and materials developed in this study are useful for breeding FHB resistance in wheat where FHB outbreak is problematic. This review draws on a series of related studies.