부산대학교 도서관

Increasing the yield of wheat (Triticumspp.) requires identifying new allelic combinations by crossing or by creating useful variation in yield limiting genes. Wheat yield is impacted by many factors, including tiller number and seeds per tiller, both of which are impacted by the Reduced height(Rht) gene. Durum wheat [T. turgidumL. subsp. durum(Desf.) van Slageren] varieties are either standard height, wild type for Rht(Rht‐B1a), or are semidwarf and carry the Rht‐B1ballele. Rht‐B1bincreases productive tillers but can result in plants too short for easy harvest in the northern United States and shorter coleoptiles that reduce dry soil germination. In this study, durum plants varying for Rhtalleles created by ethyl methanesulfonate (EMS) mutagenesis were studied to determine the impact of each allele upon agronomic and seed traits. The projects’ goal is to increase durum wheat yield through the development of a plant with height intermediate between current full‐height and semidwarf varieties. Experiments included field trials, coleoptile length and gibberellic acid (GA) responsiveness assays, and an in vitro test to determine the impact of each Rhtmutation upon binding to Gibberellin Insensitive Dwarf1 (GID1). It was found that the Rht‐B1b‐E529Kallele conferred plant height and coleoptile length intermediate between Rht‐B1band Rht‐B1acontaining plants, while two Rht‐A1alleles had lesser impacts with trends toward intermediate‐height plants. The results of this research demonstrate that hypomorphic Rhtalleles that alter Rhtbinding to GID1 may prove useful in optimizing durum wheat height to increase yield across different growing conditions. Rhthypomorphic alleles result in intermediate plant height.Rht‐Ahypomorphic mutations reduce plant height.Intermediate‐height plants carrying hypomorphic Rhtalleles have longer coleoptiles.