Genetic analysis of glume hairiness (Hg) gene in bread wheat (Triticum aestivum L.)

Hairiness is a common character in planta. Glume hairiness (Hg) is present in the full spectrum of bread wheat and its close relatives and was mainly studied in phenotypic diversity, species evolution, and mapping as a morphological marker. Previous studies indicated that Hg was controlled by a single dominant gene Hg on the short arm of chromosome 1A. However, to date, systematic and comprehensive study of Hg is not available; and markers flanking Hg were rather limited as well, hindering the fine mapping and even cloning of this gene. In the study reported here, aiming at genetically analyze Hg gene systematically, a linkage map of a recombinant inbred line (RIL) generated from the cross between the Tibetan semi-wild wheat (Triticum aestivum subsp. tibetanum Shao) Q1028 and a cultivated wheat Zhengmai 9023 (ZM9023) was constructed using diversity array technology (DArT) and reported simple sequence repeat (SSR) markers. Five SSR markers (saufc2, saufc9, saufc17, saufc25, saufc90) were further developed to accurately locate Hg in this study. Of these five SSR markers all linked to Hg, saufc2 was genetically most closed to Hg with a distance of 1.6 cM. The effectiveness of the five newly developed SSR markers were validated in another RIL derived from Q1028 and a cultivated line 99E18. To our knowledge, this is the first report on fine mapping of Hg in bread wheat. The accurate localization of the Hg and the development of the markers flanked it should facilitate the cloning of this gene and further the study of its possible physiological function in bread wheat.