Fine mapping of the TdHLS gene controlling hairy leaf sheath from wild emmer wheat.

KEY MESSAGE: (0T267/Han 87-1*2 and 0T267/AK58*2) individuals revealed this gene was delimited in a 2.3 Mb region on chromosome 4BL based on the WEW reference genome (Zavitan v1.0), and this region shows observed recombination suppression. Transcriptomic and sequence analyses identified four expressed genes containing nonsynonymous mutations between hairy and glabrous leaf sheath lines, within the 28 annotated genes located in the target interval. Among them TRIDC4BG062310 (encoding an oxysterol-binding protein-related protein) exhibited differential expression patterns, suggesting its potential role in trichome development. Collinearity analysis indicated orthologous hairy leaf sheath loci in WEW (Zavitan v1.0), barley (Morex v1.0) and Aegilops tauschii (AL8/78 v4.0), indicating the presence of evolutionarily conserved homologous genes governing this morphological characteristic. Introgression lines demonstrated successful trait incorporation without affecting plant architecture and grain characteristics. This study establishes a foundation for cloning the TdHLS gene and provides a valuable morphological marker for wheat breeding.