A natural variation of an SVP MADS-box transcription factor in Triticum petropavlovskyi leads to its ectopic expression and contributes to elongated glume

Triticum petropavlovskyi, commonly known as Xinjiang rice wheat, is a unique hexaploidy wheat grown in the Xinjiang area. T. petropavlovskyi is marked by its elongated glume (Eg) trait, which is controlled by gene P1pet located on chromosome 7A (Wang et al., 2002; Watanabe and Imamura, 2002). The origin of T. petropavlovskyi has been disputed. It is generally accepted that P1pet was introduced from tetraploid polish wheat (T. polonicum) via a hybridization with hexaploid common wheat (T. aestivum) (Akond et al., 2008; Chen et al., 2016).