Description:
<jats:title>Abstract</jats:title>
<jats:p>The sequences of x-type high-molecular-weight glutenin promoter (x-HGP) from 21 diploid <jats:italic>Triticeae</jats:italic> species were cloned and sequenced. The lengths of x-HGP varied from 897 to 955 bp, and there are 329 variable sites including 105 singleton sites and 224 polymorphic sites. Genetic distances of pairwise X-HGP sequences ranged from 0.30 to 16.40% within 21 species and four outgroup species of <jats:italic>Hordeum</jats:italic>. All five recognized regulatory elements emerged and showed higher conservation in the x-HGP of 21 <jats:italic>Triticeae</jats:italic> species. Most variations were distributed in the regions among or between regulatory elements. A 22 bp and 50 bp insertions which were the copy of adjacent region with minor change, were found in the x-HGP of <jats:italic>Ae. speltoides</jats:italic> and <jats:italic>Ps. Huashanica</jats:italic>, and could be regarded as genome specific indels. The phylogeny of media-joining network and neighbour-joining tree both supported the topology were composed of three sperate clusters. Especially, the cluster I comprising the x-HGP sequences of <jats:italic>Aegilops</jats:italic>, <jats:italic>Triticum</jats:italic>, <jats:italic>Henrardia</jats:italic>, <jats:italic>Agropyron</jats:italic> and <jats:italic>Taeniatherum</jats:italic> was highly supporting by both network and NJ tree. As conferring to higher level and temporal and spatial expression, x-HGP can used as the source of promoter for constructing transgenic plants which allow endosperm-specific expression of exogenous gene on higher level. In addition, the x-HGP has enough conservation and variation; so it should be valuable in phylogenetic analyses of <jats:italic>Triticeae</jats:italic> family members.</jats:p>