Kerby K, Kuspira J, Jones B L
Department of Genetics, University of Alberta, Edmonton, Canada.
Genome. 1988 Aug;30(4):576-81. doi: 10.1139/g88-097.
To determine whether the Triticum urartu genome is more closely related to the A or B genome of the polyploid wheats, the amino acid sequence of its purothionin was compared to the amino acid sequences of the purothionins in Triticum monococcum, Triticum turgidum, and Triticum aestivum. The residue sequence of the purothionin from T. urartu differs by five and six amino acid substitutions respectively from the alpha 1 and alpha 2 forms coded for by genes in the B and D genomes, and is identical to the beta form specified by a gene in the A genome. Therefore, the T. urartu purothionin is either coded by a gene in the A genome or a chromosome set highly homologous to it. The results demonstrate that at least a portion of the T. urartu and T. monococcum genomes is homologous and probably identical. A variety of other studies have also shown that T. urartu is very closely related to T. monococcum and, in all likelihood, also possesses the A genome. Therefore, it could be argued that either T. urartu and T. monococcum are the same species or that T. urartu rather than T. monococcum is the source of the A genome in T. turgidum and T. aestivum. Except for Johnson's results, our data and that of others suggest a revised origin of polyploid wheats. Specifically, the list of six putative B genome donor species is reduced to five, all members of the Sitopsis section of the genus Aegilops.
为了确定乌拉尔图小麦（Triticum urartu）的基因组与多倍体小麦的A基因组还是B基因组关系更为密切，将其硫醇溶蛋白的氨基酸序列与一粒小麦（Triticum monococcum）、硬粒小麦（Triticum turgidum）和普通小麦（Triticum aestivum）中硫醇溶蛋白的氨基酸序列进行了比较。乌拉尔图小麦硫醇溶蛋白的残基序列与B和D基因组中基因编码的α1和α2形式分别有5个和6个氨基酸替换的差异，并且与A基因组中一个基因指定的β形式相同。因此，乌拉尔图小麦硫醇溶蛋白要么由A基因组中的一个基因编码，要么由与其高度同源的一个染色体组编码。结果表明，乌拉尔图小麦和一粒小麦的基因组至少有一部分是同源的，可能是相同的。其他各种研究也表明，乌拉尔图小麦与一粒小麦密切相关，而且很可能也拥有A基因组。因此，可以认为要么乌拉尔图小麦和一粒小麦是同一物种，要么乌拉尔图小麦而非一粒小麦是硬粒小麦和普通小麦中A基因组的来源。除了约翰逊的结果外，我们的数据和其他人的数据都表明多倍体小麦的起源有所修正。具体来说，六个假定的B基因组供体物种名单减少到了五个，都是山羊草属（Aegilops）拟斯卑尔脱山羊草组（Sitopsis section）的成员。
