Glaucousness is the visible opaque-white or bluish-green wax which appears in plant cuticles. Although W1 and Iw1 loci on chromosome 2B mainly play a role to determine glaucousness/non-glaucousness trait in polyploid wheat, in the chromosome 2A of polyploid wheat, the non-glaucous inhibitor locus has not been reported. We explored the glaucous phenotypes for leaf, spike and stem in 274 accessions of Triticum urartu Thumanjan ex Gandilyan (2n = 2x = 14, genome A^uA^u), the A genome progenitor of polyploid wheat. The 272 accessions of T. urartu were non-glaucous for leaf, spike and stem. It was thought that non-glaucousness of T. urartu played an important role for plant adaptation throughout the Fertile Crescent. However, PI 662236 was glaucous in leaves, leaf sheaths and spikes, whereas PI 662271 was glaucous on the leaves and leaf sheaths, but non-glaucous in the spikes. Prior to heading PI 662236 and PI 662271 mimicked T. urartu by showing glaucous leaves and leaf sheaths. The plant form and somatic chromosome number indicated that PI 662236 and PI 662271 were tetraploid Triticum dicoccoides (Körn. ex Asch. & Graebn.) Schweinf. (2n = 4x = 28, BBA^uA^u genome). The occurrence of T. dicoccoides in the collections of T. urartu demonstrated that even famous botanists can make mistakes in identifying grasses. However, these mistakes lead to finding two rare types of T. dicoccoides with occurrence of glaucousness. The majority of T. dicoccoides that are non-glaucous. The genotype of PI 662236 was assigned as iw1iw1iw3iw3 for glaucousness and that of PI 662271 was iw1iw1Iw3Iw3 for the inhibitors for non-glaucous spikes.

白霜是出现在植物角质层中的可见不透明白色或蓝绿色蜡状物。尽管2B染色体上的W1和Iw1基因座主要在决定多倍体小麦的白霜性/非白霜性状中起作用，但在多倍体小麦的2A染色体上，非白霜抑制基因位点尚未见报​​道。我们研究了 274 份Triticum urartu Thumanjan ex Gandilyan（2n = 2x = 14，基因组 A ^u A ^u）（多倍体小麦的 A 基因组祖先）的叶、穗和茎的白霜表型。272份T. urartu种质的叶、穗和茎均无白霜。人们认为T. urartu 的无白霜对整个新月沃地的植物适应发挥了重要作用。然而，PI 662236 在叶、叶鞘和穗部有白霜，而 PI 662271 在叶和叶鞘上有白霜，但在穗部没有白霜。在抽穗之前 PI 662236 和 PI 662271通过显示白霜叶和叶鞘来模仿T. urartu 。植物形态和体细胞染色体数目表明，PI 662236 和 PI 662271 是四倍体Triticum dicoccoides ( Körn . ex Asch. & Graebn.) Schweinf。（2n = 4x = 28，BBA ^u A ^u基因组）。T. dicoccoides在T. urartu集合中的出现证明即使是著名的植物学家也会在识别草时犯错误。然而，这些错误导致发现了两种罕见的T. dicoccoides出现白霜。大多数T. dicoccoides是无白霜的。PI 662236 的基因型被指定为iw1iw1iw3iw3用于白光，而 PI 662271 的基因型是iw1iw1Iw3Iw3用于非白光尖峰的抑制剂。