【目的】籽粒硬度是小麦市场分级和定价的重要依据，影响磨粉和食品加工品质。CIMMYT是我国最重要小麦引种地之一，研究其硬度基因型对我国小麦引种具有重要的应用价值。【方法】以CIMMYT常用的236份小麦亲本和高代品系为材料，采用改进的颗粒指数法、特异引物的PCR扩增和改进的SDS-PAGE凝胶电泳对其SKCS硬度及其puroindoine基因型进行鉴定和分析。【结果】202份硬质麦中，165份为PINA蛋白缺失类型；37份为Pinb-D1b类型，其中19份为非CIMMYT材料，18份亲本中均含有非CIMMYT材料。在34份软质麦中，有野生型、Pina-D1a/Pinb-D1i、Pina-D1c/Pinb-D1h、Pina-D1j/Pinb-D1i和Pina-D1a/Pinb-D1j共5种基因型。两种硬质类型中，Pina-D1b类型胚乳硬质程度明显高于（PSI硬度显著低于）Pinb-D1b类型；4种软质类型中，Pina-D1c/Pinb-D1h 和Pina-D1a/Pinb-D1i类型胚乳硬质程度显著高于（PSI硬度显著低于）Pina-D1j/Pinb-D1i和Pina-D1a/Pinb-D1a类型。通过分析各类型的puroindoline基因序列发现，Pinb-D1h和Pinb-D1i编码同一种氨基酸，突变后仍表现为软质是因为第28位精氨酸变成色氨酸，其余软质变异类型色氨酸丰富区附近均未发生变化，这可能是导致其胚乳质地仍未变硬的主要原因。【结论】在先前研究基础上，本试验对CIMMYT小麦基因型作了进一步分析，发现系谱中没有外源材料的所有CIMMYT硬质麦均为Pina-D1b类型。从山羊草引进的软质突变类型之间存在一定硬度差异。

【Objective】Grain hardness, controlled by a hardness (Ha) gene, serves as a basis for classification and marketing of common wheat (Triticum aestivum L.) quality and has a profound effect on milling and end-use quality. CIMMYT is one of the most important places that regularly offer germplasm to Chinese wheat breeding program. This study can provide useful information to introduce wheat to China. 【Method】 A total of 236 wheat lines from CIMMYT crossing program, including common wheat cultivars and advanced lines derived from synthetic hexaploid wheat × common wheat crosses, are used to detect variation of puroindoline alleles by specific-primers PCR amplification and modified SDS-PAGE. PSI (particle size index) hardness was also measured for 160 genotypes. 【Result】 Results indicated that 165 hard wheat lines are Pina-D1b types and the remaining 37 are Pinb-D1b types, which are non-CIMMYT cultivars or their pedigrees contain non-CIMMYT cultivars. Pina-D1j/Pinb-D1i, Pina-D1c/Pinb-D1h, Pina-D1a-Pinb-D1i, Pina-D1a-Pinb-D1j, and wild type (Pina-D1a/Pinb-D1a) are present in 34 soft types. Genotypes with Pina-D1b are significantly harder (lower PSI hardness) than genotypes with Pinb-D1b. Genotypes with Pina-D1c/Pinb-D1h and Pina-D1a/Pinb-D1i are significant harder (lower PSI hardness) than genotypes with Pina-D1j/Pinb-D1i and Pina-D1a/Pinb-D1a. In addition, both Pinb-D1h and Pinb-D1i encode the same polypeptides and a tryptophan substitute (arginine) at position 28, which is the major reason for soft endosperm. In comparison with wild type (Pina-D1a/Pinb-D1a), no change was found in close to tryptophan-rich domain of puroindoline in other soft genotypes except for Pinb-D1h and Pinb-D1i, which may be the main reason that mutation types still remain soft endosperm. 【Conclusion】 It is concluded that all of Pinb-D1b types are non-CIMMYT cultivars or their pedigrees contain non-CIMMYT cultivars and PSI of puroindoline alleles from Ae.tauschii are difference.