Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/22/2005
Publication Date: 12/13/2005
Citation: Chen, F., He, Z.H., Xia, X.C., Xia, L., Zhang, X.Y., Lillemo, M., Morris, C.F. 2005. Molecular and biochemical characterization of puroindoline a and b alleles in chinese landraces and historical cultivars. TAG 112:400-409. Interpretive Summary: It is known that kernel hardness in bread wheat has a pronounced effect on milling and baking quality. The genetic basis for kernel hardness resides with the puroindoline a and puroindoline b genes. 219 Chinese landraces, 166 historical varieties, and 12 introduced wheats were tested for kernel hardness and puroindoline alleles. Through the course of this study a new puroindoline variant was discovered in the landrace ‘Hongheshang' from the Jiangsu province. This was actually the first novel mutation found in puroindoline a in bread wheat. The results of this study of Chinese wheat germplasm provide useful information for further understanding of the role of kernel hardness in wheat.
Technical Abstract: Kernel hardness that is conditioned by puroindoline genes has a profound effect on milling, baking and end-use quality of bread wheat. In this study, 219 landraces and 166 historical cultivars from China and 12 introduced wheats were investigated for their kernel hardness and puroindoline alleles, using molecular and biochemical markers. The results indicated that frequencies of soft, mixed and hard genotypes were 42.7, 24.3, and 33.0%, respectively, in Chinese landraces and 45.2, 13.9, and 40.9% in historical cultivars. The frequencies of PINA null, Pinb-D1b and Pinb-D1p genotypes were 43.8, 12.3, and 39.7%, respectively, in hard wheat of landraces, while 48.5, 36.8, and 14.7%, respectively, in historical hard wheats. A new Pinb-D1 allele, designated Pinb-D1t, was identified in two landraces, Guangtouxianmai and Hongmai from the Guizhou province, with the characterization of a glycine to arginine substitution at position 47 in the coding region of Pinb gene. Surprisingly, a new Pina-D1 allele, designated Pina-D1m, was detected in the landrace Hongheshang, from the Jiangsu province, with the characterization of a proline to serine substitution at position 35 in the coding region of Pina gene; it was the first novel mutation found in bread wheat, resulting in a hard endosperm with PINA null genotypes, an allele designed as Pina-D1l, was detected in five landraces with a cytosine deletion at position 265 in Pina gene. The study of puroindoline polymorphism in Chinese wheat germplasm could provide useful information for the further understanding of the molecular basis of kernel hardness in bread wheat.