Registration of Wheat Lines Carrying Novel Mutagenesis‐Derived Puroindoline Alleles

Abstract

Grain texture is an important factor in determining milling properties of wheat (Triticum aestivum L). Grain texture is mainly controlled by two tightly linked genes, Puroindoline a (Pina) and Puroindoline b (Pinb). The goal of this research was to further characterize and release near isolines for novel Puroindoline alleles with unique levels of grain hardness. Seed of soft white spring wheat ‘Alpowa’ was treated with ethyl methanesulfonate (EMS). The Pin genes were amplified by polymerase chain reaction and then sequenced, after which missense mutations in both Pina and Pinb were identified. Seven novel alleles were backcrossed twice to the Alpowa parent to produce BC2F2–derived near isolines: MT363‐4 (Reg. No. GP‐1033, PI 689449), MT421‐27 (Reg. No. GP‐1034, PI 689450), MT777‐14 (Reg. No. GP‐1035, PI 689451), MT1306‐19 (Reg. No. GP‐1036, PI 689452), MT1899‐9 (Reg. No. GP‐1037, PI 689453), MT2092‐42 (Reg. No. GP‐1038, PI 689454), and MT2252‐14 (Reg. No. GP‐1039, PI 689455). One was softer than its wild type (MT2092‐42 [PINA‐R103K/PINBa]), three had intermediate hardness (51 to 54 hardness units using the single kernel characterization system) (MT363‐4 [PINA‐P35S/PINBa]; MT1306‐19 [PINA‐G47S/PINBa]; MT1899‐9 [PINAa/PINB‐D34N]), and three were hard (>65 hardness units) (MT421‐27 [PINAa/PINB‐T38I]; MT777‐14 [PINAa/PINB‐G46D]; and MT2252‐14 [PINAa/PINB‐E51K]). Kernel weight, grain protein, and test weight for the novel alleles did not differ from their wild‐type counterparts. Some of the novel alleles provide grain hardness values outside the range of naturally occurring Pin alleles, while others provide unique PIN proteins, giving haplotype diversity at these loci.