Registration of ten soft red winter waxy wheat germplasm lines.

Waxy wheat carries null alleles at the three Wx loci encoding the granule‐bound starch synthase I and produces endosperm starch composed of mostly amylopectin with less than 5% amylose. The USDA‐ARS developed and released 10 soft red winter (SRW) waxy wheat germplasm lines, SWQL‐K‐ABD‐1, SWQL‐K‐ABD‐2, SWQL‐K‐ABD‐3, SWQL‐K‐ABD‐4, SWQL‐K‐ABD‐5, SWQL‐W‐ABD‐1, SWQL‐W‐ABD‐2, SWQL‐W‐ABD‐3, SWQL‐W‐ABD‐4, SWQL‐W‐ABD‐5 (Reg. no. GP‐1061 to Reg. no. GP‐1070, PI 698615 to PI 698624), by the introgression of the null alleles at the Wx loci from a soft spring waxy wheat germplasm to two SRW wheat cultivars adapted to the eastern region of the United States. Ten waxy wheat germplasm lines were selected from BC4 or BC5 derivatives of the SRW wheat cultivars 'Kristy' and 'Wilson' (99ID490/5*Kristy and 99ID490/6*Wilson). The kernel hardness and starch amylose content of 10 SRW waxy wheat germplasm lines ranged from 34.1 to 63.1 and 2.5–7.2%, respectively, while those of wild types and SRW wheat parents carrying the functional alleles at the three Wx loci ranged from 33.9 to 60.4 and 26.8–27.0%, respectively. The starch of the waxy wheat germplasm lines exhibited a lower pasting temperature, higher peak viscosity, and lower setback value than the corresponding wild‐type wheat starch. These waxy wheat germplasm lines would be useful for the development of SRW wheat cultivars carrying different null alleles at the Wx loci that are adapted to the eastern region of the United States. Core Ideas: Ten soft red winter waxy wheat germplasm lines were developed.They derived from BC4 or BC5 of the cultivars 'Kristy' and 'Wilson'.Starch amylose content of the germplasm lines ranges from 2.5 to 7.2%. [ABSTRACT FROM AUTHOR]