Abstract
BACKGROUND: The wheat FRIZZY PANICLE (WFZP) gene is a regulatory hub that controls spikelet formation in bread wheat, WFZP-D, as a favorable gene for wheat yield improvement. The sequences of WFZP-D in bread wheat accessions are known to be highly conserved. METHODS: In this study, re-sequencing of WFZP homoeologous genes from 98 widely distributed Aegilops tauschii (the donor of the wheat D genome) germplasms was carried out to identify natural variations at both the nucleotide and polypeptide levels. CONCLUSIONS: WFZP homeolog exhibited high conservation with no functional variants in the key AP2/ERF domain. Haplotype characterization identified five haplotypes (Hap-D1 to Hap-D5) based on nine single-nucleotide polymorphisms, five of which induced single amino acid residue substitutions downstream of the AP2/ERF domain. Hap-D1 (identical to Triticum aestivum WFZP-D) and Hap-D2 are two most common. Hap-D1 is concentrated in Iran and Azerbaijan, primarily associated with ssp. strangulata, while Hap-D2 displays broad distribution across the range and primarily belongs to ssp. tauschii. The remaining haplotypes (Hap-D3/4/5) are identified in ssp. tauschii accessions. These findings suggest that strategic integration of ssp. tauschii into wheat-breeding programs could enhance genetic diversity. The identified natural variations provide potential haplotype resources for improving wheat yield potential.