Population structure, allelic variation at Rht-B1 and Ppd-A1 loci and its effects on agronomic traits in Argentinian durum wheat

ACHILLI A; RONCALLO P; LARSEN A; DREISIGACKER S; ECHENIQUE V

Scientific Reports

Nature Research

Lugar: Londres; Año: 2022 vol. 12 p. 1 - 13

2045-2322

Exploring the genetic variability in yield and yield-related traits is essential to continue improving genetic gains. Fifty-nine Argentinian durum wheat cultivars were analyzed for important agronomic traits in three field experiments. The collection was genotyped with 3565 genome-wide SNPs and functional markers in order to determine the allelic variation at Rht ‑B1 and Ppd‑A1 genes. Population structure analyses revealed the presence of three main groups, composed by old, modern and genotypes with European or CIMMYT ancestry. The photoperiod sensitivity Ppd‑A1b allele showed higher frequency (75%) than the insensitivity one Ppd ‑A1a (GS105). The semi-dwarfism Rht ‑B1b and the Ppd‑A1a (GS105) alleles were associated with increases in harvest index and decreases in plant height, grain protein content and earlier heading date, although only the varieties carrying the Rht ‑B1variants showed differences in grain yield. Out of the two main yield components, grain number per plant was affected by allelic variants at Rht ‑B1 and Ppd ‑A1 loci, while no differences were observed in thousand kernel weight. The increases in grain number per spike associated with Rht ‑B1b were attributed to a higher grain number per spikelet, whereas Ppd‑A1a (GS105) was associated with higher grain number per spikelet, but also with lower spikelets per spike.