Creation of a core set of durum wheat accessions based on agro-morphological traits with maximum diversity and lower redundancy

Abstract A set of 710 accessions of global durum wheat panel was obtained from the International Centre for Agricultural Research in Dryland Areas (ICARDA) and evaluated for variability in 32 agro-morphological traits at the ICAR-Indian Institute of Wheat and Barley Research, Karnal, India, during 2021–22 and 2022–23. The accessions were grouped based on the type of breeding material and geographical origin, and the Shannon–Wiener diversity index (H′) was calculated for each trait as well as each group. The H′ values ranged from 0.02 (grain crease) to 1.27 (wax of ear) with an overall mean of 0.63, when considering the entire set as a single group. Landraces exhibited higher variability (H′ = 0.64) as compared to released cultivars and evolutionary pre-breeding population lines (H′ = 0.55). Furthermore, accessions originating from West Asia exhibited the highest variability (H′ = 0.63). Traits such as coleoptile colour, plant growth habit, auricle colour and pubescence, flag leaf attitude, ear shape, presence or absence of awns, awns colour and attitude, glumes shape and pubescence, beak length, peduncle attitude, grain phenol colour, grain germ width and brush hair length were found suitable for distinguishing the present durum accessions due to their higher frequency distribution and Shannon–Wiener diversity index values. A core set of 13 accessions was developed using the programme Power Core. These accessions represent the overall variability of the entire set and can therefore serve as a potential source of new genes/alleles for the genetic enhancement of durum wheat. This durum panel may also serve as a valuable reference collection for global researchers in the characterization of durum wheat accessions.