Wild introgression as an effective tool for aiding the expansion and adaptation of cultivated safflower

Safflower is a multipurpose crop grown in different regions, mainly for its high oil quality. Crop wild relatives serve as a valuable reservoir of genes that have been depleted due to evolutionary bottlenecks, which are poorly applied in safflower. During the last decade, we developed three populations from hybridization of safflower with its wild relatives and selected the superior lines to develop new varieties. From each of three different interspecific populations (TP: Carthamus tinctorius x Carthamus palaestinus, PO: C. palaestinus x Carthamus oxyacantha, and TO: C. tinctorius x C. oxyacantha), 10 genotypes were selected (a total of 30 lines) in the "F8" generation and were evaluated along with their parents (T, P, and O) and one control cultivar (Golsfid) at the field during 2019-2022 to assess genetic variation, estimate genetic parameters, and evaluate the stability. Considerable genetic variability for oil, seed yield, and other agronomic traits between and within the interspecific populations suggests the high potential of these new recombinant lines for introducing beneficial alleles. Our results indicated that recombinant inbred lines derived from the hybridization of TP were superior in terms of seed yield, oil content, and stability parameters. The use of stability indices of Wricke, Lin and Binns, Eberhart and Russell, and HMRPGVi, along with the biplot analysis, allowed the identification of preferable and stable safflower genotypes. Moderately high values of heritability were found for yield-related traits. New recombinant lines can be introduced to the safflower gene pool to improve the genetic base of this valuable oil seed crop. Crop wild relatives represent a practical gene pool for genes lost by evolutionary bottleneck. We identified several lines of evidence consistent with wild introgression aiding the expansion of safflower. Recombinant inbred lines derived from the hybridization of Carthamus tinctorius x Carthamus palaestinus were superior. New recombinant lines were introduced to the safflower gene pool.