Little is known about response of root‐related traits of barley (Hordeum vulgare L. subsp. vulgare; hereafter, Hvu) and its wild relative H. vulgare L. subsp. spontaneum (K. Koch) Thell. (hereafter, Hsp) to drought stress. Three separate experiments were conducted to assess these traits at germination, vegetative, and reproductive stages. Drought stress significantly reduced germination percentage and rate, primary root number, and shoot and root length of seedlings. Using pot experiment, drought stress reduced shoot dry weight (SDW) and root dry weight (RDW) at vegetative stage but the ratio of RDW/SDW (RSR) increased under this condition. At reproductive stage, SDW, plant height, number of fertile tiller, and relative water content decreased under drought stress, but root length, root volume, RDW, and RSR increased as the intensity of drought increased. For most of the traits the genotype × moisture environment interaction was significant. The effect of drought stress on genotypes was highly dependent to developmental stages and the intensity of water limitation. The wild barley genotypes had more drought tolerance than the cultivated ones. The results of vegetative and reproductive stages poorly matched with the ones from seed germination stage. Two wild barley genotypes from Iran were tolerant to drought stress at both vegetative and reproductive stages and may be used for genetic studies and possible breeding of barley for root‐related traits.

Seed color is a vital quality determinant of flax, significant for consumers’ acceptability, and determines the commercial values of seeds. Also, seed color as a phenotypic marker may be a convenient way to select the plants with desired traits. This study assessed a diversity panel representing 144 flax genotypes from diverse geographical origins for the existence of genetic variability for luminosity (L*) and chromaticity (a* and b*) seed color parameters, seed yield, and quality traits over two years. The genetic variance was significant for seed color parameters, demonstrating the presence of significant genetic variability, which provides a resource to objectively evaluate and select flax genotypes based on seed color according to the market demand. High heritability combined with the high genotypic coefficient of variation observed for seed yield, oil, and protein content suggested a better genetic gain upon selecting these traits. Seed yield, seed quality traits, and phenological traits showed significant negative correlation with L* and b* parameters and positive correlation with a* suggesting that the seeds’ dark background and brown color can serve as marker characters to prescreen early-flowering, high-yielding and oil and protein-rich genotypes. Interestingly 48 brown-seeded genotypes were identified as early-flowering with short height, large seeds, high thousand seed weight, and capsule diameter. In addition, 34 genotypes were characterized by light-colored yellow seeds, large seeds, late-flowering with shorter height, and high branch numbers. Our results highlighted that North America and Australia-belonged genotypes were lighter yellow-seeded than the ones from other continents. Flax genotypes from South America and Asia were high-yielding, while genotypes from North America were low-yielding genotypes. Moreover, darker brown-seeded genotypes have prevailed in the South American continent.

Despite all advances in crop breeding techniques, the fundamental role of studying and identifying new genetic material remains undeniable. In this study, a diversity panel (DP) of 120 linseeds were characterized in the field for potential use in breeding programmes during 2 years. The panel was assembled mainly from intermediate linseeds, randomly selected from IPK world collection. Traits evaluated consisted of seed yield, branches and capsules per plant; plant height; capsule diameter; seeds capsule−1; 1000‐seed weight; seed length and width and also seed oil and protein content. Results revealed a great variability in DP mainly attributable to the genetic factors (72.6%) rather than geographical origin (6.4%) or experimental years (20.9%). Among studied traits, seed yield, branches and capsules per plant showed the highest variability. However, seed size features had relatively higher broad‐sense heritability and showed the strongest correlation with seed yield per plant. The DP provides a potentially useful resource for linseed breeding; this was particularly evident for five identified elite lines, among which an Indian landrace was outstanding.

Improving seed yield and oil quality of oilseed crops can aid in provision of a nutritious diet for humans. A worldwide collection of linseed was evaluated for seed yield (YLD), seed oil (OIL) and protein content (PRO), oil fatty acid composition, omega-3 to omega-6 ratio (ω3/ω6), total tocopherol content (TTC), and total phenolic content (TPC). At 2 years, higher temperature (~7%) and lower relative humidity (~16.6%) during the seed filling and maturity period (dryer condition) were correlated with significant decreases in YLD (~18%) and OIL (~4.5%), lower contents of linolenic acid (~13%) and TTC (9.8%), and lower ω3/ω6 ratio (~31%); oleic (~9%) and linoleic acid contents (~23%) and TPC (14.4%) increased. Correlation results demonstrated some significant associations among quantitative traits such as YLD, OIL, and thousand seed weight (TSW); however, the association of these traits with qualitative indices was mostly negative. Genotypes were classified irrespective of their geographical origin and independent of seed or flower colour. In this classification, a yellow-seeded Canadian group had the lowest ω3/ω6 ratio (~0.05), the highest seed yield and high TTC, whereas groups with the highest ω3/ω6 ratio (>3.0) had the lowest oil TTC and low to average seed yield. Results suggested that some brown-seeded Asian genotypes with high grain yield and oil potential, higher ω3/ω6 ratio, and other more stable oil quality indices are suitable to develop broadly adaptive varieties under the possible fluctuation of climatic factors. Other genetic groups could also be used for breeding programs with specific objectives.