Drought stress has an adverse effect on crop production and food quality. Milk thistle (Silybum marianum L.) is an oil and medicinal crop known as an alternative oil crop with high level of unsaturated fatty acids, which makes it a favourable edible oil for use in food production. Silymarin (a mixture of flavonolignans) is the main active medicinal component. Biochemical diversity, changes induced by water deficit stress in secondary metabolites, and their relationships with production traits in native germplasm are poorly understood in milk thistle. Twenty-six ecotypes mainly collected from different regions of Iran were evaluated for oil, fatty acid profile, triacylglycerol (TAG) composition, silymarin and agro-morphological traits under non-stress and water stress conditions for 2 years. Water stress increased oil and silymarin content while decreasing fruit yield and related traits. The most abundant fatty acid averaged over all ecotypes under both moisture conditions was linoleic acid (L, 39%), followed by oleic acid (O, 36%), palmitic acid (P, 9%) and stearic acid (E, 6%). Among the 24 detected TAGs, the five major compositions were OOL, OLL + OOLn (linolenic), POL, OOO, LLL + OLLn and EOL. Superior ecotypes rich in monounsaturated and polyunsaturated fatty acids were identified and can be introduced as candidates for food, medicinal and industrial purposes. Associations among different attributes are discussed.

Wild relatives of safflower (Carthamus tinctorius L.) may contribute genes to improve cultivated species under water stress conditions. This study was conducted to increase genetic diversity of safflower for agromorphological traits and fatty acid profiles using interspecific hybridization. Three species—C. tinctorius, C. palaestinus Eig., and C. oxyacanthus M. Bieb.—were used to develop three segregating populations of C. tinctorius × C. palaestinus (TP), C. oxyacanthus × C. palaestinus (OP), and C. oxyacanthus × C. palaestinus (TO). Seventy‐three lines, along with the three parental species, were evaluated for agromorphological traits under water stress and nonstress conditions in F3 and F4 generations during 2 yr. Fatty acid analysis of interspecific progenies showed occurrence of transgressive segregation. The results showed that mean values of seed yield for TP and TO progenies, where C. tinctorius was one of their parents, were higher than mean value of seed yield for OP that derived from the two wild species. High genetic variation was observed for seed yield, capitulum diameter, and phenological traits in interspecific populations under both moisture conditions. Indirect selection for flowering and seed yield components under water deficit conditions was most efficient to improve seed yield. Results indicated that gene introgression from wild relatives of safflower into the cultivated gene pool increased genetic variation for the measured traits and allowed identifying superior genotypes for future breeding programs.

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Core Ideas Wild relatives of safflower are suitable source of genes for improvement of cultivated species.Single plant selection is simple and results in genetic gain in safflower interspecific hybridization under both water stress and non‐stress conditions.Indirect selection is more efficient than direct selection for tolerance to water limited conditions in safflower interspecific crosses. Wild relatives of safflower (Carthamus tinctorius L.) are a potential source of favorable genes for its further improvement through interspecific crosses. Therefore, two wild safflower species (C. palaestinus and C. oxyacanthus) were crossed with the cultivated counterpart in 2011. Three interspecific population progenies including C. palaestinus × C. tinctorius (PT), C. tinctorius × C. oxyacanthus (TO), and C. oxyacanthus × C. palaestinus (OP) were developed. Three selection methods including single plant selection (SPS), modified selected bulk (MSB) and modified bulk (MB) were applied at F3 generation in 2013. Selected lines were evaluated in F4 and F5 generations under water stress and non‐stress conditions during 2014 and 2015. The SPS and MSB methods resulted in higher genetic gain compared to MB under both moisture conditions. Even though, SPS and MSB were equally efficient in selecting better genotypes. SPS was much easier, less laborious, faster and cost‐effective method than MSB. A high percentage of agreement was observed between visual selection and selection based on actual yield only for SPS method by evaluating 2920 single plants. Capitulum diameter (CD) was a good criterion for visual selection of superior genotypes in the field condition under both moisture environments. The PT and TO lines that were produced by SPS and MSB methods showed slightly higher values for most measured traits when compared to the lines which were produced by MB selection method. The SPS‐derived lines were slightly earlier on maturity compared to the lines resulted from other selection methods.