A case study on the genetic origin of the high oleic acid trait through FAD2-1 DNA sequence variation in safflower (Carthamus tinctorius L.)

Abstract

The safflower (Carthamus tinctorius L.) is considered a strongly domesticated species with a long history of cultivation. The hybridization of safflower with its wild relatives has played an important role in the evolution of cultivars and is of particular interest with regards to their production of high quality edible oils. Original safflower varieties were all rich in linoleic acid, while varieties rich in oleic acid have risen to prominence in recent decades. The high oleic acid trait is controlled by a partially recessive allele ol at a single locus OL. The ol allele was found to be a defective microsomal oleate desaturase FAD2-1. Here we present DNA sequence data and Southern blot analysis suggesting that there has been an ancient hybridization and introgression of the FAD2-1 gene into C. tinctorius from its wild relative C. palaestinus. It is from this gene that FAD2-1Δ was derived more recently. Identification and characterization of the genetic origin and diversity of FAD2-1 could aid safflower breeders in reducing population size and generations required for the development of new high oleic acid varieties by using perfect molecular marker-assisted selection.

Effects of Drought Stress on Oil Characteristics of Carthamus Species

“…Previous studies have shown that C. palaestinus and C. oxyacanthus are more closely related to cultivated safflower than C. lanatus and C. glaucus [23,24]. In the present study there was a positive correlation between relative content of saturated fatty acids and kinship among the five species.…”

“…This species is considered the nearest wild relative and also the progenitor of the cultivated safflower [22]. Introgression of some important genes including oil related ones from C. palaestinus to C. tinctorius is documented [23]. In this study similarity or even the superiority of some C. palaestinus genotypes in respect to oil content was observed when compared with that of C. tinctorius.…”

“…This species is readily crossed with the cultivated safflower and produces viable fertile progenies [8]. These results could be the consequence of better compatibility of C. palaestinus genotypes to the new environment as this species is mainly cultivated in Palestine area and west of Iraq [23]. This finding is supported by higher number of branch, head diameter and grain weight, which all are positively correlated with seed yield (unpublished results).…”

The Use of Wild Relatives of Safflower to Increase Genetic Diversity for Fatty Acid Composition and Drought Tolerance

“…These features indicate that C. palaestinus is a good source of genes to improve C. tinctorius for these traits. Some researchers reported that C. palaestinus was genetically more closely related to cultivated safflower than to C. oxyacanthus (Majidi and Zadhoush, 2014; Rapson et al, 2015). The TO progenies had a higher number of branches per plant and lower plant height.…”

“…and C. oxyacanthus M. Bieb. species are the wild relatives of safflower (Ashri and Knowles, 1960; Majidi and Zadhoush, 2014; Ambreen et al, 2015; Rapson et al, 2015). Cultivated safflower is crossable with both its wild relatives to produce hybrid progenies (Ashri and Knowles, 1960).…”