Novel variation for the tocopherol profile in a sunflower created by mutagenesis and recombination

Abstract

a-Tocopherol is the main tocopherol in sunflower seeds (>90%). Because it exerts a weak antioxidant action in vitro, its partial replacement by other tocopherols is an important breeding objective in this crop. The objective of this research was to develop novel tocopherol profiles in sunflower through mutagenesis and genetic recombination. Seeds of four ÔPeredovikÕ accessions were used for chemical mutagenesis with ethyl methane sulfonate (EMS). Singleseed screening in the M 2 generation resulted in two M 2 seeds, derived from different M 1 plants, with increased c-tocopherol contents of 19.2% and 96.7%, respectively. M 3 progeny from the M 2 seed with the 96.7% content bred true for high c-tocopherol content, containing more than 90% c-tocopherol. M 3 progeny from the M 2 seed with only 19.2% c-tocopherol segregated in a range from 0 to 84.6%. Selection for high c-tocopherol content produced an M 4 : 5 line, designated IAST-1, with a stable high concentration of c-tocopherol. Crosses between IAST-1 and T589, with an increased b-tocopherol content, produced F 2 segregants with transgressive levels of up to 77% b-tocopherol or up to 68% d-tocopherol. Both novel tocopherol profiles were confirmed in the F 3 generation.Tocopherols are the most important antioxidants in sunflower seeds. They exert an antioxidant protective action both in biological systems (in vivo or by vitamin E activity) as well as in oils, fats and food (in vitro antioxidant activity) (Kamal-Eldin and Appelqvist 1996). The tocopherols occur as a family of four derivatives named a-, b-, c-, and d-tocopherol, which differ in their in vitro and in vivo antioxidant efficiency. a-Tocopherol has a maximum vitamin E activity, but its in vitro activity is relatively low. Conversely, b-, c-, and d-tocopherol possess a lower vitamin E value, but they are better in vitro antioxidants than a-tocopherol (Pongracz et al. 1995).Sunflower seeds mainly contain a-tocopherol, which accounts for more than 90% of the total tocopherols. b-and c-tocopherol can be present in sunflower seeds, usually in amounts below 5% of the total tocopherols (Demurin 1993, Velasco et al. 2002. The modification of the tocopherol profile through a partial substitution of a-tocopherol, with its weak in vitro antioxidant action, by other tocopherol derivatives is an important goal for developing sunflower oil with improved oxidative stability (Sˇkoric´1992). Breeding efforts in this direction during the past decade have led to the development and characterization of several sources of modified tocopherol profiles in sunflower. Through a strategy based on evaluation of germplasm of wild and cultivated sunflower, Demurin (1993) and Demurin et al. (1996) isolated two lines with contrasting tocopherol profiles. The line LG-15, with increased concentration of b-tocopherol (50% of the total tocopherols), was developed from the open-pollinated variety ÔVNIIMK 8931Õ, whereas the line LG-17, with increased concentration of c-tocopherol (95% of the total tocopherols), was isolated from a germplasm...

Effects of refining process on sunflower oil minor components: a review

“…This content can vary within genotypes (Ayerdi Gotor et al, 2006;Velasco et al, 2002) and environmental conditions during cultivation (Ayerdi Gotor et al, 2006, 2015. The tocopherols composition could also be modified (Velasco et al, 2004) (Tab. 2) but is not linked with the composition of fatty acids (Ayerdi Gotor et al, 2014).…”

“…Data from Fernández-Moya et al, 2006;Ghazani and Marangoni, 2013;Gunstone, 2011;Marmesat et al, 2008;O'Brien, 2009; ND = Non Detectable; SO = Sunflower Oil; HOSO: High Oleic Sunflower Oil, MOSO = Mid Oleic Sunflower Oil; HSHOSO = High Stearic High Oleic Sunflower Oil; HPHOSO = High Palmitic High Oleic Sunflower Oil. Gotor et al, 2007Gotor et al, , 2014Gunstone, 2011;Marmesat et al, 2008;Velasco et al, 2002Velasco et al, , 2004; ND = Non Detectable; SO = Sunflower Oil; HOSO: High Oleic Sunflower Oil, MOSO = Mid Oleic Sunflower Oil; HPHOSO = High Palmitic High Oleic Sunflower Oil.…”

Variabilité des teneurs et compositions des composés mineurs dans l’huile de tournesol au cours du développement du capitule

“…Une stabilité de l'expression des performances variétales, et une variabilité génétique suffisante pourraient rendre possible la sélection de variétés hybrides avec des teneurs en tocophérols élevées, voire de combiner cette sélection avec la production de profils modifiés, comme cela se fait déjà pour les acides gras. Des transformations stables du profil des tocophérols par mutagenèse ont d'ailleurs été récemment obtenues chez le tournesol [36,37]. Ainsi, les données collectées au cours de ces travaux permettent de montrer que les teneurs en tocophérols pourraient être augmentées par sélection variétale, et peut-être aussi en veillant à la conduite culturale.…”

“…Ainsi les températures élevées [34,35] ou le déficit hydrique [35] ont une influence négative sur la teneur de l'akène en tocophérols. Concernant le tournesol, la teneur totale et la composition en tocophé-rols est influencée par le génotype [27,[36][37][38] et par les effets environnementaux (lieu de culture) [30]. Toutefois, à notre connaissance aucune étude n'a été entreprise afin d'établir et de compléter les cinétiques de remplissage des akènes en tocophérols à l'aide de plusieurs génotypes et années de culture.…”

Breeding for specialty oil types in sunflower

“…All these traits are usually under embryonic control by a reduced number of genes (see review in: Fernández-Martínez et al, 2004) which facilitate their management in breeding programs. For example, three genes are involved in the control of high levels of palmitic (P1, P2, P3) and high stearic acid content (Es1, Es2, Es3) and one or two genes in the control of low levels of these fatty acids.…”