Basic Information - Genetics, Genomics and Breeding of Crop Plants - page 12

as the predominant form, and -tocopherol found in only two samples at

very low levels. Tocopherol concentration does not appear to be related to
saturated fatty acid concentration, so breeding for both can be accomplished
at the same time.
Demurin (1993) developed the first high -tocopherol line, LG-15, with

-tocopherol comprising 500 g/kg of the total tocopherols, and the first
high lines, LG-17 and LG-24, with tocopherol contents of 950 and 840 g/

kg of -tocopherol, respectively. Velasco et al. (2004b) have released two

germplasm lines, T589 with

-tocopherol compositions of 340 to 542 g/kg,

and T2100 with 850 g/kg of -tocopherol.

New variations of the tocopherol profile have been created by the use of
the chemical mutagen ethyl methanesulfate (EMS) creating lines IAST-540
and IAST-1 with a -tocopherol content of 940 g/kg (Velasco et al. 2004c).

Crosses between lines IAST-1 and T589 led to the production of IAST-5,
with 700 g/kg -tocopherol and 300 g/kg -tocopherol, and IAST-4 with

respective -tocopherol contents of 40, 30, 340, and 580 g/kg of

the total tocopherol composition.
Warner et al. (2008) found that when the

, -, - and

-tocopherol content of
mid-oleic NuSun ® oil was increased from its regular level of 20 to 300-700
ppm, the oxidative stability of the oil increased significantly compared to
NuSun ® oil with its normal low γ -tocopherol level. The modified oils had

-tocopherol contents up to 300 ppm without negatively affecting the
stability of the oil. An oil with one of the best oxidative stabilities had a
tocopherol profile of 479 ppm

, indicating that
the oxidative stability of modified NuSun ® could be improved and still be a
good source of vitamin E.

, 100 ppm and 300 ppm

1.3 Crop History

1.3.1 Origin and Domestication

During the past 50 years, Heiser (1951, 1954, 1965, 1978, 1985, 1998)
developed the following scenario for the origin and development of the
domesticated sunflower from its progenitor, wild H. annuus . Prior to the
arrival of mankind in the New World, H. annuus was restricted to the
southwestern USA. Wild H. annuus was used by Native Americans for food,
and due to its association with humans, it became a camp-following weed
and was transported eastward. This weedy sunflower was subsequently
domesticated in central USA and carried to the east and southwest.
There is strong archaeological support for the origin of the domesticated
sunflower from the central and eastern states in the USA. Large achenes
(> 7 mm in length) have been found at several archaeological sites in the
central and eastern states, whereas only wild sunflower achenes have been