Illinois High Oil Research Articles

Development Changes in Oil and Fatty Acid Content of Maize Strains Varying in Oil Content1

Changes in kernel and germ weight, germ percentage, oil percentage, weight of oil produced, and fatty acid distribution were studied in the maize (Zea mays L.) strains ‘Illinois High Oil’ (IHO), ‘Reverse High Oil’(RHO), ‘Illinois Low Oil’ (ILO), and ‘Reverse Low Oil’(RLO) and in a standard F1 hybrid, WF9 ✕ OH43, during the 1964 growing season. Nuclear magnetic resonance (NMR) was used for oil analyses and gas‐liquid chromatography (GLC) for determination of esterified fatty acids.Sixty‐five generations of selection for high oil resulted in: a) early and rapid development of the germ (scutellum and embryo axis), b) larger total germ weight, c) lower total endosperm and kernel weight, d) greater germ percentage, e) greater germ and kernel oil percent, and f) greater percent of total oil residing in the germ. The converse was true in the low oil selections except that total kernel weight was not changed. WF9 ✕ OH43 generally was intermediate for all characteristics, and reverse strains, although resembling the original selections, differed significantly from them for most characters.Percent of total oil was initially higher in the endosperm, but the majority of the oil was located in the germ by 20 days after pollination in the high oil strains, and by 36 days in all strains. A lower percentage of palmitic acid was found in mature than immature (24days after pollination) kernels for all strains. The percentage of oleic acid was lower and linoleic acid higher in the mature kernels and germs of WF9 ✕ OH43, ILO, and RLO.A positive correlation was found between percent oil and oleic acid percent (r = 0.947) and a negative correlation between percent oil and linoleic (r = −0.931) and palmitic (r = −.767) acid content.

Changes in Weight, Germ Ratio, and Oil Content Kernel Development in High Oil Corn (Zea mays L.)1

Changes in kernel and germ weight, germ percentage, oil percentage, and weight of oil were studied in the “Illinois High Oil” strain of corn during the 1962 and 1963 growing seasons. Dry weights of both whole kernels and germs (scutellum plus embryo axis) increased in linear manner from the first sampling date (19 to 21 days) until about the end of the 7th week of kernel development. The ratio of germ to whole kernel dry weight (germ percentage) continued to increase from the first sampling date until the kernel was nearly physiologically mature. Germ oil percentage rose rapidly from around 38% on the first sampling date to 54 to 56% by the end of the 4th week of kernel development, remaining nearly constant from then on. As a result, whole‐kernel oil percentage increased in about the same manner as germ proportion and did not reach maximum level until about the end of the 7th week after pollination.