Multicellular living organisms and unmodified parts thereof and – Plant – seedling – plant seed – or plant part – per se – Higher plant – seedling – plant seed – or plant part
Reexamination Certificate
1999-04-02
2003-10-28
Fox, David T. (Department: 1638)
Multicellular living organisms and unmodified parts thereof and
Plant, seedling, plant seed, or plant part, per se
Higher plant, seedling, plant seed, or plant part
C800S263000, C800S264000, C800S269000, C800S270000, C800S275000, C435S412000, C435S421000, C435S424000, C435S430000, C435S430100
Reexamination Certificate
active
06639132
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the field of corn plants, and more specifically to improved corn lines having improved nutrative content and to a method for producing such lines.
BACKGROUND OF THE INVENTION
Corn is the major crop on the cultivated land of the United States, where over 70 million acres were planted in 1995. U.S. corn production, accounting for about half of the world's annual production, added over $23.5 billion of value to the American economy in 1995 as a raw material. Products derived from corn are used for human consumption, as raw material for industry and as raw material for the production of ethanol. The primary use of farmer-produced field corn is as livestock feed. This includes feed for hogs, beef cattle, dairy cows and poultry. About 60 percent of corn production is used for feeding livestock and poultry. A small increase in value to this 60% segment of the corn market, such as an increase of 10 cents per bushel, would increase its annual value by $480 million for an eight-billion bushel total corn harvest.
Human consumption of corn includes direct consumption of sweet corn, and consumption of processed-corn products such as cereals and snacks whose manufacture involves extruder cooking (e.g., Cheetos™), ground corn eaten as grits, corn meal and corn flour. Corn oil is also used as a high-grade cooking oil and salad oil, and in margarine. Corn is used in the production of some starches, sugars (e.g., fructose) and syrups. Another important use is in the production of sweeteners, such as corn syrup used in soft drinks.
Wet-milling and dry-milling processes also produce corn starch and corn flour that have applications in industry. These include use as elements of building materials, and in products used in the paper industry and in the manufacture of textiles and starches.
The seed of an inbred corn line, the plant produced by the inbred seed, hybrid seed produced from the crossing of the inbred to another inbred, the hybrid corn plant grown from said seed, and various parts of the inbred and hybrid corn plant can thus be utilized for human food, livestock feed, and as a raw material in industry.
Theories About the Origin of Corn
According to Dr. Beryl B. Simpson of the University of Texas at Austin, there are three main theories on the origin of corn.
1. Tripartite Theory (Mangelsdorf):
The Tripartite Theory suggested in 1939 by Mangelsdorf (Mangelsdorf, P. C. and Reeves, R. G., 1939, The origin of Indian corn and its relatives, Texas Agric. Exp. Stn. Bull. 574:1-315) stated:
A. The ancestor of cultivated maize was both a popcorn and a pod corn. (This point has been borne out by the archaeological record.)
B. Teosinte is not the direct ancestor of maize but instead a taxon produced by hybridization of maize and Tripsacum.
This point in Mangelsdorf's original tripartite theory is controverted by more recent findings indicating that annual teosinte resulted from a hybridization between maize and perennial teosinte
Zea diploperennis.
C. Many modern varieties of maize have undergone genetic introgression from teosinte or Tripsacum or, both either directly or via hybridization with other land races that hold different and distinct genetic blocks or DNA sequences. (Introgression involves incorporation of foreign genetic material into a line of breeding stock.) This notion of the role of introgression has greatly increased understanding of racial variation in maize.
2. “Teosinte as an Ancestor” Hypothesis (Galinat, Beadle)
In this theory, the female “cob” of teosinte became the cob of modern corn and the male inflorescence (tassel) of teosinte is the equivalent of the modern tassel of corn. Galinat has suggested that the differences between corn and teosinte can be reduced to three distinguishing features that separate the teosinte ear from that of a maize cob: a single spikelet per cupule versus two kernels in each cupule in maize, a two-ranked arrangement in teosinte (but appearing single by abortion in the “cob”) as opposed to many-ranked (multiple rows of kernels) in maize, and shattering rachis (cob) in teosinte vs. fused rachis (cob) in maize. The changes in teosinte that led to maize are a consequence of both lateral branch condensation (reduction) and genetic mutations that were favored by humans in the process of domestication.
Galinat has proposed a series of stages leading from teosinte to the primitive maize cob. He discovered them by studying the anatomical origin of the cupule in the maize cob and by breeding teosinte against a background of Nal-Tel corn. Further breeding of the F2 population with teosinte and Nal-Tel resulted in an assorted group of plants including potential ancestral forms. Doebley has recently demonstrated the numbers and locations of the genes responsible for the major differences between corn and teosinte. There are five major genes and some pleiotropic genes involved.
3. CSTT or Catastrophic Sexual Transmutation Theory (Iltis)
According to this theory devised by Hugh Iltis, the modern corn cob is a transformed male teosinte rachis. The socket for the male flower evolved into a cupule to provide support for two developing kernels. Each teosinte spikelet consists of a pair of a fertile and a sterile floret. In the process of sexual transformation, the sterile floret became sexual again, producing two kernels (two-ranked) in each cupule leading to an expressed two-ranked condition. The size of the cob can expand because the male tassel has numerous rachises holding the florets (teosinte fruits are single ranked and pressed to the single rachis). As each tassel branch becomes fertile a longer cob is possible. Furthermore, the initial cob should have four kernel rows as a result of the alternation of floral segments. If these twist around, then the row number increases as the ear becomes more compact. None of these morphological changes require new genes, merely a switch in the development pattern—a switch that is sometimes seen in abnormal corn male tassels.
Recently Etis has modified his view of the “transformation” of male into female inflorescences (still Catastrophic Sexual Transmutation Theory). However, John Doebley has genetic data that show which genes control the characters that cause the differences in the ears of teosinte and maize.
Corn Breeding
Modern commercial corn is generally a hybrid maize plant (
Zea mays L
.) grown from seed of a cross of two inbred lines. Other sources of corn have been neglected because of the vastly superior yield that has developed over time by various breeding programs. Typically, a modern maize inbred line is self-pollinated, sib-crossed, and/or back-crossed in order to concentrate reliably inheritable characteristics into that inbred line.
According to U.S. Pat. No. 5,728,922 issued Mar. 17, 1998 to Albert R. Hornbrook (which is incorporated herein by reference), maize is a highly variable species. For hundreds of years, maize breeding consisted of isolation and selection of open-pollinated varieties. Native Americans developed many different varieties since the domestication of maize in prehistory. Theories about such domestication are described above. During the course of the nineteenth century, North American farmers and seedsmen developed a wide array of open-pollinated varieties, many of which resulted from an intentional or an accidental cross between two very different types of maize: the Southern Dents, which resemble varieties still grown in Mexico, and the Northern Flints, which seem to have moved from the Guatemalan highlands into the northerly parts of the United States and into Canada. The open-pollinated varieties which were developed during this time were maintained by selection of desirable ears from within the variety for use as foundation seed stock. The only pollination control which was practiced to generate the seed was isolation of the seed crop from pollen from other varieties. Experimentation with inbreeding in open-pollinated varieties showed that it invariably led to a marked reduction in plant vigor and stature, as well as i
Duvick Susan A.
Pollak Linda M.
White Pamela J.
Fado John D.
Fox David T.
Ribando Curtis P.
The United States of America as represented by the Secretary of
LandOfFree
Altered fatty-acid, protein, oil, and starch corn lines and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Altered fatty-acid, protein, oil, and starch corn lines and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Altered fatty-acid, protein, oil, and starch corn lines and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3142681