BACKGROUND

The goal of hybrid development is to combine, in a single hybrid, various desirable traits. For field crops, these traits may include resistance to diseases and insects, resistance to heat and drought, reducing the time to crop maturity, greater yield, and better agronomic quality. With mechanical harvesting of many crops, uniformity of plant characteristics such as germination, stand establishment, growth rate, maturity, and plant and ear height is important. Traditional plant breeding is an important tool in developing new and improved commercial crops.

SUMMARY

Provided is a novel maize,Zea maysL., variety, seed, plant, cells and its parts designated as X08N718, produced by crossing two maize inbred varieties. The hybrid maize variety X08N718, the seed, the plant and its parts produced from the seed, and variants, mutants and minor modifications of maize X08N718 are provided. Processes are provided for making a maize plant containing in its genetic material one or more traits introgressed into X08N718 through locus conversion, backcrossing and/or transformation, and to the maize seed, plant and plant parts produced thereby. Methods for producing maize varieties derived from hybrid maize variety X08N718 are also provided. Also provided are maize plants having all the physiological and morphological characteristics of the hybrid maize variety X08N718.

The hybrid maize plant may further comprise a cytoplasmic or nuclear factor capable of conferring male sterility or otherwise preventing self-pollination, such as by self-incompatibility. Parts of the maize plants disclosed herein are also provided, for example, pollen obtained from a hybrid plant and an ovule of the hybrid plant. Seed of the hybrid maize variety X08N718 is provided and may be provided as a population of maize seed of the variety designated X08N718.

Compositions are provided comprising a seed of maize variety X08N718 comprised in plant seed growth media. In certain embodiments, the plant seed growth media is a soil or synthetic cultivation medium. In specific embodiments, the growth medium may be comprised in a container or may, for example, be soil in a field.

Hybrid maize variety X08N718 is provided comprising an added heritable trait. The heritable trait may be a genetic locus that is a dominant or recessive allele. In certain embodiments, the genetic locus confers traits such as, for example, male sterility, waxy starch, reduced lignin, herbicide tolerance or resistance, insect resistance, resistance to bacterial, fungal, nematode or viral disease, and altered or modified fatty acid, phytate, protein or carbohydrate metabolism. The genetic locus may be a naturally occurring maize gene introduced into the genome of a parent of the variety by backcrossing, a natural or induced mutation, or a transgene introduced through genetic transformation techniques. When introduced through transformation, a genetic locus may comprise one or more transgenes integrated at a single chromosomal location.

A hybrid maize plant of the variety designated X08N718 is provided, wherein a cytoplasmically-inherited trait has been introduced into the hybrid plant. Such cytoplasmically-inherited traits are passed to progeny through the female parent in a particular cross. An exemplary cytoplasmically-inherited trait is the male sterility trait. Cytoplasmic-male sterility (CMS) is a pollen abortion phenomenon determined by the interaction between the genes in the cytoplasm and the nucleus. Alteration in the mitochondrial genome and the lack of restorer genes in the nucleus will lead to pollen abortion. With either a normal cytoplasm or the presence of restorer gene(s) in the nucleus, the plant will produce pollen normally. A CMS plant can be pollinated by a maintainer version of the same variety, which has a normal cytoplasm but lacks the restorer gene(s) in the nucleus, and continues to be male sterile in the next generation. The male fertility of a CMS plant can be restored by a restorer version of the same variety, which must have the restorer gene(s) in the nucleus. With the restorer gene(s) in the nucleus, the offspring of the male-sterile plant can produce normal pollen grains and propagate. A cytoplasmically inherited trait may be a naturally occurring maize trait or a trait introduced through genetic transformation techniques.

A tissue culture of regenerable cells of a plant of variety X08N718 is provided. The tissue culture can be capable of regenerating plants capable of expressing all of the physiological and morphological or phenotypic characteristics of the variety and of regenerating plants having substantially the same genotype as other plants of the variety. Examples of some of the physiological and morphological characteristics of the variety X08N718 that may be assessed include characteristics related to yield, maturity, and kernel quality. The regenerable cells in such tissue cultures can be derived, for example, from embryos, meristematic cells, immature tassels, microspores, pollen, leaves, anthers, roots, root tips, silk, flowers, kernels, ears, cobs, husks, or stalks, or from callus or protoplasts derived from those tissues. Maize plants regenerated from the tissue cultures and plants having all or essentially all of the physiological and morphological characteristics of variety X08N718 are also provided.

A method of producing hybrid maize seed comprising crossing a plant of variety PH2S9H with a plant of variety PH41M2. In a cross, either parent may serve as the male or female. Processes are also provided for producing maize seeds or plants, which processes generally comprise crossing a first parent maize plant as a male or female parent with a second parent maize plant, wherein at least one of the first or second parent maize plants is a plant of the variety designated X08N718. In such crossing, either parent may serve as the male or female parent. These processes may be further exemplified as processes for preparing hybrid maize seed or plants, wherein a first hybrid maize plant is crossed with a second maize plant of a different, distinct variety to provide a hybrid that has, as one of its parents, the hybrid maize plant variety X08N718. In these processes, crossing will result in the production of seed. The seed production occurs regardless of whether the seed is collected or not.

In some embodiments, the first step in “crossing” comprises planting, often in pollinating proximity, seeds of a first and second parent maize plant, and in many cases, seeds of a first maize plant and a second, distinct maize plant. Where the plants are not in pollinating proximity, pollination can nevertheless be accomplished by other means, such as by transferring a pollen or tassel bag from one plant to the other.

A second step comprises cultivating or growing the seeds of said first and second parent maize plants into plants that bear flowers (maize bears both male flowers (tassels) and female flowers (silks) in separate anatomical structures on the same plant).

A third step comprises preventing self-pollination of the plants, i.e., preventing the silks of a plant from being fertilized by any plant of the same variety, including the same plant. This can be done, for example, by emasculating the male flowers of the first or second parent maize plant, (i.e., treating or manipulating the flowers so as to prevent pollen production, in order to produce an emasculated parent maize plant). Self-incompatibility systems may also be used in some hybrid crops for the same purpose. Self-incompatible plants still shed viable pollen and can pollinate plants of other varieties but are incapable of pollinating themselves or other plants of the same variety.

A fourth step may comprise allowing cross-pollination to occur between the first and second parent maize plants. When the plants are not in pollinating proximity, this can be done by placing a bag, usually paper or glassine, over the tassels of the first plant and another bag over the silks of the incipient ear on the second plant. The bags are left in place for at least 24 hours. Since pollen is viable for less than 24 hours, this assures that the silks are not pollinated from other pollen sources, that any stray pollen on the tassels of the first plant is dead, and that the only pollen transferred comes from the first plant. The pollen bag over the tassel of the first plant is then shaken vigorously to enhance release of pollen from the tassels, and the shoot bag is removed from the silks of the incipient ear on the second plant. Finally, the pollen bag is removed from the tassel of the first plant and is placed over the silks of the incipient ear of the second plant, shaken again and left in place. Yet another step comprises harvesting the seeds from at least one of the parent maize plants. The harvested seed can be grown to produce a maize plant or hybrid maize plant.

Maize seed and plants are provided that are produced by a process that comprises crossing a first parent maize plant with a second parent maize plant, wherein at least one of the first or second parent maize plants is a plant of the variety designated X08N718. Maize seed and plants produced by the process are first generation hybrid maize seed and plants produced by crossing an inbred with another, distinct inbred. Seed of an F1 hybrid maize plant, an F1 hybrid maize plant and seed thereof, specifically the hybrid variety designated X08N718 is provided.

Plants described herein can be analyzed by their “genetic complement.” This term is used to refer to the aggregate of nucleotide sequences, the expression of which defines the phenotype of, for example, a maize plant, or a cell or tissue of that plant. A genetic complement thus represents the genetic makeup of a cell, tissue or plant. Provided are maize plant cells that have a genetic complement in accordance with the maize plant cells disclosed herein, and plants, seeds and diploid plants containing such cells.

Plant genetic complements may be assessed by genetic marker profiles, and by the expression of phenotypic traits that are characteristic of the expression of the genetic complement, e.g., isozyme typing profiles. It is understood that variety X08N718 could be identified by any of the many well-known techniques used for genetic profiling disclosed herein.

