Ploidy is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here sets of chromosomes refers to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair—the form in which chromosomes naturally exist. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present : monoploid, diploid, triploid, tetraploid, pentaploid, hexaploid, heptaploid or septaploid, etc. The generic term polyploid is often used to describe cells with three or more sets of chromosomes.
The oat, sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name. Oats appear to have been domesticated as a secondary crop, as their seeds resembled those of other cereals closely enough for them to be included by early cultivators. Oats tolerate cold winters less well than cereals such as wheat, barley, and rye, but need less summer heat and more rain, making them important in areas such as Northwest Europe that have cool wet summers. They can tolerate low-nutrient and acid soils. Oats grow thickly and vigorously, allowing them to outcompete many weeds, and compared to other cereals are relatively free from diseases.
Polyploidy is a condition in which the cells of an organism have more than two paired sets of (homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two complete sets of chromosomes, one from each of two parents; each set contains the same number of chromosomes, and the chromosomes are joined in pairs of homologous chromosomes. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis; the sporophyte generation is diploid and produces spores by meiosis.
Triticale is a hybrid of wheat (Triticum) and rye (Secale) first bred in laboratories during the late 19th century in Scotland and Germany. Commercially available triticale is almost always a second-generation hybrid, i.e., a cross between two kinds of primary (first-cross) triticales. As a rule, triticale combines the yield potential and grain quality of wheat with the disease and environmental tolerance of rye. Only recently has it been developed into a commercially viable crop. Depending on the cultivar, triticale can more or less resemble either of its parents. It is grown mostly for forage or fodder, although some triticale-based foods can be purchased at health food stores and can be found in some breakfast cereals.
Avena is a genus of Eurasian and African plants in the grass family. Collectively known as the oats, they include some species which have been cultivated for thousands of years as a food source for humans and livestock. They are widespread throughout Europe, Asia and northwest Africa. Several species have become naturalized in many parts of the world, and are regarded as invasive weeds where they compete with crop production. All oats have edible seeds, though they are small and hard to harvest in most species.
Durum wheat, also called pasta wheat or macaroni wheat, is a tetraploid species of wheat. It is the second most cultivated species of wheat after common wheat, although it represents only 5% to 8% of global wheat production. It was developed by artificial selection of the domesticated emmer wheat strains formerly grown in Central Europe and the Near East around 7000 BC, which developed a naked, free-threshing form. Like emmer, durum wheat is awned. It is the predominant wheat that grows in the Middle East.
Spelt, also known as dinkel wheat or hulled wheat, is a species of wheat. It is a relict crop, eaten in Central Europe and northern Spain. It is considered a health food since it is high in protein. It is comparable to farro.
Dactylis is a genus of Eurasian and North African plants in the bluegrass subfamily within the grass family. Dactylis is native to North Africa, they are found throughout the world, and are an invasive species. They are known in English as cock's-foot or cocksfoot grasses, also sometimes as orchard grasses.
Avena sterilis is a species of grass weed whose seeds are edible. Many common names of this plant refer to the movement of its panicle in the wind.
During 10,000 years of cultivation, numerous forms of wheat, many of them hybrids, have developed under a combination of artificial and natural selection. This diversity has led to much confusion in the naming of wheats. Genetic and morphological characteristics of wheat influence its classification; many common and botanical names of wheat are in current use.
Triticeae is a botanical tribe within the subfamily Pooideae of grasses that includes genera with many domesticated species. Major crop genera found in this tribe include wheat, barley, and rye; crops in other genera include some for human consumption, and others used for animal feed or rangeland protection. Among the world's cultivated species, this tribe has some of the most complex genetic histories. An example is bread wheat, which contains the genomes of three species with only one being a wheat Triticum species. Seed storage proteins in the Triticeae are implicated in various food allergies and intolerances.
Arachis villosulicarpa is a perennial peanut species, which is cultivated by indigenous people in Mato Grosso, a state of Brazil. Its wild progenitor is thought to be Arachis pietrarellii. Although it is related to the common peanut, Arachis hypogaea, it was separately domesticated: A. villosulicarpa is diploid, whereas A. hypogaea is tetraploid.
Hordeum brachyantherum, known by the common name meadow barley, is a species of barley. It is native to western North America from Alaska to northern Mexico, coastal areas of easternmost Russia (Kamchatka), and a small area of coastal Newfoundland.
A crop wild relative (CWR) is a wild plant closely related to a domesticated plant. It may be a wild ancestor of the domesticated (cultivated) plant or another closely related taxon.
Avena barbata is a species of wild oat known by the common name slender wild oat. It has edible seeds. It is a diploidized autotetraploid grass (2n=4x=28). Its diploid ancestors are A. hirtula Lag. and A. wiestii Steud (2n=2x=14), which are considered Mediterranean and desert ecotypes, respectively, comprising a single species. A. wiestii and A. hirtula are widespread in the Mediterranean Basin, growing in mixed stands with A. barbata, though they are difficult to tell apart.
Hedera cypria is a species of Ivy which is endemic to the island of Cyprus. The species is a climbing plant. It is natively found in higher altitudes in Cyprus. H. cypria has unique trichomes and fruits to separate it from closely related plants. It is not considered an invasive ivy where it is found in the United States.
Robert Wayne Allard was an American plant breeder and plant population geneticist who is widely regarded as one of the leading plant population geneticists of the 20th century. Allard became chair of the genetics department at University of California, Davis in 1967; he was elected to the National Academy of Sciences in 1973, and was awarded the DeKalb-Pfizer Distinguished Career Award and the Crop Science Science of America Award. He was honored as the Nilsson-Ehle Lecturer of the Mendelian Society of Sweden and as the Wilhelmine Key lecturer of the American Genetic Association. He also served as president of the Genetics Society of America, the American Genetic Association and the American Society of Naturalists.
Kesara Margrét Anamthawat-Jónsson is professor of botany and plant genetics at the Faculty of Life and Environmental Sciences, School of Engineering and Natural Sciences, University of Iceland.
Ernest Robert Sears was an American geneticist, botanist, pioneer of plant genetics, and leading expert on wheat cytogenetics. Sears and Sir Ralph Riley (1924–1999) are perhaps the two most important founders of chromosome engineering in plant breeding.
Avena byzantina, red oats, is a species of cultivated oat native to Greece, Turkey, Cyprus, the Transcaucasus, Iran, and Saudi Arabia. Cultivated for thousands of years, it is better suited to warmer conditions than white or common oats, but is often sown as a no‑till winter crop. There are 564 landraces and 203 cultivars of red oats listed in the European Plant Genetic Resources Search Catalogue (EURISCO). Approximately 10% of the millions of hectares worldwide under oats are devoted to red oats, principally for fodder.
