|
UAG stop codon >>> amber codon
UGMS >>> unigene derived microsatellite markers
ultracentrifugation: centrifugation carried out at high rotor speeds (<100,000 rpm) and therefore under high centrifugal forces (<750,000 g) meth
ultracentrifuge: a set-up for high-speed centrifugation between 65,000-100,000 rounds per minute prep
umbel: an inflorescence in which all the pedicels arise at the apex of an axis bot
umbellate >>> umbelliferous plants
umbelliferous plants:
tap-rooted plants with minute flowers aggregated into flat or umbrella-shaped heads (e.g., carrot, parsnip, celery, dill, parsley, etc.) bot
unavailable nutrients:
plant nutrients that are present in the soil but cannot be taken up by the plant roots because they have not been released from the rock by weathering or from organic matter agr
unavailable water:
water that is present in the soil but cannot be taken up by the roots because it is strongly adsorbed on to the surface of particles agr
unbalanced diallelic: a genotype involving a multiple allelic locus in autotetraploids where two alleles are represented an unequal number of
times gene
unbalanced experimental design: an experiment or set of data in which all treatments or treatment combinations are not equally represented; a
common cause of unbalanced experiments is unequal mortality among entries in a test meth >>> randomized-block design
unbalanced translocation: a type of chromosome translocation in which a loss of chromosomal segments results in a deleterious genetic effect cyto
uncomplete block design >>> incomplete block design
unconscious selection:
indirect selection by breeders (sometimes called “parallel selection”) when in addition to a target characteristic another trait is taken to the next generation; it can be a morphological, biochemical, or physiological trait genetically linked to the target characteristic meth
underplant crop: in horticulture, adding one or more complementary, low-growing plants beneath and around taller plants hort; in agriculture, main crops can be underplanted with vegetables; it helps these plants to have some shade in the heat of the summer and one can often get a crop longer than otherwise; wide ranges of combinations between main and underplant crops are possible and are applied for several purposes agr
underreplication:
certain heterochromatic chromosome regions and ribosomal DNA that show a slower replication as compared to the remaining genomic DNA gene
understock: the bottom or supporting part of a graft composed of either root or stem tissue or both hort >>> rootstock >>> graft
understocked:
a stand of trees so widely spaced that, even with full growth potential realized, crown closure will not occur; understocking indicates a waste of resources, as the site is not fully occupied fore
unequal crossing-over:
a crossing-over after improper pairing between chromosome homologues that are not perfectly aligned; the result is, for example, one crossing-over chromatid with one copy of the segment and another with three copies cyto >>> Figure 24
uneven-aged stand: a group of trees of a variety of ages and sizes growing together on a uniform site fore
unicellular: an organism consisting of one cell, e.g., yeast bot bio
unifactorial >>> monogenic
uniflorous: showing one flower only bot
uniform crossover: in genetic algorithms, a breeding technique in which it is randomly decided for each element of a breeding pair of individuals
whether they should be switched stat
uniformity:
describes the state of a population or group in which all the individuals are genetically identical; it is a typical feature of clonal varieties (e.g., potato); in general, lack of diversity within and between plant species is apparent in modern cultivars gene seed
unigene derived microsatellite (UGMS) marker(s): a specific type of molecular markers having the advantage of assaying variation in the expressed component of the genome with unique identity and positions biot
unilateral: the type of panicle (e.g., in oats) where the branches are all turned to one side like a pennant bot
unilateral inheritance: inheritance that is associated with linkage in sex chromosomes gene
uninemic chromosome: a >>> chromosome consisting of one double helix of DNA cyto
Union for Protection of New Varieties of Plants: Union pour la Protection des Obtentions Vegetales (UPOV); it is an intergovernmental organization
with headquarters in Geneva, Switzerland; it is based on the International Convention for the Protection of New Varieties of Plants, as revised since its signature in Paris on December 2, 1961; on April 16,
1993, the Union consisted of 23 member States; the objective of the convention is the protection of new varieties of plants by an intellectual property right
unipolar (spindle): a cell spindle with only one pole cyto
unique event polymorphisms (UEPs): single nucleotide polymorphisms (snips or SNP's) in which a particular nucleotide is changed; since
they are very rare, they also are known as unique event polymorphisms biot meth
unique identifier: an international >>> GMO identification code; every genetically modified organmism that receives authorisation is
given a "unique identifier" consisting of nine letters and/or numbers; the first two or three characters indicate the company submitting the application, while the final five or six characters specify
the respective transformation event; the last digit serves as a verifier; the identification code, known internationally as the unique identifier, was established by the >>> OECD; the OECD is now
overseen by the >>> EU and forms the basis for the legally mandated system of traceability biot org
unisexual: a flower that possesses either stamens or carpels but not both (i.e., a plant possessing only male or female flowers) bot
United States Department of Agriculture (USDA): the U.S. agency responsible for regulation of biotechnology products in plants and animals;
the major laws under which the agency has regulatory powers include the Federal Plant Pest Act (PPA), the Federal Seed Act, and the Plant Variety Act (PVA); in addition, the Science and Education (S and E)
division has nonregulatory oversight of research activities that the agency funds agr
univalent: a single chromosome observed during meiosis when bivalents are also present; it has no pairing mate cyto >>> Figure 15
univalent shift: a spontaneous change in monosomy from one chromosome to another; it is caused by partial asynapsis or desynapsis during meiosis cyto
univalent switch >>> univalent shift
universe >>> population stat
unloader: a device on a combine to transport the grains from a bunker to a transporter agr
unreduced gametes:
gametes not resulting from common meiosis, and so showing the number of chromosomes per cell that is characteristic of a sporophyte; they spontaneously arise as a consequence of irregular division in anaphase I of meiosis; they may contribute to spontaneous (meiotic) polyploidization; in rye, they were used for production of tetraploids via valence crosses cyto
unsaturated fatty acid:
a fatty acid that has a double bond between the carbon atoms at one or more places in the carbon chain; hydrogen can be added at the site of the double bond chem phys
unspecific resistance >>> horizontal resistance
upgrading: the reprocessing of a seed lot to remove low quality seeds or other materials; the remaining seeds are of higher quality than the
original seed meth
UPOV >>> Union for Protection of New Varieties of Plants >>> organizations
upper palea: upper glume >>> pale
upstream:
a term used for description of the position of a DNA sequence within a DNA or protein molecule; it means that the position of the sequence lies away from the direction of the synthesis of a DNA or protein molecule gene
uracil (U):
a pyrimidine base that occurs in RNA and constituent of nucleotides and as such one member of the base pair A-U (adenine-uracil) chem gene
urban forestry: the management of vegetation, particularly trees and forests, to improve the urban environment and the quality of life of people
who live, work, and spend their leisure time in urban and urbanizing landscapes fore >>> forestry
urea: a compound, CO(NH2)2, occurring in urine and other body fluids as a product of protein metabolism; an important plant fertilizer chem agr
uredospore: a sexual spore of the rust fungi bot
ureide: ureides (allantoin and allantoic acid) are important storage and translocatory forms of nitrogen in nodulated legumes; these are
synthesized within the nodules; many tropical legumes including export nitrogen from the nodule in the form of ureides phys
USDA >>> United States Department of Agriculture
USDA-ARS >>> United States Department of Agriculture, Agricultural Research Service >>> organizations
|
