back-lappingSee lapping, mower.
backgrounding Intensive management of young cattle (post weaning) to facilitate maximum performance.
bacteriophage A virus that infects a bacterium. Bacteriophages are widely applied in recombinant DNA technology. Usage: Usually shortened to phage.
balanced diallelic The genotype involving a multiple allelic locus in an autotetraploid where two different alleles are represented an equal number of times (e.g., a1a1a2a2).
ball roll The distance a ball moves (i) after striking the ground upon termination of its air flight, (ii) as a result of a putting stroke, or (iii) as a result of hand-imparted motion, as in lawn bowling.
BAP (1) Bacterial alkaline phosphatase, the enzyme from Escherichia coli that is used to remove 5' terminal phosphate groups from DNA chains to prevent recircularization of vector molecules during gene cloning experiments. (2) Benzylaminopurine, a cytokinin.
bare fallow Complete inversion and incorporation of residues for maximum decomposition, done to prevent the growth of all vegetation; usually associated with summer fallow.
base pair Two nucleotide bases on different strands of the nucleic acid molecule that form hydrogen bonds between them. The bases can pair in a single way only: adenine with thymine (in DNA) or uracil (in RNA), and guanine with cytosine. Usage: Indicate base pairs with a raised dot (e.g., adenine-thymine or A-T).
batch drying Drying seed in relatively small quantities held in a stationary position, as opposed to drying in a continuous moving line.
bench setting Height that the cutting plane of a mower is set above a hard, level surface.
bicollateral vascular bundle A vascular bundle with phloem on both sides of the xylem instead of on the outer side only.
bifunctional vectorSee shuttle vector.
bioassay (1) The use of living organisms to quantitatively estimate the amount of biologically active substances present in a sample. (2) In cell biology and molecular genetics: determination of the effectiveness of a compound by measuring its effect on plants or animal tissues or organisms in comparison with a standard preparation.
biological containment A strategy to reduce the risks of recombinant molecules propagated within microorganisms being released into the general environment.
biomass The weight of living organisms (plants and animals) in an ecosystem, at a given point in time, expressed as fresh or dry weight.
bioreactor Culture vessel used for large-scale bioprocessing.
biotinylated DNA DNA labeled with biotin by incorporation of biotinylated dUTP. It is used in place of radioactive probes in hybridization analyses. Hybridization is detected by use of a complex of streptavidin-biotin-horseradish peroxidase that produces green fluorescence at the location of hybridization.
bird resistance A characteristic of a genotype or individual plant in which it is avoided by birds until other food sources are exhausted, or until the plant is weathered.
blend, seed A combination of seed of varieties and/or composite-cross populations of the same kind, each present in excess of 5% by weight of the whole, and derived by growing the component varieties and/or composite-cross populations separately and mixing seed to form the commercial class of seed. Synonym: mixture, seed (Def. 1); but compare mixture, seed (Def. 2).
bloom Of sorghum: Characterized by the presence of a white, waxy, or pruinose (i.e., a whitish dust) covering on the leaves and stems. Antonym: bloomless.
bloom, full The developmental stage at which essentially all florets in the inflorescence are in anthesis.
blooming In the grass family: the period during which florets are open and anthers are extended. Synonym: anthesis.
blot (1) To transfer DNA, RNA, or protein, usually from an electrophoretic gel to an immobilizing matrix such as diazobenzyloxymethyl (DBM) paper, nitrocellulose, or nylon membranes. (2) The autoradiograph obtained from hybridization analysis after the transfer. See also electroblotting; northern blot; Southern blot; western blot.
body weight, fat-free Conceptually, in livestock, empty body weight minus body fat; in practice, generally determined from the ratio of carcass specific gravity to body specific gravity.
bollsize Weight in grams of seed cotton from one boll.
bomb calorimetry Process whereby a substance is completely oxidized in 25 to 30 atmospheres (~2.5 to 3.0 MPa) of oxygen (O2) to determine gross energy content.
botanical variety An infraspecific taxon in botanical nomenclature, below the rank of subspecies. Abbr.: var. Usage: The abbreviation in roman type; the name, in italics; no capitals. Compare cultivar.
bp The symbol for base pair, a measure of the size of a double-stranded nucleic acid. Usage: The SI prefix k may be used, but the symbol changes: 1000 bp = 1 kb (not 1 kbp).
bran Pericarp of grain.
breaking load The maximum force applied to a structure in a tensile test carried to rupture.
broadcast sprigging Vegetative turf establishment by broadcasting and covering of stolons, rhizomes, or tillers with soil.
browning The reaction between reducing sugars and free amino groups in proteins to form a complex that undergoes a series of reactions to produce brown polymers usually referred to as melanoidins. Higher temperatures and basic pH favor the reaction. The process is desirable for flavor and aroma in certain food processing situations (e.g., toasting bread) but is detrimental in other situations (e.g., drying seed and food products).
browse (1) Leaf and twig growth of shrubs, woody vines, trees, cacti, and other nonherbaceous vegetation available for animal consumption. (2) v. To consume browse in situ (of animals). Compare forage; graze.
bulk densitySee test weight.
bunchgrassSee bunch-type growth habit.