Dictionary I
Breeding Home
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Dictionary A
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Dictionary C
Dictionary D
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Dictionary I
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Rye introgression
Rye gene map
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... more 10.000 glossed keywords and links to more than 100 figures and schemes, about 100 tables etc. can be obtained in addition to this limited INTERNET version either on CD-ROM or in modified design as book by CRC Press, Taylor & Francis Group, Boca Raton, USA

I1, I2, I3, etc.: the first, second, third, etc., generations obtained by inbreeding gene meth

IAA >>> indole-acetic acid

IAEA >>> International Atomic Energy Agency, Vienna, Austria >>> organizations

IBPGR: International Board for Plant Genetic Resources, Roma, Italy; cocoordinating international plant conservation, recently renamed IPGRI >>> organizations

ICARDA >>> International Center of Agricultural Research in the Dry Areas >>> organizations

ICBN: International Code of Botanical Nomenclature >>> organizations

ICIA >>> International Crop Improvement Association

ICRISAT >>> International Crops Research Institute for the Semi-Arid Tropics >>> organizations

identical by descent: two genes that are identical in nucleotide sequence because they are both derived from a common ancestor gene

identical in structure: two genes that are identical in nucleotide sequence, regardless of whether or not they are both derived from a common ancestor gene

identity preservation (IP): a system of crop or raw material management that preserves the identity of the source or nature of the materials agr

ideotype: crop plant with model characteristics known to influence photosynthesis, growth, and grain production phys gene

ideotype breeding: a method of breeding to enhance genetic yield potential based on modifying individual traits where the breeding goal for each trait is specified meth

idioblast: a plant cell committed to develop into a cell type that differs from the surrounding tissue bot

idiochromosome: a chromosome that contributes to the determination of sex cyto

idiogamy: combination of male and female gametes from the same individual bot

idiogram: a diagrammatic representation of the karyotype of a plant cyto >>> Figure 12

idioplasm: all hereditary determinants of a plant including genotype and plasmotype gene >>> germplasm

idiotype: the sum of the hereditary determinants of a cell or plant consisting of the genotype and plasmotype gene

IITA: International Institute of Tropical Agriculture, Ibadan, Nigeria; responsible for groundnut, soybean, sweet potato, cassava, cowpea, and rice research

I-line >>> inbred line

illegitimate crossing-over >>> unequal crossing-over

illegitimate recombination: recombination between DNA fragments that do not share extensive DNA sequence homology; transposons and insertion sequences have special functions that catalyze illegitimate recombination biot

Illinois method: the separate sowing of lines or families and selection of best plants from the best families meth >>> ear-to-row selection

image processing: various mathematical procedures to improve the signal-to-noise and contrast, and to obtain quantitative intensity data from images micr

imbibe >>> imbibition

imbibition: the adsorption of liquid, usually water, into ultramicroscopic spaces or pores found in material such as cellulose, pectin, and cytoplasmic proteins in seeds bot

imidazole: a compound whose molecule forms a pentagonal ring of C and H atoms with an N and NH group attached chem

imino acid: an acid derived from an imine in which the nitrogen of the imino group and the carboxyl group are attached to the same carbon atom chem

immature: not mature or ripe phys

immaturity >>> immature

immersed: embedded in a substrate meth

immersion lens: a special microscopic lens adjusted to place material between the uppermost surface of a microscopic sample (slide or coverslip) and the objective (e.g., immersion oil) micr

immersion medium: material placed between the uppermost surface of a microscopic sample (slide) and the objective (e.g., immersion oil) micr

immigration: in genetics, the movement or flow of genes into a population, caused by immigrating individuals, which interbreed with the residents gene eco

immobile nutrient(s) - festgelegte Nährstoffe m/f pl: nutrients that cannot move around in the plant and, consequently, their deficiency symptoms appear first in the young leaves; immobile nutrients include calcium, boron, sulphur, iron, and copper phys >>> chelating agent >>> chelator

immobilization: the conversion of a chemical compound from an inorganic to an organic form as a result of biological activity phys agr

immune - immun adj: not affected by pathogens; exempt from infection; the condition of having qualities that do not allow the development of a disease phyt

immune reaction - Immunreaktion f: the reaction between a specific antigen and antibody; when plants are inoculated (e.g., with the BUK strain of tomato blacking nepovirus) they are subsequently protected against secondary infection with a similar viral strain, but not against a dissimilar strain of virus phyt

immune response >>> immune reaction

immune system - Immunsystem n: active defense of plants against infections and other invasive aggressions; it detects antigens on the invading entities and creates new antibodies to destroy them phys phyt

immunity - Immunität f: a natural or acquired resistance of a plant to a pathogenic microorganism or its products; it means that a host cannot be parasitized by a particular species of parasite; thus, coffee is immune to wheat rust, and wheat is immune to coffee rust; immunity is a non-variable; the maximum level of horizontal resistance may be an apparent immunity, but it is not true immunity because it is variable, and it can be eroded; vertical resistance has often been called immunity, but it too is an apparent immunity because it operates only against non-matching strains of the parasite phyt

immunity breeding >>> resistance breeding

immunize - immunisieren ver: to make immune phyt

immuno-electrophoresis - Immunoelektrophorese f: a technique for the differentiation of proteins in solution, based on both their electrophoretic and immunological properties; initially the proteins are separated by gel electrophoresis; they are then reacted with specific antibodies by double diffusion through the gel; the pattern of precipiting arcs thus formed can be used to identify the proteins meth sero

immunofluorescence: any of various techniques for detecting an antigen or antibody in a sample by coupling its specifically interactive antibody or antigen to a fluorescent compound, mixing with the sample and observing the reaction under an ultraviolet-light microscope meth

immunogenetics: studies using a combination of immunologic and genetic techniques, as in the investigation of genetic characters detectable only by immune reactions gene

immunochromatography method (for field-level detection of preharvest sprouting in wheat): the method detects alpha-amylase isozymes, using specific antibodies; alpha-amylase from ground grain is extracted with a salt solution and two drops of the extract is added to a zone on a disposable card; the result appears in < 5 min; if the grain is sprouted, amylases in the samples become sandwiched between gold-labeled and immobilized antibodies, and a maroon band appears in the test window; the color intensity depends on the extent of weather damage, with good (negative) correlations between test color and “falling number”; precision is as good as or better than the “falling number” test meth

immunological screening: use of an antibody to detect a polypeptide synthesized from a clone biot

immunoprecipitation: precipitation of antigens with the help of antibodies biot

immunosuppressants: a substance that results in or affects immunosuppression meth sero

impeder: an individual of any value actually impeding the development of another individual of higher grade gene meth

imperfect flower: unisexual flowers; flowers lacking either male or female parts bot

imperfect state (of fungi): the asexual state of a fungus (i.e., the state in which no sexual reproduction occurs) phyt bot

implant: material artificially placed in an organism biot

improvement planting: any planting done to improve the value of a stand and/or experiment and not to establish a regular plantation meth

imprinting >>> genomic imprinting

inarable: a field or land not arable and/or not capable of being ploughed or tilled agr

inarching syn side grafting: a method of grafting; usually a new plant growth onto a stronger root system; it is carried out by establishing young plants (sometimes, one that is in a pot) near an existing tree; at the point where they meet, at the matching areas the bark is removed; the two cut surfaces are then fitted together and bound with soft tying material until they grow together; later they can be gradually separated with the new branches attached to the older rootstock hort >>> graft

inbred: a plant resulting from successive self-fertilization of parents throughout several generations gene

inbred line: a line produced by continued inbreeding; usually a nearly homozygous line originating by continued self-fertilization, accompanied by selection gene

inbred pure lines: involves inbreeding of annual seed-propagated material; homogeneous, homozygous isolated by selection of desired recombinants or segregates in F2 to F7 generations of crosses between parental pure lines (generally monogenotypic, can be blended to form multilines, e.g., tomato, lettuce, soybean, pea, cowpea, snapbean, field bean, Arabian coffee, Capsicum pepper, eggplant, okra, lentil, and papaya) meth

inbred-variety cross: the F1 cross of an inbred line with a variety meth >>> toppers

inbreeding: the crossing of closely related plants; one important purpose of induced inbreeding is the development of genotypes that can be maintained through multiple generations of seed production; self-pollinated cultivars are reproduced for many generations by inbreeding; inbreeding is also used to reduce the frequency of deleterious recessive alleles in genotypes that serve as parents of a synthetic or a vegetatively propagated cultivar; inbreeding increases the genetic and phenotypic variability among individuals in a population; four mating systems are used to increase the homozygosity in a breeding population meth

inbreeding coefficient: the probability that the two genes at any locus in a diploid individual are identical by descent (i.e., they originated from the replication of one gene in a previous generation) gene meth >>> Table 10

inbreeding depression: the reduction in vigor often observed in progeny from matings between close relatives; it is due to the expression of recessive deleterious alleles; it is usually severe in open-pollinated outcrossing species; an effect opposite to heterosis gene >>> heterosis

inbreeding load: the extent to which a population is impaired by inbreeding bio evol >>> Table 10

inbreeding population >>> inbreeding

incertae sedis: of uncertain taxonomic position tax

inch (in): equals 2.54 cm

incipient species: populations that are too distinct to be considered as subspecies of the same species, but not sufficiently differentiated to be regarded as different species; sometimes called “semispecies” tax

inclined draper: a device for separating seeds using an inclined endless belt onto which seeds are metered; seeds are separated on the basis of their different tendencies to roll down the plane or to catch and be carried up and into a separate discharge spout seed

incompatibility (homomorphic or heteromorphic): a genetically determined inability to obtain fertilization and seed formation after self-pollination or cross-pollination; there are several types of progamous or postgamous incompatibility; in contrast to heteromorphic incompatibility (e.g., heterostyly in Primula spp.), homomorphic incompatibility is not associated with morphological differences gene >>> cross-sterility >>> cross-breeding barrier

incompatibility group: plasmids that are incompatible with each other belong to the same incompatibility group biot

incomplete block design:a >>> block design in which not every treatment occurs in a block; it is preferable where large numbers of cultivars are compared in a single yield trial; the entries in each replication are subdivided into smaller blocks, in a manner designed to reduce the error caused by soil variation; usually, it refers to a lattice design, considering the restriction that (1) the number of testers must be harvested, (2) inferior strains cannot be discarded prior to harvest to reduce harvest expenses, and (3) researchers still must analyze the experiment as a lattice design meth stat

incomplete diallel: a partial sampling; any individual family or type of family may be omitted meth >>> complete diallel

incomplete dominance >>> partial dominance

incomplete resistance: a type of resistance that is not complete and shows slow susceptibility to the pathogen phyt

increase (seed): to multiply a quantity of seed by planting it, thereby producing a larger quantity of seeds seed

incubation: the act or process of incubating meth

incubation period: the period between infection and the appearance of visible disease symptoms phyt

incubator: an apparatus in which media inoculated with microorganisms are cultivated at a constant temperature and/or air humidity prep

indehiscent: applied to fruits that do not open to release their seeds bot

indehiscent fruit >>> indehiscent

indent cylinder separator: a seed separator utilizing a rotating indented cylinder through which seeds are passed for cleaning; it lifts shorter seeds from longer seeds, thus separating them seed

indent disk separator: a seed separator utilizing multiple rotating disks inside a cylinder through which seeds are moved; it lifts seeds from longer seeded types, thus separating them seed

independence: the relationship between variables when the variation of each is uninfluenced by that of others, i.e., correlation of zero stat

independent assortment of genes: the random distribution in the gametes of separate genes; if an individual has one pair of alleles A and a, and another pair B and b then it should produce equal numbers of four types of gametes: AB, Ab, aB, and ab; it is asserted in MENDEL’s second law—the law of independent assortment gene >>> Figure 6

independent variables: if two random variables “a” and “b” are independent, then the probability of any given value of “a” is unchanged by knowledge of the value of “b” stat

indeterminate: descriptive of an inflorescence in which the terminal flower is last to open; the flowers arise from axillary buds and the floral axis may be indefinitely prolonged by a terminal bud; in some crops, such as haricot beans, can have either the determinate or the indeterminate habit; with the former, they are self-supporting, bushy plants; and with the latter, they grow as vines; on the other hand, potatoes are determinate plants but, when grafted on to tomatoes, they become indeterminate, and this is a very useful technique when many flowers are needed for the production of true seed for breeding purposes bot

index selection: a form of intentional simultaneous selection; with the index selection some index value is assigned to each candidate; the index value indicates the aggregate value of each candidate across several traits; the index selection consists of truncation selection with regard to the index values meth

indexing US: the process used to test vegetatively reproduced plants for freedom from virus diseases before multiplying them seed

indicator plant: plants that are indicative of specific site or soil conditions; it reacts markedly to the deficiency of a specific input/condition such as the deficiency of plant nutrient, soil moisture stress etc.; e.g., alfalfa, turnip, cauliflower, apple and pear to boron; lettuce to chlorine; barley, maize, oats, onion, apple, tobacco, lettuce, tomato and citrus to copper; sorghum, rice, barley, citrus, peach and cauliflower to iron; oats, maize, bean, pea, radish, apple, apricot, cherry, citrus to manganese; cabbage, cauliflower, citrus, legumes, oats and spinach to molybdenum; maize, onion, citrus and peach to zinc bot agr eco

indigenous: an organism existing in, and having originated naturally in, a particular area or environment bot eco

indirect embryogenesis: embryoid formation on callus tissues derived from zygotic or somatic embryos, seedling plants, or other tissues in culture biot

indirect fluorescence: fluorescence emitted by fluorophores that are not an endogenous part of the specimen; usually introduced into a specimen as a stain or probe micr

indirect organogenesis: organ formation on callus tissues derived from explants biot

indirect selection: the direct selection for specific traits may imply unintentional indirect selection with regard to many other traits meth

indole-3-acetic acid (IAA): a substance that acts as a growth hormone or auxin in plants, where it controls cell enlargement and, through interaction with other plant hormones, also influences cytokinesis phys

indoor culture: growing plants indoors using natural and/or artificial light and additional heating; it is used for subtropical or tropical plants or for plant propagation hort meth

indoor plant >>> indoor culture

induced mutation: a change in a gene caused by a treatment gene

induced resistance: a form of resistance activated in plants by an external stimulus, e.g. elicitor or preinoculation with a microorganism; it an be local or systemic  acquired resistance phyt biot

inducer: an effector molecule responsible for the induction of enzyme synthesis phys

induction: transcription of genes can be induced by inactivation of a repressor or by the action of an activator biot

induction media: media that can induce organs or other structures to form or media, which will cause variation and/or mutation in the tissue exposed to it biot

induction of flowering: the initiation of the production of flowers, possibly stimulated by florigen phys >>> florigen

induction of mutation: the process of causing a variation or mutation gene

industrial crop: crops that are processed on a large scale by industrial means (e.g., potato, pea, lupin, dwarf bean, or cereals for starch production; sugarbeet, beets, sweet sorghum, chicory, or Jerusalem artichoke for sugar processing; linseed, false flax, common marigold, crambe, caper spurge, Cuphea spp., meadowfoam, or jojoba for oil processing; flax, hemp, or nettles for fiber processing; foxglove, poppy, yellow bark, or cocoa for pharmaceutical utilization); industrial uses account for a relatively small but a growing and potentially much larger share of the market for agriculture commodities agr

inert: a chromosomal segment that is supposed to be genetically inactive or without coded genetic information gene

inert matter: one of the four components of a purity test; it includes non-seed material and seed material that is classified as inert according to the rules for testing seeds seed

infect: of a pathogen, to enter and establish pathogenic relationship with an organism; to enter and persist in a carrier; to make an attack on a plant phyt

infection: the invasion of the tissue of a plant by a pathogenic microorganism phyt

infection court: the site on a host plant at which infection by a parasitic organism is affected phyt

infection peg: a thickening of the host cell wall in the vicinity of the penetrating hypha; lignin, callose, cellulose, or suberin may be deposited at this site phyt

infection thread: specialized hypha of a pathogenic fungus that invades tissue of the susceptible plant phyt

inferior: applied to an ovary when the other organs of the flower are inserted above it bot

inferior pelea >>> lemma

infertile: not able to reproduce or not able to produce viable gametes bot

infertility: the situation in which a plant is unable to produce viable offspring bot

infest: attacked by animals (e.g., insects), or sometimes used of fungi in soil in the sense of contaminated phyt

infilling >>> beat(ing) up

inflected: when the keel of the, for example, wheat glume is bent inward in the upper third bot

inflorescence: a flower structure that consists of more than a single flower; the flower head terminates the culm in grasses; it may be determinate (solitary flower, simple cyme, compound cyme, scorpioid cyme, glomerule) or indeterminate (raceme, panicle, spike, catkin, spadix, umbel, head); determinate flowers are those in which the axis terminates as a flower; indeterminate flowers terminate in a bud, which continues to grow and produce flowers throughout the growing season; the latter results in flowers of different maturity within the same inflorescence bot

inflorescence meristem: the relatively undifferentiated, dividing plant tissue that gives rise to the inflorescence bot

infrared light: the part of the invisible spectrum that is contiguous to the red end of the visible spectrum and that comprises electromagnetic radiation of wavelengths from 800 nm to 1 mm phy

infructescence: a fruiting structure that consists of more than a single fruit bot

infundibular: funnel-shaped bot

infundibuliform >>> infundibular

ingraft: to insert, as a scion of one tree or plant into another, for propagation hort meth

inheritance: the transmission of genetic information from parents to progeny gene

inhibitor: a chemical substance that retards or prevents a growth process such as germination phys

injection: the act of injecting meth

inoculant: a preparation containing specific nitrogen-fixing bacteria that is added to legume seed prior to planting to assure that the resulting crop will have nitrogen fixation ability seed

inoculate: to place inoculum deliberately where it will reproduce meth

inoculation: the act or process of inoculating meth; in agriculture, addition of effective Rhizobia (bacteria) to legume seed prior to planting for the purpose of promoting nitrogen fixation agr >>> inoculate

inoculum: spores of other diseased material that may cause infection phyt

inositol: a carbocyclic or sugar alcohol that is widely distributed in plants; important for growth and development; the inositol biosynthesis is regulated by the enzymes myo-inositol phosphate synthase (MIPS) and myo-inositol monophosphatase (IMP); myo-inositol phosphate synthase (mips) genes have been identified in plants chem phys

inositol triphosphate (InsP3): a chemical compound that contributes to the spatial orientation of a plant; for example, when wheat or maize plants are pressed down to the ground, a change of orientation of starch granules occurs in the cells; after a short time (30-120 minutes) InsP3 is accumulated on the lower side of the leaves; so-called motor cells are activated; they grow longitudinal and stepwise upright the plant phys

insect herbivory: plant damage by certain insects (e.g. fall armyworm, Spodoptera frugiperda); it is responsible for about 15 % of the world's crop losses each year phyt

insecticide: a substance or preparation used for killing insects phyt

insect-pollinated plant >>> cross-pollination

insert: a piece of foreign DNA introduced into a phage, plasmid, or other vector DNA biot

insertion: a genetic mutation in which one or more nucleotides are added to DNA, or the process and the result of transferring a foreign DNA or chromosome fragment into a recipient biot

insertion sequence: DNA sequence, which can excise and integrate into DNA without the need for extensive DNA homology biot

insertion vector: cloning vector where the cloned DNA is inserted into a restriction site, as opposed to replacement vectors where a piece of DNA is replaced in the process of cloning biot

insertional duplication: insertion of extra homologous base pairs into a recipient genome, which results in a mutation (by duplicated segments) cyto gene

insertional inactivation of a gene: insertion of a DNA fragment into the coding sequence of a gene usually leads to the inactivation of this gene biot

in silico: the modern term is used to characterize biological experiments carried out entirely in a computer stat bio

in situ: in place; where naturally occurring meth

in situ conservation: refers to the maintenance of plant populations in the habitats where they naturally occur and evolved; in crop species conservation can be achieved in home gardens or on-farm, in wild species through the designation of protected areas, such as natural parks and nature reserves seed eco

in situ hybridization (ISH): a technique to locate those segments complementary to specific nucleic acid molecules; chromosomes, which are treated to denature the DNA and remove RNA and proteins, are then incubated with radioactive labeled nucleic acids or nonradioactive labeled probes of special properties; the hybridized segments are then visualized by autoradiography or directly through the microscope and photography of fluorescent signals cyto meth

inspection: the act of inspecting a pedigreed seed crop by an inspector authorized to report to the official organization on the condition of the seed crop offered for pedigreed status; the inspector reports on varietal impurities, difficult to separate other crop kinds, isolation, objectionable weed content, previous land use and the pedigree of the parent seed planted seed

instability: variation that appears to be random and occurs constantly gene

institutional plant breeding - institutionelle Pflanzenzüchtung f: plant breeding conducted by a large institutes; this kind of breeding is usually expensive and, consequently, it favors cultivars with a wide climatic adaptability org

intake auger (at a harvester): the auger tines guide the crop to the chain conveyor, which delivers it to the threshing section; any foreign bodies that may have been ingested fall into the stone trap, which is located between the conveyor and the concave agr

integrated control >>> integrated plant protection

integrated plant protection: disease and pest control by combining all available techniques, such as agronomic control, biological control, chemical control and sanitary procedures phyt

integument: the coats of the ovule (mostly two), which develop into the seed coat (testa) after fertilization bot

intellectual property rights: a system of patents that allows ownership over the applications of research biot agr seed

intensive crop: a crop that has high profit margins and which consequently justifies considerable expense in its production; horticultural crops are commonly intensive crops, while cereals are usually >>> extensive crops agr hort

intensive forestry: the practice of forestry with the objective of obtaining the maximum in volume and quality of products per unit of area through the application of the best techniques of silviculture and management fore

interagency tag(s): labels or tags applied to pedigreed seed moving from one country or state to another agr seed

interbreeding: intercrossing of individuals within a population meth

intercalary: chromosomal segments located beside terminal regions cyto

intercalary meristem: an internodal meristem, situated between differentiated tissues; it produces cells perpendicular to the growth axis and causing internode elongation bot biot

intercalary segment >>> interstitial segment

intercalate (in a Latin square): it is a subsquare of order 2, i.e., a pair of rows and a pair of columns in whose four positions just two different symbols occur, each twice stat

intercalating agent: a chemical that can insert itself between the stacked bases at the center of the DNA double helix, possibly causing a frameshift mutation chem meth

interchange: an exchange of segments between nonhomologous chromosomes resulting in translocations cyto >>> translocation

interchange trisomic: an additional chromosome to the diploid set, which is composed by two different chromosomes via translocation cyto >>> balanced tertiary trisomic

interchromosomal: effects and processes between chromosomes cyto

interclass variance >>> variance

intercropping: two or more crops produced on the same field at the same time agr

intercrossing: mating of heterozygotes meth

interference: the effect of recombination in one interval on the probability of recombination in an adjacent interval gene

interference distance: the distance within which further crossing-overs may be formed after the previous has been produced away from the centromere gene

interference microscopy: like the phase microscope, the interference microscope is used for observing transparent structures micr

interference range: the distance large enough for forming two crossing-overs without mutual interference cyto

intergeneric cross: spontaneous or experimental crosses of individuals of different genera, for example, wheat (Triticum aestivum) and rye (Secale cereale); this cross even resulted in a human-made new crop plant “triticale” meth >>> Figure 3

intergeneric hybrid >>> intergeneric cross

intergenic: effects and phenomenons between genes gene

intergenic suppressor: a mutation that suppresses the phenotype of another mutation in a gene other than that in which the suppressor mutation resides gene

intergenotypic competition >>> allocompetition

interkinesis: a resting stage that may occur between the first and second meiotic division cyto >>> interphase

interlocking: during meiotic pairing, the intertwisting of nonhomologous chromosomes and/or chromosome configurations cyto >>> Figure 13

intermated recombinant inbreds: another structure of mapping population alike F2, backcross, or near-isogenic lines; the intermating of F2 individuals result in new recombination events; therefore, intermated-recombinant-inbreds populations have improved genetic resolution biot

intermediary: a plant trait controlled by a heterozygous pair of alleles, which result in an intermediate phenotype as compared to the corresponding homozygous genotypes gene

intermediate host: a host essential to the completion of the life cycle of a parasite, but in which it does not become sexually mature phyt >>> host

internal hairs (of the glume): the hairs situated across the upper part of the internal surface of the broad wing in the glumes of, for example, wheat bot

internal inprint: the mark on the inner surface of, for example, wheat glume caused by the pressure of the enclosed lemma and grain bot

International Center of Agricultural Research in the Dry Areas (ICARDA): Aleppo, Syria; responsible for wheat, durum wheat, barley, faba beans, lentil, chickpeas, alfalfa >>> lentil >>> organizations

International Crop Improvement Association (ICIA): former name of the Association of Official Seed Certifying Agencies (AOSCA) seed org

International Crops Research Institute for the Semi-Arid Tropics (ICRISAT): this institute has a global mandate for the improvement of its mandate crops, such as sorghum, pearl millet, chickpea, pigeonpea, and groundnut; these crops are grown on large area worldwide, but generally grown on marginal land by resource-poor farmers agr >>> organizations

International Rice Research Institute (IRRI): the institute is located at Los Banos, Philippines; IRRI is a nonprofit agricultural research and training center established to improve the well-being of present and future generations of rice farmers and consumers, particularly those with low incomes; it is dedicated to helping farmers in developing countries produce more food on limited land using less water, less labor, and fewer chemical inputs, without harming the environment agr >>> organizations

International Seed Testing Association (ISTA): Bassersdorf (Switzerland); the primary purpose of ISTA is to develop, adopt, and publish standard procedures for sampling and testing seeds and to promote uniform application of these procedures for evaluation of seeds moving in international trade; the secondary purpose of ISTA is to actively promote research in all areas of seed science and technology (sampling, testing, storing, processing and distributing seeds), to encourage variety (cultivar) certification, to participate in conferences and training courses aimed at furthering these objectives and to establish and maintain liaison with other organizations having common or related interests in seed seed >>> organizations

internodal cell >>> internode

internode: the part of a stem between two consecutive nodes bot

interphase: a stage in the cell cycle in which there is no visible evidence of nuclear division; therefore sometimes it is called “resting phase” but in which there is intense activity, including replication of chromosomes cyto

interphase nucleus: a nucleus during the stage of interphase in which there is no visible dividing activity, but in which metabolic and synthetic activities are going on cyto

interplot competition: it can be avoided and/or decreased by use of plots with multiple rows in which only plants in the center rows are evaluated; in plots with three or more rows, the outermost rows are designated as the border or guard rows; they may prevent plants in adjacent plots from influencing the performance of plants in the center of the plot stat

interseeding: seeding between sod plugs, sod strips, rows, or sprigs agr

intersex: a class of individuals of a bisexual species that have sexual characteristics intermediate between the male and the female gene

inter simple sequence repeat (ISSR): a >>>PCR-based molecular marker assayof genomic sequence lying between adjacent microsatellites;ISSR primers are anchored at their 3' ends to direct the amplification of the genomic segments between the ISSRs biot meth  >>> simple sequence repeat (SSR)

interspecific: effects and phenomenons between species

interspecific cross: a crossing between two species meth >>> Figure 3

interspecific hybrid: a hybrid between two or more species meth >>> Figures 2, 3

interspecific hybridization: crossing between species meth >>> species hybridization >>> Figures 2, 3

interstitial segment: a chromosome region between the centromere and a site of rearrangement cyto

intervarietal: effects and phenomenons between varieties (cultivars)

intervening sequence: a noncoding nucleotide sequence in eukaryotic DNA, separating two portions of nucleotide sequence found to be contiguous in cytoplasmic mRNA gene

intrabreeding: a mating type in which only individuals of the same populations are combined meth

intrachromosomal: within a chromosome cyto

intragenic: effects and phenomenons within a gene or its physical unit gene

intragenic suppressor: a mutation that suppresses the phenotype of another mutation in the same gene as that in which the suppressor mutation resides gene

intragenotype competition >>> isocompetition

intraspecific: effects and phenomenons within a species

intravarietal: effects and phenomenons within a variety (cultivar)

introduced species: species not part of the original flora of a given area, rather, brought by human activity from another geographical region eco agr

introgression: the incorporation of genes of one species into the gene pool of another; if the ranges of two species overlap and fertile hybrids are produced, the hybrids tend to backcross with the more abundant species; it results in a population in which most individuals resemble the more abundant parents but also possess some of the characters of the other parent species meth

introgressive library: increasing the genetic diversity of elite breeding materials with exotic germplasm requires techniques that minimize negative side effects attributable to genetic interactions between recipient and donor; this seems achievable  by introgression library approach involving the systematic transfer of a limited and/or restricted  number of short donor chromosome segments from agricultural unadapted source (donor) into an elite line (recipient or recurrent parent); established introgression libraries represent a dynamic resource that can substantially foster breeding programs and provide an opportunity to proceed towards functional genomics meth biot

introgressive hybridization: crossbreeding of plants from different species that results in introgression meth

intron: a segment of DNA of unknown function within a gene; it may be transcribed in precursor RNA, but cannot be found in functional mRNA gene

inulin: a polysaccharide in which about 32 b-fructose units are joined in a chain by glyosidic linkages between the first and second carbon atoms on neighboring sugar units; it is found as a storage compound in roots, rhizomes, and tubers of many species of Compositae chem phys

invasion: the spreading of a pathogen through tissues of a diseased plant phyt

invasiveness: ability of a plant to spread beyond its introduction site and become established in new locations where it may provide a deleterious effect on organisms already existing there eco

inversion: a change in the arrangement of genetic material involving the excision of a chromosomal segment that is then turned through 180° and reinserted at the same position in the chromosome cyto

inversion polymorphism: the presence of two or more chromosome sequences, differing by inversions, in the homologous chromosomes of a population gene

inviability: the inability to survive bot

inviable >>> non-viable

in vitro: literally, “in glass;” but applied more generally to studies and propagation of living plant material that are performed under artificial conditions in tubes, glasses, dishes, etc. prep

in vitro collection: a collection of germplasm maintained as plant tissue grown in active culture on solid or in liquid medium; it can be maintained as plant tissue ranging from protoplast and cell suspensions to callus cultures, meristems, shoot-tips, and embryos meth

in vitro culture: the cell, organ, or tissue culture performed under artificial conditions in tubes, glasses, dishes, etc. biot

in vitro fertilization: pollination performed aseptically in vitro by direct application of the pollen to the ovule; it is used to overcome prezygotic incompatibility meth

in vitro marker: a mutation that allows identification in vitro of a cell line possessing the marker biot

in vitro mutagenesis: methods for altering DNA outside the host cells; mutagenesis can be random or specific for the site and base change depending on the technique used biot

in vitro pollination >>> in vitro fertilization

in vitro propagation: propagation of plants under a controlled and artificial environment, usually applying plastic or glass vessels, aseptic techniques, and defined growth media biot

in vitro screening: search and selection for particular characters of cells, organs, or tissues performed under artificial conditions in tubes, glasses, dishes, etc., usually in combination with special nutritional media, which allow a differentiated growth of the cells, etc. biot

in vitro selection: used to screen large numbers of plants or cells for a certain characteristic before growing them in the field or in glasshouses, e.g., salt tolerance meth

in vivo: literally, “in life;” applied to studies and propagation of whole, living organisms, on intact organ systems therein or on populations of microorganisms meth phyt

involucre: a whorl of bracts below an inflorescence bot

involute: having edges that roll under or inwards bot

iodine: a nonmetallic halogen element occurring as a grayish-black crystalline solid that sublimes to a dense violet vapor when heated; used in radiolabeling chem cyto meth

iojap: an idiomatic description of a mutant locus in maize that produces variegation gene

ion: an atom that has acquired an electric charge by the loss or gain of one or more electrons chem

IPGRI >>> International Plant Genetic Resources Institute, formerly IBPGR >>> IBPGR >>> organizations

IPR (protection of new plant varieties): like patent, copyright, trademark and industrial design protection a special protection for new plant varieties is available since 2007; the International Union for the Protection of New Plant Varieties (UPOV) and the TRIPS Agreement provide this protection; the Act of UPOV Convention in 1991 gave this important protection to the plant breeders; the UPOV office is situated in Geneva and it coordinates the Protection of New Plant species; there is a debate in many countries that the plants developed do not satisfy the non-obvious requirement in a patent application system as existing techniques are used and the new breed is obvious; therefore, a unique “sui generis” system is utilized for the Protection of New Plant Varieties; the TRIPS provides a protection for 25 years in case of trees and vines while the protection for other plants is 20 years

iris diaphragm: a composite diaphragm with a central aperture readily adjustable for size in order to regulate the amount of light admitted to a lens or optical system micr

iron (Fe): an element required by plants; it is used in reactions in which rapid reductions occur by the transfer of electrons as in photophosphorylation and oxidative phosphorylation; iron-deficient plants have chlorotic young leaves; at first the veins remain green but later they too become chlorotic; fertilizers containing iron chelates can be added to the soil or sprayed on the leaves to make iron available to the roots and foliage chem phys

irradiate: expose to radiation that may increase the mutation rate of some genes and hence may increase genetic variation; radioaktive irradiation can directly and indirectly cause damage of the DNA molecule; not only the energy of the elelctrons but also the charge of the electrons are causing damage of the molecules; slow and fast electrons may cause mutations methirradiated callus: callus that have been exposed to radiation biot

IRRI >>> International Rice Research Institute >>> organizations

irrigation: to supply land with water by artificial means, as by diverting streams, flooding, or spraying; main types of irrigation are (1) sprinkler irrigation, (2) surface irrigation, (3) subsurface irrigation agr

isoallele: an allele whose effect can only be distinguished from that of the normal allele by special tests gene

isobrachial: a chromosome with a metacentric centromere position resulting in two chromosome arms with equal length cyto >>> metacentric >>> Figure 11

isochromocentric: nuclei showing as many chromocenters as chromosomes cyto

isochromosome: a chromosome with two identical arms; it usually derives from telocentric chromosomes cyto >>> Figure 37

isocompetition: cultivation at high plant density implies the presence of strong interplant competition; when there is no genetic variation, the competition is called isocompetition stat

isodicentric chromosome: a structurally abnormal chromosome containing a duplication of part of the chromosome including the centromere; the resulting structure contains two centromeres and a point of symmetry that depends on the position of the breakpoint cyto >>> Figure 37

isoelectric focu(s)sing (IEF): a technique for the electrophoretic separation of amphoteric molecules in a gradient of pH, usually formed from a combination of buffers held on a polyacrylamide gel support medium; the molecules will move in the gradient, under the influence of an electric field, until they reach their isoelectric pH, where they form a sharp band; separation is achieved because the various molecular species will have different isoelectric values of pH meth

isoenzyme: a species of enzyme that exists in two or more structural forms, which are easily identified by electrophoretic methods phys >>> Table 29

isogamete: male and female gametes that are similar to each other bot

isogamy: the fusion of gametes that are morphologically alike bot

isogeneic: applied to a graft that involves a scion and stock that are genetically identical hort

isogenic: a group of individuals showing the same genotype gene

isogenic lines (vs. random lines): two or more lines differing from each other genetically at one locus only gene

isogeny: the situation that a group of individuals shows the same genotype gene

isograft: a graft or transplant among isogenic (i.e., genetically identical) individuals on the same organism hort

isolate: in general, to make an isolation; in genetics, a segment of a population within which assortative mating occurs gene; in plant pathology, to remove an organism (e.g., a fungus) from the plant in pure form phyt

isolation: the separation of one group from another so that crossing between groups is prevented meth >>> Table 35

isolation requirements: the distance required to isolate pedigreed seed crops from other crops which may be a source of pollen or seed contamination; used by most seed certification agencies as one of the requirements to maintain varietal purity of pedigreed seed crops seed >>> Tables 29, 35

isoleucine (Ile): a crystalline amino acid, C6H13O2, present in most proteins chem phys

isolines >>> isogenic lines

isomer: a chemical compound or nuclide that displays isomerism chem

isomerase: an enzyme that catalyzes a reaction involving the interconversion of isomers chem phys

isomeric: genes that can each produce the same or similar phenotype gene

isoprene (2-methyl butadiene): a 5-carbon compound that forms the structural basis of many biologically important compounds, such as terpenes, etc. chem phys

isoschizomer: restriction endonucleases with identical recognition sequence and cleavage sites, isolated from different bacterial species; it can differ in the amino acid sequence, temperature stability, may require different reaction conditions, and may differ in the sensitivity to DNA methylation biot

isosome: a chromosome showing morphologically and genetically identical arms cyto >>> Figure 37

isosomic: cells or individuals showing isosomes (i.e., chromosomes with genetically and morphologically identical chromosome arms), usually derived from telocentric chromosomes cyto >>> Figure 35

isotelocompensating trisomic: a compensating trisomic; a missing chromosome is compensated by one telocentric and one tertiary chromosome cyto >>> Figure 14

isotertiary compensating trisomic: a compensating trisomic; a missing chromosome is compensated by one isochromosome and one tertiary chromosome cyto >>> Figure 14

isotope: one of two or more varieties of a chemical element whose atoms have the same numbers of protons and electrons but different numbers of neutrons phy

isotope labeling >>> isotopic tracer

isotopic dating: an approach of determining the age of certain materials by reference to the relative abundances of the parent isotope and the daughter isotope; if the decay constant and the concentration of the daughter isotope are known, it is possible to calculate an age meth >>> 14C dating

isotope labeling >>> isotopic tracer

isotopic tracer: isotopically labeled precursors of nucleic acids; the labeled compounds are injected or fed to plants; subsequently, the excretions (solid, liquid or gas) or tissues are analyzed to determine by detection of radioactive tracer how the original compound has been changed; many tracers have been used but most common are 3H, 14C, 32P, and 35S prep meth

isotrisomic: when the extra chromosome shows identical arms cyto >>> Figure 14

isozyme >>> isoenzyme

ISSR >>> inter simple sequence repeat

ISTA >>> International Seed Testing Association >>> organizations

IUCN: International Union for Conservation of Nature and Natural Resources >>> organizations

Ixeris type: diplospory where a syndetic prophase leads to a restitution nucleus, which divides; it is not followed by a cell division; the resulting megaspore contains two unreduced nuclei; two further mitotic divisions lead to an eight-nucleate embryo sac bot

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