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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

gap: single-stranded region in dsDNA biot

gapping >>> beat(ting) up

galactose (Gal): a component of milk sugar (lactose) chem phys

gamete: a specialized haploid cell whose nucleus and often cytoplasm fuses with that of another gamete in the process of fertilization, thus forming a diploid zygote bot >>> Tables 2, 9

gametic selection: the influences acting to cause differential reproductive success of one allele over another in a heterozygote gene

gametocidal >>> gametocide

gametocidal gene: a gene encoding a product that destroys cells that divide to produce the gametes gene

gametocide: a chemical agent used to selectively kill either male or female gametes; it is used in hybrid seed production of autogamous crops (e.g., barley or wheat) meth

gametoclonal: regenerated from a tissue culture originating from gametic cells or tissue biot

gametoclonal variation: variation among regenerants obtained from pollen and/or anther culture biot

gametoclone: plants regenerated from cell culture derived from meiocytes or gametes biot

gametocyte: a cell that will undergo meiosis to form gametes bot

gametogamy: the fusion of the sexual gametes and the formation of the zygotic nucleus bot

gametogenesis: the formation of gametes from gametocytes bot

gametophyte: a haploid phase of the life cycle of plants during which gametes are produced by mitosis; it arises from a haploid spore produced by meiosis from a diploid sporophyte bot >>> Figure 28 >>> Table 16

gametophytic apomixis: agamic seed formation in which the embryo sac arises from an unreduced initial; it includes both diplospory and apospory bot

gametophytic self-incompatibility: self-incompatibility is based on the genotypic and phenotypic relationship between the female and male reproductive system; alleles in cells of the pistil determine its receptivity to pollen; the phenotype of the pollen, expressed as its inability to effect fertilization, may be determined by its own alleles, referred to as gametophytic incompatibility gene >>> self-incompatibility

gamet precision divider: a type of mechanical halving device for subdividing a large seed sample to obtain a smaller working sample for germination or purity analysis; it has an electrically operated rotating cup into which the seed is funneled to be spun out and into one of two spouts seed

gamopetalous: having the petals of the corolla more or less united bot

gangrene of potato: necrosis or death of soft tissue due to obstructed circulation, usually followed by decomposition and putrefaction (Phoma exigua var. foveata) phyt

gap: single-stranded region in dsDNA biot

gas chromatograph: an analytical technique for identifying the molecular composition and concentrations of various chemicals in agricultural products, water, or soil samples meth prep

GAUSS distribution >>> normal distribution

Gaussian curve >>> normal distribution

G banding: a special staining technique for chromosomes that results in a longitudinal differentiation by Giemsa stain, which is a complex of stains specific for the phosphate groups of DNA; the characteristic bands produced are called G bands; these bands are generally produced in AT-rich heterochromatic regions cyto meth >>> differential staining

GCA >>> combining ability (CA) general combining ability

geitonogamy: when neighboring flowers of the same plant can achieve pollination, as opposed to xenogamy bot

gelatin(e): a nearly transparent, glutinous substance, obtained by boiling the bones, ligaments, etc. of animals; used in making jellies chem prep

GEM: genetically engineered microorganism biot

geminivirus: a single-stranded DNA virus that causes serious diseases in cereals, vegetables, and fiber crops worldwide; like nanoviruses, it is transmitted by either whiteflies or leafhoppers; whitefly-transmitted geminiviruses are all in the genus Begomovirus, which typically have bipartite genomes (DNA A and DNA B) comprising circular DNAs of ~2,700 nucleotides, although some have been shown to be monopartite, having only a DNA A component; in contrast, the nanoviruses are a recently established group of plant viruses that are transmitted by either aphids or planthoppers, and have multipartite genomes comprising circular DNAs of ~1,000 nucleotides phyt

gemmiferous: bearing buds bot

gene: the hereditary unit that occupies a fixed position on the chromosome, which through transcription has a specific effect upon phenotype gene; it may mutate to various allelic forms; in molecular biology, a segment of DNA including regulatory sequences (promoter[s], operator[s], terminator) that encodes an RNA and/or protein molecule biot >>> cistron >>> Table 9

gene action: the expression of the gene based on the transcription into complementary RNA sequences, the subsequent translation of mRNA into polypeptides, which may form a specific protein gene

gene activation: different mechanisms of repressing and activation of genes gene

genealogy: descent from an original form or progenitor; ancestry evol

gene amplification: the more or less specific production of multiple copies of a gene gene

gene bank: an establishment in which both somatic and hereditary genetic material are conserved (seeds, pollen, whole plants, extracted DNA); it stores in a viable form, material from plants that are in danger of extinction in the wild and cultivars that are not currently in popular use; the stored genetic material can be called up when required; the normal method of storage is to reduce the water content of seed material to around 4 % and keep it at 0°C or less (–20°C); all stored stocks are periodically checked by germination tests meth >>> gene library

gene center: it refers to the center of origin of a given crop plant evol gene >>> center of diversity >>> center of origin

gene cloning: insertion of a DNA fragment carrying a gene into a cloning vector; subsequent propagation of the recombinant DNA molecule in a host organism results in many identical copies of the gene (clones) in a form that is more easily accessible than the original chromosomal copy gene biot

gene conservation population: a population used to maintain original genetic variation in species meth

gene construction: an experimentally engineered gene with functional and nonfunctional properties gene biot

gene conversion: a process whereby one member of a gene family acts as a blueprint for the correction of the other; this can result in either the suppression of a new mutation or its lateral spread in the genome gene

gene dosage (dose): the number of times a given gene is present in the nucleus of a cell and/or individual gene

gene duplication: a process in evolution in which a gene is copied twice; the two copies lie side by side along the same chromosome gene

gene expression: the phenotypic manifestation of a gene depending on the different levels of gene activation, or the process by which the information in a gene is used to produce a protein; in molecular genetics, the full use of the information in a gene via transcription and translation leading to production of a protein and hence the appearance of the phenotype determined by that gene; gene expression is assumed to be controlled at various points in the sequence leading to protein synthesis; this control is thought to be the major determinant of cellular differentiation gene >>> Table 9


gene family: a group of similar or identical genes, usually along the same chromosome, that originate by gene duplication of a single original gene; some members of the family may work in concert, others may be silenced and become pseudogenes gene


gene flow: the spread of new genes, which takes place within an interbreeding group as a result of crossing with immigrants evol

gene-for-gene theory: in certain plant-pathogen interactions; a gene for resistance in the host corresponds to and is directed against a gene for virulence in the pathogen phyt

gene frequency: the number of loci at which a particular allele is found divided by the total number of loci at which it could occur for a given population, expressed as a proportion or percentage gene

gene insertion: the addition of one or more copies of a normal gene into a defective chromosome biot

gene interaction: modification of gene action by a nonallelic gene or genes, generally the interaction between products of nonallelic genes gene

gene library: in molecular genetics, a random collection of cloned DNA fragments in a number of vectors that ideally includes all genetic information of that species biot

gene linkage >>> linkage

gene location: determination of physical or relative distances of a gene on a particular chromosome gene

gene locus: the fixed position that a gene occupies on a chromosome gene

gene machine: in common literature, an idiomatic description of an automated oligonucleotide synthesizer biotgene map: a graphic presentation of the linear arrangement of a chromosome or segment; it shows the relative distance between loci gained in linkage experiments gene

gene mapping: determination of the position of genes on a DNA molecule biot >>> Figure 89 >>> genetic mapping

gene mutation: a heritable change of gene revealed by phenotypic modifications gene

gene pairs: the two copies of a gene present in a diploid, one on each homologous chromosome gene

gene patenting: protection provided by governmental or nongovernmental institutions to the discoverer of new genes, genotypes, strains, or testing procedures so that the detailed information can be declared publicly; recently, a synthetic gene but not a natural gene itself can be patented, however its sequenced functional unit or specific utilization can be a matter of patent biot

gene pool: the reservoir of different genes of a certain plant species or lower and higher taxa available for crossing and selection; it may be differentiated between (1) primary gene pools (consists of those species that readily hybridize, produce viable hybrids and have chromosomes that may freely recombine), (2) secondary gene pools (consists of those species with a certain degree of hybridization barrier due to ploidy differences, chromosome alterations, or incompatibility genes), and (3) tertiary gene pools (consists of distinct species or higher taxa with strong crossing barriers); in general, the total number of genes or the amount of genetic information that is possessed by all the reproductive members of a population of sexually reproducing organisms gene >>> primary gene pool >>> secondary gene pool

genepool system: it consists of  three informal categories in order to provide a genetic perspective and focus for cultivated plants meth gene

general combining ability >>> combining ability (CA)

general resistance: resistance against all biotypes of a pathogen; nonspecific host-plant resistance phyt

generalized resistance >>> general resistance

general seed blower: a precision seed blower used to aid in separating light seed and inert matter from heavy seed seed

generation time: the time required for a culture to double its cell number biot

generative: sexual processes bot

generative meristem: gives rise to parts, such as floral organs that ultimately produce fruits and seeds bot

generative nucleus: a haploid nucleus of a pollen grain that produces two sperm nuclei by mitosis (pollen grain mitosis) cyto >>> sperm nucleus >>> Figures 25, 35

gene recombination >>> recombination

gene redundancy: the presence of a gene(s) in multiple copies due to polyploidy, polytenic chromosomes, gene amplification, or chromosomal duplications gene

generic: referring to the genus tax

generic diversity: the differences between individuals of different genera evol eco tax

gene redundancy: the presence of a gene(s) in multiple copies due to polyploidy, polytenic chromosomes, gene amplification, or chromosomal duplications gene

gene splicing: combining genes from different organisms into one organism biot

gene stacking: the insertion of two or more (possibly synthetic) genes into the genome (e.g., the bat gene from Bacillus thuringiensis and a gene for resistance to a specific herbicide) biot

gene substitution: the replacement of one allele by another mutant allele in a population by natural or directed selection gene

gene symbol: designating a gene, usually by an abbreviation of the name or description of a given gene; in the past, genes have been described by Latin names, and subsequently the one- to three-letter abbreviations; currently, several systems of naming and symbolization are in use, although a comparable, uniform symbolization is sought gene >>> genetic nomenclature

gene tagging: the labeling of a gene by a marker gene or specific DNA sequence closely linked with the gene in question gene biot

gene targeting: the insertion of antisense DNA molecules in vivo into selected cells of the body in order to block the activity of undesirable genes; these genes might include oncogenes or genes crucial to the life cycle of parasites biot

gene technology: in a broad sense, it is the artificial transfer of genes between cells or individuals by means of molecular and in vitro techniques; prerequisites are (1) the presence of a gene, which is available as a DNA fragment, (2) a clonable DNA, (3) the fragment has to be transferable by different systems, (4) the incorporation of the DNA fragment into a recipient cellular genome has to be feasible, (5) the transformed cells have to be regenerable into a normal plant, and (6) the gene that was transferred must be expressed in the alien genetic background biot

genetic: pertaining to the origin or common ancestor or ancestral type gene

genetic advance: the expected gain in the mean of a population for a particular quantitative character by one generation of selection of a specified percent of the highest-ranking plants gene

genetically modified organisms (GMO): a term, currently used most often in official discussions, that designates crops, which carry new traits that have been inserted through advanced genetic engineering methods, e.g., flavor-saver tomato, roundup-ready soybeans, Bt cotton or Bt maize agr

genetic architecture: the distribution of genetic variation in a species, usually described hierarchically as variation at the regional, local, family and individual levels, and also relating to proportions of additive and non-additive inheritance meth

genetic advance: the expected gain in the mean of a population for a particular quantitative character by one generation of selection of a specified percent of the highest-ranking plants gene

genetic background: the remaining genetic constitution when a particular locus or allele of a given individual or taxon is studied gene

genetic balance: the optimal interaction of coadapted genes, alleles, or genetic systems within a given individual gene

genetic block: the reduction or stop of an enzyme activity caused by a specific gene mutation gene

genetic code: the set of correspondences between base triplets in DNA and amino acids in protein; these base triplets carry the genetic information for protein synthesis gene

genetic complement >>> genome

genetic complementation: the complementary action of homologous sets of genomes gene

genetic correlation: the correlation between the genotypic values of two characters with respect to the genetic character stat gene

genetic death: death of an individual without reproducing; caused by mutationally arisen alleles that reduce the fitness of a genotype and/or taxon gene evol

genetic distance: a measure of gene differences between individuals or populations measured by the differences of several characters; such distance may be based on phenotypic traits, allele frequencies, or DNA sequences (e.g., genetic distance between two populations having the same allele frequencies at a particular locus and based solely on that locus is zero); the distance for one locus is maximum when the two populations are fixed for different alleles; when allele frequencies are estimated for many loci, the genetic distance is calculated by averaging over these loci gene

genetic drift: the random fluctuations of gene frequencies in a population such that the genes amongst offspring are not a perfectly representative sampling of the parental genes gene

genetic engineering: the manipulation of DNA using restriction enzymes, which can split the DNA molecule and then rejoin it to form a hybrid molecule—a new combination of nonhomologous DNA; the technique allows the bypassing of all the biological restraints to genetic exchange and mixing, and even permits the combination of genes from widely differing species biot

genetic equilibrium: an equilibrium in which the frequencies of two alleles at a given locus are maintained at the same values generation after generation; a tendency for the population to equilibrate its genetic composition and resist sudden change is called genetic homoeostasis gene >>> homoeostasis

genetic erosion: the loss of genetic information that occurs when highly adaptable cultivars are developed and threaten the survival of their more locally adapted ancestors, which form the genetic base of the crop gene evol

genetic gain: the change achieved by artificial selection in a specific trait; the gain is usually expressed as the change per generation or the change per year; it is influenced by selection intensity, parental variation, and heritability gene

genetic homoeostasis >>> genetic equilibrium

genetic homology: the identity or near identity of DNA sequences, genes, or alleles gene

genetic information: the information contained in a sequence of nucleotide bases in a nucleic acid molecule gene

genetic instability: different mechanisms that give rise phenotypic variation gene

genetic interaction: the interaction between genes resulting in different phenotypic expressions gene

geneticist: a specialist in genetics gene

genetic load: the average number of lethal mutations per individual in a population gene evol

genetic (linkage) map: the linear arrangement of gene loci on a chromosome, deduced from genetic recombination experiments; a genetic map unit is defined as the distance between gene pairs for which one product of meiosis out of a hundred is recombinant (i.e., it equals a recombination frequency of 1 %) gene

genetic mapping: the process of determination of a genetic map gene

genetic marker: any phenotypic difference, controlled by genes, that can be used for studying recombination processes or selection of a more or less closely associated target gene gene

genetic material: all single- or double-stranded DNA carrying genetic information or that is a substantial part of the genetic information gene

genetic nomenclature: the designation of genes by abbreviated gene descriptions or symbols, usually a beginning capital letter of the abbreviation represents a dominant allele, while a small beginning letter refers to a recessive allele gene >>> gene symbol

genetic polymorphism: an occurrence in a population of two or more genotypes in frequencies that cannot be accounted for by recurrent mutation gene

genetic recombination: a number of interacting processes that lead to new linkage relationships of genes gene

genetic resistance: resistance against pathogens or pests due to specific or general gene action gene >>> passive resistance

genetic resources: the gene pool in natural and cultivated stocks of organisms that are available for human exploitation gene

genetic segregation >>> segregation

genetic sterility: a type of male sterility conditioned by nuclear genes, as opposed to cytoplasmic sterility gene

genetic stock: a variety or strain known to carry specific genes, alleles, or linkage groups gene

genetic system: the organization of genetic material in a given species and its method of transmission from the parental generation to its filial generations gene

genetic targeting >>> gene targeting

genetic variability: individuals differing in their genotypes due to mutational, recombinational, or selective mechanisms gene

genetic variance (Vgen): a portion of phenotypic variance that results from the varying genotypes of the individuals in a population; together with the environmental variance, it adds up to the total phenotypic variance observed amongst individuals in a population; it is divided into additive (resulting from differences between homozygotes, Vadd) and dominance variance (resulting from specific effects of various alleles in heterozygotes, Vdom); Vgen = Vadd + Vdom; the quotient Vadd / Vdom is termed heritability in a narrow sense stat >>> heritability

genetically modified organisms (GMO): a term, currently used most often in official discussions, that designates crops that carry new traits which have been inserted through advanced genetic engineering methods (e.g., flavor-saver tomato, roundup-ready soybeans, Bt cotton, or Bt maize) agr

geneticist: a specialist in genetics gene

genetics: the scientific study of genes and heredity gene

genetic thinning: in seed orchards, it refers to the removal of orchard genotypes based on their supposed breeding value meth hort fore >>> rouging

genetic vulnerability: the susceptibility of genetically uniform crops to damage or destruction caused by outbreaks of a disease or pest or unusually poor weather conditions or climatic change agr phyt

gene transfer: the physical transfer of a gene by crossing, chromosomal manipulation, and molecular means; in biotechnology, different methods are described, such as (1) microinjection, (2) insertion via microprojectiles (particle gun, particle bombardment) using silicon fibers as carriers of the DNA, (3) direct transfer, or (4) a vector-mediated transfer biot >>> Figure 27

gene translocation: the transfer or movement of a gene or gene fragment from one chromosomal location to another; often it alters or abolishes expression gene cyto biot >>> position (positional) effect

geniculate: bent abruptly like a knee bot

genome: the total genetic information carried by a single set of chromosomes in a haploid nucleus; for example, genome sizes: lamda phage 48.5 kb, Escherichia coli 4,500 kb, yeast 1.6 × 104 kb, Drosophila 1.2 × 105 kb; in 2000, the total nucleotide sequence of a plant genome, Arabidopsis thaliana, was for the first time identified; the sequenced genome contains about 120 kb; common wheat has one of the largest genomes with over 150,000 genes as compared to humans with 35,000 or rice with about 40,000; in 2006, the samllest genome size was discovered; the complete genome sequence of the psyllid symbiont, Carsonella ruddii, consists of a circular chromosome of 159,662 base pairs, averaging 16.5 % GC content; it is by far the smallest and most AT-rich bacterial genome yet characterized; the genome has a high coding density (97%) with many overlapping genes and reduced gene length; genes for translation and amino acid biosynthesis are relatively well represented, but numerous genes considered essential for life are missing, suggesting that Carsonella may have achieved organelle-like status gene >>> Tables 8, 14 >>> lamda phage

genome allopolyploids >>> allopolyploid

genome analysis: the study of the genome by combination of cytogenetics, karyotyping, and crossing cyto gene >>> Table 8

genome doubling >>> autopolyploidization

genome formula >>> genome symbol

genome mutation: spontaneous or induced changes in the number of complete chromosomes that result either in polyploids or aneuploids cyto gene >>> Figure 37

genome symbol: the description of specific genome by a symbol, usually a capital letter with or without a specification gene

genomic imprinting: the phenomenon whereby genes function differently depending on whether they are inherited from the maternal or paternal parent; this is thought to be caused by information superimposed on DNA sequences, which is different in male and female gametes; such information is transmitted, or inherited, in somatic cells but usually erased and reset in the germ line; it is due tomethylationof one of the alleles depending of its origing ene

genomic in situ hybridization (GISH): an in situ hybridization technique that uses total genomic DNA of a given species as a probe and total genomic DNA of another species as a blocking DNA; it is based on fluorescence in situ hybridization; it is a useful method to detect interspecific or intergeneric genome differentiation, chromosome rearrangements (translocations), and substitutions or additionscyto meth >>> Figures 77, 78, 79

genomic library: a type of DNA library in which the cloned DNA is from a genomic DNA of the plant and/or organism; since genome sizes are relatively large compared to individual cDNAs, a different set of vectors is usually employed in addition to plasmid and phage biot >>> bacterial artificial chromosomes (BAC) >>> yeast artificial chromosomes (YAC) >>> cosmid

genomics: the scientific study of genes and their role in a structure, growth, health, and disease of a plant (e.g., how a certain number of genes contributes to the shape, function, and the development of the organism) biot

genomic selection (GS): a method in which the number of polymorphic bands resembling the recurrent parent is used as the selection criterion biot

genomic technology: includes DNA synthesis, sequencing, genotyping, and expression profiling, proteomics (peptide synthesis, protein sequencing, and mass spectrometry); more recently, it includes applications of nanobiotechnology, isolation, imaging, and characterization of single molecules meth biot

genotoxic: it refers to substances and circumstances inducing mutants and damage of the heritable material gene

genotype: the genetic constitution of an organism, as opposed to its physical appearance (phenotype); usually, it refers to the specific allelic composition of a particular gene or set of genes in each cell of an organism, but it may also refer to the entire genome gene >>> Tables 2, 9

genotype-environment interaction: besides allelic and non-allelic interactions a third type of interaction, namely between genes and their environment; several statistical procedures; such as analysis of variance, the AZZALINI/COX test, the HILDEBRAND procedure, the KUBINGER approach, and the DE KROON/VAN DER LAAN technique, can be applied for the analysis of genotype environment interactions in cross-classified data sets from cultivar performance yield trials with rows = cultivars and columns = environments (locations and/or years); the procedures HILDEBRAND, KUBINGER and DE KROON/VAN DER LAAN are non-parametric methods based on ranks, while analysis of variance and the AZZALINI/COX test proceed from the original absolute yield data; the AZZALINI/COX and DE KROON/VAN DER LAAN methods are based on the crossover concept of interaction (different rank orders) while the other methods are based on the usual concept of interaction (deviations from additivity of main effects).; for an analysis of usual interactions the procedures HILDEBRAND, KUBINGER and analysis of variance are approximately equivalent; for the crossover concept of interaction, the AZZALINI/COX approach might be recommended, especially if one is particularly interested in rank changes between environments within genotypes gene stat

genotypic: phenomenons and processes that are associated with the genotype gene

genotypic variance >>> genetic variance (Vgen)

genus (genera pl): a taxonomic grouping of similar species tax

genus name: name of a taxonomic group tax

geometric mean: the square root of the product of two numbers stat

geophyte: a land plant that survives an unfavorable period by means of underground food-storage organs (rhizomes, tubers, bulbs, e.g., onions, tulips, potato, asparagus, Jerusalem artichoke, etc.) bot

geotaxis: oriented movement of a motile organism toward or away from a gravitational force bot

germ: the embryo; or a collective name given to the embryonic roots and shoot, and the scutellum tissue of the grain bot

germability: the degree of potential for germination bot >>> germination test

germ cell >>> gamete

germicidal: it refers to any substance or condition that kills the embryo seed

germinal: referring to the germ or germination bot

germinal selection: the selection during gametogenesis against induced mutations that retard the spread of mutant cells gene

germination: the beginning of growth of a seed, spore, or other structure, usually following a period of dormancy and generally in response to the return of favorable external conditions; when it takes place a root is produced that grows down into the soil (e.g., in wild wheat. the dispersal unit bears two pronounced awns thatbalance the unit as it falls; the awns arealso able to propel the seeds on and into the ground; the arrangementof cellulose fibrils causes bending of the awns with changesin humidity; silicified hairs that cover the awns allow propulsionof the unit only in the direction of the seeds; tthe dead tissue is analogous to a motor, fueled by thedaily humidity cycle, the awns induce the motility requiredfor seed dispersal); at the same time, a stem and leaves are growing upwardbot >>> awn

germination test: a procedure to determine the proportion of seeds that are capable of germinating under particular conditions; commonly, a standard germination is conducted on a 400 seed sample at +25 °C for 7 days and seedlings are evaluated in accordance with the Association of Official Seed Analysts (AOSA, Rules for Testing Seeds), several analysts evaluate each sample, all fungal species are identified, and when abnormal seedlings exist the primary abnormal-type is noted seed >>> germinator

germinative cell >>> germ cell

germinator: an apparatus with which seed germination is realized under more or less controlled conditions seed prep

germ line: the lineage of cells from which the gametes are derived and which therefore bridge the gaps between generations, unlike somatic cells in the body of an organism bot

germplasm: the hereditary material transmitted to offspring through the germ cells and giving rise in each individual to the cells gene

germplasm bank >>> gene bank

germplasm collection >>> gene bank

germ pore: an area, or hollow, in a spore wall through which a germ tube may come out bot

germ tube: the filament that emerges when a spore germinates bot phyt >>> pollen tube

gibberellic acid (GA): a group of growth-promoting substances; they regulate many growth responses and appear to be a universal component of seeds and plants phys >>> short-straw mutant >>> aleuron(e) layer

gibberellin: the generic name of a group of plant hormones that stimulate the growth of leaves and shoots; they tend to affect the whole plant and do not induce localized bending movements; they are thought to act either at a transcriptional level or as inducers of enzymes; first isolated from the fungus Gibberella fujikuroi, which causes the Bakanae disease in rice phys phyt >>> aleuron(e) layer >>> short-straw mutant

Giemsa stain >>> banding

gigantism: abnormal overdevelopment due to an increase in cell size (hypertrophy); for example, in roots of crucifers infected with club root (Plasmodiophora brassicae), or abnormal overdevelopment as a result of an increase in the number of cells in response to a disease-production agent (hyperplasia), for example, witches broom, cankers, galls, leaf cure, or scab phys phyt

ginned lint: cotton fibers after they have been removed from the seed agr

GIPB >>> Global Partnership Initiative for Plant Breeding Capacity Building

girdle: the act of removing a band of bark from around a tree trunk hort fore

GISH >>> genomic in situ hybridization

glabrous: without hair or smooth bot

gland: organs or swellings that usually secrete a watery or characteristic substance; many oily and aromatic products are glandular in origin bot

glandular: having or showing glands bot

glass slide >>> heating

glasshouse >>> greenhouse

glassy grain >>> hyaline grain

glaucous: with waxy bloom present on the surface of the plant structure; a whitish, grayish, or bluish appearance is often imparted bot

gliadin: any prolamin and a simple protein of cereal grains that imparts elastic properties to flour; it is a monomeric molecule between 30,000 and 75,000 kDa; it is divided in alpha-, gamma-, and omega-gliadins; it may form large polymeric structures as a result of intermolecular disulfide bonds chem phys >>> Table 15

Global Partnership Initiative for Plant Breeding Capacity Building (GIPB): a multi-party initiative of knowledge institutions around the world that have a track record in supporting agricultural research and development, working in partnership with country programs committed to developing stronger and effective plant breeding capacity;; itwas elaborated in Madrid in June 2006; the goalof the initiative is to enhance the capacity of developing countries to improve crop productivity for food security and sustainable development through sustainable use of plant genetic resources using better plant breeding and seed delivery systems; an internationally facilitated partnershipforms the basis for achieving the goal of the initiative by catalyzing and supporting national, regional and global actionamong relevant international organizations, foundations, universities and research institutes, private sector, civil societies, and national and regional bodies; the office is hosted by FAO Plant Production and Protection Division, Rome, Italy org

globulin: one of a group of globular, simple proteins, which are insoluble or only sparingly soluble in water, but soluble in salt solutions; they occur in plant seeds (mainly in dicots), where they have a variety of functions (e.g., legumin, vignin, glycinin, vacilin, or arachin) chem phys >>> Table 15

glomerule: a very compact cyme; a cluster of flowers bot

glucide >>> carbohydrate

glucose >>> dextrose

glucoside: glucosides are soluble in water and alcohol; some of them are highly poisonous (e.g., saponin, from tung); they are found in vegetative organs and some in seeds (e.g., salicin in bark and leaves of willows; amygdalin in seeds of almonds, peaches, or plums; sinigrin in black mustard; aesculin in horse chestnut seeds; quereitron in the bark of oaks) phys

glume(s): the outermost pair of bractlike structures of each spikelet; a chaff-like bract bot >>> Table 34

glume surface: the upper external surface of the broad wing of the glume (e.g., in wheat, which is described as being rough and/or smooth when scratched with a needle point) bot

glutamate (Glu): a salt or ester of glutamic acid chem phys

glutamic acid: an amino acid (HOOC(CH2)2CH(NH2)COOH) involved in purine biosynthesis, occasionally added to plant tissue culture media; it may replace ammonium ions as the nitrogen source; it is of key importance in pollen growth in vitro chem phys

glutathione: a tripeptide containing glutamic acid, cystein, and glycine capable of being alternately oxidized and reduced; it plays an important role in the cellular oxidation chem phys

gluten: a term that is utilized to refer to a naturally occurring mixture of two different proteins (glutenin and gliadin) in the seeds of, for example, wheat; it is the principal protein in cereal seeds; it consists of a long polypeptide chain; in wheat, it possesses particular elasticity, which allows production of high-quality bread (strength and elasticity of the flour); for example, more of the high-molecular-weight glutenin (which is “stretchy” and imparts physical strength to a dough) results in a flour that is better suited to manufacture high-quality yeast-raised bread products chem phys >>> gliadin >>> glutenin >>> Table 15


glutenin: it is soluble in aqueous or saline solutions or ethyl alcohol; it can also be extracted with strong acid or alkaline solutions; it is found in cereal seeds (e.g., glutenin in wheat or oryzinin in rice); it is divided in a low-molecular-weight glutenin subunit (LMW-GS) and in a high-molecular-weight glutenin subunit (HMW-GS) of about 65,000-90,000 kDa chem phys >>> Table 15


glycerin(e): a three-carbon trihydroxy alcohol that combines with fatty acids to produce esters, which are fats and oils; it may serve as a cryoprotectant chem phys >>> cryoprotectant >>> refraction index

glycerol >>> glycerin(e)

glycine (Gly): an amino acetic acid; the simplest alpha amino acid chem phys

glycinin >>> globulin

glycoll >>> glycine

glycoprotein: a conjugated protein that consists of a carbohydrate covalently lined to a protein chem phys

glycoside >>> glucoside

glycosylation: the attachment of a carbohydrate to another molecule phys

glyoxaline >>> imidazole

glyphosate: a chemical compound used as a herbicide; glyphosate resistance is a subject of biotechnological approaches (e.g., tobacco and tomato transformants may show an overexpression of 5-enolpyruvyl shikimate-e-phosphate synthase [EPSPS], which is usually blocked at normal concentrations by the herbicide); transformed cells, callus, or individuals proved to be tolerant to high glyphosate concentrations phyt biot

gm food >>> genetically modified organisms

GMO >>> genetically modified organisms

GMO testing: polymerase chain reaction detects the presence of a certain DNA sequence and is used to test maize, soybean, rice, cotton and canola tissue resulting in qualitative results; tests for the 35S promoter gene associated with GMO; DNA is extracted from ground material; a certain section of the DNA is replicated numerous times to attain sufficient DNA to identify the promotor through electrophoresis; electrophoresis separates different size particles, allowing the 35S promoter to be detected when compared to a known 35S sample meth seed

GOLGI apparatus: a system of flattened, smooth-surfaced, membranaceous cisternae, arranged in parallel 20-30 nm apart and surrounded by numerous vesicles; a feature of almost all eukaryotic cells; this structure is involved in the packaging of many products of cell metabolism bot

goodness of fit: methods to test the conformity of an observed empirical distribution function of data with a posited theoretical distribution function (e.g., chi-square test) by comparing observed and expected frequency counts; the KOLMOGOROV-SMIRNOV test calculates the maximum vertical distance between the empirical and posited distribution functions stat

gossypol: a dark pigment, C30H30O8, derived from cottonseed oil chem phys

gradation: the successive increase of organisms in a more or less cyclic or spontaneous pattern evol eco

gradient: a gradual change in a quantitative property over a specific distance or time prep

graft: to transfer a part (a small piece of tissue or organs) of an organism from its normal position to another position on the same organism (autograft) or to a different organism or species (heterograft); the stem or shoot that is inserted into a rooted plant is called the scion; the plant or part of a plant into which the scion is inserted is called the stock or understock; there are many different methods of grafting (e.g., wood grafting, cleft grafting, stub grafting, bark grafting, awl grafting, veneer grafting, bud grafting, flat grafting, split grafting or side grafting); sometimes the term is used in order to describe the point where a scion is inserted in the stock hort >>> transplant >>> scion

graft chimera >>> graft hybrid

graft hybrid: a plant made up of two genetically distinct tissues due to fusion of host and donor tissues after grafting hort

grafting: the joining together of parts of plants; the united parts will continue their growth as one plant hort

grafting tape: tape backed with biodegradable cloth; used in budding and grafting operations and in banding tree wounds hort

grafting thread: a fine-waxed string used in budding and grafting operations hort prep

grafting wax: a wax or related substance that is used to cover all injured parts of the rootstock and the scion after grafting and thus prevent infection by fungi or bacteria prep hort

grain: a cereal caryopsis that may or may not be enclosed by the lemma an palea bot >>> corn

grain grade: a market standard established to describe the amount of contamination, grain damage, immaturity, test weight, and marketable traits seed meth

Gramineae: any of the monocotyledonous, mostly herbaceous plants, having jointed stems, slender sheathing leaves, and flowers borne in spikelets of bracts; the species in which the cereals are included appeared during the Cretaceous period (136-65 million years ago) bot evol; generally, in grassland agriculture the term does not include cereals when grown for grain but does include forage species of legumes often grown in association with grasses agr >>> Table 32

gramineous >>> Gramineae

GRAM’s stain: an important bacteriological staining procedure discovered empirically in 1884 by the Danish scientist C. GRAM; a technique used to distinguish between two major bacterial groups based on stain retention by their cell walls; bacteria are heat-fixed, stained with crystal violet, a basic dye, then with iodine solution; this is followed by an alcohol or acetone rinse; GRAM-positive bacteria are stained bright purple; GRAM-negative bacteria are decolorized; safranin is used to stain them meth

granary: a storehouse or repository for grain agr

granum (grana pl): stacks of circular thylakoids, composed of lamellae in higher green plant chloroplasts, containing pigments and other essential components of photosynthetic light reactions bot

grape sugar >>> dextrose

grasses >>> Gramineae

gravitational water: the water that flows freely through the soil in response to gravity agr

gravity separator: a machine utilizing a vibrating porous deck and air flow to separate seed on the basis of their different specific gravities seed

gray level: the brightness of pixels in a digitized video and/or computer image; for an 8-bit signal, this ranges from 0 (black) to 225 (white) micr

graze: the eating of crops by animals in the field agr

green chop: green plants cut into small sections for animal feed agr

gray level: the brightness of pixels in a digitized video and/or computer image; for an 8-bit signal, this ranges from 0 (black) to 225 (white) micr

green fluorescent protein (GFP): protein from the jelly fish, Aequorea victoria (Scyphozoa); the gene is used as a reporter gene; it fluoresces in UV light; several variants have been developed, which each exhibit characteristic spectra; a significant advantages are that the protein can be seen in living tissue and are not toxic biot

greenhouse: a building, room, or area, usually of glass, in which the temperature is maintained within a desired range; used for cultivating tender plants or growing plants out of season prep hort

green manuring >>> green manure crops

green manure crops: crops that are grown for the purpose of being ploughed into the soil to improve soil fertility and organic content; phacelia may be a green manure crop in some regions, as are various legumes, such as lupins; the crops are ploughed into the soil while they are still green agr

green revolution: advances in genetics, petroindustry, and machinery that culminated in a dramatic increase in crop productivity during the third quarter of the twentieth century agr

grid design: for the grid design, plants or variants are divided into blocks and the best ones chosen from each stat >>> Figure 32

grist: a mixture of grain (e.g., wheat or barley) utilized by, for example, the miller for grinding or the maltster for producing malt; grist may contain a mixture of several varieties meth prep agr

grits >>> semolina

groat: the caryopsis of oats after the husk has been removed agr seed

ground germination rate >>> field germination

group coancestry: the probability that two genes taken from a gene pool of a population are identical by decent, or the average of the cells in a coancestry matrix for the population concerned stat meth >>> coancestry

group merit: the genetic merit of a group as a function (weighted average or index) of its breeding value and gene diversity; it is an index to quantify the merit of a group as a weighted average of its advance in breeding value and its loss in gene diversity relative to some reference population stat meth

group merit progress: group merit changes over generations, mainly as breeding produces a genetic gain but at the same time a loss; group merit progress (per year) takes genetic gain, gene diversity and time into consideration, and ought thus be a good measure of the progress in breeding meth stat

group merit selection: maximising the group merit of selections given the candidates and group merit measure; the selection method was initially called „population merit selection“ stat meth

group-selection method: a method of regenerating and maintaining uneven-aged stands in which trees are removed in small groups meth fore

growth form: the form of a plant; the habit in which a plant grows (e.g., shrubby plant, climbing plant, leaf plant etc.) bot >>> growth habit >>> habit

growing tray: a tray having compartments like an ice-cube tray, used for starting seeds hort prep

growing tray: a tray having compartments like an ice-cube tray, used for starting seeds hort prep

growth analysis: a mathematical analysis of crop or plant growth using relative growth rate, net assimilation rate, leaf area growth rate, and crop growth rate agr phys

growth curve: a curve showing the change in the number of cells in a growing culture as a function of time phys

growth form: the form of a plant; the habit in which a plant grows (e.g., shrubby plant, climbing plant, leaf plant, etc.) bot >>> growth habit >>> habit(us)


growth habit: the mode of growth of a plant; crops may be classified as (1) annuals (e.g., barley), (2) biennials (e.g., sugarbeet), or (3) perennials (e.g., alfalfa) phys


growth inhibitor: any substance that retards the growth of a plant or plant part; almost any substance will inhibit growth when concentrations are high enough; common inhibitors are abscisic acid and ethylene; other inhibitors, such as phenolics, quinones, terpens, fatty acids, and amino acids affect plants at very low concentrations phys >>> growth promoter

growth promoter: a growth substance that stimulates cell division (e.g., cytokinin) or cell elongation (e.g., gibberellin) phys >>> growth inhibitor

growth rate (of crop): the crop growth rate is a specific plant growth analysis term denoting the absolute growth rate of mass per unit land, etc. phys agr

growth regulator: despite natural growth regulators, a synthetic compound that, when applied to a plant, promotes, inhibits, or otherwise modifies the growth of that plant phys >>> brassinosteroid >>> cytokinin >>> gibberellin

growth stages syn developmental stage: the discrete portion of the life cycle of a plant, such as vegetative growth, reproduction, or senescence; there are systems to various crops in order to subdivide the broad physiological and/or morphological stages phys


growth substance: a naturally occurring compound, other than a nutrient, that promotes, inhibits, or otherwise modifies the growth of a plant phys

GS >>> genomic selection

guanidine: a crystalline, alkaline, water-soluble solid, CH5N3, used in making resins chem phys

guanine (G): a purine base that occurs in both DNA and RNA chem gene

guanylic acid: guanosine monophosphate; a ribonucleotide constituent of ribonucleic acid that is the phosphoric acid ester of nucleoside guanosine chem

guard cell: a specialized type of plant epidermal cells; two of which surround each stoma; changes in their turgidity cause stomatal opening and closing bot phys >>> photosynthesis >>> respiration

Guidelines for Classifying Cultivated Plant Populations: a regulation act of USA approved in 1978; it appeared as  appendix to the Federal Seed Program Review (1980), which gives more precise definitions of the various categories of cultivated varieties seed

guidepost >>> landmark

GUS gene: a gene that codes for production of beta-glucuronidase (GUS protein) in Escherichia coli bacteria biot

guttation: the tearlike extrusion of water and sometimes salts from the aerial parts of plants, particularly at night when transpiration rates are low; it is the process of water being exuded from hydathodes at the enlarged terminations of veins around the margins of the leaves bot; in biotechnology, used for exudation of specific proteins made by artificially inserted genes biot

gymnosperm(ous): a kind of plant that produces seeds but not fruits; the seeds are not borne within an ovary and are called naked bot

gymnosperms >>> gymnosperm(ous)

gynaecium >>> gynoecium

gynandromorph: an individual exhibiting both male and female sexual differentiation gene

gynic: female bot

gynodioecy: plant species or population in which female plants as well as hermaphroditic plants occur bot

gynoecious >>> gynoecium

gynoecium: the collective term for the female reproductive organs of a flower, comprising one or more carpels bot

gynophore: the stalk that pushes pollinated peanut flowers into the soil bot

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