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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

vacilin >>> globulin

vacuole: a transparent vesicle that is usually large and singular in mature cells but small in some meristematic cells; it is filled with a dilute solution that is isotonic with the cytoplasm bot

valence cross: crossing of individuals of different ploidy level; a method, for example, used in production of tetraploid rye varieties by crossing a tetraploid genotype as female and a diploid as male, respectively; tetraploid F1 seeds could be selected by green-grained xenia on a pale-grained mother plant, caused by fusion of reduced gametes of the mother plant (carrying a recessive allele for pale seed color) with unreduced gametes of the male parent (carrying the dominant allele for green seed color) meth

valine (Val): an aliphatic, nonpolar amino acid chem phys

value-added grains >>> nutrient-enhanced varieties

value-enhanced grains >>> nutrient-enhanced varieties

variability: the sum of different genetic or phenotypic characters within different taxa gene

variance: when all values in a population are expressed as plus and minus deviations from the population mean, the variance is the mean of the squared deviations; it is a measure of variation of a population; it can be divided into phenotypic variance, genotypic variance, and environmental variance stat

variance balance: a >>> block design is variance-balanced if the variances of the best estimators of all the normalized treatment contrasts are equal stat

variant: any seed or plant which (a) is distinct within the variety but occurs naturally within the variety, (b) is stable and predictable with a degree of reliability compared to other varieties of the same kind, within known tolerances; and (c) is described as a variation in the official variety; it is not an off-type, and only considered an impurity if reported in excess of the acceptable level specified by the responsible breeder seed

variate: a single observation or measurement stat

variation: differences in form or function between individuals or other taxa gene

variegate >>> variegation

variegation: the phenomenon in some plants in which patches of two or more different colors occur on the leaves or flowers; it may be an inherited characteristic or may be due to virus infection bot

varietal hybrid: the product resulting from the mating of two varieties meth

varietal protection >>> protected variety

varietal purity: trueness to type or variety agr meth

variety: a plant differing from the other member of the species to which it belongs by the possession of some hereditary traits; breeding varieties can be classified according to the manner of propagation, such as clone varieties (maintained by vegetative propagation), line varieties (maintained by self-fertilization), panmictic varieties (propagated by cross-fertilization) or hybrid varieties (produced by directed crosses) meth

variety listing: it refers to a list of new varieties recommended for agriculture and horticulture; after official performance tests, only those varieties that meet the standards are accepted for a national or international variety list; important for variety listing are the testing for value and use as well as distinctness, homogeneity, and stability of the candidates seed agr

variety machine: a term introduced by N. F. JENSEN illustrating his breeding program; it refers to a segmented time process composed of from 10 to 15 annual input segments of homozygous selections, each of which decreases in number with attrition over time until all of the selections in a segment disappear, either through discard or elevation to parent or variety status; the “machine” is fed with about 10,000 new selections annually; not much time is needed to spend on the so-called “annual procedural flow”; most time should be spent on quality of the material fed into the “machine”; the production of superior fixed lines can be more or less automatic meth >>> Figure 42

variety maintainer: a special status elite parent seed or select/foundation plot seed grower recognized by an official organization (e.g., Canadian Seed Growers’ Assoication) as eligible to produce breeder, inbreds or hybrid seed under the supervision of a plant breeder recognized by the organization agr meth

variety mixture: a composite population made up of a random mixture of different varieties; it may exhibit considerable phenotypic variation in one or more characters, but which have one or more desirable agronomic traits in common agr >>> blend

variety release: the official approval of a variety for multiplication and distribution seed

vascular: furnished with vessels or ducts bot

vascular bundle: a discrete, longitudinal strand that consists principally of vascular tissue bot

vector: an organism capable of transmitting inoculum phyt; in genetics, a vehicle, such as a plasmid or virus, for carrying recombinant DNA into a living cell gene

vegetation: a collection of plants of diverse or the same species eco

vegetational analysis: any of various methods of studying small (sample) areas of constituent plants, often counting the numbers of plants of communities to make extrapolations to a larger area (e.g., estimating the yield) meth agr

vegetative: applied to a stage or structure that is concerned with feeding and growth rather than with sexual reproduction bot gene

vegetative cone: in flowering plants, the vegetative cone consists of three different layers; they are called dermatogen (L1), subdermatogen (L2), and corpus (L3); from the dermatogen the epidermis is formed, from the subdermatogen the mesophyll and the gametes, and from the corpus the vascular bundle, the flesh, the pith, and the adventitious roots; the cell division of the dermatogen and the subdermatogen is usually anticline in other words, vertical to the layer (in this way the layers show surface expansion); the cell division of the corpus is usually periclinal (i.e., the cells divide parallel to the layers) bot

vegetative meristem: gives rise to parts, such as stems, leaves, roots, etc. bot

vegetative nucleus: the tube-nucleus of a pollen grain in a flowering plant bot >>> Figures 25, 35

vegetative propagation: a reproductive process that is asexual and so does not involve a recombination of genetic material (e.g., cloning of potato) meth >>> Figure 28

vegetative reproduction >>> vegetative propagation

vegetative stage >>> whorl stage

vein >>> veinure

veinure: threads of fibrovascular tissue in a leaf or other organ, especially those that branch bot

venation >>> nervature

venom >>> toxicity

venomous: toxic phys

ventral: the inner side, furrowed in the grain of, for example, wheat, barley and in the caryopsis of oats bot

ventral furrow: the groove running along the length of the ventral side of the caryopsis bot

ventral groove >>> ventral furrow

vermiculite: a porous form of mica, a mineral that makes good rooting media for seed germination because of its capacity to retain moisture and permit aeration meth

vernalin: a hypothetical hormonelike substance found in plant meristematic regions, produced by vernalization; this substance is apparently graft transmissible, but has not yet been identified; different cold-requiring species may form different substances during vernalization phys

vernalization: the treatment of germinating seeds with low temperatures to induce flowering at a particular preferred time; in the genetic model plant, Arabidopsis thaliana, a gene Flc suppresses the formation of flowers during cold periods; another gene Vrn2 triggers that suppression; however, in spring the suppression is raised in a way that the gene “remembers” the previous cold period, because the gene Vrn2 itself is cold-insensitive; there is a similar gene in Drosophila melanogaster, which also serves like “chemical memory” meth phys

vernation: the arrangement of bud scales or young leaves in a shoot bud bot

vertical gene transfer >>> outcrossing

vertical resistance: the existence of differential levels of resistance to different races of a given pathogen conditioned by one or a few qualitative genes phyt >>> resistance

verticilate: whorled bot

viability: the probability that a fertilized egg will survive and develop into an adult organism; the term is also often applied to plant germination experiments with comparisons across phenotypic classes under standard specific environmental conditions phys seed

viable: capable of germinating, living, growing, or sufficiently developed physically as to be capable of living phys seed

vibrator separator: a machine utilizing a vibrating deck for separating seeds on the basis of their shape and differing surface textures seed

vicilin: a protein common in broad bean phys

video microscopy: microscopy that takes advantage of video as an imaging, image-processing, or controlling device micr

vignin >>> globulin

vigor test: vigor tests of seed determine the potential ability to develop into normal, healthy plants under a wide range of field conditions; stress tests, accelerated ageing and other techniques are used to provide a more sensitive index of seed quality; poor emergence, dormancy, seed deterioration and other quality factors can be identified through vigor testing seed

http://www.plantstress.com

vine: climbing plants with woody or herbaceous stems that climb, twist, adhere, or scramble over other taller objects; they can climb by tendrils, aerial roots, twining stems, twining leafstalks, adhesive disks, or hooks bot

vine-growing >>> viticulture

vine-louse: a plant louse (Phylloxera vitifoliae) that injures the grapevine phyt

viniculture >>> viticulture

virescence: greening of tissue that is normally devoid of chlorophyll (e.g., the abnormal development of flowers in which all organs are green and partly or wholly transformed into structures like small leaves) phyt

virion: an individual virus particle gene

viroid: a piece of infectious nucleic acid; in plant pathology, any of a class of plant pathogenic agents consisting of an infectious, single-stranded, free RNA molecule gene

virulence: the relative ability of a microorganism to overcome the resistance of a host phyt >>> aggressiveness

http://www.EpiLogic.de

virulent >>> virulence

viruliferous aphids: aphids acting as vector for plant viruses phyt zoo

virus: a type of noncellular “organism,” that has no metabolism of its own; a nucleoprotein entity that can replicate within living cells; it passes through bacterium-retaining filters bot gene

virus-free plant: a plant that shows no sign of viral particles or symptoms phyt

viscid: sticky bot

vital coloring test >>> vital staining

vital dye >>> vital staining

vital staining: a stain that is capable of entering and staining a living cell without causing an injury meth cyto seed >>> fluorescin diacetate (FDA) staining

vitamin: an organic compound produced by plants (often functions as a coenzyme) that is required in relatively small amounts in the diet for the normal growth of animal organisms phys

vitamin B1 >>> thiamine

vitamin E >>> tocopherol

vitamin H >>> biotin(e)

viticulture: the science, culture, or cultivation of grapes and grapevines hort

vitreous grain: characterizing slightly translucent kernels agr >>> Figure 70

viviparity >>> viviparous

viviparous: a process promoting the germination of embryos while still attached to the mother plant; applied to a plant whose seeds germinate within and obtain nourishment from the fruit; it refers also to a plant that reproduces vegetatively from shoots rather than an inflorescence bot

vivipary >>> viviparity

vivisection: the action of cutting into or dissecting a living body meth

vivotoxin >>> pathotoxin

volunteer >>> self-sown cereals >>> volunteer plants

volunteer plants: plants that have resulted from natural propagation, as opposed to having been deliberately planted by humans seed

vomitoxin (syn deoxynivalenol, DON): itis a naturally occurring >>>mycotoxin produced by several species of Fusarium fungi; wet and cool weather from flowering time to maturity promotes infection, resulting in scab or head blight in barley, wheat, oats, and rye; wheat infected with scab has a tendency to have lighter weight kernels, some of which are removed during normal harvesting and cleaning operations phyt

vulnerability: crop vulnerability is defined as susceptibility to an absent, foreign parasite that has epidemiological competence in the area in question; some crop vulnerabilities are particularly severe, e.g., the vulnerability of potatoes in Ireland to blight phyt

v/v: may indicate simple proportion (e.g., 3:1 v/v); may indicate percent volume in volume meth

vybrid: the first- and subsequent-generation progenies of crosses of heterozygous facultative apomicts bot

© by R. Schlegel 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

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