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APPENDIX- VIII
GLOSSARY
Abnonnal seedlings: Thase seedlings which dO'nat shaw the patential to'
develap intO'a narmal plant when grown in gaod quality sail under favaurable
canditians.
Achene: A dry indehiscent, ane seeded fruit, with the seed caat distinct from
the fruit wall.
Accelerated aging test: A seed vigaur test that assesses the patential af a
seed lat in prolanged ambient starage.
Accept Number: A number small enaugh to' lead to' the decision that the seed
lat has nO'foreign seed af the species in questian.
Caryopsis:
Naked grass-fruit in which the seed coat is united with the fruit wall.
CWamydospores : An asexual spore ariginatingby modificatianaf a hyphal
segment and possessing an inner secondary wall impregnated with hydraphabic
material.
Cold test: A seed vigaur test that measures the patential af a se~d lat subjected
to' law temperature during emergence.
Coleoptile: The sheath enclasing the shoot apex af certain species that protects
the plumule as it emerges (e.g. in Gramineae).
Coleorhiza: A transitary membrane covering the roat apex in same species
that protects the radicle as it emerges (e.g. in Gramineae).
Conductivity test: A seed vigaur test designed to' measure the electrical
conductivity af leachates from seeds after saaking in water.
Controlled deterioration:. A method to' manitor vigaur level af seeds by
subjecting them to'a predetermined maisture content and then incubating them at
high temperature (50°C) avernight.
Cotyledon:
Seed leaves af the embryO'. In mast dicotyledan seeds they are
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thickened and are storage sites of reserve food for use by germinating seedling.
Decanted: Drained off.
Decay: Break-down of organic tissue, usually associated with the presence of
microorganisms.
Defective seedling: A seedling that is damaged, deformed or decayed to such
an extent that normal development is prevented.
Deficiency: An apparent deficiency exists if an estimate is less than a 'first'
estimate or a specification for a desired attrihutc. or if an estimate is more than a
first estimate of a specification for an undesirable attribute.
Dicotyledons:
A group of plants so classifed because the embryo usually has
two cotyledons (see 'monocotyledons').
Discolouration: Alternation or loss of colour.
Dormancy: The state of inhibited growth of viable seeds, even in the presence
.
of otherWisefavourable germinating conditions, duc to external factors.
Electrophoresis: A method for seperating and mapping protein bands from
homogenizedseed(orplant)preparations.Tnesepcrationare madcwithin'agdlpreparation acre&;an electricalfield.It is usedin cultivaridentificationandcultivarpurity.
.
Embryo: The generative part ora seed that develops from the union of egg
cell and sperm cell and during germination becomes the young plant.
Endosperm: Nutritive tissue originating from fertilisation and retained at
maturity in some seeds as a storage tissue for food reserves and provides nutrition
to the growing embryo. It develops from sexual fusion of the polar nuclei of the
ovule and the second sperm cell.
Enzyme: Enzymes are specialised proteins capable of promoting chemical
reactions without themselves enteringinto the reaction; consequently they are not
changedor deStroyed. .
Epicotyl: The part ofthe seedling axis immediately above the cotyledons and
below the primary leaf or pairofleaves.
.
. .
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Epi~eal germination:
A type of germination in which cotyledons and shoot
are carried above the soil by the hypoC<?tylelongation (see 'hypogealgermination
').
Ergot: Dark spur shaped sclerotium that develops in place of a healthy seed
in a diseased int1orescence.Disease of cereals and grasses.
Esti mate: Any determ inat ion of the va lue of a seed attribu te from exam ination
of a sample.
(i) First estimate is an stimate which is tested by a second estimate and by a
one-way test. The first estimate is one stated by a vendor, or on a label, an invoice,
or an international certificate.
(ii) Second estimate is one used to test<thefirst estimate by a one-way test.
The first estimate is usually made before the second but it need not be. When two
estimates are compared by a two-way test, the estimates are not distinguished as
first and second. The 'first' is by or for a vendor and 'second' is by or for a buyer
of an officiaL
Excised embryo test: A quick test for evaluating the growth potential of a
root-shoot axis that has been detached from the remainder of the seed.
First count: A seed vigour test which measures the rapidity of germination
before the final count.
Floret: The lemma and palea with enclosed pistil and stamens or the mature
caryopsis in Gramineae.
Fresh ungerminted: Seed<;,other than hard seeds, which remain firm and
apparently viable even after the appropriate treatment lor breaking dormancy.
Foreign seed: Undesirable seed. It includes weed seed and other crop seed.
Formazon: The compound formed after the reduction of tetrazolium
chloride/bromide in the seed. It is pinkish to red in colour and insolouble in water.
Geotropism: Plant growth response to gravity.
Germinable: The ability of the embryo to resume growth and develop into a
normal seedling.
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Germination: The resumption of growth by the embryo and development of
a young plant from the seed. Germination, in a laboratory test, is the emergence
and development from the seed embryo of those essential structures which for the
kind of seed being tested indicate the ability to develop into a normal plant under
favourable conditions.
Germination cabinet: i\ type of seed germinator in which temperature and
rclativehumidity
could be controlled and most commonly u~ed ina seed laboratory.
Germination index: Summation of number of seedlings emerging on a
specific day divided by the number of day on which the germination was counted.
Genetic purity: Trueness to type or cultivar.
Gibberellic acids: A group of plant growth promoting chemicals used to
overcome seed dormancy.
Glumes: The pairof chaffy bracts that occur at the base of grassspikelet, often
completely closing it.
Glutamic
Acid Decarboxylase
Activity test (GADA): A bio-chemical
vigour test which meausres the activity of GAD enzyme present in the seed.
Hard seeds: Seeds which remain hard at the end of prescribed test period
because of non-imbibition of water due to impermeable seed coat.
Hiltner test: AL<;oknown as brick gravel test. A vigour test designed to assess
the potential of a cereal seedling to emerge from a specified layer of brick gravel.
Hilum: A scar remaining on the seed at the place of its detachment from the
seed stalk.
HuskIess seed: The seeds of paddy which arc completely devoid of husk
(dehullcd seeds. rice).
lIypocotyl: The part of the embryo axis between the cotyledons and primary
root which gives rise to the stalk of the young plant.
lIypogeal germination: A type of germination in which the cotyledons
remain in the soil while the epicotyl grows and emerges above the ground.
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.Imbibition: The initial step in seed germination involving the uptake of water
by absorption from the germination media and hydration of the seed tissue.
Inert Matter: Inert matter includes seed units and all other matter and
structures that are not defined as pure seed, other crop seed or weed seed.
Infection: Entrance and spread of disease organisms in living material (e.g.
seedlingStructures).not necessarilybut oftencausing disease symptoms and decay.
Inseparable
other crop seeds: Seeds of crop species specified as inseparable
other crop seeds for a seed crop in Indian Minim urn Seed Certification standards
(For classification as other crop seeds or inert matter, in a purity analysis the rules
. described under pure seed shall be applicable).
Leachate: When seeds are removed from water after imbibing for a certa~n
period of time containing water soluble substances.
Lemma: One or two bracts of the grass floret; it is located on the side nearest
the embryo and opposite the rachilla.
Looped stmcture:
Seedling structure (e.g. hypocotyl.
coleoptile) which
completes a loop or cirde instead of being more or less straight.
Lot: A seed lot is a physically identifiable quantity of seed which is
homogeneous.
Mericarp:
One section of a two to many sectioned schizocarpic fruit, seperat-
ing at maturity into indehescent one-seeded mericarps (e.g. Umbelliferae with two
mericarps, many Malvaceae with several mericarps).
Micropyle: Opening of the ovule through which the pollen tube enters prior
to fertilization.
Monocotyledon:
.
The plants having one cotyledon.
Mycelium: A mass of hyphae; the thallus of a fungus.
Normal seedlings: Those seedling which show the potential for continued
development into a satisfactory plant when grown in good soil under favourable
condition.
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Objectionable weeds: Seeds of crop species speci.ried as objectionab Ie weeds
for a seed crop in Indian MinimumSccd Certification Standards..
(i) One-way test: A one way test is made to decide if a 'second' estimate is
significantly either poorer or better than a 'first' estimate or to decide if an estimate
is significantly either poorer or better than a specification.
(ii) Two-way test is made to decide if one value is significantly either better
or poorer than the other.
.
Oospores: The resting spore from a fertilized (X)spherc.
Other crop seeds: The other crop seeds arc the seeds of plants which are grown
as crops, other than main crop seeds (For classification as other crop seeds or inert
maJter, in a purity analysis the rules described under pure seed shall be applicable).
Other distinguishable
variety seeds: Seeds of other varieties oft he same kind
on the basis of readily apparent differences in thestab1e morphological characteristics of the seeds.
Ovary: The ovule-bearing part of the pistil:
Palea: One of the thin bracts of a grass Doret enclosing the caryopsis that is
located on the side opposite the embryo.
Paper
piercing
test: A seed vigour test which measures the potential of
emerging seedlings to pierce the paper of aspccified
standard.
Pathogen: Any organism capable of causing disease by obtaining its nutrition
either partially or wholly from its disease host.
Pericarp: The outer covering, the ovary wall. It may be thin and fused with
the seed coat as in maize. fleshy as in berry or h~rdand dryas in pods of legumes.
Physiologic race: One of a group of forms alike in morphology but unlike in
certain physiological, pathological, biochemical or other characters.
Phytotoxic: Poisonous to plants.
Plumule: The major young bud of the embryo from which will develop the aerial
320
.
portions of
the plant. that part of the emhryonic
plant axis ahove the cotyledons.
Positive ~eotropism: Downward growth (e.g. normal primary root).
J)rimary leaf: The rirsl leal or pair or leaves found after the cotyledons
(see 'cotyledon').
Primary
Main rool of the seedling. developing from the radicle of the
root:
emhryo (see 'radicle').
Probability:
chance alone.
I)rimordia:
Prohahility
is the relative
frequency
of an occurance due to
Organs in their earliest stage of development;
as a leaf primordia.
Pure seed: 'Jl1e pure seed means the seeds (and pieces of seed units larger
than
one-half the original size) of kind/species state by the sender. or found to
predominate in the test.
Purity Analysis: l11e purity analysis of a seed sample in the seed testing
laboratory refers to the determination of the physical composition of the seed
samples in terms of the percentage (by weight) of seeds of the kind under
consideration (Pure seed), other crop seeds,weed seedsand the inert matter.
Rachilla: A secondary rachis, In grassesthe axis that bears the nord.
Rachis: The main axis oj"an inl1orescence.
Radicle: The rudimentary root of the embryo, developing into the primary
root after emergence through the seed coat during germination (seed 'primary
root ').
Random: Chosen entirely by chance with no personal influence.
Reject number: A number large enough to lead to the decision
that the seed
lot hasmore foreign seedsofthc species in question thanstatcd by a 'spccification'
or a 'first estimatc'.
Respiratory quotient (R.Q.): Ratio of CO2 evolved and 02 consumed in
respiration.
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Retarded root: A root usually with an intact tip but much too short and weak
to be in balance with the oth~r structures of the seedling.
Room germinator: It is a modification of germination cabinet constructed on
the same principles but is large enough to permit the workers to enter into it and
place the test samples along either side of a central passage.
Sample: A portion of a seed lot [rom which see<Lquality attributes are
estimated.
(i) Composite sample: The composite sample is formed by combining and
mixing all the primary samples taken from the lot.
(ii) Primary sample: A primary sam pIe is a small portion taken from one point
in the lot.
(iii) Sub-sample: A Sub-sample is the portion of a sample obtained by
reducing the composite sample using one of the prescribed sampling methods.
(iv) Submitted sample: A submitted sample is a sample submitted to the seed
testing laboratory. It must be of at least the size specified and may comprise either
the whole or a sub-sample of the composite sample.
Sampling intensity: Refers to the number of containers/bags samples for
obtaining primary samples in relation to the size of whole seed lot. The minimum
requisite number of containers/bags must be sampled.
Scarification: The process of mechanically scarring or rubbing the hard seed
coat to make it more permeable to water.
Schizocarp: A dry fruit which seperates into two or more unite (mericarps) at
maturity (e.g. Umbelliferae.)
Sclerotium: A rounded or irregular mass of fungus hyphae. Capable of
remaining dormant for long periods and eventually giving rise to fruiting bodies.
Scutellum: A shield-shaped structure that is part of the cotyledon in some
Gramineae and through which nutrients are absorbed from the endosperm into the
embryo.
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Sealed (seed lots and seed samples): Sealed means that the container or
individual containers in which the seed is held are closed in such a way that they
cannot be opened to gain ac~ess to the seed.
Secondary root: Used in seed testing to mean any root other than the primary
root.
Seed: A mature ovule consisting of an embry6nic plant together with a store
of food, all surrounded bya protective coal.
Seed coat: The outermost protective covering of a seed.
Seedling: A young plant grown from seed.
Seedling growth rate: A vigour test designed to assess the rapidity of seedling
growth by measuring seedling length or dry weight under specified condition.Seed sampling: Obtaining a sample of the required size and consisting of the
same components as that of the whole lot of seeds.
Seed testing: The science of evaluating the quality of seed before it is sown.
Seed vigour: Sum total of those propertic..<;of the seed which determine the
level of activity and performance of the seed or seed lot during germination and
seedling emergence.
Seed vigour index: A product of germination percentage multiplied by
seedling length of a seed lot.
Seminal roots: The roots arising from the embryo compared to adventitious
roots that arise later.
Sequential test: A sequential test is one in which additional testing is done
because of a result from a pervious test. Because a result .showed an - apparent
deficiency-either significant or non-significant, another working sample is examined to obtain further evidence.
Shoot apex: Terminal portion of the shoot, that contains the main.growing
point.
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Significance: The difference between two values is sigQificant.in the statistical sense. if the difference is so large that it would occur rarely due to chance
alone. when there is no difference. The two values may be unbiased estimates for
the same lot or one value may be an unbiasedestimate and the other a specification.
Speed ofgerrnination:
1\ seed vigour test which measures the relative
germ ination speed of different seed lots.
Spikelet: The unit of a grass inl1orescencecomprising one or more florets,
subtended by one or two sterile glumes.
Spores: In seed plant, the spore is the first cell of the gametophyte generation.
The two kinds. microspore and megaspore. produce male and female garnets
respectively.
Stalk: The stem of any plant organ.
Stratification: Exposing seed imbibing water to low temperature conditions
(5-1DoC)for a few days prior to germination for breaking dormancy.
Stubby root: The kind of root characteristic for seedlings ~ith phytotoxic
symptoms (it is usually short and club-shaped. though often with an intact root tip
(see 'stunted roo!').
Stunted root: Root with a missing or defective root tip. irrespective of the
lengthof theroot(see'stubbyroot').
.
Temperature alternating: In germination testing. specifie temperatures with
seeds being held at both the lower and higher temperatures for a designated time
eachday.
Temperature constant: In germination testing, a specific temperatures which
should not vary by more than 1.
Terminal bud: The shoot apex enveloped by several more or less differentiated leaves.
Tetrazoliurn vigour test: A bio-chemical vigour test which measures the
intensity
of dehydrogenase
group of enzymes presentintheseed.
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Testa: The outer covering of seed, the seed coat.
Tolerance: The greatest non-significant difference between two values. The
two values may be two estimatc..<.;.
or a spccHidltiOriand an estimate. Tolerances
arc usuallybasedon normalrandomvariation,or samplingerror. .
Truncation: In a scquentialtcst. discontinuing the examination ofsecd whilc
the number 61'foreign sccds is between the accept and reject values.
Twisted structure: Seedling structure (e.g. hypocotyl. coleoptilc) which
twists around its main axis or elongation.
TZ Test: Quick tc..<.;t
to determine seed viability by using 2.3.-5.
tetrazolium chloride or bromidc.
triphenyl
Viable: Alivc. A viable seed is capable of germinating undcr proper conditions.
Weed seeds. Thc wced seeds are the seeds of plants ofthose species rccognised
as weeds- by Laws, official regulations (objectionable weeds). (For classification
as other crop seeds or.inert matter. in a purity analysis the rules described under
pure seed shall be app~icable).
. Working sample: The working sample. is a sub7sample takenfro(11 the
submitted sample in thc laboratory for a given quality test.
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