Seed Formation - Ppt

8/15/2019 Seed Formation - Ppt

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GENERAL PRINCIPLES OFGENERAL PRINCIPLES OFANGIOSPERMANGIOSPERMSEED FORMATIONSEED FORMATION

Julio Marcos FilhoJulio Marcos FilhoDEPTO. PRODUDEPTO. PRODUÇÇÃO VEGETALÃO VEGETAL

USP/ESALQUSP/ESALQ

MULTIPLICATION PROCESSES IN PLAMULTIPLICATION PROCESSES IN PLA

REPRODUCTIONREPRODUCTION SEXUAL: SEEDSSEXUAL: SEEDS

Vegetative parts, cells or plant tissues, that possesVegetative parts, cells or plant tissues, that possescapacity of regeneration; there is no fusion capacity of regeneration; there is no fusion sexual cellssexual cells production of clonesproduction of clones

Production of a new organism with active participatiProduction of a new organism with active participatiosexual nuclei or cells (the combination of a male asexual nuclei or cells (the combination of a male afemale gametes)female gametes) there is a renewal ofthere is a renewal ofindivindiví í dualsduals

PROPAGATIONPROPAGATION ASEXUAL: PROPAGULESASEXUAL: PROPAGULES

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FLORAL INDUCTIONFLORAL INDUCTIONPhysiological change that permits the development ofPhysiological change that permits the development of

reproductivereproductiveprimordiaprimordia. This change is induced by. This change is induced byexternal stimuli.external stimuli.

- Water

- Photoperiod

- Chemicals

- Nutritional status- Temperature

33

FLORAL INITIATIONFLORAL INITIATIONMorphological expression of the induced state. Usua

occurs within the meristems of a plant.

FLOWERINGFLOWERING PHASE OF THE PLANT LIFE CYPHASE OF THE PLANT LIFE CYTHAT PROMOTES FRUIT AND SEED FORMTHAT PROMOTES FRUIT AND SEED FORM

a) THERMAL UNITS: energy accumulationa) THERMAL UNITS: energy accumulationb) JUVENILLE PERIODb) JUVENILLE PERIOD

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- Types of plants: Annuals x biennials x perennials

SOME TYPES OF INFLORESCENCESSOME TYPES OF INFLORESCENCES

headheadspikespike

umbelumbelcompositecomposite

umbelumbel55

SOME TYPES OF INFLORESCENCESSOME TYPES OF INFLORESCENCES

paniclepanicle

racemeraceme

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TYPES OF FLOWERSTYPES OF FLOWERS

-- Perfect:Perfect:possess stamens and pistilpossess stamens and pistil

-- Complete:Complete:possess sepals, petals, stamens andpossess sepals, petals, stamens andpistilpistil

-- Imperfect:Imperfect:unisexual (unisexual (lacks either stamens or pistillacks either stamens or pistil))

-- IncompleteIncomplete

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TYPES OF FLOWERS ACCORDING TO SEXUAL STRTYPES OF FLOWERS ACCORDING TO SEXUAL STR

TYPES OF PLANTS ACCORDING TO SEXTYPES OF PLANTS ACCORDING TO SEX

HERMAPHRODITESHERMAPHRODITESUNISEXUALUNISEXUAL

HERMAPHRODITESHERMAPHRODITES: all flowers are hermaphroditic: all flowers are hermaphroditic

UNISEXUALUNISEXUAL::MonoeciousMonoecious:: maize, cucumber,maize, cucumber,PinusPinusDioeciousDioecious:: papaya, pecan,papaya, pecan, Araucaria Araucaria

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petal

filament

ovary

anther

style

stigmapollen grain

sepal

embryo sac

ovule

micropyle

TYPICAL COMPLETE FLOWERTYPICAL COMPLETE FLOWER(Marcos(MarcosFilhoFilho, 2005), 2005)99

PARTS OF FLOWER INVOLVED IN THPARTS OF FLOWER INVOLVED IN THREPRODUCTION PROCESSREPRODUCTION PROCESS

ANDROECIUMANDROECIUMSet of stamens:Set of stamens:Filament + Anther Filament + Anther

GYNOECIUM (pistil)GYNOECIUM (pistil)StigmaStigma

StyleStyleOvaryOvary

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STAMEN OVARY

fl

spgp

ovlc

ANTHER AND TRILOCULE OVARY CROSS SECTIONS (MarcosANTHER AND TRILOCULE OVARY CROSS SECTIONS (MarcosFilhoFilho, 2005), 2005)fl = filament;fl = filament;gpgp = pollen grain; sp = pollen sac;= pollen grain; sp = pollen sac;ovov= ovule;= ovule;lclc==loculelocule

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MICROSPOROGENESISMICROSPOROGENESISandand

MICROGAMETOGENESISMICROGAMETOGENESIS

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Tétrades

AntherAntherPrimodiaPrimodia Mother cellsMother cellsdifferentiationdifferentiation

Pollen sacPollen sac

Microspore motherMicrospore mothercell (2n)cell (2n)

Tetrad ofTetrad ofmicrospores (n)microspores (n)PorePore

ExineExine

IntineIntine

generative (sperm)generative (sperm)cell (n)cell (n)

vegetative cell (n)vegetative cell (n)

MeiosisMeiosis

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POLLEN GRAINPOLLEN GRAIN

Characteristics of the ExineCharacteristics of the ExineImportanceImportance

Exine PorosityExine Porosity

Characteristics of the IntineCharacteristics of the IntineImportanceImportance

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MEGASPOROGENESISMEGASPOROGENESISandand

MEGAGAMETOGENESISMEGAGAMETOGENESIS

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OvaryOvary

OvuleOvule

OvuleOvuleIntegumentsInteguments

ArchesporialArchesporialcell (2n)cell (2n)

OvaryOvary

OvuleOvule

Embryo SacEmbryo Sac

NucellusNucellusFuniculus

AntAnt í í podalspodals (n)(n)

MicropyleMicropyle

SynergidsSynergids (n)(n)

EggEgg cellcell (n)(n)

Polar nuclei (2n)Polar nuclei (2n)

IntegumentsInteguments

FunctionalFunctionalMegasporeMegaspore

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TYPESTYPESSELFSELF--POLLINATION:POLLINATION:citrus, lettuce, tomato, okra,citrus, lettuce, tomato, okra,

tobacco, eggplant, cotton, soybean, rice, wheat,tobacco, eggplant, cotton, soybean, rice, wheat,peanut, field beanpeanut, field bean

CROSSCROSS--POLLINATION:POLLINATION:maize, rye,maize, rye,CrotalariaCrotalaria juncea juncea ,,sorghum, onion, cabbage, carrot, passion flower,sorghum, onion, cabbage, carrot, passion flower,castor bean, sunflower, cucurbits,castor bean, sunflower, cucurbits,brassicasbrassicas

POLLINATIONPOLLINATION

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POLINNATIONPOLINNATIONAGENTSAGENTS

WIND:WIND:pollen characteristics and flower structurepollen characteristics and flower structure

Pearl MilletPearl Millet1818


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INSECTS:INSECTS:pollen characteristics and dispersionpollen characteristics and dispersionCrotalariaCrotalaria juncea juncea , sunflower, onion, carrot,, sunflower, onion, carrot,cabbage, passion flower, cucumber cabbage, passion flower, cucumber

LPV/USPLPV/USP

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BIRDS; BATS; HUMAN; WATER

POLLINATIONPOLLINATION

male flowers

femaleflowers

Plant ofPlant ofVallisneriaVallisneria sp.sp.((BhojwaniBhojwaniee Bhatagnar Bhatagnar , 1976), 1976) 2020

POLLINATIONPOLLINATIONDIFFICULTIESDIFFICULTIES

DICHOGAMYDICHOGAMY

-- PROTANDRY:PROTANDRY:maize, carrot, onion, pecanmaize, carrot, onion, pecan

-- PROTOGYNY:PROTOGYNY:mango, pearl millet, cauliflower mango, pearl millet, cauliflower

GENETIC OR MORPHOLIGICAL SELF INCOMPATIBILITYGENETIC OR MORPHOLIGICAL SELF INCOMPATIBILITY::cabbage, Crotalaria, passion flower, sunflower, radish,cabbage, Crotalaria, passion flower, sunflower, radish,rye, orangerye, orange

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POLLINATIONPOLLINATIONIMPORTANCEIMPORTANCE

Male sterility:Male sterility:maize, cabbage, carrot

GENETIC PURITYGENETIC PURITYCrop isolationCrop isolationWind directionWind direction

Proportion of parental linesProportion of parental lines

Split:Split:maize, tomato, sorghum

Cucumber Cucumber :: monoeciousmonoecious,, androeciousandroeciousandandgynoeciousgynoeciousflowering habitsflowering habits

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Hybrid Corn Hybrid Sorghum

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Hybrid Pearl Millet

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POLLINATIONPOLLINATIONIMPORTANCEIMPORTANCE

PRODUCTIONPRODUCTION

Temperature x pollen viabilityTemperature x pollen viability

Presence of insectsPresence of insects

Geography of AreaGeography of Area

Insect controlInsect control

Sowing date and climate duringSowing date and climate duringflowering and fruit developmentflowering and fruit development

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PetalsPetalsPistilPistil StamensStamens

OvaryOvarySepalsSepals

AbscissionAbscissionlayer layer

Flower abortionFlower abortion

Anther Anther conecone

AA B

Tomato flower (A) and inflorescences with flower in different stTomato flower (A) and inflorescences with flower in different stages of development (B)ages of development (B)

P.C.T.P.C.T.MeloMelo2727 P.C.T. MeloP.C.T. Melo2929

FERTILIZATIONGERMINATION OF THE POLLEN TUBEGERMINATION OF THE POLLEN TUBE

embryo sacembryo sac

ovuleovule

pollenpollengerminationgermination

pollen tubepollen tube

ovaryovary

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PollinationPollination

Anther Anther

Sperm cellsSperm cells(n)(n)

Vegetative cellVegetative cell

Pollen TubePollen Tube

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FERTILIZATIONFERTILIZATIONSYNGAMY:SYNGAMY:

TRIPLE FUSION:TRIPLE FUSION:

EMBRYOEMBRYO

ZYGOTE (2n)ZYGOTE (2n)sperm cell (n) + egg cell (n)sperm cell (n) + egg cell (n)

sperm cell (n) + polar nuclei (2n)sperm cell (n) + polar nuclei (2n)ENDOSPERMENDOSPERMNUCLEUSNUCLEUS(3n)(3n)

ENDOSPERM (?)ENDOSPERM (?)3131 TYPICAL EMBRYO DEVELOPMENT OF DICOTYLEDONOUS ANTYPICAL EMBRYO DEVELOPMENT OF DICOTYLEDONOUS ANMONOTYLEDONOUS SPECIESMONOTYLEDONOUS SPECIES(Copeland and McDonald)(Copeland and McDonald)3232

ENDOSPERM DEVELOPMENTENDOSPERM DEVELOPMENT

ENDOSPERM NUCLEUSENDOSPERM NUCLEUSdivisionsdivisions

differentiationdifferentiationENDOSPERMENDOSPERM

A) STORAGE TISSUEA) STORAGE TISSUE

ALBUMINOUS SEEDS :monocotyledonous, castor bean,monocotyledonous, castor bean,coffee, rubber tree, tomato, sugar beet, lettucecoffee, rubber tree, tomato, sugar beet, lettuce

GERMINATIONGERMINATION

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PericarpPericarp

EndospermEndosperm

Cotyledon (Cotyledon (scutellumscutellum):):protection of embryoprotection of embryoaxis and reserve transferaxis and reserve transfer

coleoptilecoleoptile

primary rootprimary root

seminal rootsseminal roots

plumuleplumule

coleoptilecoleoptile

coleorhizacoleorhiza

Seminal rootsSeminal roots((cotyledonarycotyledonarynodenode))

radradí í clecle

plumule (plumule (primary leavesprimary leaves))

MAIZE EMBRYOMAIZE EMBRYO3434

EMBRYO DEVELOPMENTEMBRYO DEVELOPMENT

EXALBUMINOUS SEEDS: in general, dicotyledonousleguminous,leguminous,malvaceousmalvaceous, cucurbits,, cucurbits,brassicasbrassicas

B) STORAGE TISSUEB) STORAGE TISSUE

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ENDOSPERM DEVELOPMENTENDOSPERM DEVELOPMENT

CotyledonsCotyledons

cotyledonscotyledons

primary rootprimary roothypocotylhypocotyl

HypocotylHypocotylRadicleRadicle

plumule + primary leavesplumule + primary leaves

PlumulePlumule

FIELD BEANFIELD BEANEMBRYOEMBRYO3636


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EMBRYO PARTSEMBRYO PARTS-- RADICLE: produces the seedling rootRADICLE: produces the seedling root-- HYPOCOTYL:HYPOCOTYL:part between the cotyledons and radiclepart between the cotyledons and radicle-- COTYLCOTYLÉÉDON(S):DON(S):

DicotyledonousDicotyledonous→→ storage of reserves or embryo leavesstorage of reserves or embryo leaves

MonocotyledonousMonocotyledonous→→ protection of embryo axis and transfer of protection of embryo axis and transfer of reserves from endosperm treserves from endosperm to embryoo embryo

-- PLUMULE:PLUMULE:mass of meristematic cellsmass of meristematic cells→→ major leaf bud of the seedmajor leaf bud of the seed

-- EPICOTYL:EPICOTYL:the portion of the embryo above the cotyledons;the portion of the embryo above the cotyledons;in general,in general,is present in the plumule, as a meristematicis present in the plumule, as a meristematictissue or is well developed and visibletissue or is well developed and visible

-- ColeorhizaColeorhiza,, coleoptilecoleoptile, seminal roots (, seminal roots (cotyledonarycotyledonarynode)node) 3737

PERISPERMPERISPERM

Development of theDevelopment of thenucellar nucellar tissuetissue

Examples: coffee, sugar beetExamples: coffee, sugar beet

PerispermPerispermEndospermEndosperm

EmbryoEmbryo

Longitudinal section of a sugar beet seedLongitudinal section of a sugar beet seed3838

SEED COATSSEED COATSTESTATESTA(External)(External)PRIMINEPRIMINE

SECUNDINESECUNDINE TEGMATEGMA(Inner)(Inner)

FunctionsFunctions

-- Cohesion among the seed partsCohesion among the seed parts

-- Protection against the action of biotic andProtection against the action of biotic andabioticabioticfactorsfactors

-- Regulation of water and gaseous exchangeRegulation of water and gaseous exchange

-- Regulation of germination and dormancy mechanismsRegulation of germination and dormancy mechanisms

-- Control of seed dispersion: wings,Control of seed dispersion: wings,aculeusaculeus, hairs, mucilage, hairs, mucilage

3939 FRUIT AND SEEDFRUIT AND SEEDFRUIT A MATURE OVARY AND ASSOCIATED PARTS, WITA MATURE OVARY AND ASSOCIATED PARTS, WITONE OR MORE SEEDSONE OR MORE SEEDS

PARTSPARTS::

a) PERICARPa) PERICARP

EXOCARPEXOCARP

MESOCARPMESOCARP

ENDOCARPENDOCARP

b) SEEDb) SEED

SEED COATSEED COAT

ENDOSPERMENDOSPERM(?)(?)

EMBRYOEMBRYOAXISAXIS

COTYLEDON (s)COTYLEDON (s)4040

DRY FRUITS :DRY FRUITS :caryopsiscaryopsis((grassesgrasses).).acheneachene((suflower suflower ,, lettucelettuce),),schizocarpschizocarp((carrotcarrot)),, nutsnuts

FRUIT AND SEEDFRUIT AND SEED

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APOMIXISAPOMIXISASEXUAL DEVELOPMENT OF SEEDS WHOSE STASEXUAL DEVELOPMENT OF SEEDS WHOSE ST

IS SIMILAR TO THOSE PRODUCED AFTER THE FIS SIMILAR TO THOSE PRODUCED AFTER THE FTHE EGG AND SPERM CELLSTHE EGG AND SPERM CELLSSEEDS ARE FORMED FROM OVULE DIPLOID CELLS BY SEEDS ARE FORMED FROM OVULE DIPLOID CELLS BY MECHANISMS, BUTMECHANISMS, BUTFERTILIZATIONFERTILIZATIONDOES NOT OCCURDOES NOT OCCUR

CHARACTERISTICS OF THE PROCESSCHARACTERISTICS OF THE PROCESS-- REPRODUCTION IS REPLACED BY ASEXUAL MULTIPLREPRODUCTION IS REPLACED BY ASEXUAL MULTIPL

-- THERE IS NO FUSION BETWEEN MALE AND FEMALE GTHERE IS NO FUSION BETWEEN MALE AND FEMALE G

-- OCCURS IN PARTS OF PLANT USUALLY INVOLVOCCURS IN PARTS OF PLANT USUALLY INVOLVREPRODUCTIONREPRODUCTION4242


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EXAMPLES OF SEEDEXAMPLES OF SEEDSTRUCTURESTRUCTURE

4343


Embryo axisEmbryo axis

PEA SEEDPEA SEED4444

EMBRYO AXISEMBRYO AXIS

COTYLEDONCOTYLEDONSEED COATSEED COAT

PUMPKIN SEEDPUMPKIN SEED4545

Seed coatSeed coat

EndospermEndosperm


Embryo axisEmbryo axis

CASTOR BEAN SEEDCASTOR BEAN SEED4646

PlumulePlumule

CotyledonCotyledon

HypocotylHypocotyl--radicleradicleaxisaxisEndospermEndosperm

ONION SEEDONION SEED4747

SEEDSEEDMATURATIONMATURATION

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SEED DEVELOPMENT OR MATURATIONSEED DEVELOPMENT OR MATURATION

Sequence of connected steps in preparation forSequence of connected steps in preparation forsuccessful germinationsuccessful germination

Very importantVery important relationship to proper harvestrelationship to proper harvesttime and seed physiological potentialtime and seed physiological potential

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DeloucheDelouche(1971)(1971)

Seed maturationSeed maturationis a process whichis a process whichincludes a sequence of morphologicalincludes a sequence of morphologicalphysical, biochemical and physiologicphysical, biochemical and physiologicachanges from ovule fertilization to thchanges from ovule fertilization to thpoint when the seed becomespoint when the seed becomesphysiologically independent of the parenphysiologically independent of the parenplantplant

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SEED DEVELOPMENTSEED DEVELOPMENT

1. Variations of seed moisture content1. Variations of seed moisture content

Seeds in fleshy or in dry fruitsSeeds in fleshy or in dry fruits

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M O I S T U R E C O N T E N T ( % )

M O I S T U R E C O N T E N T ( % )

TIMETIME

DryDry

FleshyFleshy

Variations in moisture content during seed maturation iVariations in moisture content during seed maturation ifleshy and dry fruitsfleshy and dry fruits

++ 8080

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R6R6R5R5

2. Seed size changes2. Seed size changes

Development of soybean seeds and legumes (Ritchie et al., 1994)Development of soybean seeds and legumes (Ritchie et al., 1994)R6 R7 R8

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3.3.SeedSeeddrydryweightweight

Dure III (1975)Dure III (1975)DaysDaysafter after floweringflowering

E m

b r y o

E m

b r y o

d r y

d r y w e i g

h t

w e i g

h t

CELL DIVISION ANDCELL DIVISION ANDEXPANSIONEXPANSION

((PHASES I e IIPHASES I e II))

DRY MATTER ACCUMULATIONDRY MATTER ACCUMULATION(PH(PHASEASEIIIIII))

DESiCCATIONDESiCCATION(PH(PHASEASEIVIV))

MoistureMoisturecontentcontent

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4. Germination4. Germination

5. Vigor 5. Vigor

SEED DEVELOPMENTSEED DEVELOPMENT

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moisture contentseed size

vigor

germination

dry weight

General alterations of seed characteristics during maturationGeneral alterations of seed characteristics during maturation((CarvalhoCarvalhoand Nakagawa, 2000)and Nakagawa, 2000)

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DETERMINATION OF PHYSIOLOGICAL MATURITYDETERMINATION OF PHYSIOLOGICAL MATURITY

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SEED MATURITY x HARVEST TIMESEED MATURITY x HARVEST TIME

-- Physiological Maturity: IdentificationPhysiological Maturity: Identification

Black layer Black layer

Milk lineMilk line

SoybeanSoybean

Wheat, barley, oatWheat, barley, oat

Vegetables, FruitsVegetables, Fruits5858

-- Physiological Maturity: identificationPhysiological Maturity: identification

AnaAnaNovembreNovembre5959

-- Determination of harvest timeDetermination of harvest time

ParametersParameters

SEED MATURITY x HARVEST TIMESEED MATURITY x HARVEST TIME

Seed moisture contentSeed moisture content

Seed and plant characteristicsSeed and plant characteristics

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CONCLUSIONCONCLUSIONCROP TECHNOLOGYCROP TECHNOLOGYClimate, sowing time, sowing management, inspections, harvestClimate, sowing time, sowing management, inspections, harvest

BASIS FOR DIAGNOSIS AND HARVEST DECISIONSBASIS FOR DIAGNOSIS AND HARVEST DECISIONS

PRE AND POST HARVEST SEED MANAGEMENTPRE AND POST HARVEST SEED MANAGEMENT

POLLINATION CONTROLPOLLINATION CONTROL

SEED TESTING:SEED TESTING:routine analysis androutine analysis and““in housein house”” quality controlquality control

BIOTECHOLOGYBIOTECHOLOGYSomaticSomaticembryogenyembryogenyArtificial seedsArtificial seeds 6161

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