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1. COTTONBREEDING
By
MUHAMMAD ANAS
Roll No.250 Bs.c (Hon) 7th
semester
Departmentof Plant BreedingAnd Genetics
Submittedto
Prof. Dr. FARHATULLAH SIR
Acting Deanin the Faculty of Crop Production Sciences
The University of Agriculture Peshawar Pakistan

2. INTRODUCTION
ScientificName:Gossypiumspp
Family:malvaceae
Chromosome No.: 2n =26, 4n=52
GEOGRAPHICALDistribution:Cultivatedall overthe world
Area: 7-8 m ha
Production: 2.6 m bales
Indiaranksfirstin area andsecondinproduction
Chinafirstinproduction
Leadingcountriesare India,USA,Russia,China,Brazil Pakistan,Egypt.
All the fourspeciesare growinginIndia
Progenitors:Gossypiumafricanum,G.raimondii,Gossypiumafricanum –reachedIndiabytradersand
travelersanddifferentiatedintotwospeciesG.herbaceumandG.arboretum.
BOTONY
 Cottonplanthas veryprominenterectstemleavesare arrangedalternatelyandspirallyaround
the Stem.
 leavesare petioledandlobed
 The stemand leavesare pubscentthe large leaf veinsbearexternal glandsknownasnectaries
and excrete asweetishfluid.
FLOWER
 Cottonflowersoccursingly(solitary)
 Producedonsympodial branchesfromthe terminal buds
 Base of flowersurroundedbythree leafliketriangularbracts(epicalyx)
 The calyx is reducedtoa small cupshapedstructure withfive lobes
The branchingof cotton2 types
A) monopodial branching
B) fruitingorsympodial branching
Vegetativestructurallylikemainstemsympodial branchesbearsflowersandfruits
COROLLA
 Brightyellow
 5 petals
 Gamopetalous
 In interiorpetalsunitedtobase of staminal column

3. ANDROECIUM
 Numerousstamens
 Filamentsare unitedtoforma tubularstaminal column(Monadelphous) aroundthe style
 Anthersarrangedinfive rowsonstaminal tube
GYNOECIUM
 Pistilsconsistsof 3-5carpelscorrespondingtoloculesinfruit
 Ovary – superior,
 Style – Single
 Ovarydevelopsintoacapsule orbole
 Each locule have 8-12 ovules
 5-9 ovulesmature
ANTHESIS
 Twistedcorollaemergesfromthe bracts
 Variationintime of floweropening
 Maximumfloweropening –8 to 10a
 Temperature alsoaffectsfloweropening
 Stigmabecomesreceptivesoonafterfloweropening
 Stigmareceptivity –24 hrs
 Pollenviability –12 hrs
POLLINATION
 Self-Pollinatedcropbecause pollenissheddirectlyonstigma
 Crosspollinationdue toinsects
 Crosspollinationrangesfrom5-25% sometimesexceeds50%
 Hence cotton isan often-crosspollinatedcrop
FERTILIZATION & FRUIT SET
 Fertilizationiscompletedin36-40 hrs afterpollination
 6 to 8 weeksfromfirstflowertoripe fruit
 Fruitis boll
 Young fruitor fruitbudiscalleda square
SELFING TECHNIQUES
 Paperbag method
 Ringmethod
 Mud smear
 Othermethods
CROSSINGTECHNIQUES
 Emasculation
 Pollencollection
 Artificial pollination

4. SELECTION OF FLOWER BUD
 The crossingwork isinitiatedafterone weekof flowerinitiation.
 The flowerbudsof properstage (budswhichare likelytoopenthe nextday) are selectedfor
emasculation.
 Such budshave generallycreamcolourandare well developed.
Emasculation and crossing techniques
 Hand emasculationandcrossing
 Humphreyandtullermethod
EMASCULATION
 An incisionismade atthe bottomnear calyx
 A circularshallowcutis givensothatthe corollaandstamentube surroundingstyle come off
 Bag withbutterpaperand tag it
Hand emasculationand crossing
 Done in female parentonthe evening
 Usingnailsof thumbof both the handsthe staminal columnalongwithanthersandattached
petalsare removed
 Duringnextdaymorningthe anthersof male flowersare rubbedagainstthe stigmaof
emasculatedflowerandthenbagged
POLLEN COLLECTION
 Collectflowersfromthe male parentduringearlymorninghours
 Collectpolleninstrawtube
 Pollinate nextmorningbetween8amto1pm
 Insertthe straw tube containingpollen,onemasculatedflowerstigma
Fertilization and fruitset
 In handemasculation65-70%successwill be seen
 Afterfertilizationwhite flowersturntopinkor red
CultivatedSpecies:
I. Asiaticcottonsor old-worldcotton(Diploidcotton – 2n = 26)
1. G. arboretum
2. G. herbaceum
II. Newworldcotton(Tetraploidcottons –2n = 52)
3. G. hirsutum– American/uplandcotton
4. G. barbadense – Egyption/seaislandcotton
G. hirsutumispredominantspecieswhichcontributesabout90% to the currentworldproduction.
Besidescultivatedspeciesthereare about46 wildspeciesIndiaisthe onlycountrywhere all the 4
cultivatedspeciesare grownforcommercial cultivation

5. ORIGIN & EVOLUTION
GenusGossypiumisoriginatedinCentral Africa
 G. arboreumandG. herbaceumorigininAsia
 G. barbadense origininEgypt
 G. hirsutumorigininAmerica
Ancestor: G.herbaceum(AA) andG.raimondii (DD)
CottonbelongstogenusGossypium.The genushas35 diploid(ABCDEFgenomes) and6tetraploid
speciesoutof these onlytwodiploidandtwotetraploidspeciesare categorizedascultivated.
Sr.No Botanical Name Chromosome
No
Genome Remarks
1. G.hebacium 2n=26 A1A1 Deshi or oldworldcotton
2. G.arboreum 2n=26 A2A2 Deshi or oldworldcotton
3. G.hirsutum 2n=52 A1A1D1D1
Americanornew world
cotton
4. G.barbadense 2n=52 A2A2D2D2
Americanornew world
cotton
The newworldtetraploidspeciesare allapolyploids,whichoriginatedbyhybridizationbetweenold
worldand the newworlddiploidspecies.
DiploidoldworldspeciesXDiploidnew worldspecies
2n = 26 (AA) 2n = 26 (DD) F1 2n=26 (AD)
Chromosome doubled4n=52 (AADD)
Tetraploidnewworldspecies
Gossypiumhirsutumwasfirsttime introducedintoBombayin1790 and mostearlyintroductionsfailed
due to attack of Jassidsandleaf minor.Duringrecentyearsmanyagricultural varietiesare developed.
Newvarietiesoriginatedfromcrossesinvolvingoldervarietiesracesorspecies.
The cultivatednewworldAllotetraploidcottonspeciesdominate worldcottonproductionGossypium
barbadense isknownforextralogfine andstrongfiber.CultivatedGossypiumhirsutumuplandcotton
accounts formajor worldproduction.
IMPORTANCE
 Cottonconstitutes85%of raw material fortextile industry
 Around80% of the pesticide isconsumedbycottononly
 Cottonseedoil usedinlubricationindustry

6.  Seedcontainalkaloidgossypol
Breeding Objectives:
1. Highyieldandearlymaturity.
2. Resistanttodisease andpests
3. Breedingforstaple length,fiberstrength,finenessof fiber.
4. Increasedlinttoseedratio.
Breeding Methods:
i. Introduction:
Cambodiacottonin1906 from America,AndrewsfromseaIsland.
ii. Pure Line Section:
Pure line selectionispractisedformaintainersof geneticpurityof existingvarietiesand
developmentof newbyselectionwithinhybridpopulation.Pure linesvarietiesdeveloped
one Ganga-1, CC-2,MCU-5, SRT-1, Eknath,Sanjay.
iii. Hybridization:
Normallypollensheddirectlyonthe stigmawhenanthersopen.Pollenisrarelywindborn,
as it isheavyand sticky.Cross – pollinationtothe extentof 5 to 30 % ispossible byinsects,
mostly honeybees.
For hybridizationemasculationisdone one dayearlierof the floweropening.Corollais
removedbyhandor cut away withscissors.The stamensare removedwithforceps.Ripe
anthersare collectedfrompollenparentinstraw tube and slippedoveremasculatedstigma
and stigmaimmediatelyenclosedwithbractbywire.Similarly,ripeantherscanbe rubbed
on the stigmaof the emasculatedflower.The pollinationisusuallydone adayafter
emasculation.The emasculationmaybe done
1) By takingcircularcut at the base and piercingneedle throughstaminal tube or
2) Removedof anthersbypointedforceps.Itisalsobe done bythumb andnail method
and insteadof baggingsmall piece of straw tube insertedoverstigmaof emasculated
flowerand tiedalongwithbractswiththread.
iv. Pedigree Method:
Thismethodpractisedbycrossingtwocomplementingparental lines.Inthe early
generationsthe individual bothplantprogeniesare grownasin the self-pollinatedcropsand
selectionispractisedboth betweenandwithinrowsforfavorable traits.Inlatersegregating
generationspromisinglinesforplanttype,insectpestanddisease varieties.
v. HeterosisBreeding:
Indiaiscreatedfirstcountrywhere hybridcotton(H4) wasusedon commercial scale in1970
on seedproductionbyhandemasculation.Lateronnumberof hybridswere releasedfor
commercial cultivation.