Growth of flower parts ( Auxin)&

Growth of lateral buds (Cytokinins)

ByJewel

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Effect of Auxin

Cell division

Vascular tissue differentiation

Root initiation

Tropistic responses

Apical dominance

Leaf senescence

Leaf and fruit abscission2

Cont.

Fruit setting and growth

Assimilate partitioning

Fruit ripening

Flowering

Growth of flower parts

Promotes femaleness in dioecious flowers (via

ethylene)3

Introduction of auxin in flower parts Minor role - flowering and development of

reproductive organs

Necessary – for initiation of floral primordia

Specifying - number and identify of floral organ

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AuxinProduce in stem tip(bud), young leaves,

flower, fruit and shoot tip

Auxin promote pollen-tube growth towards the ovules

Family – Bromeliaceae a strong flower (Eg – pineapple) response

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Cont. Most plants - do not initiate the production of

flower (after auxin treatment)

Auxins in flower prevent flower formation

(under noninductive conditions)

Low amounts of promote flower formation auxin levels (under partial induction condition)

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Cont.In low concentrations delay the senescence

of flowers

IAA - promotes the formation of female flower - apparently stimulates the production of

ethylene.

Ethylene - important part of natural determination of flower sex.

Ethylene - involved flower opening (different ways) 7

Cont.Low conc; of ethylene - accelerate opening flower (Eg - carnation bud &roses)

Depending on cultivar

Lovely girl plants - strongly inhabit by low conc; ethylene

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Effect of cytokinin

Growth of lateral buds

Leaf expansion

Delay leaf senescence

Enhance stomatal opening in some species

Chloroplast development

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Cytokinin• Two types of cytokinins: Adenine-type cytokinins - kinetin,zeatin and

6 benzylaminopurine• Most adenine-type cytokinins - synthesized in roots.

Phenylurea-type cytokinins- diphenylurea and Thidiazuron(TDZ)

• Phenylurea cytokinins - no found in plants.10

Cont.Cytokinin occur in most plant – mosses, frens , conifers,

algae , diatoms

Zeatin – most active & naturally occur

Direct application– promote growth of lateral buds of cytokinin

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Growth of lateral buds in cytokinin

Moves from the roots into the shoots eventually signalling lateral bud growth.

Transpiration system in xylem promote bud growth by induction cell division

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Cont.High auxin suppresses release of lateral bud (from

dormancy)

While cytokinin stimulates their growth

Exogenous application of cytokinin – dormant lateral bud.

Auxin : Cytokinin – central factor controlling the growth of axillary bud 14

Exogenous auxin : cytokinin antagonistic

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Thank you very much

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• Lilium 'Lovely Girl' is: Deciduous• Flower: Reddish-brown, Yellow, White in Summer• Foliage: Green in Spring; Green in Summer; Green in Autumn• Habit: Clump-forming, Erect

Diatoms are algae with distinctive, transparent cell walls made of hydrated silica.

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