PPT 12 Fruit Development.pptx

Fruit Development In angiosperms.Fruit is a ripened ovary and devlops aftert the flower s fertilized. The ovary becomes the fruit and the ovules become the seeds. Fruit developments starts with fruit setting and ends with maturation.Fruit development and number of fruits and their sizes are affected by many factors of the plant and envionment

1. WHAT YOU WILL KNOW IN THIS LESSON IN THIS LESSON YOU WILL KNOW- WHAT IS A FRUIT AND WHAT IS FRUIT SETTING. IMPORTANCE OF FRUIT IN PLANT LIFE WHICH PART OF FLOWER DEVELOPS TO FRUIT. STRUCTURE OF FRUIT HOW FRUIT DEVELOPS. WHAT INITIATES FRUIT DEVELOPMENT. STAGES OF FRUIT DEVELOPMENT. PHYSICAL AND PHYSIOLOGICAL CHANGES DURING DEVELOPMENT.

2. WHAT IS A FRUIT? FRUIT IS A POST FERTILIZATION PRODUCT IN A FLOWER. AFTER FERTLIZATION THE OVARY IS CONVERTED TO A FRIUT. SO FRUIT IS A MATURED OVARY AFTER FERTILIZATION AND CONTAINS SEED/S INSIDE IT. EACH OVARY IN THE CARPEL MATURES TO ONE FRUIT AFTER FERTILIZATION . GYMNOSPERMS DO NOT PRODUCE FRUITS DUE TO ABSENCE OF OVARY .

3. IMPORTANCE OF FRUITS FRUITS HAVE MAINLY THE FOLLOWING FUNCTIONS IN PLANT LIFE FRUITS PROTECT THE SEEDS FROM EXTERNAL ENVIRONMENT. DEVELOPING FRUIT PROMPTES OVULE AND SEED DEVELOMENT BY PREVENTING DESSICATION AND ENSURING MOIST ENVIRONMENT FOR THE EMBRYO. IN SOME SPECIES FRUITS CAUSE SEED DORMANCY OR PREVENT PREMATURE SEED GERMINATION. FRUIT WALL PREVENTS THE EASY ACCESS OF INSECTS TO SEEDS. FRUITS HELP IN DISPERSAL OF SEEDS THEREBY HELP IN PROPAGATION OF THE PLANT. SOME FRUITS ACT DIRECTLY AS PROPAGULES AND PUT IN SOIL TO GROW PLANT.

4. TRUE FRUITS AND FALSE FRUITS AFTER POLLINATION AND FERTILIZATION THE OVARY STARTS DEVELOPING TO FRUIT’ THE FRUIT THAT DEVLOPS FROM THE OVARY IS CALLED TRUE FRUIT. ( Mango,Grapes,Brinjal etc ) HOWEVER IN SOME CASES IN ADDITION TO OVARY OTHER PARTS OF THE FLOWER SUCH AS TEPALS, BRACTS, THALAMUS, ETC ALSO TAKE PART IN FRUIT FORMATION. SUCH FRUITS ARE CALLED FALSE FRUITS.( Apple, Cashew nut, Pine apple etc ) IN TRUE FRUITS GENERALLY WE EAT THE OVARY AND SEEDS IN FALSE FRUITS WE EAT EITHER THALAMUS, BRACTS, SEPALS BUT NOT THE OVARY AND SEEDS. FALSE FRUITS ARE ALSO CALLED PSEUDO -FRUITS OR SPURIOUS FRUITS .

5. FRUIT STRUCTURE A FRUIT CONTAINS MAINLY TWO PARTS FRUIT WALL SEED OR SEEDS FRUIT WALL IS CALLED PERICARP AND HAS THREE LAYERS OUTER EXOCARP OR EPICARP MIDDLE MESOCARP INNER ENDOCARP IF ALL 3 LAYERS ARE FLESHY –THE FRUIT IS A BERRY (GRAPE) IF ENDOCARP IS STONY- FRUIT IS A DRUPE(MANGO) IF ALL 3 LAYERS ARE HARD – FRUIT IS A NUT

6. FRUIT TYPES FRUIT STRUCTURE AND TYPE IS DETERMINED BY THE POSITION OF OVARY NUMBER OF OVARIES (SEPARATE) PER FLOWER MULTIPLE FLOWERS IN THE INFLORESCENCE GENERALLY- SINGLE FLOWERS HAVING ONE OR MORE SEPARATE CARPELS DEVELOP TO SIMPLE FRUITS(MANGO,GRAPE). SINGLE PISTIL WITH TWO OR MORE FUSED CARPELS GIVE RISE TO SYNCARPOUS FRUITS.(ORANGE,) MULTIPLE SEPARATE OVARIES IN A FLOWER GIVE TO AGGREGATE FRUIT. (BLACK BERRY, CUSTARD APPLE) MULTIPLE FLOWERS IN AN INFLORESCENCE DEVELOP TO A COMPOSITE OR MULTIPLE FRUIT(PINEAPPLE,JACK FRUIT) A SUPERIOR OVARY IN A FLOWER DEVELOPS TO A BERRY (MOSTLY THE OVARY) AN INFERIOR OVARY IN A FLOWR DEVELOPS TO A POME (APPLE)

7. Aggregate fruit due to multiple ovaries in a flower

8. Composite or multiple fruits

9. FRUIT DEVELOPMENT FRUIT DEVELOPMENT BEGINS AFTER POLLINATION AND FERTILIZATION. IT STARTS WITH FRUIT SETTING AND ENDS WITH MATURITY. IT CAN LAST FROM ONE TO SOME MONTHS DEPENDING ON THE SPECIES. FRUIT DEVELOPMENT IS CHARACTERIZED THROUGH FOUR STAGES FRUIT SET( INVOLVES OVARY DEVELOPMENT) FRUIT GROWTH CELL DIVISION AND CELL EXPANSION) FRUIT MATURATION (INVOLVES RIPENING)

10. FRUIT SETTING FRUIT SETTING IS A TRANSITION PHASE OF OVARY FROM THE FLOWER TO THE DEVELOPING FRUIT. IT IS INITIATED AFTER SUCCESSFUL POLLINATION AND FERTILIZATION. THIS IS A SENSITIVE STAGE AND DETERMINES THE NUMBER OF FRUITS THAT WILL REMAIN ON THE PLANT. A GOOD FRUIT SETTING IS A START FOR GOOD PRODUCTION. FRUIT SETTING PREVENTS FRUIT ABORTION. FRUIT SETTING IS MAINLY DUE TO A HORMONE CALLED GA ( GIBBERLLIC ACID) IF GA IS NOT PRODUCED OR LITTLE PRODUCED DUE TO LACK OF POLLINATION OR FERTILIZATION THE EXPANSION OF OVARY IS INHIBITED. IN THE FLOWERS WHICH DONOT GET POLLINATED OR FERTILIZED THE OVARY WILL SENESCE AND FALL .

11. CELL DIVISION THIS IS THE SECOND PHASE OF FRUIT DEVELOPMENT. CELL DIVISION SETS POTENTIALS FOR ULTIMATE SIZE OF THE FRUIT. THIS PHASE LASTS BETWEEN 7 TO 10 DAYS DURING WHICH CELL DIVISION OCCURS THROUGHOUT THE FRUIT. FINAL FRUIT SIZE IS DIRECTLY RELATED TO THE NUMBER OF CELLS PRODUCED IN THE PERIOD IMMEDIATELY FOLLOWING POLLINATION. MORE CELLS MEANS THE FRUIT SIZE WILL BE BIG. CELL DIVISIONS OCCUR MAINLY IN THE WHOLE PERICARP BUT RELATIVELY MORE IN THE OUTER PERICARP. IN FRUIT DEVELOPMENT IT IS THE DEVELOPING SEEDS OR THE NUMBER OF FERTLIZED OVULES THAT CONTROL THE RATE OF CELL DIVISION IN THE OVARY. A HORMONE CALLED CYTOKININ PRESENT IN THE SURROUNDING TISSUES OF THE SEEDS HELP THIS CELL DIVISION.

12. CELL EXPANSION THIS IS THE THIRD PHASE IN FRUIT DEVELOMENT. DUE TO CELL EXPANSION THE FRUIT ATTAINS THE FULL SIZE. THE PRIMARY STIMULANT DRIVING THE CELL EXPANSION IS AUXIN. THIS IS THOUGHT THAT THE HIGH SEED AUXIN CONCENTRATION EITHER DIRECTLY PROMOTE CELL EXPANSION OR PROMOTE THE PRODUCTION OF ANOTHER STIMULATORY MOLECULE IN THE SEED . THIS DIFFUSES OR TRANSPORTED TO SURROUNDING TISSUE AND STIMULATES CELL EXPANSION.

13. FRUIT SIZE FRUIT SIZE HAS ECONOMIC SIGNIFICANCE TO THE PRODUCER . IT IS AFFECTED BY NUMBER OF CELLS PER FRUIT NUMBER OF LEAVES ON THE PLANT PER FRUIT INTRA-PLANT COMPETITION FOR PHOTOSYNTHESIS. SEED FORMATION

14. NUMBER OF LEAVES PER FRUIT LEAVES ARE THE SITES OF PHOTOSYNTHESIS AND FRUITS ARE THE SINKS MORE LEAVES PER FRUIT MEANS BIGGER THE SIZE BUT UPTO CERTAIN LIMIT. NATURAL FRUIT FALL AT THE BEGINING HELPS IN BIG SIZE OF THE FRUIT. SOMETIMES REMOVING SOME FRUITS AT THE EARLY STAGE MAKES REMAINING FRUITS TO BE BIGGER IN SIZE.

15. SEED FORMATION AND FRUIT SIZE SEED FORMATION IS AN IMPORTANT FACTOR IN FRUIT DEVLOPMENT. FEW SEED FORMATION LEADS TO MIS-SHAPEING OF THE FRUIT. TOO MANY SEED FORMATION MAY LEAD TO FRUIT ABORTION. EACH DEVELOPING SEED SENDS A HORMONE AUXIN THAT STIMULATES THE PERICARP OR THE RECEPTACLE TO DEVELOP. HOWEVER FRUIT CAN ALSO DEVELOP WITHOUT ANY SEED FORMATION – CALLED PARTHENOCARPY. ( WILL BE DISCUSSED IN NEXT VIDEO)

16. FRUIT MATURATION IT IS THE FINAL STAGE OF FRUIT DVELOPMENT WHEN THE FRUIT ATTENDS THE FULL SIZE IT STOPS GROWING FURTHER AND SETS TO RIPE. DURING THIS MATURATION AND RIPENING PROCESS A LOT OF PHYSIOLOGICAL CHANGES OCCUR IN THE FRUIT. THERE ARE CHANGES IN THE COLOUR , AND CONTENTS OF THE FRUIT. THE UNRIPE FRUITS ARE GENERALLY HARD, GREEN AND SOUR TO TASTE. BUT THE RIPENED FRUITS ARE SOFT, COLOURS ARE YELLOW, RED OR ORANGE, AND MOSTLY SWEET TO TASTE. WHEN A FRUIT IS READY TO RIPE, IT IS SAID TO BE FULLY DEVELOPED AND MATURED.

17. SUMMARY FRUIT IS A RIPENED OVARY AND IT DEVELOPS FROM THE OVARY AFTER POLLINATION AND FERTILIZATION. THE NATURE OF FRUIT DEPENDS ON THE POSITION OF THE FLOWER AND THE NATURE OF THE OVARY. THE FRUIT THAT DEVELOPS SOLELY FROM THE OVARY IS TRUE FRUIT. THE FRUIT HAS A PERICARP CONTAINING THREE LAYERS. FRUIT DEVELOPMENT OCCURS IN FOUR STAGES- FRUIT SETTING, CELL DIVISION, CELL EXPANSION, FRUIT MATURATION . GA HELPS IN FRUIT SETTING, CYTOKININ HELPS IN CELL DIVISION , AUXIN HELPS IN CELL EXPANSION AND ETHYLENE HELPS IN FRUIT RIPENING. FRUIT SIZE IS DEPENDENT ON NUMBER OF LEAVES PER FRUIT, NUMBER OF SEEDS IN A FRUIT AND NUMBER OF CELL DIVISIONS DURING DEVELOMENT.

18. SELF ASSESSMENT-1 FILL UP THE BLANKS WITH APPROPRIATE ANSWERS FROM THE CHOICES GIVEN UNDER EACH QUESTIONS- 1-A FRUIT IS A -----. a) Post fertilized product of pistil b)Product of flower c)Body having seeds d) Post fertilized product of ovary. 2-A TRUE FRUIT IS FORMED FROM----- a) Ovary b) Ovary & thalamus c) Ovary & calyx d) Ovary and receptacle 3-A FRUIT WHICH DEVELOPS FROM A SINGLE OVARY OF A SINGLE FLOWER IS -------FRUIT a)accessary b)simple c) single d)Pseudo 4-IF THE ENDOCARP OF A FRUIT IS STONY THEN IT IS A ----- a) Berry b) Drupe c) Pome d) Nut 5- IN A NUT WHICH LAYER IS HARD? a) Epicarp b) Endocarp c) Mesocarp d) all layers.

19. SELF ASSESSMENT-1 CONTD . 6-MULTIPLE SEPARATE OVARIES IN A FLOWER GIVE RISE TO FRUIT WHICH IS --- a) an aggregate fruit b) Composite fruit c) Simple fruit d) None 7-MULTIPLE FLOWERS IN AN INFLORESCENCE DEVELOP TO A --- FRUIT. a)Aggregate b) Composite c) Simple d) None 8-A FLOWER HAS TWO SEPARATE CARPELS. THE FRUIT DEVELOPING FROM THAT FLOWER WILL BE Simple type, b) aggregate type, c) composite type d) false fruit 9-WHICH IS THE CORRECT SQUENCE OF FRUIT DEVELOPMENT? Cell division-Cell expansion-Maturation – Ripening b)Cell expansion-Cell division-Maturation- Ripening c)Cell division-fruit setting-Maturation-Ripening d)Cell division-fruit setting- Cell expansion-Ripening 10-GA HELPS IN a) Fruit setting b) Fruit Ripening c) Fruit dehiscence d) all the above

20. SELF ASSESSMENT-1 CONTD. 11-WHICH OF THE FOLLOWINGS HELP S IN INCREASE IN NUMBER OF CELLS DURING FRUIT DEVELOPMENT a)GA b) Cytokinin c) Auxin d) ABA 12-CELL EXPANSION DURING FRUIT DEVELOPMENT IS EFFECTED BY— a) GA b) Auxin c) Cytokinin d) Ethylene 13-WHICH IS THE CORRECT SEQUENCE OF HORMONES AFFECTING DIFFERENT STAGES OF FRUIT DEVELOPMENT? GA—Cytokinin—Auxin– Ethylene b) Auxin-Cytokinin-GA—Ethylene c) Cytokinin—Auxin—GA—Ethylene d) GA-Auxin- Cytokinin-Ethylene

21. SELF ASSESSMENT -2 GIVE VERY SHORT ANSWER TO THE FOLLOWING QUESTIONS IN 2-3 LINES. What is a fruit? What is a true fruit and a false fruit? Why gymnosperms do not produce fruits? Write any two significance of fruits in plants. Write one difference between a simple fruit and an aggregate fruit. What are the stages of fruit development? What do you mean by fruit setting? Name the different plant hormones that take part in fruit development . What is pericarp and name its layers.