The document discusses seedless fruits and the concept of parthenocarpy, which is the formation of fruit without fertilization, categorized into natural and induced forms. Factors influencing parthenocarpy include genetic mutations, environmental conditions, and the application of hormones such as auxin and gibberellins. It highlights the significance of parthenocarpic fruits in agriculture, food preservation, and consumer preference due to the absence of seeds.

1. :SEEDLESS FRUITS

2. ._definition by nitsch (1965)
: Formation of fruits without fertilisation.
,Absence of seeds.

3. ▪ 1:Natural parthenocarpy_ bananas which known to develop naturally..
▪ 2:Induced parthenocarpy_fruit formation is stimulated.
▪ Based on stimulating factors,;
▪ *Genetical parthenocarpy
▪ . *Environmental parthenocarpy
▪ . *Chemical parthenocarpy
▪ BASED ON POLLINATION
▪ Vegetative parthenocarpy/Autonomous:The fruit development without pollination.
▪ Eg...banana
▪ Stimulative/aitonomous parthenocarpy:The fruit development with pollination.

4. CONDITION FOR PLANT TO PRODUCE PARTHENOCARPICFRUIT
*Fruit develop after fertilisation.then sometimes the seed stop
development and result in seedless fruit.eg-grapes
*Pollination as usual and pollen tube grow to certain distance but fruit
develop without fertilisation.eg-nicotiana.
*Dead pollen or non viable pollen placed on stigma encourages fruit
formation.
*Fruits may be developed without pollination.eg-tomato,banana,fig.
THUS PARTHENOCARY IS AN NATURAL ACCIDENT OR IT CAN BE
INDUCED ARTIFICIALLY BY THE HELP OF HORMONE LIKE AUXIN AND
GIBBERELLINS.

5. GENETICAL PARTHENOCARPY
*Common in cultivated than in wild plants.
*Mutations,hybridization,incompatibility are the reasons.
*In incompatible plants ,pollen tube growth is extremely slow and flowers fall much before the tube
reaches the ovary.
• In natural genitical parthenocarpy,is associated with high auxin content and are triploids.eg-grapes.

6. • Incomplete dominant gene P
• In homozygous condition PP produces non
parthenocarpic fruits.
• Heterozygous Pp produces parthenocarpic fruits.

9. ▪ Climatic factors like fog , temperature particularly nocturnal temperature.
▪ The low temperature slows down pollen tube growth and pollen tube fails to reach the ovary.
▪ Some of the varieties of pears and apples are parthenocarpic in South Africa while seeded in
USA.
▪ In cucurbits pepo,preventing the pollination factor and subjecting the plant to 15 c during
night can induces parthenocarpy.
▪ Low temperature and short day promote pistillate flowers in cucurbits and inhibits flower
abscission in tomato and thereby promote parthenocarpy.

10. ▪ Gustafson (1939)made a comparative study of hormone in seeded and seedless fruits and
found that seedless varieties have bigger auxin ccontent.
▪ Application of auxin:
*prevent abscission layer and encourage the development of vascular system in the stalk.
*Auxin brings abortion of seeds.
*Auxin spray also reduces loss of water from fruits.
* Starch synthesis is increased.
*Effect enzymatic activity and increase oxygen uptake.
* Vegetative parthenocarpy can be induced in morus alba if pollination is prevented
through bagging.

11. Application of gibberellin
*GA3 if injected in ovary of zephyranthes would stimulate the
development of ovaries with seeds but without embryos.
* Low concentration of gibberellin (20ppm) can induce
parthenocarpy.
• Induces seedless fruits in tomatoes,figs,apples,pears.
• Both 2-NOA(2-naphthoxy acetic acid) and 24D can induce fruit
formation in tomato if the same fails to grow in low temperature.

12. PARTHENOGENESIS
*Kerner (1976) in Antennaria alpina,staminate flowers are present
fertile pollen are very few.
*In this plant, megaspore mother cell directly functions as
megaspore without meiosis and diploid megaspore directly
develops to embryo without fertilisation.
• This kind of development of embryo without fertilisation is termed
as parthenogenesis.
• Haploid parthenogenesis
• Diploid parparthenogenesis
• Facultative parthenogenesis
• Induced parthenogenesis

13. # In haploid parthenogenesis,the egg is formed after reduction division of
mega spore mother cell and develops to embyo.As it contain only a single set
of chromosomes it cannot establish it’s generation.
# Diploid embryos may be formed without fertilisation if megaspore mother
cell develops to megaspore directly.this is called diploid embryogenesis.
# Development of embryo is only a chance is included in facultative
embryogenesis.reported in orchis maculata.
#A number of physiological and chemical treatment for induced
parthenogenesis like,~exposing ovary to low /high temperature soon after
pollination,~exposing stigma to x-rayed pollen,~using pollen of unrelated
plants or delayed pollination,~chemical treatment.
Eg:Tritium monoccum.

14. METHODS FOR THE INDUCTION OF PARTHENOCARPY
*Interspecific and intergeneric crosses are responsible for the parthenogenesis in Brassicas.
*Delayed pollination will help to obtain haploid embryos
*Use of chemical Belvitan in petunia violaceae result in enlargement of micellar cells and
formation of pro embryos.
*When applying the growth regulator it must be penetrate the cuticle or tissues so esters are
effective.
*Fumigation with ester vapour possible only in green houses.
*In pears frost injury of ovary is beneficial
*treatment of grapes floral clusters,dipping in GA3 is useful in large scale production in Japan.
*In strawberry,2NAA at concentration of 50mg/l sprayed after two weeks of pollination.
* Artificial changes in temperature is also successful.

15. SIGNIFICANCE OF
PARTHENOCARPY/ECONOMICAL
IMPORTANTANCE
Parthenocarpic fruits are required by food
preservationist for making
jams,jellies,sauces,fruit drinks etc.because
the edible fleshy part of fruit may increased
by the absence of seeds.
😊Helps the growers to keep the insect and
pest away because there no need for
pollinating agent.So it improves the crop
yield without using pesticides.
,😀 Preferred by consumers.
😀 Plants need not to be pollinated.

20. ▪WHY SOME FRUITS
DEVELOP
PARTHENOCARPICALY
IN NATUREWHILE
OTHERS DO NOT?