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CLONAL SELECTION IN CROP PRODUCTION:
This presentation details about clonal selection.
Selection of desirable clones from the mixed population of vegetative propagated crops is known as clonal selection.In India, clonal selection has been successfully used for developing new varieties in potato, sugarcane, banana, citrus and grapes.Bombay green, Pride monthan and High gate in banana have been developed by clonal selection.
2. •Historical background
•Clones
•Characters of clones
•Clonal selection
•Procedure
•Merits and demerits
CONTENTS
INTRODUCTION
•Achivements by clonal
selection
PRESENTATION ON
CONCLUSION
1
2
3
3. ❏ Humans have manipulated plant asexual
reproduction through methods like grafting
and stem cuttings for more than 2,000 years.
❏ The modern era of laboratory cloning began in
1958 when F. C. Steward cloned carrot plants
from mature single cells placed in a nutrient
culture containing hormones.
INTRODUCTION
4. ❏In 1838 German scientists Matthias Schleiden and Theodor Schwann presented their cell
theory
❏This theory formed the basis for the concept of totipotency.
❏ In 1939 Professor R. J. Gautheret and colleagues demonstrated the first successful culture of
isolated plant tissues
❏The term callus is defined as an unorganized mass of dividing cells, such as in a wound
response
❏It was not until 1954, however, that the first whole plant was regenerated, or cloned, from a
single adult plant cell by W.H.Muir et al.
❏In 1964, F.C. Steward cloned a full carrot.
HISTORICAL BACKGROUND
5.
6. ❏ The term“clone” is derived from the Greek word
"klon," meaning a "slip or twig".
❏ A variety that is propagated vegetative from a
single plant is known as clones
CLONES
7. CHARACTERS OF CLONES
❏All the individuals of a clone are genotypically and phenotypically identical.
❏Genetically, all the members of a clone are homogeneous and heterozygous
❏Clones are stable- They retain their original traits just like pure line variety
❏Theoretically clones are immortal
❏Phenotypic variation if any in clones is due to environmental impact.
❏ Continuous inbreeding of clones which are heterozygous might lead to severe loss in
vigour and also inbreeding depression.
8. SELECTION OF CLONES DIFFER FROM CROP TO CROP
❏Stem Cutting:Sugarcane, betel vine, black pepper, fodder grasses, some ornamental and
hedge plants.
❏Grafts and buds:Mango, citrus, apple, many fruit trees, rose, and many ornamental plants.
❏Tuber:Potato.
❏Suckers:Banana, Pine-apple, aloe, agave, Chrysanthemum.
❏Bulbs:Onion, Garlic, tulip, lilies.
❏Runners:Oxalis, Doob grass.
❏Stolons:Mint, Mentha etc.
❏Rhizomes and Corms:Ginger, Canna, Turmeric, Colocasia, etc.
❏Root and root cuttings:Sweet potato, Dahlia, Asparagus, mango ginger etc.
9. Selection of desirable clones from the
mixed population of vegetative
propagated crops is known as clonal
selection
CLONAL SELECTION
10. SOURCES OF CLONAL
SELECTION
Superior clones can be isolated
from three types of materials
viz
1) Local variety,
2) Introduced variety, and
3) Inter crossed populations.
11. Clonal selection generally may be practiced with non-flowering or those
species which produce seeds poorly or only under special conditions.
❏Non flowering species: Garlic, ginger, betel etc.
❏Low seed setting species:Sugarcane, potato, sweet potato etc.
❏Normal flowering and seed setting species:Citrus, mango, pear, peach apple,
litchi, loquat and many ornamental plants (to maintain the heterozygous balance
vegetative reproduction is essential).
❏Apomictic species:Agave, Onion, Lilium, Allium, Jasminum, Roses, Bryophyllum
etc. (no seeds produced when apomixis occurs).
12. THINGS NEED TO NOTE WHILE SELECTING
❏The phenotypic value of a plant or a clone is due to its genotype (G),
the environment (E) and the genotype x environment interaction (GE).
Of these, only the G effects are heritable and stable
❏A selection for polygenic characters like yield on the basis of
unreplicated clonal plots would also often be misleading and unreliable.
❏The value of clone can be reliably estimated only through replicated
yield trials.
❏However, selection for highly heritable characters, such as plant
height, days to flowering, colour, disease resistance, etc., is easy and
effective even on the basis of single plant or plot
14. The year-wise scheme of clonal selection is as
follows:
FIRST YEAR
❏ From a mixed variable population, few hundreds to few thousand desirable
plants are selected.
❏ A rigid selection can be done for simply inherited characters with high
heritability.
❏ Plants with obvious weaknesses are eliminated.
15. SECOND YEAR
❏ Clones from the selected plants are grown separately, generally, without replication .
❏ This is done in view of the limited supply of the propagating material for each clone, and
because of the large number of clones involved.
❏ The characteristics of clones will be more clear now than in the previous generation when the
observations were based on individual plants
❏ The number of clones is drastically reduced and inferior clones eliminated.
❏ The selection is based on visual observations and on the basis of clonal characteristics
❏ Fifty to one hundred clones may be selected on the basis of clonal characteristics
16. ❏ Replicated preliminary yield trial is conducted. Suitable, checks included for
comparison.
❏ Few superior performing clones with desirable characteristics selected
formultilocation trials.
❏ At this stage, selection for quality is also done.
❏ If necessary, separate disease nurseries may be planted to evaluate the disease
resistance of selected clones.
17. FOURTH TO SIXTH YEAR
❏ Replicated yield trials are conducted at several locations along with a suitable
check.
❏ The yielding ability, quality and disease resistance, etc. of the clones are
rigidly evaluated.
❏ The best clone that is superior to the check in one or more characteristics is
identified for release as a new variety.
18. SEVENTH YEAR
❏ The superior clone is multiplied released as a new variety.
❏ The variety produced is stable possessing all the original
characters of the parental clone as such.
19. MERITS
❏It is the only method to improve the clonal crops.
❏It offers an opportunity to exploit desirable mutations in
somatic parts of plants.
❏It also helps to eliminate unproductive and undesirable
types.
❏This method is helpful in conserving hybrid vigour for
several generations.
❏Varieties are as stable as pure lines and easy to maintain
because there is no danger of deterioration due to
segregation and recombination.
20. ❏ In this method no new genetic variability can be
created.
❏ This method is applicable only to vegetatively
propagated crops.
DEMERITS
21. ACHIEVEMENTS
In India, clonal selection has been successfully
used for developing new varieties in potato,
sugarcane, banana, citrus and grapes.
❏Varieties Kufri Red and Kufri safed in
potato;
❏ Ko 11, Ko 22 and Neelam in mango; and
❏ Bombay green, Pride monthan and High
gate in banana have been developed by
clonal selection.
