1. PRESENTED BY,
S. SHARVESH,
M.Sc. HORTICULTURE,
DEPARTMENT OF HORTICULTURE,
FACULTY OF AGRICULTUR,
ANNAMALAI UNIVERSITY.

2. CLONE AND CLONAL SELECTION

3. CLONE AND CLONAL SELECTION :
Clone is a plant or group of genetically uniform plants derived exclusively
from a single individual plant which is true to type to mother plant
through vegetative/asexual method of reproduction.
Most of the fruit plants after identification or selection of a best
performing individuals are propagated vegetatively resulting into
production of clones. Therefore, All the progenies derived from a single
plant through vegetative propagation make a clone.
Pureline : progeny of a single homozygous self pollinated plant(pureline is
homozygous and homogeneous).

4. Characteristics of clones :
Clone can be compared with purelines.
1.Clones are stable and retain their original trait just like pure line
variety . ( clones are true to type). They have same genotypic and
phenotypic expressions.
2.Clones are immortal : Clones can be maintained indefinitely by asexual
reproduction with the same genotypic composition, however they are
very much susceptible to pest and diseases infestation and spread once
they break the resistance.
E.G: Pomegranate-Bacterial blight
Bunchy top- hill banana

5. 3.Identical genotype : All the members of the clones are homogeneous
as they are mitotically derived from same plant, therefore
homogeneity in phenotype and any variation in clone is due to
environmental impact but not because of genotype.
(P =G x E)
P = M + G + E + GE
4.Individual clone is heterozygous or homozygous but it is homogeneous
in nature and show severe loss in vigour due to inbreeding.
5.Clones are vegetatively propagated plants.
6.Genetic variation with in the clones may be due to mutation
mechanical mixture , bud sprouts, somaclonal variations and sexual
reproduction.

6. Clonal degeneration : The loss in vigour and productivity of clones over a
time is known as clonal degeneration and it may be due to mutations,
infection of viruses , bacteria etc.
E.G : susceptibility of pomegranate ( kesar or bhagwa ) – bacterial blight
Papaya ( Taiwan ) – Ring spot virus
Coorg mandarin, Nanjangud rasbale.
The phenotype of a clone is due to the effects of genotype ( G ), the
environment ( E ) and the genotype x environment interaction ( GxE ) over
the population mean (M).Therefore phenotype of a clone is expressed as :
P = M + G + E + GE
E.G : Alphonso

7. Steps in clonal selection
SELECT PLANTS OF SUPERIOR
CLONES
EVALUATE SELECTED CLONES
- SELECT DESIREABLE CLONES
PRELIMINARY YIELD TRIAL WITH
SUITABLE CHECK AND SELECTED
OUTSTANDING CLONES
FIRST YEAR
SECOND YEAR
THIRD YEAR

8. MULTILOCATION TRIALS
WITH STANDARD CHECKS
AND RELEASE OF
SUPERIOR CLONE AS NEW
VARITIES
SUPERIOR AND OUTSTANDING
CLONE RELEASED AS NEW
VARIETY LARGE SCALE
NINTH YEAR
FOURTH – EIGTH YEAR

9. Procedure for clonal selection
Clonal selection is the selection of desirable individual from the mixed
population of asexually propagated plants of same variety. eg Alphanso
Clonal selection within DHS – 2 sapota hybrid.

10. Few to several hundred plants are
selected(superior plants)
From same variety
clones from selected plots grown
separately
primary yield trails with standard
check
multilocational trails with
standard check
First year
Desirable clones are selected
Best clone is selected
Second year
Third year
Fourth to eighth year

11. Best clone identified for release of
variety
best clones is released as variety
multiplication of plants and its distribution
Ninth year

12. Advantages of clonal selection :
1. Uniformity of population ( homogeneous population )
2. Clonal selection is easy and less time consuming as compare to traditional
methods.
3. Easy maintenance because there is no problem of out crossing and loss of
seed viability. Variation occurs due to somatic mutations only which can be
removed by roughing of undesirable plants .
4. Permanent hybrids : heterotic clones on selection may be used as permanent
hybrids as they are vegetatively propagated. Heterosis can be exploited for
longer time without production of hybrid seeds every year.
E.G : DHS-1, 2
Amarpalli and Mallika
5. Clonal selection is the only method of breeding in vegetatively propagated
fruit plants . E.G : banana, seedless grapes, pineapple

13. Limitations :
1. There are limited chances of getting new and useful type of variability
( narrowing of genetic base )
2. Low multiplication rate.
3. Monoculture .
4. It is only useful for vegetatively propagated plants.
5. Individuals derived from clonal selection has same genetic background
as such infestation and spread of pest and diseases is very rapid .
6. Potential for latent genetic mutations ( off types ) .
7. Potential for systemic infection. ( viruses, viroides and transmissible
pathogens ) E.G : viruses, MLO in citrus, banana etc .

14. EXAMPLES :
Mango –clone – Akshay ( D-51) from dashehari
Aishwarya from Alphonso
Tommy atkins – from Haden
Pusa Surya – from Elden
Cardoz mankurd – from Goa mankurd
Niranjan – ( off season bearing )