Breeding methods for Self-pollinated crops

1. PRESENTED BY :
Dr. VIINOD S. PAWAR
M.Sc Agriculture, Ph.D (Genetics and Plant Breeding)

3. Selection methods in self pollinated crops
1. Pure line selection
2. Mass selection
3. Pedigree method
1)Pure line : a pure line is the progeny of a single homozygous plant of a self –
pollinated species.
The concept of pure line selection was developed in the middle of 19th century in
Sweden (Le-Couteur. Shireff, Hallet and Vilmorin between 1840—1860)
Concept proposed by Johannsen in 1903 on the basis of his studies with French bean
(Phaseolus vulgaries) a strictly self pollinated species.
The development of new variety through identification and isolation of single best
plant progeny is known as pureline selection or individual plant selection.
Vilmorin used this method for the improvement of wheat and barley.

4. Main feature
1. Homogeneous
2. Non-heritable variation
3. Highly uniform
4. Selection is ineffective
5. Narrow adaptation
6. More prone to new diseases
7. Isolation of purelines
8. Sources of variation : in a pureline variety, natural
outccrossing, mutation and mechanical mixtures are the
important sources of genetic variation.

5. Use of Purelines
1. As a variety
2. As a parent in hybridization programme
3. In studies of mutation
4. Other studies
Application of Pureline selection
1. Improvement of local variety: eg. Pusa sawani bhendi, T1 mungbean
2. Selection in introduced varieties: eg. Shinning Mung 1 is a pureline selection from
the introduced variety Kulu type 1
3. Improvement of old pureline variety: gram Chafa 816: Pusa baisakhi from T44
mungbean
4. Selection for a new characteristics in a pureline :

6. The year wise procedure
First year: from the base population select 200- 1000 best looking plants
having the desirable characters. Harvest them on single plant basis.
Second year: the selected single plant plants are grown in progeny rows and
estimate the performance. Reject unwanted progeny. The top 15-20 progenies
are selected and seed of all plants in each progeny is bulked which constitutes
strains.
Third year: the strains constituted in second year are evaluated in replicated
field trails and top performing few strains are selected for further evaluation.
Fourth to seventh year : selected stains are evaluated in field trails for 2-3
years for yield performance. In India selected entries (strains) are evaluated in
All India Coordinated Crop Improvement Project. The best genotypes
identified on the basis of yield performance..
Eight to Tenth year: the best performance strain is released and notified ass
a variety. Then breeder, foundation and certified seed produced.

8. Merits
1. This is a good method of isolating the best genotypes for yield, disease , insect
resistance, earliness, quality etc. From a heterogeneous, or mixed population of an old
variety.
2. The variety developed by this method is ,more uniform and more attractive than mass
selection variety.
3. This is easy and cheap method of crop improvement.
Demerits
1. This method can isolate only superior genotypes from the mixed population. It can not
develop new genotypes.
2. This method is applicable to self pollinated species only.
3. The variety developed by praline selection have poor adaptability due to narrow
genetic base.

10. Mass selection : a large number of plants of similar phenotypes are selected and their
seeds are mixed together to constitute the new variety.
Is one of the oldest method of crop improvement.
Main feature :
1. Application : both self and cross pollinated species.
2. Genetic constitution: in self pollinated crops, a mass selected variety is homozygous
but heterogeneous, because it is a mixture of several purelines. In cross pollinated
crops, such varieties are mixture of homo and heterozygotes and are heterogeneous,
because they consist of several homo and heterozygous genotypes.
3. Adaptation : wide adaptation and more stable
4. Variation : heritable
5. Selection : effective
6. Quality : less uniform than purelines.
7. Resistance: mass selected varieties are less prone to the attack of new diseases due to
genetic diversity.
8. Roughing: periodic removal of off type plants is essential to maintain the yield of
mass selected varieties.

11. Types of mass selection
1. Positive mass selection:
2. Negative mass selection:
The success of mass selection mainly depends on the three
factors, viz.,
1. Variability in the base population
2. Mode of inheritance of characters to be improved
3. Heritability of the characters

12. First year : the individuals plants (200-2000) are selected on the basis of phenotypic
performance. The selected plant are harvested at maturity and their seeds are mixed
together to grow next generation. This process is repeated till desirable results sre
achieved.
Second year: material are evaluated in preliminary yield trail along with the standard
variety as a check for comparison of performance.
Third to fifth year: evaluation in coordinated yield trail at several locations.
Sixth to eight year: the variety released and named in seventh year and seed is
multiplied.inn the eighth year the seed is ready for distribution.

13. Procedure for evolving variety by mass selection
Original population
First year
i. Large number of phenotypically similar plants having desirable
characters are selected.
ii. Seeds from selected plants are composited to raise next generation.
Second year
i. Bulked seed from selected plant grow
ii. Mass selection may be repeated i.e. item from (i.) and (ii.) from first year
may be repeated.
Third year
X X X X X X
X X X X X X
X X X X X X
X X X X X X
X X X X X X
X X X X X X
X X X X X X
X X X X X X
i. Composited seed planted in a PYT along with
standard checks.
ii. Phenotypic characteristics of the variety are
critically examined and evaluated.
The variety is evaluated in coordinated yield trails at several locations. It is
evaluated in an initial evaluation (IET) trail for one year. If found superior
it is promoted to main yield trails for 2 to 3 years.
Seed multiplied and released after giving a suitable name.
4th to 6th year
7th year

14. Merits :
1. This is good method for improvement of old variety and land races.
2. Also used for purification of improved varieties.
3. Mass selected varieties are more stable in their performance
4. Mass selected varieties are provide good protection against diseases.
5. It requires 8 years for the release of a new variety
6. This method is applicable to both self and cross pollinated species.
Demerits:
1. The selection is based on the phenotypic performance. The phenotype is not always an
indication of superior genotype.
2. In cross pollinated species, there is no control on the pollination. This results in rapid
deterioration of variety developed by mass selection.
3. In cross pollinated crops large number of plants have to be selected for bulking,
because small sample will lead to inbreeding depression.
4. The produce of varieties developed by mass selection is less uniform than purelines.

15. Achievements:
Cotton : Dharwad American Cotton
Bajra : Pusa moti,
Baja puri,
Jamnagar gaint,
AF3,
ICMR 312 was developed at
ICRISAT by mass selection

17. Pedigree refers to record of the ancestry of an individual selected plant. Pedigree
breeding is a method of genetic improvement of self pollinated species in which
superior genotypes are selected from segregating generations and proper records
of the ancestry of selected plants are maintained in each generation.
Main feature
1.Application : This method is widely used for the development of varieties in
self-pollinated crops for development of new varieties while it used in cross
pollinated species for development of inbred lines.
2. Maintenance of pedigree records : in this method proper record of the
ancestry of each selected plant or plant progeny is maintained for all generations
of selection. Important characters of each selected plant and progeny are
recorded.
3. Selection ; artificial
4. Time taken : 14-15 years.
5. Genetic constitution : variety developed by this method is homozygous and
homogeneous, because it is a progeny of single homozygote.

18. The various methods evaluated for parent selection
1. Selection based on parent performance
i. Midparent value
ii. Divergence of coefficient of parentage
iii. Charecter complementation
iv. Multivariate analysis
v. Least square method, parental complementation and ideal genotype
vi. Ecogeographic diversity
vii. Molecular marker based screening
2. Selection based on the performance of progeny
i. Based on F1 data
ii. Method based on f2/f3 data
iii. Selection within crosses a) Grind method b) honeycomb design c) Indirect selection d)
Visual selection
iv. Double haploid or advanced generation lines

19. 1st year : cross is made between the parents possessing desirable characters.
2nd year : Sow the F1 seed giving wide spacing so that each F1 plant produces
more seeds. Raise as many F1 plants as possible to produce large number of F2
seeds. Harvest in bulk.
3rd year : Grow 2000-10000 plants of F2 giving wide spacing for full expression
of the characters in F2 generation plants. Grow parents for comparision.
Depending upon the facilities and objectives of the programme about 100-500
superior plants are selected. The value of selection depend on the skill of the
breeder. He has to judge which F2 plant will produce superior progeny for
characters under consideration. The breeder develops this skill through close
study of the crop for many generations. The selection in F2 is done for simply
inherited characters like head type disease resistance etc. and selection for
characters governed by many genes like yield will be reserved for later
generations. The selected plants are harvested separately and given serial
numbers and description entered in pedigree registers.
4th year : Progeny rows of F3 i.e. seeds of one selection plant in one row are
space planted along with parents and checks. From superior progeny rows,
individual plants with desirable characters are selected (about 50-100 families
and about 5 plants in each family and harvested separately). Diseased,
lodging and undersirable progenies are discarded.

20. 5th year : F4 plants raised again as head to row. Desirable plants are selected
from desirable rows and harvested separately.
6th year : F5 plants raised in 3 row plots i.e. seeds of each selected plant sown in
3 rows. By this time many families might have become reasonly homozygous. For
comparision check variety is grown for every 3 or 5 block. Progenies are
evaluated for yield and the inferior ones are rejected. The number should be
reduced to 25-50. superior plants from superior progenies are selected. Plants
from each progeny are bulked.
7th year : F6 individual plant progenies are grown in multi-row plots and
evaluated. Inferior progenies are rejected and superior progenies are selected.
Plants of each progeny are harvested in bulk. Diseased and inferior plants from
the progenies are removed.
8th year : F7 preliminary yield trial with 3 or more replications ar conducted to
identify superior lines. The progenies are evaluated for many characters including
yield. Standard commercial varieties must be included as checks. Two to five
outstanding lines are selected and advanced to coordinated yield trials.
9th, 10 th & 11th year : selected lines are tested in several localities for 2
or 3 years for adaptation tests. Lines are evaluated for all characters mainly yield
and disease resistance. A line that is superior to commercial variety in yield and
other characters is selected.
11th and 12th year : Selected superior lines is named, multiplied and released
as a new variety. Number of year can be reduced if generations are advanced
during off seasons either in green house or under irrigated conditions.

23. Merits :
1. This method gives maximum opportunity for the breeder to use his skill and judgement
for selection of desirable plants, particularly in early segregating generation.
2. It takes less times than bulk method
3. It is well suited for the improvement of easily identified and simply inherited
characters
4. Breeder obtained information about the inheritance of qualitative characters from the
pedigree records
Demerits :
1. Handling of the material is so difficult.
2. Selection in early generation is laborious and time consuming.
3. Success of this method is depend upon the skill of breeder.
4. There is no opportunity for natural selection
5. Selection for yield in f2 and f3 is ineffective.
Achievement :
Rice : jaya, Padma
Pigeonpea ; T21, Prabhat
Pea: Pant matar 2