The document discusses breeding methods for cross-pollinated crops, focusing on techniques such as mass selection, ear-to-row method, and progeny selection schemes. It highlights the characteristics of cross-pollinated populations and the advantages and challenges associated with various breeding methods, including their effectiveness in improving traits controlled by multiple genes. In addition, it outlines modifications to traditional methods to enhance selection efficiency and control over pollination.

1. Acharya N.G Ranga Agricultural University
S. V. Agricultural College, Tirupati
Department of Genetics and Plant Breeding
Topic : Breeding methods in cross pollinated crops
Mass selection, ear to row method
and Progeny selection schemes
Submitted by
M. Venkata Rama Sai
TAM/2022-24

2. Breeding method in Cross pollinated crops
 Population of Cross pollinated crops are highly heterozygous and
heterogenous
 They have broad genetic base and more adaptability and flexibility to the
environment
 Heterosis can be fully exploited
 They show variable inbreeding depression ranging from low to severe
 Breeding methods for cross pollinated crops are broadly categorised into
two types
1. Population improvement
2. Hybrid and Synthetic varieties

3. Methods of Breeding:
 Plant introduction
 Mass and Progeny selection
 Back cross method
 Heterosis breeding
 Synthetic breeding
 Composite breeding
 Polyploidy breeding
 Distant Hybridization
 Transgenic breeding

4. Population improvement:
 In cross pollinated crops for population improvement three
breeding approaches are made
1. Recurrent Selection
2. Disruptive Selection
3. Biparental mating

5. Breeding methods :
 Breeding methods without progeny testing:
1. Mass Selection
 Breeding methods with progeny testing:
1. Ear to row method and recurrent selection
Progeny testing : It refers to the evaluation of Plants on the basis of
their progeny performance.
• The most effective way of distinguishing among single plants whose
superiority is environmentally induced and those whose superiority
stems from superior genotypes.

6. Breeding methods without progeny testing
Mass Selection:
 Plants are selected on the basis of their phenotype and no progeny
testing is done.
 The selected plants are allowed to open pollinate.
 Open pollinated seeds from them are bulked together to raise the next
generation
 The efficiency of mass selection depends on the number of genes
controlling the character , gene frequencies and heritability of the
concerned trait.
 Selection is based on maternal parent only
 The selection cycle maybe repeated one or more times to increase the
frequency of favourable alleles, such a selection scheme is generally
known as phenotypic recurrent selection

7.  Thus mass selection has been useful in developing varieties for
special purposes and in changing the adaptation of varieties to fit
them to new production areas.
 On the other hand mass selection has not been effective in
modifying characters such as yield, that are governed by many
genes on the basis of single appearance of Plants
 The ineffectiveness is due to :
1. Inability to identify superior genotypes from phenotypic
appearance of single plants
2. Uncontrolled pollination
3. Strict selection leading to reduced population size, which in turn
leads to inbreeding depression
Effectiveness of mass selection

8. Types of Mass Selection:
Positive Mass Selection
 Desirable plants are selected from a mixed population
 Base material is old varieties or land races.
Negative mass selection
 Undesirable plants are removed from mixed population.
 Used for varietal purification in seed production and certification
Programmes

9. Procedure:
1. From a variable population 200-2000 plants with Desirable
traits are selected
2. The seed from selected plant are composited.
1. The Composited yield is planted in a PLYT along with
standard check
2. Phenotype of the selected plants are clearly evaluated
1. The promising selections are evaluated in coordinated
yield trails at several locations
2. Outstanding lines are raised as new varieties
1. Seed multiplication for distribution

10. Achievements:
 Pearl millet : Pusa Moti, Babapuri, Jamnagar Giant, AF3 etc
 Maize : Jaunpuri, T41, T19 etc
 Cotton : C402, K12, C520 from Desi cotton
100F, 216F, A19 from American cotton
 Castor : S20, B1 and B4.

11. Merits:
 The varieties developed through mass selection has broad genetic base and
widely adoptable than pureline varieties.
 It retains considerable variability and hence further improvement is possible
in future by selection
 Useful for purification of varieties
 It is highly efficient in Improvement of Characters governed by few genes
with high heritability and characters that are easily identified visually.
 Extremely simple and work of breeder is kept to a minimum since selection is
based on phenotype

12. Demerits
 Varieties are not uniform
 Since no progeny testing is done, the genotype of the selected plants is
unknown
 Since selection is based on phenotype and no control over pollination
the improvement brought about is not permanent, since most of
quantitative characters are considerably effected by environment.
 It cannot create any new genotype but utilizes existing genetic
variability
 Characters which are governed by large number of genes and characters
which have low heritability cannot be improved

13. Modifications of mass selection:
 The two basic defects of mass selection 1) lack of control on pollen
source 2) Confusing effect of environment on phenotype
1) Inferior plants in the field are detasseled and plants are allowed to open
pollinate. This modification allows some control on pollen source
2) Pollen from selected plants is bulked and bulk pollen is used to
pollinate selected plants. This allows complete control over pollen source
 In both of these, identification of inferior plants is based on characters
expressed before flowering

14. 3) Stratified Mass Selection: Suggested by Gardner in 1961, is also known as
grid method of mass selection. The field is divided into several small plots
each having 40-50 plants. Equal no. of superior plants are selected from each
plot i.e., selection is done within plots not among them. The seeds are bulked
 The basis for this modification is that variation due to environment, soil
heterogeneity will be much smaller within small plots and thus selection in
small plots is expected to be more effective
4) Plants of single genotype: A single cross hybrid, are planted as check after
every two or four plants of the variety under selection. The yields of Plants
under selection are expressed as percent of yield of nearest check plant
 This scheme is designed to minimize the environmental influence on the
yields of Plants being selected, and employs principle of contiguous
control.

15. Ear to row method:
 This is a modification of mass selection.
 This is proposed by Hopkins in 1896.
 The ear to row method attempts to determine the relative breeding value
of different ears by planting a portion of seed from them, an ear to row,
and measuring the yielding ability of resulting plots.
 The difference between simple mass selection and ear to row method is
in basing the selection on performance of progeny.
 Inbreeding depression can be avoided
 Each selection cycle has generally two years
Breeding methods with progeny testing

16. Procedure:
• 50-100 Plants are selected on the basis of their
phenotype.
• Open pollinated seeds from each plant harvested
separately
• 10-50 seeds each selected plant are grown in separate
progeny rows
• These rows are evaluated and superior ones are
identified and are allowed to open pollinate and
seeds are harvest separately
• This maybe repeated one or more times and seeds
are released for yield trails

17. Merits:
 Selection is based on progeny test and not merely on basis of
phenotype
 Selection cycle is of one year only
 Method is easy and simple

18. Demerits:
 No control on pollination and selection is based on maternal
parent.
 Superior progenies are re-pollinated by inferior pollen

19. Modification of ear to row method
 The ear to row method suffers from the effect that superior
progenies are pollinated by inferior plants since there is no
control over pollen source
 In order to mitigate the above, modified ear to row method is
based

20. Procedure:
 First year : Several plants are selected on the basis of their phenotype and
open pollinated seed from them are harvested separately
 Second year : Small progeny rows are grown, evaluated and superior ones
are identified and remaining seed from each of the plot are kept separately
 Third year: The remaining seed that produced superior progenies are
bulked and planted in the third year , this constitutes the selected version of
population . Plants are allowed to open pollinate and selection cycle is
repeated one or more times
 The difference is plants from superior progenies are only allowed to
mate among themselves which provides control over pollen source.
 This modification is widely used in breeding of Maize in USA

21. Modifications of progeny selection:
 Several other modifications of ear to row method of selection are
available
1) Seeds for progeny testing are obtained by selfing of the selected
plants in the place of open pollination. This is known as S1 Family
selection. This variation is the basis for simple recurrent selection.
 When the seeds for progeny test are obtained after two generations
of selfing, the scheme is termed as S2 Family selection
2) Seeds for progeny testing are obtained by crossing the selected
plants to a common tester – maybe an OPV, a hybrid or an inbred.
This variation has been refined as recurrent selection for SCA, GCA
and reciprocal recurrent selection

22. Modified ear to row method:
 The progeny test consists of a replicated yield trail in
place of a single row so that environmental effects can be
separated and the actual value of each progeny can be
more accurately estimated
 This modification is proposed by Lonnquist in 1964 and
is by far the most successful progeny selection method
 Progenies from the selected plants are planted in
replicated yield trails as well as in crossing block.
 The progenies in crossing block are detasseled, they are
pollinated by pollen from the rows of a random bulk of
all progenies
 Superior progenies are identified on the basis of yield
trial. Best plants from superior progenies in the crossing
block are selected and their seeds are harvested
separately

23. Merits of progeny selection
 Selection is not just based on phenotype but on progeny test which
provided dependable reflection of genotypic worth of selected plants
 More efficient than mass selection in improving the yielding ability
 Inbreeding maybe avoided if care is taken to select a sufficiently large
number of progenies and if selected progenies are not closely related
to each other
 The selection is still simple and easy, but some of it’s modifications
are tedious

24. Demerits of Progeny selection:
 The progeny selection scheme are allowed to open pollinate. As a
result selection is based on only maternal parent which reduces
efficiency of selection
 Many of modifications to schemes are complicated and involve
considerable work
 Selection cycle is usually of two years. It takes twice as much
time as mass selection