Plant Breeding 24 Jun 2026 · 17 views · By Shrikant Sir

PB Ch 16. Mass Selection

Mass selection: Selection of a large number of phenotypically similar desirable plants from a population, mixing their seeds, and using the composite seed as the new variety.
Oldest selection method — practised by prehistoric man since domestication.
No progeny testing is done. Variety developed is heterogeneous and heterozygous ( a mixture of different homozygous pure lines).

Procedure

Year 1:

Select large number of phenotypically similar plants with desirable characters (few hundred to few thousand).
Seeds from ALL selected plants are composited (mixed) to raise the next generation.

Year 2:

Composited seed planted in preliminary field trial with standard checks.
Original variety also included. Phenotypic characteristics evaluated.

Years 3-6:

Coordinated yield trials at several locations.
Initial Evaluation Trial (IET) for one year; main yield trials for 2-3 years.

Year 7:

If variety proves superior, multiplied, named, and released after official variety release committee approval.

Modified Mass Selection

Year 1: Select large number of plants; harvest individually (not composited yet)
Year 2: Grow individual plant progenies; reject inferior, segregating progenies; select uniform superior rows; bulk their seed
Year 3: Preliminary yield trial; Years 4-7: Multilocation tests

Merits and Demerits

Merits	Demerits
Can be practised in BOTH self-pollinated AND cross-pollinated crops	Varieties not as uniform as pure lines — mixture of genotypes
Varieties are more widely adapted than pure lines — genetic heterogeneity provides buffering	No progeny test — genotype of selected plant unknown; phenotype may not reflect genotype
Retains considerable variability — further improvement possible in future	Improvement not permanent — must be repeated every 2-3 years to purify variety
Helps preserve landraces and traditional varieties	Cannot improve characters governed by many genes with low heritability
Useful for purification of deteriorated pure line varieties	Cannot create new genotypes
Less expensive, less time-consuming than pure line selection	Difficult to use for quality traits not visible in field

Achievements of Mass Selection in India

Crop	Variety
Cotton	Dharwad American Cotton
Groundnut	TMV-1, TMV-2
Pearl millet	Pusa Moti, Bajra Puri, Jamnagar Giant, AF3
Sorghum	RS 1
Rice	SLO 13, MTU-15
Potato	K 122

Mass Selection vs Pure Line Selection

S.No.	Mass Selection	Pure Line Selection
1	Used in BOTH self-pollinated AND cross-pollinated crops	Practised primarily in self-pollinated crops only
2	Large number of plants selected (few hundred to few thousand)	Fewer plants selected (200-3000) with greater individual attention
3	Produce of ALL selected plants mixed (composited) and sown as bulk	Produce of EACH plant kept separate; individual progeny rows raised
4	No control over pollination	Pollination is controlled (isolation/bagging in SP crops)
5	Variety developed is heterozygous and heterogeneous — not fully uniform	Variety is homozygous, homogeneous and uniform — all plants same genotype
6	Variety deteriorates quickly due to heterozygosity and heterogeneity	Variety lasts long and remains stable due to homozygosity
7	Must be repeated every 2-3 years to re-purify variety	No need to repeat — variety maintains itself through selfing
8	Wider adaptability due to genetic heterogeneity — buffers against environmental variation	Narrow adaptability — suitable for specific, well-defined environments only
9	No specialised knowledge required — more an art; simple to practise	Genetic knowledge and breeder skill required
10	Selection within the variety (repeated mass selection) is effective over time	Selection within a pure line variety is NOT effective — no heritable variation
11	Difficult to identify in seed certification programmes	Easy to identify in seed certification due to complete uniformity

CSE 2017 (Q2c, 10M) — Write on mass selection vs pure-line selection.

← PB Ch 15. Pure Line Selection

PB Ch 17. Pedigree Method →