This document provides an overview of mutation breeding including: 1. Mutation can occur through changes in nuclear or cytoplasmic DNA, with cytoplasmic male sterility being a useful example. 2. Early work in the 1920s-1940s established induced mutation techniques using radiation and chemicals. This opened the door to mutation breeding in crops. 3. Mutation breeding involves inducing desirable mutations through mutagens like radiation or chemicals and using them for crop improvement traits like increased yield, drought tolerance, etc. 4. Several countries including India have successful mutation breeding programs that have developed improved crop varieties through this technique.

1. MUTTURAJ M D
Jr.M.Sc (GPB)
UAHS Shivamogga

2. Introduction
Mutation refers to sudden heritable change in the phenotype of an
individual.
Mutation occurs in two ways :
(1) By alteration in nuclear DNA ( point mutations)
(2) By change in cytoplasmic DNA(cytoplasmic mutation)
The best example of useful cytoplasmic mutation is cytoplasm male sterility.
1927 – First proof of induced mutations in plants; radium ray treatment of
Datura stramonium (Gager and Blakeslee).
1927 - Muller working with Drosphila provides proof of mutation induction
by X-rays Muller champions induced mutation for animal and plant
breeding and opens a new era in genetics and breeding.

3. 1928 Stadler publishes the first results of mutation
induction in crop plants, barley, maize, wheat and
oat, but is sceptical about the use of induced
mutation for crop improvement.
1936 The first induced mutant variety is released,
tobacco var. ‘Chlorina’ using X-rays in Indonesia.
1942 First report of induced disease resistance in a
crop plant; X-ray induced mildew resistance in barley
(Freisleben and Lein, 1942).
1944/46 First reports of chemical induced mutation
(Auerbach and Robson, 1944).
Father of mutation breeding - Ake Gustafsson.

4. TYPES OF MUTATION
A.Spontaneous mutations : Mutation occur in
natural populations .
B. Induced mutations: Mutation may be artificially
induced by various mutagenic agents.
Induced mutations are of two types:
1.Macro-mutations: Mutation with distinct
morphological changes in the phenotype.
2.Micro-mutations: Mutations with invisible
phenotypic changes.

5. MUTATION BREEDING
• Inducing desirable mutations and exploiting them for
crop improvement. It is commonly used in self
pollinated crops and used to produce traits in crops
such as larger seeds ,new colour.
• Important steps to know before mutation breeding are,
1.Selection of variety for mutation breeding, It should be
the best variety available in crop and Seed shold be pure
2.Part of the plant to be treated
3.Dose of the mutagen, Mutagens generally induce a high
frequency of chromosomal changes and meiotic and mitotic
irregularities, Optimum mutagen dose is one, which produces
maximum frequency of mutations and causes the minimum
killing.

6. MUTAGENS
• Mutagen : Physical or chemical agent which
greatly enhance the frequency of mutation.
• Types of mutagens: A.Physical mutagens:
1.Ionising radiation:
(a)Particulate radiations: alpha-rays , beta-rays,
fast netrons and thermal netrons.
(b)Non-particulate radiations: x-rays and
gamma rays.
2.Non-ionising radiation: ultraviolet radiation.

7. • B.Chemical mutagens:
1.Alkylating agents: EMS `(ethyl methane
sulphonate),methyl methane sulphonate
(MMS),sulphur mustard, nitrogen mustard
2.Acridine dyes: proflavin,acridine orange,
acridine yellow and ethidium bromide.
3.Base Analogues:5 Bromo Uracil,5-chlorouracil.
4.Other mutagens: Nitrous Acid, Sodium Azide.

8. BREEDING PROCEDURE

9. M1
M2
M3
M4
M5
M6-M8
M9
i. Mutagen -treated seeds space planted
ii. Seeds from individual plants harvested separately
i. Individual plant progenies are grown
ii. Fertile, vigorous, normal looking plants harvested separately
i. Individual plant progenies from selected plants grown
ii. Superior plants selected from superior progenies showing
segregation
iii. Homogeneous mutant progenies may be harvested in bulk
i. Individual plant progenies from selected plants grown
ii. Superior homogeneous lines harvested in bulk
i. Preliminary yield trial with a suitable check
ii. Superior lines selected
i. Multi-location yield trial
ii. Outstanding line released as new variety
i. Seed multiplication for distribution 9

10. Screening/selection
Mainly three types screening/selection techniques are
used in M2 and subsequent generation.
1. Visual : most effective and efficient method for
identifying mutant phenotypes.
2.Mechanical/Physical : Very efficient for seed size,
shape, weight, density, etc., using appropriate sieving
machinery.
3.Other methods : Low alkaloid content mutants can be
selected using colorimetric tests.
- chromatographic or electrophoresis techniques may
be used to select isolate protein variants

11. Advantages of mutation breeding
a) Mutation breeding is a cheap and rapid
method of developing new varieties.
b) Induced mutagenes is used for the induction
of CMS. Ethidium bromide (EB) has been
used for induction of CMS in barley.
c) Mutation breeding is more effective for the
improvement of oligogenic characters.
d) Mutation breeding is the simple, quick and
the best way when a new character is to be
induced.

12. Limitations
a) The process is generally random and unpredictable.
b) Useful mutants are rare and predominantly recessive.
c) Mutants can have strong negative pleiotropic effects on
other traits.
d) Health risks: handling, chemical mutagens; radiations,
fast neutrons treatments.
e) Most mutants are of no use to breeding even if a large
number of mutants can be produced.
f) Field trialling and germplasm storage can be expensive
and require a lot of space and careful management if
large mutant populations are handled.

13. The primary research centres and institutes in
India that participated in the development and
release of various mutants
 Indian Agricultural Research Institute (IARI)- New Delhi
 Bhabha Atomic Research Centre- Mumbai
 Tamil Nadu Agricultural University –TN and
 National Botanical Research Institute – Lucknow, UP

14. Achievements of mutation breeding
Higher yield Barley (DL 253), Pea (Hans),
Groundnut (Co 2, TG 17).
 Short stature Barley (RDB 1),Rice (Prabhavati).
 Earliness Rice (IIT 48,IIT 60,Indira,Padmini)
Stress resistance Salt tolerance in Rice (Mohan)
water logging tolerance in jute ( Padma)
Bold seed size Groundnut (PB 1,PB 2,Vikram) and
Rice ( Jagannath).