TEST BANK For Radiologic Science for Technologists, 12th Edition by Stewart C...
Aims and methods of experimental breeding
1. AIM, BASIS AND METHOD INVOLVE IN
EXPERIMENTAL BREEDING
BY
A.M DARMA
2. EXPERIMENTAL BREEDING
1. Introduction
2. Concept of plant Breeding
3. History of plant breeding
4. Aim/Objectives of plant breeding
5. Methods of plant breeding
Content
3. INTRODUCTION
Experimental breeding is the deliberate attempt or
process through which new organism with desirable
features were developed from the already existing
organisms.
It is also be described as the application of genetic
principles to produce organisms (plants & animals and
sometimes microorganisms) with unique feature that are
more useful to humans.
4. Introduction cont….
In experimental breeding, permanent irreversible
and heritable changes are made to the selected
organism.
Experimental breeding involve the manipulation
of the structure, arrangement and sometimes the
composition of the organism’s genome
5. Introduction cont….
Experimental Breeders specializes in several breeding
types, i.e. Mutation breeding, or Polyploidy breeding or
even Transgenic breeding.
The principles and concepts of the above breeding
types is so broad, and is therefore divided into two
disciplines, these are;
– Plant breeding
– Animal breeding
For the purpose of this presentation, the discussion will be
focused more on plant breeding only.
6. THE CONCEPT OF PLANT BREEDING
Plant breeding is defined as the art and science for the
improvement of crop plant science.
Humans have been breeding and selecting improved
plants for centuries, choosing crops with better yield,
bigger fruit or less susceptibility to pests and diseases.
A large number of most valuable varieties of fruit trees
of the present time are the creation of the art of the
plant breeding.
7. HISTORY OF PLANT BREEDING
In more common sense, the history of plant breeding
can be divided into Four major events;
1. Pre Mendelian era:- before 1900.
2. Mendelian era:- 1900 to 1920.
3. Post Mendelian period:- 1921 to 1950.
4. Modern era:- after 1950.
8. OBJECTIVES OF PLANT BREEDING
Before initiating any breeding experiment, clear
breeding aim and/or objectives must be defined, and
this should be based on certain factors such as:
producer needs,
consumer preferences and
environmental impact.
9. Objectives of plant breeding cont.....
Typically, each breeder has his own preferred set of
breeding goals, however, the major aims for breeding
include the following:
– Increase yield: higher yield of grain, fodder, fibre and
other plant products;
– Improved quality: such as shape, size, color,
nutrition, taste, etc in food grains, vegetables, fruits
– Resistance to Pest: development of Crop plants that
are resistant to attacked by various insects, weeds
10. Objectives of plant breeding cont.....
Resistance to abiotic conditions: produce resistance to
abiotic factors such as drought, soil salinity, extreme
temperatures, heat, wind, cold and frost.
Desirable Agronomic Characteristics: It includes plant
height, branching, growth habit, erect or trailing habit.
Accelerated Germination period
Accelerated maturity Duration:
11. METHODS OF PLANT BREEDING
Various approaches have been used for plant breeding,
they are referred to as: plant breeding methods,
procedures or breeding techniques.
The choice of breeding methods mainly depends on the
– Mode of pollination of the plant (whether cross of self
pollinated plant),
– Mode of reproduction, and
– Breeding objective of crop species.
12. Methods of Plant Breeding cont....
Various breeding procedures that are more commonly
used in plant breeding include:
– Plant Introduction,
– Acclimatization
– Selection
– hybridization
13. Plant Introduction & Acclimatization
Plant Introduction: This involves shifting or transfer of
plants from originally growing place to a new place
either though seeds or cuttings after qualifying seed
testing.
Acclimatization: This is the process in which the
introduced plants adjustment to gradual changes of
climatic condition in its new environment (such as
change in temperature, humidity, photoperiod and pH).
14. Selection
Selection: This involves sorting out from a mixed
population a plant or a group of plants with desired
characters.
Two types of selection are often practiced in breeding
– Mass selection: A large population of plants are
selected for gene variability.
– Pureline selection: To develop improved progeny
from a single homozygous plant in self pollinating
crops
15. Hybridization
Hybridization is the process that involves crossing
different organism to produce a hybrid.
In hybridization, the desirable characters of two or more
species, varieties or lines are combined together or
transferred from one organism to another.
16. Hybridization cont....
Various methods of hybridization exist depending on the
mode of reproduction taking place in the plant. These
methods include:
Self-pollinated,
Cross-pollinated and
Vegetative propagated plants
17. REFERENCES
George Acquaah (2007) Principles of Plant Genetics and
Breeding, Blackwell, United Kingdom.
Simmonds, N.W. and Smatt, J. (1999) Principles of Crop
Improvement, 2nd Edition, Blackwell Science, United Kingdom.
Sinha, U. and Sinha, S. (1982) Cytogenetics, Plant Breeding and
Evolution, 2nd Edition, Vikas, New Delhi.
Singh B.D (2010) Plant breeding, principles and methods, 8th
revice edition. Kalyani publishers New delhi. India
