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