Principles of Plant Genetics and Breeding

Purpose and expected outcomes
The methods and techniques of plant breeding change over time as science and technology advance. Whereas new
technologies have and continue to be incorporated into plant breeding to facilitate the selection process (leading to
the concept of molecular breeding), the classic methods of breeding appear to have remained relatively unchanged in
recent times. No new major breeding methods have been developed in recent times, even though many biotechnological
techniques have been introduced. Nonetheless, a few approaches are receiving some attention, even though they
are not yet mainstream breeding concepts. These are the concepts of decentralized participatory plant breeding and
organic breeding. These concepts are being formally introduced in this textbook to enable students to become
engaged in the discussion of some of these topics while in training.
After completing this chapter, the student should be able to:
1 Explain the concept of decentralized participatory plant breeding.
2 Discuss the scientific basis of decentralized participatory plant breeding.
3 Discuss the advantages and disadvantages of decentralized participatory plant breeding.
4 Discuss the concept of organic plant breeding.
5 Discuss the concept of naturalness.
6 Discuss the acceptable techniques for organic breeding.
Concept of centralized plant breeding
The traditional approach to plant breeding is for
researchers to independently initiate and conduct a
plant breeding program at a specific research station or
institute, without input from farmers (centralized plant
breeding). Then, they evaluate advanced generations
of genotypes over selected locations, after which they
release a genotype as a new cultivar. At the very best,
farmers are occasionally invited to observe finished
products during field days. Even on such occasions,
their input is limited to choosing among different
finished products. Some breeders believe that engaging
farmers at some point in the actual breeding process is
advantageous. There is a disconnection between the site
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Emerging concepts in
plant breeding
of selection (site of breeding) and the target environment
(where the product will be used). Consequently,
as S. Cicarelli pointed out, the selection efficiency
decreases as the selection environment becomes increasingly
different from the target environment. In developed
countries, crop producers often have facilities
to duplicate the favorable selection environments that
occur at the research stations. Unfortunately, in developing
countries, breeders address the problems of
poor farmers, who operate in unfavorable conditions,
from their national research stations (and from the
International Agricultural Reseach Centers, IARCs). As
previously discussed (see Chapter 23), plant breeders
interpret G × E interactions in their cultivar release
decision-making process. Some researchers such as