Principles of Plant Genetics and Breeding

438 CHAPTER 24
developed. It is very capital intensive and occurs in
both the private and public sectors, as previously
noted.
2 Seed production. Once a cultivar with potential has
been developed, certain steps are followed to increase
the seed to make it available to farmers. These steps
are described next.
3 Seed conditioning. Seed conditioning is the process
of readying the seed for market, whereby the certified
seed is properly dried, cleaned, sorted, treated (where
applicable), and packaged for sale. Tests for quality
standards are conducted (see later in this chapter).
4 Seed marketing and distribution. Seeds are marketed
at different levels, including direct marketing by the
seed companies, or through licensed distributors.
Local distribution may involve farmer dealers, farmers’
associations, sales persons of the seed companies,
private wholesalers, and retailers.
Cultivar release process
This is the ultimate goal of a plant breeding program –
to release a cultivar with higher yield and superior performance
to existing cultivars. After analyzing the data
from the field test, taking into account the G × E interactions
as well as the stability analysis, and considering
local issues (e.g., market needs), the breeder will elect
to declare one genotype a cultivar for release to the
agricultural system for use by producers. As previously
discussed, this cultivar may be released for specific adaptation
or broad adaptation. One of the decisions during
cultivar release is naming the new cultivar. Whereas
there are no rules for naming cultivars, it is often done
thoughtfully and strategically. Some breeders name cultivars
in honor of people or special things of meaning to
the breeder or the organization. Sometimes, the name
may reflect a special attribute (e.g., physical appeal,
color, size, nutritional quality, etc.) of the cultivar that
producers can readily identify with, or it may be a town
or locality in the production region. In the case of small
grains in the USA, a cultivar name must be approved by
the National Small Grains Authority.
The specific steps of the cultivar release process vary
among countries and even among crops in the same
country. In addition to natural seed organizations or
committees, there may be regional, state, and cropspecific
bodies that oversee the process. The breeder (or
organization) is required to submit certain specific data
to the appropriate review board for review and recommendation
for release. Generally, the committees will
evaluate the data to ascertain the genetic distinctness,
uniformity, stability of performance, and general agricultural
merit.
Multiplication of pedigree seed
Pedigree seed is seed of a named cultivar that is produced
under supervision of a certifying agency for compliance
with genetic purity and identity of the original
source. After developing, naming, and registering (and
securing other legal rights), the breeder makes the cultivar
available for commercial multiplication for sale to
the public. In introducing a new cultivar into the food
production system, the obligation to maintain it in a
marketable form so that it can be released at intervals, as
needed, in its authentic form for commercial multiplication,
is the responsibility of the breeder.
Classes of seed in a certification system
This is a limited generation system for maintenance of
pedigree seed. To maintain the original genetic identity
and purity, multiplication of a newly released cultivar is
limited to four generations or classes of seed, the main
difference among them being the quantity of material
generated. These classes are breeder seed, foundation
seed, registered seed, and certified seed. These categories
essentially represent multiplication classes in the
ancestry of certified seed. The Organization for Economic
Cooperation and Development (OECD) terminology
for these classes are pre-basic, basic, first generation
certified, and second or successive-generation certified
seed, respectively.
Breeder seed
Breeder seed (or vegetative propagating material) is in
the direct control of the plant breeder (or organization)
responsible for developing the cultivar. The breeder
assumes responsibility for preserving the genetic constitution
of the cultivar, being the one uniquely familiar
with the true genetic identity of the product. This class
of seed is expected to have the highest level of genetic
purity of any class of seed. The quantity held in reserve is
variable but may range from a few kilograms to several
sacks. It is used to establish the next class of seed (the
foundation seed). The breeder seed plot (especially for
self-pollinating species) comprises progeny rows of seed
from individual plants (called nucleus seed) from the
previous planting. Upon inspection, all deviant rows
(possibly from natural outcrossing) are discarded. Seed
from rows that are true to type are bulked to form the