RA 00048.pdf - OAR@ICRISAT

to be produced and the nature of facilities that are
developed. The capital investment is usually much
higher in the market oriented economy because
the shortage and high cost of human resources
demand mechanization and automation. The finance
may be received as a government grant,
loan from institutions responsible for rural development
and/or from commercial banks.
Research Responsibility
Agro-research scientists working in the universities,
plant breeding stations and international
research centers cooperate to maintain a continuous
flow of superior hybrids and improved
varieties to replace the existing ones. The superiority
may be for yield, resistance to pests or
diseases, ability to withstand environmental
stress or any other trait of economic value. In
advanced countries, many private seed enterprises
have also created research facilities and
thus share the responsibility to evolve better
sorghum hybrids and varieties. They do not
disclose their pedigree and thus enjoy a monopoly
on the production and sale of their seed.
In most developing countries, the responsibility
to develop, test and release superior hybrids or
varieties is entirely that of national research
institutes. International research organizations
such as ICRISAT also supply improved variety/
hybrid trials and assist developing countries to
plant and identify superior adaptable types. These
are of open pedigree and any agency in the public
or private sector can produce their seeds.
Seed Classes—Their
Maintenance and Increase
The objective of seed production is to build a
strong chain of multiplication of the various seed
classes. Three stages of multiplication recognized
in seed certification are:
1. Breeder's seed
2. Basic (foundation) seed, and
3. Commercial (certified) seed.
Breeder's seed is the first multiplication stage
after a new superior variety or hybrid has been
officially released, notified and recommended for
cultivation. The responsibility for the increase of
this seed class is usually with the originating
breeder or his station. If the variety/hybrid has
been developed through the cooperative efforts
of a national or international research project, the
coordinator nominates the breeder or breeders
who will be responsible for breeder seed multiplication
and supply within each country. In case of a
hybrid, the male sterile line (A line), the maintainer
line (B line) and the restorer line (R line) comprise
the breeder's seed.
Breeder's seed of maintainer line, restorer line
and variety are multiplied in a small plot, either
under complete isolation or by controlled pollination
usually on a university or research farm. The
male-sterile line is increased by planting in an
isolated plot A and B lines in alternate sets of rows
(frequently 4 : 2 or 6: 2 A and B lines respectively).
Each plant is examined at the vegetative, flowering
and seed ripening stages for trueness-to-type
and seed-borne diseases. The breeder and his
staff ensure that the seed meets the highest
standards of genetic purity, as one off-type plant
will give rise to hundreds of such plants in the
subsequent multiplication stages. Maximum care
is taken to avoid all chances of mechanical
mixtures during harvesting, threshing, cleaning,
grading, packing and labeling of this seed class.
The general standards and specific requirements
of breeder's seed are frequently not
stipulated by most official seed certification agencies
in the world, possibly because the authority
competent to label breeder's seed is the originating/nominated
breeder himself and he is beyond
the purview of the certification agency. However,
the breeder's seed must be field tested before it
is released as a source for basic seed multiplication.
The field test may be jointly conducted by the
breeder and the seed certification agency.
As a matter of policy and convenience, adequate
quantities of breeder's seed to last for 3 - 4
years should be multiplied at one time. The extra
seed can be retained as a buffer stock for any
sudden rise in demand or increased projected
requirements. It will also avoid errors that tend to
arise with frequent handling. Variations which
tend to develop from delayed segregation, mutation,
outcrossing, genetic drift or selection bias of
the breeder will also be minimized. A suitable cold
storage facility should be created at the research
station to store the planned carry-over stock.
Basic (foundation) seed is frequently produced
from breeder's seed. It is not necessary that
production of all basic seed be from breeder's
seed. As long as trueness-to-type is maintained it
can be produced from existing basic seed. Gener-
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