For healthy potatoes - Bayer CropScience

Hugely successful in corn, the use of
hybridization by plant breeders to improve
crop productivity is now prevalent in a vast
array of cereal, horticultural and vegetable
crops. Bayer CropScience has developed
an expertise in the production of quality
hybrid seed in canola and, to a smaller
extent, cotton and in the most recent crop
embracing hybrid vigor, rice.
Breeding and plant pollination
A hybrid is the result of a cross between
two genetically distinct parent lines. When
the right parents are selected, a hybrid will
have both greater vigor and yield than
either of the parents. Hybrids also tend to
have increased resistance to diseases and
insects.
The process of breeding hybrids,
“hybridization”, is achieved through the
use of what is called a pollination control
system that renders the pollen of one parent
line non-viable (male sterile or female
line) to ensure pollination by the chosen
parent line. One of the most common
methods to eliminate self-pollination is
emasculation through the mechanical
removal of the anthers.
In corn, where the male flowers are separated
from the female flowers, the process
is called “detasseling” and involves the
removal of the male flowers from the plant.
Genetic methods can also be used to generate
the desired male sterility in hybrid
seed production, particularly in crops that
possess full or “perfect” flowers (male and
female) and that “have a moderate degree
of out-crossing, produce few seeds per
flower, and for which the costs of manual
castration techniques cannot be recovered
by the price of the seed.” 2
Why Farmers use F1 Hybrids
There are three very good reasons why
farmers are interested in first generation
filial (F1) hybrids. The first is to obtain
higher yields through a phenomenon
known as hybrid vigor (heterosis) or heterozygote
advantage. The second is uniformity.
Every plant in an F1 is identical (with
some genetic variation in the inbreds that
gets multiplied when the inbreds are
crossed) and this uniformity can be advantageous
when you are trying to harvest a
field at one time, by a machine. The third
is the availability of certain hybrid gene
combinations that are only present in a
commercial F1 and that are technically
impossible in an inbred line.
If farmers plant the seeds of a hybrid
crop (F2, F3…), then the resulting crop
will deliver disappointing results. The
growth will not be uniform, harvests will
show mixed grain types and will have lost
its yield advantage. For this reason, a fresh
batch of F1 hybrid seed should be planted
for every crop. Indeed, from a farmer’s perspective,
hybrids are best used when the
increased yields from hybrid vigor will
more than pay for the extra cost of planting
seed; the added premium being uniformity. 3
Producing Commercial F1 Seed
The production of commercial hybrid seed
for sale to farmers is an expertise intensive
– as opposed to capital intensive – exercise.
It requires considerable agronomic and
genetic expertise to produce quality seed in
general and hybrid seed in particular.
Within Bayer CropScience, the process
begins with our expert breeders developing
and then selecting the most desirable parent
lines to form a high quality male and
female gene pool. Once selected, these
lines are handed over to our expert ‘Parent
Seed Team’ to be grown and multiplied.
The parent lines are then coded and dispatched
to contracted farmers who will
grow the seed under the supervision of our
Certified F1 Seed Production Team. The
team is comprised of expert breeding and
production agronomists who ensure the
quality and grade of the seed throughout
the product cycle. The parent lines are kept
separate in the field and are often sown at
different times to ensure the synchronized
development (flowering) of the male and
female lines and to maximize cross-pollination.
The team works with the contracted
farmers who are paid a premium for growing
the coded parent lines in accordance
with the specified protocol. The harvested
seed is then sent back from the farms to
Bayer CropScience for quality evaluation
and grading and is cleaned, treated, coated,
bagged and distributed.
1+2) Introduction to Plant Breeding –
Briggs & Knowles 1967
3) Ibid
2/06 COURIER 17