Manila, The Philippines
May 18, 2009Source:
PhilRice
They say that a human’s
fingerprint has a lot to say about a person. Recent discoveries
show that inferences on personality can be derived from the
fingerprint.
Fingerprinting, however, is not solely done on humans. Genetic
fingerprinting is now a major technique in crop biology research
such as in rice.
In the paper,
Genetic fingerprinting: Advancing the frontiers of crop
biology research , Dr. Gabriel O. Romero, Cheryl Adeva,
and Zosimo Battad II documented how Filipino scientists seize
the benefits of deoxyribonucleic acid (DNA) fingerprinting in
crop research.
Fingerprinting is used to characterize a DNA. DNA contains the
traits of an organism. Through fingerprinting, these traits are
revealed helping the breeders select the traits that they can
use in their plant breeding activities.
Years ago, DNA fingerprinting
was a tedious process. The discovery of the polymerase chain
reaction (PCR) has paved the way for a more convenient analysis
of DNA variation. PCR magnifies a section of a DNA making it
possible for scientists to study and/or characterize that area.
Scientists are now using markers, which make assaying a lot more
convenient. Markers are specific DNA sequences attached to a
trait. Hence, the presence of a marker signifies that a trait is
present.
Application
Taxa identification and
phylogeny, diversity analysis, hybridity testing, gene mapping,
marker-aided introgression, somaclonal variation, and patenting
are some of the areas where genetic fingerprinting is useful.
Through genetic fingerprinting, scientists can tell sequence of
events involved in the development of a rice plant. This
information can give inferences on traits of a variety. For
example, through genetic fingerprinting, it can be learned that
PSB Rc28 is one of the parents of PSB Rc82.
Varieties always interest farmers. While seeds may thrive in
different conditions, there are just a few that can deliver the
highest yield given challenging environments. Varietal
recommendation, therefore, is crucial. Genetic fingerprinting is
useful in diversity analysis measuring the level of genetic
similarities or differences among materials. Decoded traits of a
variety are good inputs in rice breeding. This will guide the
breeders in selecting the traits that they can transfer to
another variety.
Moreover, genetic information provides good input in
conservation. There are germplasms requiring stringent measures
for conservation. Gene-banking is very important to maintain a
repository of varieties so that at the advent of environmental
woes such as pests and diseases, there would be ready
substitutes for farmers.
In making hybrid rice varieties where 50:50 parental
contribution is crucial, genetic fingerprinting is also very
useful. Scientists say that proper identification and selection
is crucial for “proper identification and varietal protection,
genetic identity stability, complete characterization and
measurement of crop genetic diversity, and for uniformity of
appear-ance and agronomic performance of produced variety that
will meet the demand of the farmers and consumers”. Genetic
fingerprinting gives precise results minimizing mistakes in the
breeding process.
Rice outputs
In plants, as in humans, there are
recessive and dominant traits. Recessive traits are
characteristics not commonly expressed by plants that show a
uniform trait. Hence, if the physical appearance will be the
sole basis for some traits possessed by a rice plant, that will
not be very accurate. Through the use of markers, the recessive
genes are identified easily making it possible for scientists to
select properly the traits that they want to incorporate into
another variety. Tubigan 7 (NSIC Rc142) and Tubigan 11 (NSIC
Rc154) are the first two products of marker-aided selection.
They have resistance genes Xa4 and Xa21 against bacterial leaf
blight.
Somaclonal variation refers to the variations seen in plants via
plant tissue culture. The variations may be in the form of
mutation such as alteration of cell’s ability to repair damaged
and mutated DNA.
The team led by Dr. Nenita V. Desamero uses somaclonal variation
to breed varieties that can live in drought-prone areas. IVC-2
and IVC-21 are the first two products of somaclonal variation in
rice breeding that qualified in the National Cooperative
Trial.
Prospects
Genetic fingerprinting can
strengthen the claims for patenting rice varieties. The physical
appearance of varieties cannot exactly express the distinction
between two almost similar varieties. Through genetic
fingerprinting, the traits within the variety can be seen, and
hence, strengthen the claim of plant breeders.
There’s no way back from here. Genetic fingerprinting solely
used before on humans has found its way to hasten breeding
process, having immense impact on crop biology research in
general. |
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