PhilRice, Nueva Ecija, The
Philippines
June 15, 2009
Source:
Business Mirror
via SEAMEO SEARCA
A fingerprint has a lot to say about a person.
However, fingerprinting is not solely done on humans nowadays.
There is genetic fingerprinting which is a major technique in
crop-biology research.
In the paper, “Genetic Fingerprinting: Advancing the
Frontiers of Crop Biology Research,” Dr. Gabriel 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 that contains the
traits of an organism. Through crop fingerprinting, as in
humans, the crop’s traits are revealed that help breeders select
the traits that they can use in the plant breeding, the
scientists said.
Previously, DNA fingerprinting was a tedious process, until the
discovery of the polymerase chain reaction (PCR) that has paved
the way for a more convenient analysis of DNA variation, the
paper said.
PCR magnifies a section of a DNA that makes it possible for
scientists to study and/or characterize a specific trait of the
crop.
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.
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, the scientists said.
Through genetic fingerprinting, they said, scientists can tell
the sequence of events involved in the development of a rice
plant, for example. This information can give inferences on
traits of a rice variety.
For example, through genetic fingerprinting, it can be learned
that PSB Rc28 is one of the parents of PSB Rc82, they said.
Rice 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 and 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 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 claim 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
appearance 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 the cell’s ability to repair
damaged and mutated DNA.
The team, led by Dr. Nenita 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 the breeding
process, having immense impact on crop-biology research in
general. |
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