PHILRICE, Nueva Ecija—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.