Enhanced breeding of superior crops through biotechnology

Posted by on Mar 24, 2015 in Activities, News | 0 comments

 

 

 

 

 

 

 

[24 March 2015]

 

Biotechnology is an ancient technology that continues to develop through advances in science and finds numerous applications – including more precise and efficient way of breeding superior agricultural crops

 

Biotechnology is not new.

Dr. Antonio Alfonso presented the science, history and applications of biotechnology during the recently concluded Seminar-Workshop on Understanding Agricultural Biotechnology for regional officers of the Department of Agriculture held at the Plaza del Norte Hotel and Convention Center in Laoag, Ilocos Norte. Dr. Alfonso is the director of the Philippine Agriculture and Fisheries Biotechnology Program or DA Biotech Program, and an expert in plant breeding, genetics and molecular biology at the Philippine Rice Research Institute. He discussed biotechnology and its applications for more precise and rapid breeding of varieties of crops with desirable traits.

“Biotechnology,” he said, “is generally defined as the use of living organisms or their parts to make or modify products, or improve plants, animals and microorganisms”.

The use of biotechnology dates back from over 10,000 years ago when our forefathers started keeping plants and animals as reliable sources of food. Rice, for instance, is one of the first domesticated plants. Wild animals were tamed for milk or meat production and farm work.

Building on ancient biotechnology is classical biotechnology in 7000 BCE (before-Christ era) wherein microorganisms were used to make bread, cheese, and alcoholic beverages such as wine and beer through the process of fermentation.

Development and application of biotechnological tools continue to expand with advances in science, integration of different fields, and as man gains more profound understanding of the biological process around him. The 1980s marked the start of the application of modern biotechnology by directly manipulating the genetic information in organism.

From classical applications such as cross pollination or traditional breeding, biocontrol, biopesticides and biofertilizers, newer biotechnological techniques with applications in agriculture have emerged, including tissue culture, use of molecular markers, and genetic engineering. Advances in computer programming and instrumentation facilitated the generation, storage, analysis and management of biological data.

Breeders typically produce large populations from individual crosses to increase the chance of finding a few individual plants possessing complementary traits from the male and female parents. Following sexual hybridization, a major bottleneck is the long and tedious process of plant selection to identify a few superior plants from the rest of the population. This is done repeatedly for several generations until such time that a few uniform and stable populations are produced.

At this point, confirmatory and additional tests are conducted before new varieties are released. Altogether, this process takes from 8 to 11 years.

Tools of biotechnology can help facilitate the entire process by dramatically increasing the efficiency of selection, and reducing the time and resources needed to achieve these results.

“DNA markers” associated with important traits allow indirect selection for that trait. For example, breeders can already select plants with specific grain quality traits even before they produce grains. DNA samples taken from the leaves of young seedlings provide information necessary for the breeders to make the crucial decision.

The effectiveness of certain DNA markers is established by first establishing their association with the trait. When they are present, the traits are also likely to be present, thus allowing “indirect” selection for the traits.

Molecular markers can also be used in DNA profiling, varietal identification, genetic diversity documentation and analysis, establishing genetic relationship, and creating genetic “maps” for identifying genes containing desirable traits and determining their specific location in the whole genome or genetic structure of the plants. In using molecular markers, breeders become more efficient and they are armed with useful information necessary to do their work.

Molecular markers are currently being utilized in the development of varieties including those with tolerance to extreme climatic conditions such as drought, prolonged flooding, as well as high temperature.

Tissue culture is another biotechnology tool that is useful in plant breeding. This technique entails growing small plant parts or tissues in culture vessels supplied with all the necessary nutrients for growth. This condition allows the tissues to produce calli (callus, singular) that eventually regenerate into whole plants. While tissue culture is more popularly known for rapid mass production of uniform and disease-free planting materials like those in orchids and bananas, the occasional emergence of useful variants makes it a good breeding strategy.

The use of anthers in tissue culture provides a unique advantage since the resulting plant regenerants are already genetically uniform and stable even if they are derived from crosses or genetically non-uniform plants. Without this process, it typically takes 3-4 years to produce uniform lines from crosses.

Categorized as modern biotechnology, genetic engineering involves direct transfer of one or a few useful genes into an otherwise elite variety to express a new trait or regulate the expression of another trait.

This is in direct contrast with sexual hybridization wherein all the genes from both parents are mixed resulting in an almost infinite combinations of approximately 30,000 genes. This highlights the importance of having big populations of plants and the breeder’s skills in selecting individual plants with the optimal combination of useful genes.

The power of genetic engineering resides on the technique’s ability to bypass sexual compatibility barriers and the precision of controlling which genes to transfer and how they should be expressed.

This can be illustrated by the Bt corn, which has been commercialized in the Philippines and many other countries for more than a decade. Bacillus thuringensis (Bt) is a common soil bacterium that produces a crystalline protein that is toxic to a certain class of insect pests, but does not harm other insects and other animals. Whereas traditional biotechnology has utilized Bt as a biopesticide in a sprayable form, modern biotechnology has produced Bt corn, which has in-built resistance to corn borer.

The development of Bt corn varieties took 10 years from the time the donor gene was discovered. Many countries such as Argentina, Brazil, India, Canada, China, Bangladesh, to name a few, have been cultivating modern biotechnology crops. Biotech crops already in the market include soybean, cotton, corn, canola, sugar beet, alfalfa, papaya, sweet pepper, tomato, and poplar. Most recently, modern biotechnology method is being explored to develop drought-tolerant varieties of sugarcane and corn in Indonesia and for Africa, respectively.

These tools of biotechnology are being employed to develop superior varieties of crops – in terms of ability to ward off destructive insects and diseases, quality, nutritional and ability to survive under adverse conditions. They open opportunities beyond what can be achieved through conventional breeding in the hope of producing sufficient and affordable food to more than seven billion people in the world, estimated to reach nine billion by 2050.

For more information, please feel free to contact:

Dr. Antonio Alfonso
Director, Biotechnology Program
Department of Agriculture
Tel. No. (632) 922-0057
Email Address: tonyalfonso2002@yahoo.com; biotechpiu@yahoo.com

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