Role of Plant Breeding in Organic Agriculture
Critics of organic agriculture claim it is too low-yielding to be a viable alternative to conventional agriculture. However, a growing body of evidence suggests that poor performance is not an intrinsic property of organic production, but rather the result of growing poorly adapted varieties. It is estimated that over 95% of organic agriculture is based on conventionally adapted varieties, even though the production environments found in organic vs. conventional farming systems are vastly different due to their distinctive management practices. Most notably, organic farmers have fewer inputs available than conventional growers to control their production environments. Breeding varieties specifically adapted to the unique conditions of organic agriculture is critical for this sector to realize its full potential. This requires selection for traits such as:
- Water use efficiency
- Nutrient use efficiency (particularly nitrogen and phosphorus)
- Weed competitiveness
- Tolerance of mechanical weed control
- Pest/disease resistance
- Early maturity (as a mechanism for avoidance of particular stresses)
- Abiotic stress tolerance (i.e. drought, salinity, etc...)
Currently, few breeding programs are directed at organic agriculture and until recently those that did address this sector have generally relied on indirect selection (i.e. selection in conventional environments for traits considered important for organic agriculture). However, because the difference between organic and conventional environments is large, a given genotype may perform very differently in each environment due to an interaction between genes and the environment (see gene-environment interaction). If this interaction is severe enough, an important trait required for the organic environment may not be revealed in the conventional environment, which can result in the selection of poorly adapted individuals. To ensure the most adapted varieties are identified, advocates of organic breeding now promote the use of direct selection (i.e. selection in the target environment) for many agronomic traits.
There are many classical and modern breeding techniques that can be utilized for crop improvement in organic agriculture despite the ban on genetically modified organisms. For instance, controlled crosses between individuals allow desirable genetic variation to be recombined and transferred to seed progeny via natural processes. Marker assisted selection can also be employed as a diagnostics tool to facilitate selection of progeny who possess the desired trait(s), greatly speeding up the breeding process. This technique has proven particularly useful for the introgression of resistance genes into new backgrounds, as well as the efficient selection of many resistance genes pyramided into a single individual. Unfortunately, molecular markers are not currently available for many important traits, especially complex ones controlled by many genes.
Read more about this topic: Plant Breeding
Famous quotes containing the words role of, role, plant, breeding, organic and/or agriculture:
“What is charm then? The free giving of a grace, the spending of something given by nature in her role of spendthrift ... something extra, superfluous, unnecessary, essentially a power thrown away.”
—Doris Lessing (b. 1919)
“My role in society, or any artist or poet’s role, is to try and express what we all feel. Not to tell people how to feel. Not as a preacher, not as a leader, but as a reflection of us all.”
—John Lennon (1940–1980)
“Evolution was in a strange mood when that creation came along.... It makes one wonder just where the plant world leaves off and the animal world begins.”
—John Colton (1886–1946)
“Courtesy is breeding. Breeding is an excellent thing. Always remember that.”
—Lillian Hellman (1905–1984)
“When life has been well spent, age is a loss of what it can well spare,—muscular strength, organic instincts, gross bulk, and works that belong to these. But the central wisdom, which was old in infancy, is young in fourscore years, and dropping off obstructions, leaves in happy subjects the mind purified and wise.”
—Ralph Waldo Emerson (1803–1882)
“But the nomads were the terror of all those whom the soil or the advantages of the market had induced to build towns. Agriculture therefore was a religious injunction, because of the perils of the state from nomadism.”
—Ralph Waldo Emerson (1803–1882)