Plant breeding is the science and business of crop improvement. It is an innovation based sector, focused on developing plants better adapted to the environment and to human needs.
The demand for new varieties of agricultural crops, adapted to unique growing conditions (each European country is divided in many unique environments), is never ending, driven by the challenges of new pest and disease pressures, weather patterns and changing market requirements. The development of crop varieties with improved yields, end-use quality and environmental performance provides the essential foundation for a sustainable and efficient agriculture. As the world faces up to the major challenges of population growth, climate change and pressure on natural resources, the contribution of plant breeding is increasingly recognised as a key factor in addressing global concerns over food security and sustainable development and in stimulating a vibrant economy.
Origins of plant breeding
The origins of plant breeding stretch back thousands of years to the first primitive farmers who selected the best plants in one year to provide seed for their next crop. More recent scientific and technological developments have allowed a much greater rate of improvement.
Plant breeding today
Modern plant breeding is a sophisticated, high investment business. Much of the basic underpinning crop genetic research is still conducted in the public sector, but commercial plant breeders provide the only route to market for improved crop varieties. More than 60 plant breeding companies, based in the UK, are active across the entire spectrum of plant species used for food, feed and energy. Plant breeding makes a significant contribution to the nation’s gross domestic product and to the growth and competitiveness of the UK’s food economy.
Some key people
Gregor Mendel : Gregor Mendel first provided a scientific explanation of genetic inheritance in the mid- 19th century. In his experiments with peas, Mendel crossed plants with different characteristics such as whether the seed is round or wrinkled. He found that the offspring had either round or wrinkled seed, the same as the parents with no intermediate types, and that when these offspring were crossed with each other, the round and wrinkled seed types were inherited in a stable 3:1 ratio. Mendel’s work went largely unrecognised in his own lifetime and it was not until the early 20th century that it was rediscovered to form the explanation of heredity and pave the way for modern plant breeding
Norman Borlaug: Norman Borlaug and his colleagues working in Mexico made a major breakthrough in scientific plant breeding when they were able to introduce dwarfing genes into wheat to produce new varieties with much higher yield potential and greater response to fertiliser than traditional varieties. This started the Green Revolution, a step change in the development of higher yielding varieties for the developing world and the foundation of much of today’s crop breeding. You can watch a video from the USDA on his life here
Creating new varieties
The basic aim of all plant breeding techniques is to generate new genetic diversity and then select plants with the desired improved characteristics. The creation of each new variety is a complex, costly and skilled operation. It is also time-consuming – early-stage varieties in today’s breeding programmes must anticipate the needs of farmers, consumers and the environment in ten years’ time and beyond! Breeding techniques vary between crop species, but the scientific principles of plant breeding remain true to Mendel’s first discovery that selected parent plants can be cross-pollinated to combine desired characteristics in a single variety. These characteristics are determined by genes – units of hereditary material that are transferred from one generation to the next. Since each plant contains many thousands of genes, and the breeder is seeking to combine a range of traits in one plant (such as high yield, quality and resistance to disease), developing a successful variety has been compared to playing a fruit machine
– not with three reels but several hundred. The skill of the plant breeder lies in improving the chances of hitting the jackpot by combining all the desired characteristics in the same variety
”Future food-production increases will have to come from higher yields. Unless progress with agricultural yields remains very strong, the next century will experience sheer human misery that, on a numerical scale, will exceed the worst of everything that has come before…” Norman E. Borlaug, 1970
Pedigree plant breeding (exemples of wheat and barley)
The pedigree breeding involves crossing carefully chosen parent plants then selecting the best plants from the resulting offspring to be grown on for further selection. For cereal crops, hundreds of individual crosses are carried out to create seed for the first filial (or F1) generation. The resulting F1 plants are uniform, but the following (F2) generation segregates out into many thousands of different plants. It is this enormous diversity of new gene combinations which may hold the key to a successful new variety. Seed from the best of these F2 plants is grown on in small rows or plots and the best plants again selected. As promising new lines emerge, tests are conducted to assess factors such as yield, disease resistance and end-use quality. This process is repeated year after year until pure lines of only the very best plants remain, ready for seed multiplication and entry into official trials.
Hybrid breeding (exemple of maize)
The hybrid breeding exploits the performance boost derived in a single season from the first cross between two carefully selected parent lines. This breeding method is widely used to produce commercial varieties of field vegetables, sugar beet, maize and oilseed rape. F1 hybrid varieties are unique in expressing heterosis, or ‘hybrid vigour’ in the growing crops for a single year. This may result in higher yields, greater uniformity, or improvements in quality. While inbred lines breed true year after year, the performance gains of F1 hybrids are not maintained as subsequent generations segregate to produce highly variable offspring.
Some other facts of breeding on the society: Why plant breeding matters?
Economy : Why plant breeding matters?
A constant flow of new crop varieties with improved yields, performance and end-use quality provides the essential foundation for a competitive farming industry and a dynamic food chain. Independent economic research has demonstrated that every 1Euro invested in plant breeding generates at least 40Euros within the wider food economy. The economic benefits of improved varieties range from increased yields and input savings at the farm level through to import substitution, export earnings and enhanced processing efficiency with the food and drink manufacturing sector. The forty-fold return on investment associated with plant breeding significantly outperforms other research-based sectors. By improving the productivity and output value of our major crops, plant breeding provides the starting point for a competitive European food and drink industry.
Environment : Why plant breeding matters?
The combined challenges of population growth, climate change and increasing pressure on the world’s natural resources of land, water and energy have prompted calls for the ‘sustainable intensification’ of global agriculture. At its most basic level, this means increasing productivity while consuming fewer resources and with reduced impact on the environment. Plant breeding will be at the forefront of the genetic innovation needed to deliver the required gains in sustainable, efficient production, for example by developing higher-yielding, more climate-resilient crop varieties better adapted to cope with extreme weather conditions and by improving the resource-use efficiency of our major crop plants. The development of improved crop varieties can also help protect our countryside and farmland biodiversity. Increasing productivity on land that is already farmed, for example through the adoption of higher-yielding varieties and farming systems, reduces pressure on uncultivated land and natural habitats.
Food : Why plant breeding matters?
The combined pressures of population growth, climate change and declining natural reserves of land, energy and water are driving global concern about the security and sustainability of our future food supply.
The world’s population is set to exceed 9 billion by 2050, and the UN Food and Agriculture Organisation (FAO) predicts that food production must increase by at least 70% over the next 40 years to keep pace. But with limited land available to bring into production, the only realistic prospect of delivering sustainable food security is through increased productivity and improved efficiency on land that is already farmed.
Increasing pressure on the use of pesticide and fertiliser inputs – through tighter environmental controls and spiralling costs – means that crop genetic improvement, delivered to the market through locally-based plant breeding programmes, will underpin this second Green Revolution. By delivering higheryielding, more climate resilient crop varieties, resistant to the emergence of new and more virulent pests and diseases, advances in plant breeding will underpin the ‘sustainable intensification’ of agriculture required to secure our future food supplies. At the same time, plant breeders must respond to the changing demands and expectations of consumers, and meet the exacting quality specifications of the food chain with improved varieties, tailored to the needs of specific end-markets.
Health : Why plant breeding matters
Food safety and nutrition are key priorities for today’s health-conscious consumers. Progress in plant breeding can deliver health-related benefits in a number of ways.
Expanding choice in fresh produce: By providing continuous improvements in the quality, taste, convenience and seasonality of our fresh fruit and vegetables, innovation in plant breeding is increasing choice, diversity and excitement for consumers, contributing positively to the nation’s five-a-day healthy eating targets.
Delivering health benefits : Plant breeders are developing a range of new crop varieties with specific health advantages, from oilseed crops with healthier oil profiles to brassica crops with increased levels of beneficial nutrients and oats with enhanced levels of antioxidants and beta-glucan.
Improving food safety: Progress in plant breeding is also addressing key food safety concerns. Improvements in disease resistance, for example, can help reduce levels of harmful mycotoxins caused by fungal infections, while quality improvements can help reduce or eliminate anti-nutritional factors such as erucic acid in oilseed rape.
Lifestyle : – Why plant breeding matters?
By improving the on-farm performance and enduse quality of our major food crops, plant breeding makes a significant contribution to our quality of life by providing the essential starting point for a secure and affordable food supply. But plant breeding also contributes to a better quality of life in many other ways:
– by supporting improvements in crop productivity, the development of higher-yielding new varieties helps protect marginal habitats and landscapes for wildlife and recreation;
– gardeners enjoy the benefit of improved varieties of shrubs, ornamentals, fruit and vegetables, and a choice of grass seed adapted to a range of uses, from lowmaintenance landscaping to hard-wearing lawns;
– innovation in vegetable breeding has broadened choice, diversity and convenience in the fresh produce market, helping the nation meet its ‘five-a-day’ target for healthy eating.
The text for the key facts was adpated from the BSPB leaflet : Plant Breeding Matters
More informations and examples can be found on: www.bspb.co.uk