Crop diseases and sustainable production

The future for plant biotechnology is bright. The first complete genetic map of a plant species will be available later this year for Arabidopsis, a member of the mustard family that is widely used in plant research. The genome map of its 20,000 genes will be followed in 2003 by the complete DNA sequence of rice, the most important cereal crop on the planet. The DNA sequences of other commercially important plant species (wheat, oil seed rape, potato, grasses, etc) are also being mapped. These developments have spawned several new techniques (collectively referred to as genomics) aimed at understanding the complex function of genes and their role in development, growth and productivity.

The genomics revolution is at an early phase, and to date most of the international research effort focused on the medical and pharmaceutical applications. The greatest global impact of genomics, however, will result from manipulating the DNA of plants, and ultimately genetically improved vegetation and trees will provide the world with most of its food, fuel, fibre, chemical feedstocks, and even drugs. Conventional breeding methods have made slow but steady progress in genetically improving plants. Now, universities, research institutions and companies throughout the country are starting major biotechnological initiatives to identify the specific genes that code for desirable production and disease resistance characters. This should lead to significant advances and enable us to create low-input systems and to produce varieties breed for specific purposes and for the Irish conditions.

These advances should prove useful across a wide range of areas, but perhaps most important in the Irish context is grass growing, as this accounts for over 90% of Irish agricultural land, and supports over 7 million cattle and 5 million sheep. Other areas that can expect to benefit from biotechnology include cereals, forage crops, fruit and vegetable production, forestry and horticulture.

Low-input production

Techniques that lower our use of agricultural chemicals will help minimise the environmental risks, and enable us to produce food that is safer, more nutritious, longer lasting and hopefully, less costly. The primary target species are: grass (which is of general national importance), the main cereal and forage crops, and important commercial species including potatoes and sugar beet. Priorities for research are:

Use biotechnology to maximise grass growth rate, length of growing season and digestibility; as cereals and grasses share many genes, comparative mapping should be possible to elucidate such traits
To lower or eliminate the use of chemicals to treat plant pests and diseases, by using a combination of conventional breeding for resistance factors, and by developing GM crops with traits that reduce /eliminate the need for pesticides
Develop new varieties, especially potatoes, cereals and sugar beet, adapted to the Irish production environment (soils, climate, conditions)
Develop new and improved biological pest control systems (such as the nematode worms currently used to control weevil infestation in mushrooms)
Design integrated pest and disease management systems to reduce the use of chemicals

Genetic markers for plant improvement

Thanks to the various genome mapping projects, many key agronomic plant genes can now be identified, as can the genetic 'markers' associated with important traits. This information makes it possible to use marker-assisted selection as a powerful new adjunct to traditional breeding methods. Long-term aims include producing new and improved plant varieties with better nutritional content (added vitamins and minerals, for example), or higher yield, improved pest or disease resistance, or lower levels of toxins (such as the glycoalkaloids found in potatoes). The following areas using marker-assisted selection and related techniques, have been identified as priorities:

Improve the disease resistance of our most important crop species (eg by identifying markers associated with resistance to Septoria)
Develop superior animal feed crops (eg forage species with improved nutritional content and digestibility); this should significantly benefit animal health, welfare and productivity
Select for better adapted beneficial organisms, such as those used in integrated pest and disease management systems for the main crops grown in Ireland.