Identification and pyramiding of mutated genes: novel approaches for improving crop tolerance to salinity and drought


Background:

Increasing human populations, greater competition for water, unchecked environmental degradation and potential global change are leading to a need for sustainable increases in food production worldwide. The problem is particularly severe in arid and semiarid regions, which are suffering increased drought and soil salinization, and where crop production is becoming reliant on increasingly marginal lands with water supplies of decreasing quantity and quality. The improvement of drought and salinity tolerance traits (including its associated sodicity and waterlogging) is, therefore, one of the most important goals in plant breeding. It is of great economic and social importance, especially for developing countries. A major constraint to improved tolerance is a lack of understanding of its complex genetic basis and the difficulty in efficiently combining favourable alleles into an optimal genotype, which has led to limited success up until now. Many claims have been made for the improvement of drought and salinity tolerance through genetic engineering, but there have been few if any successful examples of these resulting in increased yields in farmers' fields. Conventional breeding for drought has been rather more successful, although for salinity only a few examples of improved cultivars have been released. In view of the complex relationships between, and the number of traits involved in, tolerance to both drought and salinity, pyramiding using marker-assisted breeding, induced mutation and other biotechnologies, combined with the participation of farmers, is likely to provide the best route towards the development of region-specific tolerant crop germplasm. This CRP will use these new technologies to accelerate improvement in tolerance, focusing on those cereals and grain legumes, which are important for food security at least at the local level. The combination of biotechnological and participatory aspects in this CRP would not only be a first for IAEA, but would put this project at the vanguard of current research thinking.

Overall objectives:

To identify and develop germplasm of cereals and grain legumes with superior resource use efficiency and adapted to stress environments, in order to increase its availability and exchange between member states.

Specific objectives:

  1. To generate genetic variability and to use existing mutated and naturally tolerant germplasm of crop plant genetic resources to identify genes controlling various traits contributing to tolerance to drought and salinity in defined environments and so gain a better understanding of the physiological and molecular basis of plant tolerance to drought and salinity.
  2. To develop refined nuclear and molecular techniques for screening large germplasm populations for improved yield and water use efficiency under saline and drought conditions.
  3. To pyramid identified genes and genotypes for effective improvement of stress tolerance in locally important cereals and grain legumes which contribute to food security using marker-assisted and other biotechnologies as well as farmer-participatory selection.
  4. To foster relationships, transfer knowledge, technology, and genetic and molecular resources between all participating research groups for their mutual benefit.

Participants:

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Project Officer:

M.M. Spencer