The IAEA, in cooperation with the Food and Agriculture Organization of the United Nations (FAO), is calling on research institutes to join a new Coordinated Research Project (CRP) on resistance against Fusarium wilt disease (Foc TR4) in banana, with a time frame of five years from 2023 to 2027.
Banana (Musa species) plays a very important role in food security and income for about 400 million people in more than 135 banana producing countries in the world. It is among the 10 most important sources of carbohydrates in the tropical and sub-tropical regions with more than 86% of its global production consumed locally and the rest traded internationally. Genetic improvement of this important crop will contribute to meeting the United Nations Sustainable Development Goals (SDGs) related to reducing poverty and hunger.
Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) is considered a major disease of banana, causing annual losses of millions of US dollars and predicted to reach about US$10 billion globally by 2040. Foc TR4 is spreading around the world, threatening the banana production since most banana and plantain cultivars are susceptible to this disease. Therefore, breeding efforts for Foc TR4 resistance must maintain production traits and be accompanied by integrated strategies that will contain/reduce pathogen dispersal. To date, the most promising methods for the control of Foc TR4 are the use of beneficial microbes for disease suppression in infected soils and the use of varieties that are resistant to Foc TR4.
A previous CRP related to mutation breeding in banana (D22005), focused on developing efficient screening techniques to identify new varieties with disease resistance. The recently published screening protocols developed from that CRP will contribute to the selection of Foc TR4 resistant banana varieties by Member States.
The new CRP is aimed at developing state-of-the-art tools and methods for managing the disease by developing resistant varieties, developing improved pathogen detection tools, and using beneficial microbes to suppress the disease.
Mutation induction to generate heritable variation has been used for the improvement of numerous crops for different traits over several decades, including vegetatively propagated crops. Therefore, it holds great promise to diversify further the genetic base of banana resistance to diseases. Mutant banana clones with Foc TR4 resistance have been developed from past efforts using chemical and physical mutagenesis.
The induction of new traits in beneficial microorganisms by mutagenesis is a new approach that could enhance their biological activity, colonization efficiency into host plants and its ability to suppress Fusarium wilt (Foc TR4). The use of random mutagenesis such as chemical or physical mutagens to modify the natural microbial strains will contribute to the improvement of biocontrol abilities and plant growth promotion by boosting the synthesis of antifungal enzymes and other metabolites. The mutated beneficial microbes can be used for bio-priming resistant banana plants not only for the sustainable management of this deadly disease of banana but also for the prevention of risk of breakdown of resistance due to high inoculum pressure of the pathogen or during continuous cultivation of Foc TR4 resistant plants.
Functional genomic technologies that establish genetic associations for candidate gene discovery are needed to understand the mechanisms associated with Foc TR4 resistance in bananas. The establishment of genetic associations will promote the development of resistant germplasms using gene editing and markers to enhance breeding efficiency.
Rapid, reliable, and affordable methods of detection such as DNA-based and/or remote sensing are needed to allow early field detection and monitoring of Foc TR4. Significant advances made in recent years in the remote detection of diseased plants in the field could also be used to develop technologies for detecting banana Fusarium wilt (Foc TR4) in countries and production areas where it was not previously known to occur.
CRP Objectives
This CRP is aimed at improving disease resistance in banana and developing microbes with enhanced beneficial activities through induced mutagenesis for the management of Fusarium wilt (Foc TR4) disease.
The specific research objectives are
- To generate induced genetic diversity in bananas using physical mutagenesis for developing resistance to Fusarium wilt (Foc TR4) disease.
- To generate functional genomics tools and methodologies for understanding the mechanisms of disease resistance using available resistant germplasm that will contribute to markers development and gene editing.
- To develop rapid and reliable diagnostic protocols for field detection of Foc TR4.
- To develop protocols for physical mutagenesis of microbes for enhanced biocontrol and plant growth promotion activities, and evaluation against Fusarium wilt (Foc TR4) disease.
The expected outputs of the project are
- Foc TR4 resistant mutant banana clones generated,
- Banana mutants tested for improved field resistance and production traits,
- Genomic regions/candidate genes associated to disease resistance and molecular markers identified,
- Technology packages developed for gene editing in banana,
- Validated and field-tested Foc TR4 diagnostic protocols,
- Mutation induction protocols developed for beneficial microbes,
- Protocols developed for greenhouse/field evaluations of mutant beneficial microbes, and
- Foc TR4 effective mutant microbes generated.
How to join this CRP
Up to ten technical and research contracts are expected to be awarded; two to three contracts per specific research objective. Up to five no-cost agreement holders from advanced laboratories are also expected to participate. Research institutes with recognized expertise in the targeted technologies will be invited to share their experience with the contract holders and contribute to the development and validation of the planned technical packages.
Coordination and technical management will be handled by the scientific secretary in the IAEA's Plant Breeding and Genetics Section with involvement of the Plant Breeding and Genetics Laboratory.
Proposals on banana mutation induction should have available methods for banana cell/tissue culture and/or Foc TR4 resistance screening. Proposals on microbial mutagenesis are encouraged to include available methodologies for beneficial microbes' isolation, conservation, and identification. Proposals on functional genomics of Foc TR4 resistance should indicate available germplasm, facilities, methodologies, or data for candidate gene identification and/or gene editing.
