Obtaining resistance to Pyricularia grisea in rice in the Southern Cone

Executive Summary

The characterization of the pathogen populations is the first step, unavoidable, to identify its genetic and pathogenic nature and, in paralell, identify the genes in rice, which give it resistance to the disease. With this information available, the resistance alleles can be introduced into improved cultivars, giving them greater and more durable resistance to the presence of the pathogen in favor of the productivity and lower production costs of the crop. To this end, the project molecularly characterized the pathogen and defined its variability, identified the lineages present in each participating country and described its geographical distribution, identified non-pathogenic lineages on other grasses, characterized the degree of pathogenicity of representative isolates of the various lineages, identified sources of incompatibility (resistance genes) in rice, introduced the identified sources of resistance in elite rice material common to all countries, identified the molecular markers linked to the sources of resistance for use in the process of selection and breeding of commercial varieties, developed NIL lines (near isogenic lines) with the different resistance genes and established models for predicting the population of the pathogen using AFLP (amplified fragment length polymorphism) markers. 

The technological solution

Information was obtained to describe the population of the pathogen in the Southern Cone and 

identified resistance genes in rice, incompatible with the lineages of the pathogen present in the region. All these advances allowed crosses to incorporate into high-yield material genes that confer resistance to the pathogenic lineages present. The selection by molecular markers facilitates the introduction of these sources of resistance that provide a broad spectrum protection. It is considered that the new lines containing the resistance gene pool will offer greater protection to the crop for longer. The reference production sector is rice, especially in the context of family farming. 

Results

Beneficiaries

The direct beneficiaries are the crop-breeding organisms that now have elite lines resistant to the pathogen that will serve as the basis for selection programs of commercial rice varieties with extended disease resistance. They also have information on the molecular characterization of the pathogen and its variability as well as its degree of incompatibility with the rice genome.  The researchers have benefited from the acquisition of new analytical techniques. In the long term, farmers will benefit from the release of improved disease-resistant rice varieties. 

Sustainable Development Goals

Main donors