Blast resistant rice varieties for temperate regions

Background: 

One of the most dangerous rice illnesses in the world is called rice blast, which is brought by the fungal infection Magnaporthe oryzae. Host resistance has been regarded as the most practical and cost-efficient method for controlling rice blasts in fields. To date, it has been revealed that more than 100 resistance genes against rice blasts exist. However, long-term cultivation of uniform rice varieties with very specific resistance genes frequently led to the establishment of more virulent strains of the rice blast fungus and ultimately the collapse of the rice types' resistance. Therefore, a comprehensive breeding approach is required to create rice varieties that are long-lasting blast resistant and can defend against rice blasts over a long period of time and in a wide geographic region.

In terms of field resistance for long-term rice production, both major and partial resistance genes can be helpful in enhancing rice blast resistance. Pyramiding of resistance genes has been shown to be a highly effective method for granting long-lasting and all-encompassing resistance to blast. On the other hand, close monitoring of pathogen field isolates is necessary to delay the rapid loss of pathogen resistance and to maximize the use of resistant cultivars in fields. For effective control of blast in fields, cultivars pyramided with resistance genes must be deployed together with constant observation of blast isolates in the field.

Objectives

• Develop monogenic and pyramided lines harboring both major and partial blast resistance genes against rice blast in a Japonica type genetic background.

• Develop a high-throughput monitoring tool for rice blast in fields to guide the deployment of blast-resistant varieties.
  
  

Participation of TRRC members in the project

• TRRC members will be requested to recommend varieties used as the parental background, those as the resistance donor, and resistance genes to be incorporated in the breeding lines to be developed by the research team.

• The research team will share blast-resistant monogenic lines and pyramided lines developed in the project with TRRC members. TRRC members may evaluate the reactions of the blast resistant lines to their local blast isolates to assess the durability of resistance.

• The research team will share the information on the association between Avr and effector protein gene alleles of blast isolates and the virulence of the isolates. TRRC members and the research team may examine Avr and effector protein gene alleles, and the virulence of their local blast isolates to validate their association. 

• The research team will offer a high-throughput monitoring tool for blast. TRRC members will be requested to examine the reliability of the monitoring tool using their local blast isolates.