Accumulating candidate genes for broad-spectrum resistance to rice blast in a drought-tolerant rice cultivar

Maria Gay C Carrillo,Jan E Leach,J C Bhatt,Alvaro L Perez-Quintero,Federico Martin,Mukund Variar,Casiana M Vera Cruz,Hei Leung

doi:10.1038/s41598-021-00759-9

Abstract

Biotic stresses, including diseases, severely affect rice production, compromising producers’ ability to meet increasing global consumption. Understanding quantitative responses for resistance to diverse pathogens can guide development of reliable molecular markers, which, combined with advanced backcross populations, can accelerate the production of more resistant varieties. A candidate gene (CG) approach was used to accumulate different disease QTL from Moroberekan, a blast-resistant rice variety, into Vandana, a drought-tolerant variety. The advanced backcross progeny were evaluated for resistance to blast and tolerance to drought at five sites in India and the Philippines. Gene-based markers were designed to determine introgression of Moroberekan alleles for 11 CGs into the progeny. Six CGs, coding for chitinase, HSP90, oxalate oxidase, germin-like proteins, peroxidase and thaumatin-like protein, and 21 SSR markers were significantly associated with resistance to blast across screening sites. Multiple lines with different combinations, classes and numbers of CGs were associated with significant levels of race non-specific resistance to rice blast and sheath blight. Overall, the level of resistance effective in multiple locations was proportional to the number of CG alleles accumulated in advanced breeding lines. These disease resistant lines maintained tolerance to drought stress at the reproductive stage under blast disease pressure.

Highlights

Biotic stresses, including diseases, severely affect rice production, compromising producers’ ability to meet increasing global consumption
These candidate gene (CG) included resistance gene analogs and a number of defense response genes that code for chitinase (CHI), oxalate oxidase (OXO), germin-like proteins (GLP), peroxidase (POX), phenylalanine ammonia lyase (PAL), superoxide dismutase, 14-3-3 proteins, and thaumatinlike protein (PR5), which are associated with QTL conferring resistance to fungal and bacterial pathogens of rice as well as resistance to brown plant h opper[15,16,17,18,19,20,21,22]
We developed cultivars with QTL-based resistance to rice blast by pyramiding different combinations of CGs associated with rice blast QTL while simultaneously selecting progenies with good agronomic traits for cultivar release

Summary

Introduction

Biotic stresses, including diseases, severely affect rice production, compromising producers’ ability to meet increasing global consumption. The candidate gene approach, which is based on the principle that genes with known functions in the traits of interest may reside in major loci[9], has been used to map known genes to QTL of multiple traits, including disease resistance, in various rice mapping populations[10,11,12,13,14] These CGs included resistance gene analogs and a number of defense response genes that code for chitinase (CHI), oxalate oxidase (OXO), germin-like proteins (GLP), peroxidase (POX), phenylalanine ammonia lyase (PAL), superoxide dismutase, 14-3-3 proteins, and thaumatinlike protein (PR5), which are associated with QTL conferring resistance to fungal and bacterial pathogens of rice as well as resistance to brown plant h opper[15,16,17,18,19,20,21,22]. F4 (n=60) Screened for resistance to rice blast in India and the Philippines and for yield under blast conditions

Methods

Results

Conclusion