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Publications

Journal Article Epublish

PubMed: 42835320 DOI: 10.3389/fpls.2026.1890133

Genomic insights into sheath blight resistance: leveraging natural variation in the Bengal-Assam-Aus rice panel for multi-season association mapping.

Front Plant Sci 17:1890133

Authors: R Naveenkumar, Siddharth Panda, Challa Vijay Kumar Reddy, S R Prabhukarthikeyan, G Sangeetha, Annamalai Anandan, Licon Kumar Acharya, Jauhar Ali

Affiliations

  • Crop Improvement Division, Indian Council of Agricultural Research (ICAR)-Central Rice Research Institute (CRRI), Cuttack, India. Department of Plant Pathology, Amrita School of Agricultural Sciences, Amrita Vishwa Vidyapeetham, Coimbatore, India.
  • Crop Improvement Division, Indian Council of Agricultural Research (ICAR)-Central Rice Research Institute (CRRI), Cuttack, India.
  • Department of Genetics and Plant Breeding, Institute of Agricultural Sciences (IAS), Siksha O Anusandhan Deemed to be University (DU), Bhubaneswar, India.
  • Department of Genetics and Plant Breeding, College of Agriculture, Odisha University of Agriculture and Technology (OUAT), Bhubaneswar, India.
  • Crop Protection Division, Indian Council of Agricultural Research (ICAR)-Central Rice Research Institute (CRRI), Cuttack, India.
  • Crop Protection Division, ICAR-Indian Institute of Horticulture Research, Bengaluru, India.
  • CAR-National Institute of Seed Science & Technology, Regional Station, Bengaluru, India.
  • ICAR- National Research Institute for Integrated Pest Management, New Delhi, India. Division of Plant Pathology, Indian Council of Agricultural Research (ICAR) - Indian Agricultural Research Institute, New Delhi, India.
  • Rice Breeding Innovation Department, International Rice Research Institute (IRRI), Los Baños, Laguna, Philippines.

Abstract

INTRODUCTION

Sheath blight ranks among rice's most damaging diseases, cutting yield by up to half in severe outbreaks. No source of complete, durable resistance exists, so identifying the genetic basis of partial or quantitative resistance is a priority for breeding.

METHODS

We performed GWAS on 130 genotypes from the Bengal-Assam-Aus Panel (BAAP), phenotyped over three seasons viz., Wet 2018, Wet 2019, and Dry 2018-19, scoring disease severity by per cent disease index (PDI) and area under the disease progress curve (AUDPC).

RESULTS

Trait distributions were near-normal with substantial variation across genotypes, pointing to polygenic control of resistance. A strong genotype-by-environment interaction meant combined analysis wasn't appropriate, so we ran GWAS separately per season. This turned up 27 associated loci, three of which on chromosomes 1, 9, and 10 were consistent and high-confidence. The candidate genes underlying these peaks were LOC_Os01g03360 (BBTI4, a Bowman-Birk protease inhibitor), LOC_Os09g11790 (DEFL14, a defensin-like peptide), and LOC_Os10g04860 (AO2, an aldehyde oxidase).

DISCUSSION

The predicted functions include protease inhibition, antifungal activity, and hormone regulation. Instead of relying on a single-gene mechanism, it's advisable to suggest a layered defense response. Collectively, these findings enhance our understanding of the genetic and biochemical aspects of sheath blight tolerance, providing breeders with specific targets to focus on in their efforts.

MeSH

Genes, Multiple Chronic Conditions, Peptide Hydrolases, Genotype