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Updated: Sep 29, 2025
Genome-wide Analysis of Histone Modifications Distribution using the Chromatin Immunoprecipitation Sequencing Method in Magnaporthe oryzae
Published on: June 2, 2021
Multilocus sequence analysis and identification of mating-type idiomorphs distribution in Magnaporthe oryzae
Amoghavarsha Chittaragi1,2, Devanna Pramesh2, Ganesha R Naik1
1Department of Plant Pathology, University of Agricultural and Horticultural Sciences, Shivamogga, Karnataka, India.
Aims:
To investigate the genetic diversity, population structure and mating-type distribution among the eco-distinct isolates of Magnaporthe oryzae from Karnataka, India.
Methods And Results:
A set of 38 isolates of M. oryzae associated with leaf blast disease of rice were collected from different rice ecosystems of Karnataka, India, and analysed for their diversity at actin, β-tubulin, calmodulin, translation elongation factor 1-α (TEF-1-α), and internal transcribed spacer (ITS) genes/region. The isolates were grouped into two clusters based on the multilocus sequence diversity, the majority being in cluster-IA (n = 37), and only one isolate formed cluster-IB. Population structure was analysed using 123 SNP data to understand the genetic relationship. Based on K = 2 and ancestry threshold of >70%, blast strains were classified into two subgroups (SG1 and SG2) whereas, based on K = 4 and ancestry threshold of >70%, blast strains were classified into four subgroups (SG1, SG2, SG3 and SG4). We have identified 13 haplotype groups where haplotype group 2 was predominant (n = 20) in the population. The Tajima's and Fu's Fs neutrality tests exhibited many rare alleles. Further, the mating-type analysis was also performed using MAT1 gene-specific primers to find the potentiality of sexual reproduction in different ecosystems. The majority of the isolates (54.5%) had MAT1-2 idiomorph, whereas 45.5% of the isolates possessed MAT1-1 idiomorph.
Conclusions:
The present study found the genetically homogenous population of M. oryzae by multilocus sequence analysis. Both mating types, MAT1-1 and MAT1-2, were found within the M. oryzae population of Karnataka.
Significance And Impact Of Study:
The study on the population structure and sexual mating behaviour of M. oryzae is important in developing region-specific blast-resistant rice cultivars. This is the first report of MAT1 idiomorphs distribution in the M. oryzae population in any Southern state of India.
