Munasqarr: novel soybean genetic source for charcoal rot resistance breeding

Overview

Charcoal rot (CR), caused by Macrophomina phaseolina (Mp), is a devastating soybean disease that causes significant yield losses worldwide. MunasqaRR is the first elite soybean cultivar reported as resistant to multiple Mp isolates under both controlled and field conditions across different regions. This research program provides a deep understanding of the genetic, biochemical, and molecular resistance mechanisms in MunasqaRR, enabling breeders to introduce durable CR resistance into other germplasm and supporting sustainable soybean production.

Technical specifications

Research approach and key features:

• Validated resistance source: MunasqaRR demonstrated superior response to Mp compared with the moderately resistant genotype DT 97-4290, establishing it as a novel source of resistance to charcoal rot.
• Optimized in vitro assay: A standardized method enables rapid analysis of soybean–Mp interactions without environmental variation, revealing isolate-specific responses.
• QTL mapping: Recombinant inbred lines (RILs) derived from MunasqaRR are being phenotyped and genotyped to localize genomic regions associated with complex Mp resistance.
• Molecular marker discovery: Identified QTLs will yield molecular markers directly applicable in marker-assisted selection for soybean breeding programs.
• Transcriptomic profiling (RNaseq): Planned RNA sequencing of MunasqaRR versus the susceptible progenitor will reveal differentially expressed genes and metabolic pathways underlying the defence response.
• Biochemical validation: Hormone profiling (salicylic acid, jasmonic acid, abscisic acid) and quantification of defence metabolites such as callose and phenolic compounds will confirm candidate resistance pathways.

Technology readiness level

The resistance of MunasqaRR to multiple Mp isolates has been validated under controlled conditions and in field trials across multiple regions. The in vitro interaction assay is operational and reproducible. QTL mapping and molecular marker identification are currently in progress using a RIL population. Transcriptomic and biochemical validation studies are planned as the next development phase. Outputs—validated QTLs, molecular markers, and characterized resistance mechanisms—are positioned to integrate directly into soybean breeding pipelines for charcoal rot management.