Blast disease of foxtail millet (Setaria italica): pathogen biology, host defense and management strategies under changing climate

Foxtail millet (Setaria italica (L.) P. Beauv.), a nutritionally valuable ancient cereal, is increasingly threatened by blast disease caused by Pyricularia setariae Nishikado (teleomorph: Magnaporthe grisea). While currently only a moderate concern across South Asia, changing climatic conditions particularly temperature and humidity shifts combined with widespread reliance on susceptible varieties in dryland farming systems, are positioning blast as a growing threat to crop yields. This review synthesises existing knowledge on the taxonomy, morphology, host specificity, and genetic makeup of pathogen populations, along with epidemiological factors influencing disease severity, the molecular basis of host defence mechanisms, and management approaches encompassing cultural, genetic, chemical, and biological control methods. Germplasm evaluation efforts in India have identified a small number of stable resistant lines, though their integration into breeding programmes remains limited. Microsatellite analyses reveal considerable genetic variation and gene flow among pathogen populations, raising concerns about potential resistance breakdown. Advances in whole genome sequencing, GWAS, and CRISPR/Cas9 functional genomics are enhancing understanding of host pathogen interactions, yet translating these findings into field stable resistance remains challenging. Multi omics strategies integrating transcriptomic, proteomic, and metabolomic data present promising avenues for identifying resistance related genetic loci. This review highlights key research priorities essential for protecting S. italica production amid ongoing climate change.

Konda Sravan Simha Reddy is a research scholar at Yogi Vemana University, Kadapa, Andhra Pradesh, India, working on blast disease of foxtail millet (Setaria italica) caused by Pyricularia setariae. His research covers pathogen biology, host defence mechanisms, and disease management, with a focus on screening germplasm to identify stable resistance sources. He trained at ICRISAT through an 8 month research placement and a 1 year training programme, gaining hands on experience in disease screening and phenotyping. His interests include host pathogen interactions, resistance breeding, and integrating genomic and multi omics tools with cultural, biological, and chemical management strategies for climate resilient millet production in South Asian dryland systems.