Taxonomy, distribution and dispersal of Calonectria species : important pathogens of forestry, agricultural and horticultural crops

Abstract

PURPOSE OF THE REVIEW : Calonectria is a globally distributed genus of plant-pathogenic fungi causing destructive diseases across a wide range of woody and herbaceous hosts. This review synthesizes recent advances in the species delimitation, host range dynamics, reproductive strategies, and global dispersal patterns of Calonectria. Particular attention is given to the ecological adaptability, cryptic diversity, and climate-driven shifts in distribution of these important fungi. The review identifies key knowledge gaps and provides recent research regarding genome-based diagnostics, adaptive disease management, and forward-looking biosecurity measures. RECENT FINDINGS : Polyphasic taxonomic approaches and molecular systematics have substantially refined the classification of Calonectria, which now includes 136 species grouped into 11 species complexes. Some species, such as Ca. pseudonaviculata, exhibit strict host specificity; others like Ca. pauciramosa have wide host ranges and are globally invasive. Both sexual and asexual reproduction enhance persistence and facilitate dispersal, often via infected nursery stock and contaminated substrates. Climate change is projected to expand the distribution of multiple Calonectria species into new regions. Despite increasing reports of international spread, genomic surveillance remains limited, and diagnostic inconsistencies continue to hinder effective detection and containment. SUMMARY : The broad host range, complex reproductive biology, and environmental adaptability of Calonectria species enhances their growing threat to plant health worldwide. Their spread is accelerated by global trade and climate change, while unresolved taxonomic challenges and underdeveloped molecular tools constrain opportunities for their management. Integrated strategies that combine phylogenomics, risk modeling, and coordinated surveillance are urgently needed to mitigate its impact across agricultural, horticultural, and forest systems.