New species and new records of genus Melampsora (Melampsoraceae) from Pakistan using electron microscopy and DNA barcoding techniques.

The genus Melampsora, known for its significant role as a plant pathogen, exhibits a rich species diversity. Current study reports Melampsora himalayensis sp. nov. as new species with M. ferrinii and M. populnea as new records from different regions (Fairy Meadows, Gilgit Baltistan; Khanspur, Khyber Pakhtunkhwa) of Pakistan, contributing to the knowledge of rust fungi diversity and distribution. Their placement within genus Melampsora was validated by comparative morpho-anatomical investigation. Detailed morphological characterization was employed using Scanning electron microscopy which provided features of spore morphology including their surface ornamentation. Additionally, molecular analysis was performed for species delimitation and to resolve phylogenetic relationships within genus Melampsora. Combined morpho-anatomical and phylogenetic data led to the discovery of previously unrecorded species, Melampsora ferrinii and M. populnea from Pakistan, including a novel taxon, Melampsora himalayensis sp. nov. This study provides information about taxonomy, host range and distribution of Melampsora in Pakistan.