Morphological characterization of Gibberella coronicola sp. nov., obtained through mating experiments of Fusarium pseudograminearum

Mating experiments were performed among 18 strains of Fusarium pseudograminearum, formerly recognized as the Group 1 population of F. graminearum. Heterothallic production of perithecia was observed in eight out of all 153 possible combinations. Mature asci and viable ascospores were recovered in seven of the eight combinations. Perithecia in the fertile pairings were subglobose to ovoid, dark, 120–370 μm diam and formed directly on the surface of rice stems placed on the culture media. Asci were unitunicate and 8-spored when mature. Mature ascospores were primarily hyaline, fusoid, straight or curved, with rounded ends and (1-)3-septate. Dimensions of the teleomorph obtained for F. pseudograminearum were different from those of the G. zeae teleomorph of F. graminearum. A new species of Gibberella, G. coronicola, is described and illustrated for the teleomorph of F. pseudograminearum. The Group 1 and Group 2 populations recognized previously within F. graminearum differ in their anamorphic and teleomorphic morphology, ecological habitats, pathogenicity, mode of sexual reproduction and phylogenetic relationships.