VARIABILITY OF Phomopsis POPULATIONS IN SUNFLOWER (Helianthus annuus L.)

SUMMARY Various reports state that the sunflower disease, primarily caused by Diaporthe/Phomopsis helianthi Munt.-Cvet. et al., has a wide geographic distribution in Europe, USA, Argentina and Australia. Various Phomopsis isolates obtained during this investigation of the sunflower disease differed in conidial type (α , β, α and β). Phomopsis helianthi was the only isolate producing exclusively β-conidia and perithecia on debris (Diaporthe helianthi). The other Phomopsis isolates were saprobes on sunflower plants.