First record of leaf-spot caused by Acroconidiella tropaeoli on Tropaeolum majus in Brazil

Abstract

(nasturtium, local name chagas orcapuchinho) is a member of the Tropaeolaceae and nativeto Peru and Brazil. In Brazil it is commonly used as anornamental (Lorenzi & Souza, 1995), but it is increasinglybeing grown as a vegetable for its edible and showy red,orange or yellow flowers used for decorating salads.Damaging leaf spots were found affecting a group of plantsin Vicosa and also at Catas Altas, state of Minas Gerais,Brazil.Leaf lesions initially were yellow and punctiform,becoming circular with a brown centre, 2–25 mm. Necrotictissue often cracked or fell, resulting in shot-hole symptomscoalescing and leading to extensive necrosis of the leaves.Severely affected areas or whole leaves became yellow anddied.The fungus had conidiophores arising from the hyphaethat are cylindrical, straight to slightly flexuose, branched,64–301 × 4–8 µ m, pluriseptate, smooth and pale brown.Conidia were clavate, ellipsoidal to ovoid, 15–50 × 6–19 µ m, mostly two-septate, echinulate and brown. Themorphology of the fungus associated with the symptomswas equivalent to that described for