The anamorphic state of Leveillula taurica recorded on Cleome spinosa in north-eastern Brazil

Abstract

Introduction The genus Cleome L. belongs to Cleomaceae (Capparaceae s.l.) and has approximately 250 species; most are adapted to seasonal drought. Several species are used as medicinal or ornamental, while a few are regarded as weeds (Mabberley 2008). Cleome spinosa Jacq., popularly known as spiny spider-flower could be included in the last category. In semiarid regions of north-eastern Brazil, where drought is quite frequent, this plant is widespread, but occurs mainly near humid lowlands (Lorenzi 2000). In December of 2010 scattered plants of C. spinosa whit a white powdery mass covering its leaves where observed in the experimental field of the Embrapa Algodao (Brazilian Center of Cotton Research) in Paraiba State. A sample was collected and examined under a microscope revealing the presence of a fungus that was identified as belonging to the genus Oidiopsis Scalia, the anamorphic state of Leveillula G. Arnaud. After that, during field trips in 2011 and 2012 plants of C. spinosa showing the same white powdery mass were observed in several new locations through Paraiba State. New samples were collected and after a microscopic examination a fungus with similar morphology of that previously identified as Oidiopsis was observed. There are several erysiphaceous fungi recorded on the genus Cleome, but only two belonging to Leveillula, viz. L. taurica (Lev.) G. Arnaud (Farr & Rossman 2012) and L. cleomes Simonyan & V.P. Heluta (Simonyan & Heluta 1989). The aim of this study was describe the morphology and identify the species of the powdery mildew fungus occurring on C. spinosa in north-eastern Brazil.