Occurrence of Cylindrocladium pauciramosum Causing Leaf Spot on Strelitzia reginae in Southern Brazil

Abstract

Bird of paradise, also known as crane flower (Strelitzia reginae), is a monocotyledonous flowering native plant of South Africa. It is commonly grown and commercialized as an ornamental plant and is appreciated for its beautiful flowers (Luz et al., 2005). In September 2016, plants with severe spots on leaves were found in a commercial field (−31°48'S; −52°24'W) located in Pelotas, Rio Grande do Sul state, Brazil. The spots 0.1 to 2 cm in diameter on the leaves had a shape from circular to irregular with a light gray center and a dark gray to black border. Some leaf spots coalesced and, in severe cases, covered 50% of the of the leaf surface. Leaf lesion samples were surface sterilized (1% NaOCl solution for 1 min) and placed on potato dextrose agar (PDA). To identify the fungus responsible for those spots, a morphological analysis was carried out, and a molecular characterization was performed by amplifying and sequencing the internal transcribed spacer (ITS), β-tubulin (TUB2), calmodulin (CAL), translat...