Morphological characterization and molecular identification of <i>Colletotrichum</i> spp. associated with <i>Schlumbergera gaertneri</i>

Abstract

The Whitsun cactus (Schlumbergera gaertneri), native to Brazil, is used as ornamental plant worldwide. Symptoms of anthracnose were identified in plants cultivated in southern Brazil, causing the loss of ornamental value of the affected plants. Thus, the objective of this work was to isolate, characterize and identify the causal agent of anthracnose in S. gaertneri, through morphological and molecular characters. For the pathogenicity test, seedlings were injured with a toothpick and inoculated with a conidia suspension, while the morphological characterization of the causal agent was performed in Mathur culture medium. The Internal Transcribed Spacer (ITS), Actin, ?-tubulin, Glyceraldehyde-3-phosphate dehydrogenase and Calmodulin regions were used to molecularly identify the species. The isolates obtained were pathogenic to S. gaertneri, presenting morphological characteristics compatible with species of the genus Colletotrichum. By sequencing the genomic regions, Glyceraldehyde-3-phosphate dehydrogenase, Calmodulin and ?-tubulin we identified Colletotrichum karsti and C. siamensis as causal agents of anthracnose in S. gaertneri.