Systematic revision of species of Atractilina and Spiropes hyperparasitic on Meliolales (Ascomycota) in the tropics

Abstract

Atractilina Dearn. & Barthol. and Spiropes Cif. are genera of asexual fungi that comprise species mainly hyperparasitic on black mildews (Meliolales, Ascomycota). Although a common group of anamorphic fungi, they have been described up to now only by morphology and their systematic position is unknown. The present study provides a morphological treatise of all known species of Atractilina and Spiropes hyperparasitic on Meliolales, including insights into their systematic position, based on DNA sequences generated here for the first time. The study was conducted, based on 33 herbarium specimens and 23 specimens recently collected in Benin and Panama. The obtained DNA sequence data (28S rDNA and ITS rDNA) of A. parasitica and of two species of Spiropes show systematic placements in the Dothideomycetes and Leotiomycetes, respectively. The sequence data of the two Spiropes spp. do not group together. Moreover, the anamorph-teleomorph connection between Atractilina parasitica and Malacaria meliolicola, a pseudothecioid fungus, is confirmed. Three species in the genus Spiropes are proposed as new to science, namely S. angylocalycis, S. carpolobiae and S. croissantiformis. Four species are reported for Benin for the first time, three species for Panama and one species for mainland America. Atractilina and Spiropes are currently two genera with highly heterogeneous species and they might have to be split in the future, once the taxonomic concepts are validated by morphology and molecular sequence data.