A new species of Chaetothyrina on branches of mango, and introducing Phaeothecoidiellaceae fam. nov.

Abstract

The new family Phaeothecoidiellaceae, introduced in this paper, comprises several species which cause sooty blotch and flyspeck diseases of several economic fruits. This results in quality issues with fruits and plants, due to the black thallus and small black dots coating the surface. Most species of Phaeothecoidiellaceae are biotrophs and are unculturable without the host material, and direct-sequencing is difficult because of the very small and flattened thyriothecia. Therefore, this fungal group is relative poorly known due to limited sampling and few in-depth studies. "Microthyriales"-like taxa appearing as small black dots on the surface of mango trees were collected in northern Thailand. Taxa were studied based on morphological characters and molecular analyses. Maximum likelihood and Bayesian analyses of combined ITS, LSU and SSU sequence data, indicated that the collection from branches of mango is a previously undescribed species. The new species, Chaetothyrina guttulata, is introduced in this paper with descriptions and illustrations.