Saccharicola, a new genus for two Leptosphaeria species on sugar cane

Abstract

Leptosphaeria bicolor, causal agent of a leaf scorch disease of sugar cane, is referred to the new genus Saccharicola. The ascospores are 1-3 transseptate and hyaline at first but become melanized and rough after release, as is the case in some members of Massarina and Lophiostoma. SSU rDNA data indicate that it is closely related to M. eburnea but is biotrophic in leaves of sugar cane and not corticolous, the ascomata are less melanized, and it has Stagonosporaand Phoma-like synanamorphs, not a Ceratophoma-like anamorph. A second species, Leptosphaeria taiwanensis, is transferred to Saccharicola. It differs in slightly larger, normally 1-septate, hyaline spores with more attenuated ends. The family Massarinaceae is resurrected to accommodate Massarina s. str., Keissleriella, Saccharicola and Helminthosporium. These genera formed a clade with 100% bootstrap support in a parsimony analysis of SSU rDNA sequences from 38 ascomycetes, 30 of them members of Pleosporales (including Melanommatales).