Fungos fitopatogênicos associados a capim-amargoso (Digitaria insularis) em localidades da Zona da Mata e Triângulo Mineiro

Abstract

Digitaria insularis, popularly known as sourgrass, is a perennial weed, considered difficult to manage and that defies control measures due to its high potential for competition and infestation. The plant has a high rate of dispersal, prolificacy, high percentage of germination and herbicide-resistant biotypes. A preliminary survey of the mycobiota associated with D. insularis in the Triângulo Mineiro and Zona da Mata regions of Minas Gerais, with emphasis on the municipalities of Monte Carmelo and Viçosa, resulted in three isolates of phytopathogenic fungi associated with this host. The present study aimed to clarify the identity of two these isolates, through molecular and morphological methods. Phylogenetic analysis based on ITS, revealed that one of the isolates, causing smut in panicles of D. insularis, belongs to the species Anthracocystis panici-leucophaei and morphological observations contributed to this identification. The other isolate which causes leaf lesions, belongs to the genus Microdochium, and through phylogenetic inferences from ITS, LSU and RPB2 and morphological observations, it was recognized as a representative of a previously unreported species named Microdochium maculosum.