Morphological characteristics of Eutypa lata isolates from grapevine in Serbia

Abstract

In an in vitro experiment, the morphological characteristics of three Eutypa lata isolates (EL129, EL153 and EL199), previously determined at the molecular level, and two reference isolates BX1.10 and 8F obtained from the Institute National de la Recherche Agronomique, INRA, France were observed. The following morphological features of the studied isolates were studied on the nutrient medium of potato dextrose agar (PDA): macroscopic (appearance, color and zoning of the front and back of the culture) and microscopic (vegetative organs of mycelium, reproductive organs of anamorphs - conidia, pycnidia, conidiophores and reproductive organs of teleomorphs - perithecium, ascus with ascospore). On potato dextrose medium (PDA) 24 h after placing, the studied E. lata isolates formed at the beginning a white mycelium. After 10 days, the mycelium had a cottony appearance, white color with a weak air growth. The entire colony developed evenly and had a fine diffuse edge. After 30 days, the face of the colony was white with a thick cotton aerial mycelium and a pale yellow conidial mass, which was excreted from the pycnidia. The studied E. lata isolates formed pycnidia, which were formed in culture. The pycnidia of the studied E. lata isolates were spherical or irregular in shape, from dark brown to black in color. The dimensions of the pycnidia were from 0.5 to 1 mm. Conidial mass was a cream to pale orange color on a PDA base. All studied isolates formed conidia in culture. None of the studied E. lata isolates, originating from the stem and branches of the grapevine from Serbia, as well as the control isolates, formed perithecia in culture.