Variation of some morphological and molecular characteristics of Hungarian Crivellia and Brachycladium isolates from opium poppy (Papaver somniferum L.)

Abstract

A destructive seed-borne pathogen, formerly described as Pleospora papaveracea affects opium poppy (Papaver somniferum L.) plants, grown in Hungary, causing considerable qualitative and quantitative losses. The symptoms of the disease were frequently observed in the field between 1999 and 2006. Seventeen Hungarian isolates were obtained from poppy and cultures were established on malt extract agar from naturally infected seeds, diseased foliage, pods and stem. The pathogens proved to be Crivellia papaveracea and a distinct taxon, Brachycladium papaveris based on morphological characterization of conidia, conidiophores and cultures, moreover molecular investigation of the ITS region. Significant morphological differences were observed among the isolates originating from distinct plant parts, however, cultural characteristics were similar. Molecular studies revealed that morphological and cultural differences or similarities do not correspond with taxonomic position of the isolates. Morphological variation of the isolates mainly depended on their origin and might be explained with the differences of microclimatic conditions.