Vegetative incompatibility of isolates of Phomopsis spp. from plum trees

Abstract

Isolates of Phomopsis spp. obtained from plum trees (Prunus domestica L.) with symptoms of die-back. There were significant morpho-physiological and pathogenic differences between the isolates. The genetic variability (12 isolates of Phomopsis spp. and isolate of Photopia pernicious, which was used as control ) was proved by study of vegetative compatibility. These isolates were inoculated in Petri dishes in pairs in all possible cross combinations, on potato dextrose agar. After 5 and 10 days the interaction between colonies were scored according to appearance of contact lines of paired cultures. On the contact line on two different isolates distinct barrage zones of inhibition - vegetative incompatibility reaction. The barrage zones generally became black and sometimes showed formation of pycnidia. Necrotic parts of hyphen that formed line of reaction were observed. A compatible reaction was observed only when cultures of the same isolate were paired.

Izolati Phomopsis spp. dobijeni sa grana i stabla šljive (Prunus domestica L.) sa simptomima sušenja i izumiranja ispoljili su značajne razlike u morfolo-fiziološkim i patogenim karakteristikama. Primenom metode vegetativne kompatibilnosti potvrđena je genetska varijabilnost 12 izolata Phomopsis spp. i kontrolnog izolata Phomopsis perniciosa. Isečci ispitivanih kultura zasejavani su u Petri kutije po parovima i u svim mogućim unakrsnim kombinacijama, na podlozi KGA. Očitavanje rezultata je vršeno petog i desetog dana i podrazumevalo je praćenje izgleda linije međusobnog kontakta uparivanih izolata. Nakon perioda inkubacije između ispitivanih kultura dolazi do formiranja crne reakcione linije - barijere, a u pojedinim slučajevima i reproduktivnih organa - piknida (reakcija vegetativne inkompatibilnosti). Delovi hifa koje sačinjavaju crnu reakcionu liniju bili su nekrotirani. Vegetativna kompatibilnost konstatovana je samo u slučajevima kada su izolati uparivani sami sa sobom.