Botryosphaeria obtusa causer of apple fruit rot in Serbia

Abstract

The symptoms of apple fruit black rot of different cultivars caused by Botryo­sphaeria obtusa were found in the refrigerated warehouse of PIK "Južni Banat", Vršac, and on the trees in the field in Šabac town vincinity during 2003 and 2004. The optimal temperature for both pathogen development and spore germination were between 25° and 30°C for all isolates marked as J-1, J-2, J-15 and J-16, respectively. The results of morphological investigation of the isolates indicated that two different morphotypes of pathogen B.obtusa exist on apple fruits, (type A: isolates J-1 and J-2 and type B: isolates J-15 and J-16). Both types of isolates could caused rotting of apple fruits, but there were significant differences in their aggressiveness.

Botryosphaeria obtusa, prouzrokovač erne truleži jabuke, izolovana je sa plodova u skladištima PIK "Južni Banat" i plodova prikupljenih u voćnjacima u okolini Šapca tokom 2003. i 2004. godine. Optimalna temperatura za razvoj patogena i klijanje konidija je između 25° i 30°C. Rezultati ispitivanja morfologije patogena (izgled kolonija, izgled i veličina piknidiospora, način formiranja piknidia i njihova brojnost) ukazuju na postojanje dva morfotipa B.obtusa (tip A: izolati J-l i J-2 i tip B: izolati J-15 i J-16). Iako izolati oba tipa mogu uzrokovati trulež plodova, razlike u njihovoj agresivnosti bile su značajne.