Sectorial resistance of plum to sharka (Plum Pox Virus)

Abstract

One unusual aspect of resistance to sharka (Plum Pox Virus, PPV) has been discovered and studied in plum trees in the six consecutive years. The absence of sharka symptoms in some of primary branches of infected plum trees characterized as resistance. Symptoms appearance was observed and PPV presence was checked serologically by DAS- ELISA test as well as by grafting transmission. That aspect of resistance mainly appears in a portion of the tree crown, i.e. on some primary branches of young plum trees and it is diminishing in following years. That distinct resistance to sharka (PPV) was found in trees of Čačanska rodna, Stanley and Crvena ranka cvs. In selected plum trees in the parts with such resistance no sharka symptoms appeared nor PPV was proved. The absence of sharka symptoms as well as PPV in a portion of a plum tree otherwise diseased by sharka is considered as a sign of resistance. For such aspect of resistance the name “Sectorial Resistance” is proposed. It is continues more and detail research on sectorial resistance of plum to PPV are in progress.

Kod stabala šljive sorti Čačanska rodna, Stenli i Crvena ranka obolelih od virusa šarke šljive (VŠŠ, Plum pox virus - PPV) uočeno je prisustvo tipičnih simptoma u određenim delovima krune, a odsustvo u drugim. Izostank simptoma i virusa šarke šljive u delu krune obolelog stabla je nazvana “sektorijalna otpornost”. Okuliranje pupoljaka ovih sorti iz zaraženih delova krune u podlogu-džanariku rezultiralo je prisustvom virusa već u jednogodišnjim prirastima i manifestovanjem bolesti preko tipičnih simptoma u prvoj godini po kalemljenju. Međutim, okuliranje pupoljaka istih sorti iz sektorijalno zdravih delova krune, dalo je potpuno suprotan rezultat. Odsustvo VŠŠ proveravano je serološki DAS-ELISA testom. Na osnovu iznetog može se zaključiti da se kalemljenjem sektorijalna otpornost uspešno prenosi na nove serije sadnica i buduće voćke.