Resistance of topinambour (Helianthus tuberosus L) to sunflower stem canker in field conditions

Abstract

Topinambour is a perennial species originating from central part of North America. This species is known to be a potential source of resistance to some diseases of cultivated sunflower like stem canker. In this research we evaluated 141 populations of Helianthus tuberosus from the collection of Institute of Field and Vegetable Crops in Novi Sad. Plants in the collection field and in the experimental field were artificially inoculated using Phomopsis helianthi isolate from Rimski Šančevi. After seven days of growing on PDA (Potato-Dextrose Agar) medium, mycelial plugs were placed on leaf tip and wrapped with aluminum foil. Disease progress was measured in regular intervals. Occurrence of natural infections was also evaluated and all diseases were noted. As a result of this survey significant differences were detected among populations regarding disease intensity. Out of all assessed populations those labeled as TUB2046, TUB2062 and TUB CG 65 were most resistant.

Topinambur je višegodišnja vrsta suncokreta poreklom iz centralnog dela Severne Amerike. Ova vrsta je prepoznata kao potencijalni izvor otpornosti na neke od ekonomski značajnih bolesti koje se javljaju kod gajenog suncokreta kao što je sivo-mrka pegavost stabla. U ogledu je korišćena ukupno 141 populacija topinambura na karantinskoj parceli Instituta za ratarstvo i povrtarstvo u Novom Sadu. Inokulisane su biljke u stalnom zasadu i u oglednoj parceli na kojoj su sađene krtole izolatima Phomopsis helianthi sa Rimskih Šančeva. Nakon sedam dana gajenja na PDA (Potato-Dextrose Agar) podlozi isečci micelije gljive Phomopsis helianthi su stavljani na vrh lista i potom prekrivani folijom. Napredovanje bolesti je mereno u pravilnim vremenskim intervalima. Praćen je intenzitet prirodne infekcije i zabeležena pojava ostalih bolesti. Utvrđene su značajne razlike u brzini napredovanja bolesti između pojedinih populacija. Populacije TUB2046, TUB2062, TUB CG 65 su pokazale najveću otpornost.