Archive of SID

nd Proceedings of 22 Iranian Plant Protection Congress, 27-30 August 2016 262 College of Agriculture and Natural Resources, University of Tehran, Karaj, IRAN

Interaction of different apple cultivars against artificial inoculations with Diplodia bulgarica

M. Ketabchi.1, Y. Ghosta.1 and L. Naseri2

1.Department of Plant Protection, College of Agriculture, Urmia University, Iran. 2.Department of Horticultural Science, College of Agriculture, Urmia University [email protected]

In this study, interaction of 22 different apple cultivars was evaluated under field conditions against Diplodia bulgarica, the causal agent of apple canker and decline. 1-2 years olds shoots from apple cultivars including Golab, Sib-e-Torsh, Sib-e-Shirin, Ghezel, Golden Delicious, Red Delicious, Granny Smith, Delbarestivale, Idared, Fuji, Braeburn, Gami Almasi, Ingride Marie, Golden Primrose, Smoothee Golden Primrose, MM109, MM106, MM104, M9, M7, M4 and M2 were selected at four directions of the trees and were surface sterilized with 70% ethanol. Small plugs (7 mm diameter) from shoot barks were taken with sterile cork borer and were inoculated with the same diameter of mycelial plugs from actively growing fungal isolates. In controls, agar plugs without mycelium was used. Small pieces of wet cotton were placed near the agar plugs and were sealed with parafilm. The inoculated sites were evaluated after two months. Bark browning and shoot rot around the inoculated sites were considered as pathogenicity of the fungal isolates on shoots. Isolation and identification of the inoculated fungus from symptomatic shoots was done. The discolored bark area around the inoculated sites were calculated based on ellipsoid formula and were used in comparisons. Results showed that all the studied cultivars were susceptible to the fungus and showed disease symptoms, but comparisons of data means showed statistically significant differences (p<0.01). Apple cultivars Golab, Ghezel, Sib-e-Shirin and Sib-e-Torsh were determined as highly susceptible, Gami Almasi and Ingride Marie as low susceptible and other cultivars as moderately susceptible. This is the first study on the interaction of apple cultivars to artificial inoculation with Diplodia bulgarica isolates.

Keywords: Apple cultivars, Host rang, Diplodia bulgarica, Pathogenicity, Azarbaijan.