Screening selected apricot hybrids for bacterial canker resistance

Bacterial canker disease caused by Pseudominas syringae is a major disease in apricot. In this project the relative resistance of a number of local selected apricot hybrids was investigated in orchard condition. For preparing inoculums, the pathovar of three local bacterial agents was determined using LOPAT and GATTa tests and their mixture was used. Evaluation was performed in orchard in two-years-old seedlings (22 hybrids) and adult trss (9 hybrids) in Cold and Temperate Center, Karaj, and Sahand Research Station, Tabriz, respectively. The plants were inoculated in autumn 2016and canker severity reported in autumn 2017.Based on results, all three bacterial isolates were identified as P. syringae pv. syringae. Analysis of variance of canker length data revealed a significant different between hybrids in both seedling and adultd trees.In seedlings, AD1033 and AC111 and in adult trees, AD405 and AD503 exhibited the most and least canker length, respectively. No correlation was found in canker length between seedlings and adults. Based on result, apricot hybrids have varius resistance to bacterial canker and inoculation of adult trees in orchard condition is the best resistance evalution method in apricots. Keywords: bacterial canker, resistance, Pseudomonas syringae, apricot