Articles
SUSCEPTIBILITY OF SELECTED APPLE ROOTSTOCKS TO FIRE BLIGHT CAUSED BY ERWINIA AMYLOVORA
Article number
1058_61
Pages
493 – 498
Language
English
Abstract
The study was conducted in the years 2009-2010. It involved 15 apple root-stocks originating from different rootstock breeding programs.
Ten rootstocks (P 2, P 14, P 16, P 22, P 59, P 60, P 66, P 67, P 68) originated from the Polish breeding program, four (M.7, M.9, M.26 and MM.106) were bred in the UK and two (CG 11 and CG 16) were obtained at Cornell University (USA). At the end of March of each year, 20 plants of each genotype (stem diameter of 8-10 mm) were planted in 5 litre containers filled with a mixture (1:1 by volume) of peat substrate and compost soil, and placed in a high plastic tunnel.
After planting, the rootstocks shoots were cut back to a length of 20 cm and grown till the emerging main shoots had reached a height of about 60-70 cm.
At that stage, the terminal shoot tips were inoculated (on 16 June 2009 and 14 June 2010) with a highly virulent strain (Ea 659) of Erwinia amylovora (107 cfu/ml) using scissors.
The progress and severity of fire blight symptoms were assessed 2, 4 and 6 weeks after inoculation.
The calculated disease severity values (percentages of shoot necrosis) were presented as disease susceptibility scores according to the scale proposed by Le Lezec et al. (1997). Based on the two-year evaluation, the tested rootstocks can be classified as follows: CG 16 resistant (no symptoms), P 59 and M.7 moderately susceptible, and P 2, P 14, P 16, P 22, P 60, P 66, P 67, P 68, M.9, M.26 and MM.106 very susceptible.
Ten rootstocks (P 2, P 14, P 16, P 22, P 59, P 60, P 66, P 67, P 68) originated from the Polish breeding program, four (M.7, M.9, M.26 and MM.106) were bred in the UK and two (CG 11 and CG 16) were obtained at Cornell University (USA). At the end of March of each year, 20 plants of each genotype (stem diameter of 8-10 mm) were planted in 5 litre containers filled with a mixture (1:1 by volume) of peat substrate and compost soil, and placed in a high plastic tunnel.
After planting, the rootstocks shoots were cut back to a length of 20 cm and grown till the emerging main shoots had reached a height of about 60-70 cm.
At that stage, the terminal shoot tips were inoculated (on 16 June 2009 and 14 June 2010) with a highly virulent strain (Ea 659) of Erwinia amylovora (107 cfu/ml) using scissors.
The progress and severity of fire blight symptoms were assessed 2, 4 and 6 weeks after inoculation.
The calculated disease severity values (percentages of shoot necrosis) were presented as disease susceptibility scores according to the scale proposed by Le Lezec et al. (1997). Based on the two-year evaluation, the tested rootstocks can be classified as follows: CG 16 resistant (no symptoms), P 59 and M.7 moderately susceptible, and P 2, P 14, P 16, P 22, P 60, P 66, P 67, P 68, M.9, M.26 and MM.106 very susceptible.
Publication
Authors
M. Lewandowski, P. Sobiczewski, E. Żurawicz , A. Mikiciński
Keywords
Malus × domestica, artificial inoculation, fire blight symptoms
Online Articles (87)