TY - GEN
T1 - Selection for fire blight resistance of apple genotypes originating from European genetic resources and breeding programs
AU - Sobiczewski, P.
AU - Mikiciński, A.
AU - Lewandowski, M.
AU - Zurawicz, E.
AU - Richter, K.
AU - Peil, A.
AU - Kellerhals, M.
PY - 2011/5/13
Y1 - 2011/5/13
N2 - The study was conducted at two locations (RIPF, JKI) in 2007-2010 on apple genotypes originating from Belgium, Hungary, Germany, Poland, Sweden and Switzerland. Scions were hand-grafted on 'M.9' rootstock. Each genotype was evaluated two times over two years. At RIPF, terminal shoots of potted trees of 38 genotypes were inoculated by cutting-off their tips using scissors immersed in a water suspension of Erwinia amylovora strain Ea 659 (107 cfu/ml). Observations and measurements of the progress and severity of fire blight were performed after 6 weeks. The plant germplasm Pi-AS 12,53, 'Reanda', 'Free Redstar', Pi-AS 50,74 and MR-10 appeared to be the most resistant, whereas CRA Ma B 28, CRA Ma A 70, CRA Ma A 40, CRA Ma D 30, 'Jakob Lebel', Pi-AS 26,56, CRA Ma A 68, 'Bohnapfel', 'Blauacher Wädenswil', and MR-12, were classified as very susceptible. Significant differences were found in the case of 'Enterprise' which in 2008 showed very low susceptibility but in 2009 showed low susceptibility. Similarly, clone CRA Ma A 4 in 2007 was rated as being low susceptible, but in 2009 as moderately susceptible. Further evaluation in 2010 confirmed the low susceptibility of 'Enterprise'. At JKI, actively growing shoots of potted trees of 27 genotypes placed in a greenhouse were inoculated by cutting the tips of the youngest leaves using scissors previously immersed in a suspension of a mixture of three highly virulent strains of E. amylovora (109 cfu/ml). Observations and measurements of the progress and severity of fire blight were performed 4 weeks after inoculation. MR-10, Pi-AS 36,164, Pi-AS 50,74 appeared to be the most resistant whereas 'Bohnapfel', 'Blauacher Wädenswil' and 'Idared' were classified as very susceptible in each of the two screening years. Big differences in necrosis length (>30%) between years 2008 and 2009 were found for 'Enterprise', 'Kalmare Glas', and Pi-AS 12,53. Therefore they and additionally 'Spartan' and 'Idared' were phenotyped a third year. Pi-AS 12,53 and 'Enterprise' showed very similar results to the first year of testing with 'Enterprise' and Pi-AS 12,53 being highly resistant, whereas 'Kalmare Glas' 2010 showed a value in between the values of 2008 and 2009. Summarizing, evaluation of some common genotypes at RIPF and JKI showed that in general highly resistant clones and highly susceptible clones react in the same manner independently of test site (i.e., institute) and inoculation procedure.
AB - The study was conducted at two locations (RIPF, JKI) in 2007-2010 on apple genotypes originating from Belgium, Hungary, Germany, Poland, Sweden and Switzerland. Scions were hand-grafted on 'M.9' rootstock. Each genotype was evaluated two times over two years. At RIPF, terminal shoots of potted trees of 38 genotypes were inoculated by cutting-off their tips using scissors immersed in a water suspension of Erwinia amylovora strain Ea 659 (107 cfu/ml). Observations and measurements of the progress and severity of fire blight were performed after 6 weeks. The plant germplasm Pi-AS 12,53, 'Reanda', 'Free Redstar', Pi-AS 50,74 and MR-10 appeared to be the most resistant, whereas CRA Ma B 28, CRA Ma A 70, CRA Ma A 40, CRA Ma D 30, 'Jakob Lebel', Pi-AS 26,56, CRA Ma A 68, 'Bohnapfel', 'Blauacher Wädenswil', and MR-12, were classified as very susceptible. Significant differences were found in the case of 'Enterprise' which in 2008 showed very low susceptibility but in 2009 showed low susceptibility. Similarly, clone CRA Ma A 4 in 2007 was rated as being low susceptible, but in 2009 as moderately susceptible. Further evaluation in 2010 confirmed the low susceptibility of 'Enterprise'. At JKI, actively growing shoots of potted trees of 27 genotypes placed in a greenhouse were inoculated by cutting the tips of the youngest leaves using scissors previously immersed in a suspension of a mixture of three highly virulent strains of E. amylovora (109 cfu/ml). Observations and measurements of the progress and severity of fire blight were performed 4 weeks after inoculation. MR-10, Pi-AS 36,164, Pi-AS 50,74 appeared to be the most resistant whereas 'Bohnapfel', 'Blauacher Wädenswil' and 'Idared' were classified as very susceptible in each of the two screening years. Big differences in necrosis length (>30%) between years 2008 and 2009 were found for 'Enterprise', 'Kalmare Glas', and Pi-AS 12,53. Therefore they and additionally 'Spartan' and 'Idared' were phenotyped a third year. Pi-AS 12,53 and 'Enterprise' showed very similar results to the first year of testing with 'Enterprise' and Pi-AS 12,53 being highly resistant, whereas 'Kalmare Glas' 2010 showed a value in between the values of 2008 and 2009. Summarizing, evaluation of some common genotypes at RIPF and JKI showed that in general highly resistant clones and highly susceptible clones react in the same manner independently of test site (i.e., institute) and inoculation procedure.
KW - Disease resistance
KW - Erwinia amylovora
KW - Malus × domestica
UR - http://www.scopus.com/inward/record.url?scp=80053376954&partnerID=8YFLogxK
U2 - 10.17660/actahortic.2011.896.57
DO - 10.17660/actahortic.2011.896.57
M3 - Conference contribution
AN - SCOPUS:80053376954
SN - 9789066051171
T3 - Acta Horticulturae
SP - 399
EP - 406
BT - XII International Workshop on Fire Blight
PB - International Society for Horticultural Science
ER -