New Zealand Plant Protection 68 (2015): 257-263
The fungus Neonectria ditissima causes European canker of apple. To determine the pathogenicity of different isolates, conidial inoculum of each isolate needs to be prepared. Freezing inoculum ensures that conidia do not germinate before inoculation, and facilitates screening of large numbers of isolates. In this study, conidial suspensions of three different isolates and 'field conidia' collected from apple cankers were used to inoculate dormant potted 1-year-old 'Royal Gala' trees in a glasshouse. Each conidial suspension were removed and inoculated, with four replicates of two shoots per treatment. Significant differences in disease incidence and lesion size were observed between the different isolates at each assessment date, 5 to 15 weeks after inoculation (P<0.003), but freezing the inoculum had no effect on disease incidence or lesion size. Frozen conidial suspensions can be used for pathogenicity studies and may also be a long-term storage option for cultures.
Keywords: European canker, Neonectria galligena, Nectria galligena, conidia, inoculation, temperature, freezing, pathogenicity, disease incidence, lesion size.
|Agar media for isolation of Neonectria ditissima from symptomatic and asymptomatic apple tissues and production of infective conidia|
N.T. Amponsah, M. Walter and R.W.A. Scheper (2014)
New Zealand Plant Protection 67: 116-122
|Effect of culture medium, light and air circulation on sporulation of Neonectria ditissima|
R.W.A. Scheper, B.M. Fisher, N.T. Amponsah and M. Walter (2014)
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|Pathogenicity of field and laboratory-grown inoculum of Neonectria galligena on potted apple trees|
R.W.A. Scheper, B.M. Fisher and P.N. Wood (2010)
New Zealand Plant Protection 63: 280
Copyright © 2015 New Zealand Plant Protection Society (Inc.).