Articles
EFFICIENT SURFACE STERILIZATION OF SNOWDROP BULB EXPLANTS WITH PPM
Article number
886_36
Pages
259 – 265
Language
English
Abstract
We report here a reliable method to surface sterilize bulb chip explants of Galanthus nivalis and G. elwesii. Experiments involved NaOCl treatments of whole bulbs either alone, or in combination with an initial hot-water treatment of 43°C for 45 min (HWT), prior to cutting chip explants.
These methods were also tested in combination with steeping bulb-chip explants in Plant Preservative Mixture (PPM) (2-5% PPM in 50 mg L-1 MgSO4 for 9 h) directly before inoculation.
The effects of including PPM (0.1%), or the fungicides benomyl (B), carbendazim (C), imazalil (I) and a mixture of C and I (CI), each at 20 mg (a.i.) L-1 in the culture medium, were also assessed.
Conventional NaOCl treatments with immersion in 0.46-1.38% NaOCl for 20 min were ineffective, even when combined with initial HWT. Indeed, HWT increased the levels of microbial contamination found on the explants.
Microbial contamination remaining after these relatively mild NaOCl and HWT treatments was not reduced by either PPM or B in the medium.
Increasing NaOCl concentration to 5.0 or 10.0% gave improved control over contamination, particularly when combined with I or CI in the medium.
C alone in the medium was ineffective.
Steeping bulb-chip explants in 4-5% PPM for 9h following whole bulb sterilization for 20 min in 2.3% NaOCl gave virtually complete control of infection in all three bulb batches used, and rendered the use of PPM or fungicides in the medium unnecessary.
These methods were also tested in combination with steeping bulb-chip explants in Plant Preservative Mixture (PPM) (2-5% PPM in 50 mg L-1 MgSO4 for 9 h) directly before inoculation.
The effects of including PPM (0.1%), or the fungicides benomyl (B), carbendazim (C), imazalil (I) and a mixture of C and I (CI), each at 20 mg (a.i.) L-1 in the culture medium, were also assessed.
Conventional NaOCl treatments with immersion in 0.46-1.38% NaOCl for 20 min were ineffective, even when combined with initial HWT. Indeed, HWT increased the levels of microbial contamination found on the explants.
Microbial contamination remaining after these relatively mild NaOCl and HWT treatments was not reduced by either PPM or B in the medium.
Increasing NaOCl concentration to 5.0 or 10.0% gave improved control over contamination, particularly when combined with I or CI in the medium.
C alone in the medium was ineffective.
Steeping bulb-chip explants in 4-5% PPM for 9h following whole bulb sterilization for 20 min in 2.3% NaOCl gave virtually complete control of infection in all three bulb batches used, and rendered the use of PPM or fungicides in the medium unnecessary.
Authors
I. Staikidou, C. Selby, S. Watson
Keywords
Galanthus nivalis, Galanthus elwesii, fungicide, HWT
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