Summary
Microbial contaminants were detected in surface-sterilized strawberry runner explants partially submerged in half-strength liquid Murashige and Skoog medium. From June to August, 1994, 45 of 70 strawberry genotypes were found to be contaminated, whereas from June to August, 1995, 53 of 72 contained contaminants. There were more bacterial than fungal contaminants. Bacterial contaminants from 22 strawberry genotypes were isolated, purified, and identified to genus by standard biochemical tests such as Gram’s stain, motility, oxidase, and gelatinase, and carbon source utilization (Biolog Microplates, Biolog, Inc., Hayward, CA). Among the 30 isolates identified with the Biology system, the majority were fluorescent pseudomonads including Pseudomonas fluorescens types A, F, and G. P. corrugata, P. tolaasii, P. paucimobilis, Xanthomonas campestris, Xanthomonas spp., and Enterobacter cloacae were also identified. Five Gram-negative and two Gram-positive contaminants could not be identified by the Biology test. Biochemical tests were used to characterize the bacteria and to confirm Biolog test results. Bacteria identified in this study were soil, water, and plant related, indicating that efforts to reduce explant contaminant levels should be centered on the care of stock plants or the sterility of the watering system.
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References
Bastiaens, L. Endogenous bacteria in plants and their implications in tissue culture—a review. Med. Fac. Landbouww. Rijksuniv. Gent. 48:1–11; 1983.
Blake, J. Mites and thrips as bacterial and fungal vectors between plant tissue cultures. Acta Hort. 225:163–166; 1988.
Boxus, P.; Terzi, J. M. Big losses due to bacterial contamination can be avoided in mass propagation scheme. Acta Hort. 212:91–93; 1987.
Bradbury, J. F. Identification of cultivable bacteria from plants and plant tissue cultures by use of simple classical methods. Acta Hort. 225:27–37; 1988.
Buckley, P. M.; DeWilde, T. N.; Reed, B. M. Characterization and identification of bacteria isolated from micropropagated mint plants. In Vitro Cell. Dev. Biol. 31P:58–64; 1995.
Cassells, A. C. Problems in tissue culture: culture contamination. In: Debergh, P. C.; Zimmerman, R. H., ed. Micropropagation technology and application. Dordrecht, Netherlands: Kluwer Academic Publishers; 1991:31–44.
Debergh, P. C.; Vanderschaeghe, A. M. Some symptoms indicating the presence of bacterial contaminants in plant tissue culture. Acta Hort. 255:77–81; 1988.
Finer, J. J.; Saxton, R. W.; Norris, B. L., et al. Growth and disinfestation of 6 different bacteria in embryogenic suspension cultures of cotton. Plant Cell Rep. 10:380–383; 1991.
Holmes, B.; Owen, R. J.; Evans, A., et al. Pseudomonas paucimobilis, a new species isolated from human clinical specimens, the hospital environment, and other sources. Int. J. Syst. Bacteriol. 27:133–146; 1977.
Jones, J. B.; Chase, A. R.; Harris, G. K. Evaluation of the Biolog GN MicroPlate system for identification of some plant-pathogenic bacteria. Plant Dis. 77:553–558; 1993.
Kane, M. E. Indexing explants and cultures to maintain clean stock. In Vitro Cell. Dev. Biol. 31:25A; 1995.
Klement, Z.; Rudolph, K.; Sands, D. C., ed. Methods in phytobacteriology. Budapest: Akademiai Kiado; 1990.
Kneifel, W.; Leonhardt, W. Testing of different antibiotics against gram positive and gram negative bacteria isolated from plant tissue cultures. Plant Cell Tissue Organ Cult. 29:139–144; 1992.
Krieg, N. R.; Holt, J. G., ed. Bergey’s manual of systematic bacteriology. Vol. 1. Baltimore: Williams and Wilkens; 1984.
Lacroix, M.; Vezina, L.; Desjardins, S., et al. Comparison of identification methods for Erwinia and Pseudomonas species causing soft rot diseases. Phytoprotection 76:27–37; 1994
Leggatt, I. V.; Waites, W. M.; Leifert, C., et al. Characterization of microorganisms isolated from plants during micropropagation. Acta Hort. 255:93–102; 1988.
Leifert, C.; Pryce, S.; Lumsden, P. J., et al. Effect of medium acidity on growth and rooting of different plant species growing in vitro. Plant Cell Tissue Organ Cult. 30:171–179; 1992.
Leifert, C.; Waites, W. M. Bacterial growth in plant tissue culture media. J. Appl. Bact. 72:460–466; 1992.
Leifert, C.; Waites, W. M.; Nicholas, J. R. Bacterial contamination of micropropagated plant tissue cultures. J. Appl. Bact. 67:353–361; 1989.
Murashige, T.; Skoog, F. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15:473–497; 1962.
Norman, D. J.; Alvarez, A. M. Latent infections of in vitro anthurium caused by Xanthomonas campestris pv. dieffenbachiae. Plant Cell Tissue Organ Cult. 39:55–61; 1994.
Reed, B. M.; Buckley, P. M.; DeWilde, T. N. Detection and eradication of endophytic bacteria from micropropagated mint plants. In Vitro Cell. Dev. Biol. 31P:53–57; 1995.
Seabrook, J. E. A.; Farrell, G. City water can contaminate tissue culture stock plants. HortScience 28:628–629; 1993.
Singha, S.; Bissonnette, G. K.; Double, M. L. Methods for sterilizing instruments contaminated with Bacillus sp. from plant tissue cultures. HortScience 22:659; 1987.
Skirvin, R. M.; McMeans, O.; Wang, W. L. Storage water is a source of latent bacterial contamination in vitro. Plant Pathol. 1:63–65; 1993.
Stanier, R. Y.; Palleroni, N. J.; Doudoroff, M. The aerobic pseudomonads: a taxonomic study. J. Gen. Microbiol. 43:159–271; 1966.
Verniere, C.; Pruvost, O.; Civerolo, E. L., et al. Evaluation of the biolog substrate utilization system to identify and assess metabolic variation among strains of Xanthomonas campestris pv. citri. Appl. Envir. Microbiol. 59:243–249; 1993.
Viss, P. R.; Brooks, E. M.; Driver, J. A. A simplified method for the control of bacterial contamination in woody plant tissue culture. In Vitro Cell. Dev. Biol. 27P:42; 1991.
Wong, W. C.; Preece, T. F. Identification of Pseudomonas tolaasii: the white line in agar and mushroom tissue block rapid pitting tests. J. Appl. Bact. 47:401–407; 1979.
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Parts of this manuscript are included in a summary of a poster presented at the Second International Symposium on Bacterial and Bacteria-Like Contaminants of Plant Tissue Cultures, Cork, Ireland, September 1996.
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Tanprasert, P., Reed, B.M. Detection and identification of bacterial contaminants from strawberry runner explants. In Vitro Cell.Dev.Biol.-Plant 33, 221–226 (1997). https://doi.org/10.1007/s11627-997-0026-6
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DOI: https://doi.org/10.1007/s11627-997-0026-6