Seventeen percent of cucumber plants grown in a Uzbek greenhouse were diseased. The major cucumber and tomato pathogens of Uzbek agricultural soils were identified as strains of Fusarium solani. Fifty two beneficial bacteria from collections of our institutes were screened for their ability to promote growth and/or to control diseases caused by F. solani on cucumber and tomato plants. The five best strains were used in large scale greenhouse trials. Four out of five strains significantly controlled cucumber foot and root rot, reducing the percentage of diseased plants from 54% in the negative control to between 10 and 29% in bacterized plants. All five strains increased the dry weight, by 29 up to 62%. In two consecutive years all five strains significantly increased the plant height (by 4 to 15%) as well as the fruit yield (by 12 to 32%). Tests of plant-beneficial traits suggest that auxin production, antibiosis and competition for nutrients and niches are mechanisms involved in the observed plant growth stimulation and biocontrol. The results with tomato were similar. We conclude that many beneficial bacteria isolated from plants grown on non-salinated soil are perfectly able to promote plant growth and control plant diseases in salinated soil. In other words, salination caused by a possible future climate change does not seem to be a threat for the application of presently used plant-beneficial bacteria. In addition, our results show that the dogma that beneficial strains should be isolated from the plant and climate on/in which they should be applied is not valid: all our strains were isolated from plants other than cucumber and came from cold or moderate climates.
|Publication status||Published - 2012|
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