ISSN:
1573-8469
Keywords:
biocontrol
;
hydroponics
;
Pythium aphanidermatum
;
Pythium ‘group F’
;
Pythium oligandrum
;
Pythium periplocum
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Hydroponically grown cucumber (Cucumis sativus) seedlings were inoculated with zoospores of 1 mycoparasitic (Pythium oligandrum) and 2 pathogenic (Pythium aphanidermatum and Pythium ‘group F’) Pythium spp. During the first 2 days after inoculation, all the Pythium spp. caused reduction in the root length. However, roots treated with Pythium oligandrum quickly reached the length of the control and on the 8th day, and for the rest of the experimental period, stimulation of root elongation was noted. Pythium oligandrum was not pathogenic on cucumber and no differences in the fresh weights of control and Pythium oligandrum inoculated plants were observed in the course of the experiment. Pythium ‘group F’ and Pythium aphanidermatum were pathogenic on cucumber seedlings, but their pathogenicities differed. Thus, while Pythium ‘group F’ had a constant, negative influence on root length and plant growth, measured as fresh weight, Pythium aphanidermatum caused generalized necroses of the root system, inhibiting consistently root elongation and plant growth and finally causing plant death. Moreover, the zoospores of 2 mycoparasitic species, Pythium oligandrum and Pythium periplocum, were not attracted to roots of cucumber and accumulated on the roots in very low numbers compared to those of the pathogenic species, Pythium aphanidermatum, which were strongly attracted and accumulated in large numbers. Finally, it was also found that Pythium oligandrum colonized the roots very poorly, while Pythium ‘group F’ and Pythium aphanidermatum were significantly better root colonizers. The significance of these findings is discussed in relation to the ecology of Pythium species and biocontrol.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008662927507
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