Growth of Scots pine seedlings and Armillaria ostoyae rhizomorphs under elevated air CO2 concentration conditions
Comparative cultivation experiment was carried out to verify the assumed positive dependence of the rate of growth of Scots pine (Pinus sylvestris L.) seedlings on the elevated (750 ppm) level of CO2, as well as its negative dependence on the presence of an inoculum of Armillaria ostoyae (Romagn.) Herink. Eight months after germination, 5 months after the introduction of the A. ostoyae inoculum and 4 months after the raising of CO2 concentrations in the air, most values for the analyzed biometric features of Scots pine seedlings were found to be significantly higher than those in the control CO2 conditions(ambient air at approximately 380 ppm). Width at the stem base was significantly higher of 0,08 mm, dry mass of roots – of 15,69 mg and dry mass of stem – of 12,01 mg. No effects of the introduced pathogen inoculum on seedling growth were recorded either in the control, or at the elevated CO2 concentration in the air. In a great majority of seedlings subjected to inoculation, no root contacts with rhizomorphs or infections were noted, except for a very few cases with elevated CO2 concentration. The production of A. ostoyae rhizomorphs was also found to be significantly and positively dependent on higher CO2 concentration. These initial results indicate that the pathogen-host relationship at elevated CO2 concentration and longer cultivation time needs further studies with the application of older plants to overcome the experiment’s limitations.
|Type of article