Vicia faba cv. Aguadulce was grown in fumigation chambers ventilated with filtered air or air containing sulphur dioxide (SO2) at controlled concentrations, and inoculated with the rust fungus Uromyces viciae-fabae. The influence of the pollutant was rated in terms of production of uredia and dehiscent urediospores. Exposures to SO2 levels around 70-90 nl litre-1 enhanced uredia density. Pre-inoculation fumigations at 70-86 nl litre-1 increased uredia density, whilst post-inoculation fumigations stimulated urediospore production. Lower concentrations increased diffusion resistance of the host plant and slightly increased uredia density. Concentrations between 100 and 130 nl litre-1 were somewhat inhibitory for the parasite, even in the absence of any visible damage symptoms on the host. Total sulphur accumulation in leaf tissue was reduced by the presence of the fungal infection. Growing under SO2 pollution neither decreased germination ability nor modified morphological parameters of the urediospores. However, elongation of the germination tube of spores coming from filtered air was adversely affected by the pollutant.
The effects of sulphur dioxide on the parasitism of the rust fungus Uromyces viciae-fabae on Vicia faba
LORENZINI, GIACOMO;GUIDI, LUCIA
1990-01-01
Abstract
Vicia faba cv. Aguadulce was grown in fumigation chambers ventilated with filtered air or air containing sulphur dioxide (SO2) at controlled concentrations, and inoculated with the rust fungus Uromyces viciae-fabae. The influence of the pollutant was rated in terms of production of uredia and dehiscent urediospores. Exposures to SO2 levels around 70-90 nl litre-1 enhanced uredia density. Pre-inoculation fumigations at 70-86 nl litre-1 increased uredia density, whilst post-inoculation fumigations stimulated urediospore production. Lower concentrations increased diffusion resistance of the host plant and slightly increased uredia density. Concentrations between 100 and 130 nl litre-1 were somewhat inhibitory for the parasite, even in the absence of any visible damage symptoms on the host. Total sulphur accumulation in leaf tissue was reduced by the presence of the fungal infection. Growing under SO2 pollution neither decreased germination ability nor modified morphological parameters of the urediospores. However, elongation of the germination tube of spores coming from filtered air was adversely affected by the pollutant.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
