Anaerobic stimulation of root exudates and disease of peas

Abstract

The relationships between root exudation, root disease and anaerobic root stresses were investigated. Sand culture and mist chamber studies demonstrated that low O2 and high CO2 reduced plant growth and increased the exudation of ethanol, amino acids, and sugars by pea roots. The relative loss of ethanol by roots was much greater in treatments with atmospheres of N2 containing 30% CO2 than in treatments of air containing 30% CO2 or N2. Ethanol was not detected in the nutrient solution of aerated plant roots. Atmospheres of N2 plus 30% CO2 caused 500% greater mycelial growth ofFusarium solani f. sp.pisi and 400% more disease of inoculated pea roots. Relative losses of four amino acids and four sugars were much greater in atmospheres of N2 plus 30% CO2 than in N2 or air.