Effect of boron on nitrogen fixation and carbohydrate content in faba bean (Vida faba L.)‎

Abstract EN

One variety (blandine) and two pure lines of faba bean were cultivated in a greenhouse with a nutrient solution containing three boron concentrations : 0, 2 and 32 mg b i" 1.

the growth of the root system and nodulation, symbiotic fixation activity and modifications of leaves soluble sugars content were determined.

deficiency and excess of boron resulted in the restriction of root growth, diminution of the fresh weight of nodules per plant and acetylene reduction activity (ARA) level.

absence of boron in the nutrient solution I resulted in an accumulation of soluble sugars in leaves, particularly sucrose.

the negative effect of boron deficiency could be explained by a limitation of carbon supply to the nodules as well as by its direct effect on the ARA activity of nitrogenase.

boron toxicity may affect the activity of this enzyme by its antagonistic effect on molybdenum and/or by its effect on the availability of magnesium.