Soybean N2 fixation estimates, ureide
concentration, and yield responses to drought.
Sap was collected at the pod-fill stage by Vacuum Extraction Method and stored in the freezer at -15degC, then concentrations of ureides
, nitrate and amino-N were determined to calculate the relative ureide
- N (%) and percent nitrogen derived from atmosphere (% Ndfa) by the following formula:
Sicardi M, Izaguirre-Mayoral ML (1993) Ureide
content and growth of cowpea (Vigna unguiculata (L) Walp var.
An additional finely ground biomass subsample was analyzed for total ureide
content using the following procedure.
However, a recent study showed that ureide
metabolism was also involved, because urea was found to be a product of ureidoglycolate degradation in different organs of chickpea (Munoz et al.
It has been suggested that oxalate accumulation in soybean seeds might be the result of ureide
catabolism (Ilarslan et al.
Inheritance studies using ureide
accumulation (Kueneman et al.
concentration is multiplied by four because there are four N atoms in the ureide
Recent studies have focused on ureide
accumulation and feedback on nodule activity as being crucial in influencing soybean [N.
degradation rates in leaves may be particularly important in the expression of [N.
Decreased volumetric flow of phloem supply to nodules would decrease the amount of water available for ureide
export in the xylem (Walsh et al.
In their study, Jackson also was found to have the lowest level of xylem-sap ureide
concentration among eight cultivars that were compared.