The components of leghaemoglobin (Lb) from twelve different Pisum sativum L. cvs and three near-isogenic foliar mutants were investigated by anion-exchange high-performance liquid chromatography (HPLC). Five different Lb component profiles could he found. The number of components varied from four to six dependent on cultivar used. An Lb pattern composed of four Lb components could be detected in thirteen P. sativum cultivars and lines. Ten of them showed an identical profile. In nodules of each cultivar, the two known major components, LbI and LbV, but also LbIV, could be detected. Additionally, cultivar-specific Lb components could be identified, each representing up to 10%, of total Lb. One of these components, LbIII, has been described previously, but three new Lb components (LbII, LbVI, and LbVII) were found. The presence of all Lb components detected by HPLC was confirmed by analytical isoelectric focusing. Further, it was shown that age-dependent changes in the relative concentrations of LbI and LbV are common in P. sativum and that these variations are independent of breeding lines and cultivars.
Keywords: Pisum sativum (pea); leghaemoglobin (Lb) components; nitrogen fixation.