EFFICACY OF SYMBIOSIS FORMATION BY PEA PLANTS WITH LOCAL WESTERN UKRAINIAN STRAINS OF RHIZOBIUM

Abstract

The chemotaxic activity and the effect of nodule bacteria strains, isolated from pea plants (Рisum sativum L.) in Western Ukraine, on legume-rhizobium symbiosis efficacy were studied. Two nodule strains were selected, RRL8 and RRL9, and their effects on the plants were compared to plants treated with the standard collection Rhizobium leguminosarum 245а strain. Sucrose, aspartic acid, serine, glycine, and valine were the most effective attractants for the selected bacteria strains among the various carbohydrates, organic acids and amino acids tested. Seeds inoculated with RRL8 and RRL9 isolates showed higher plant wet mass and number of nodules in comparison to controls and to plants inoculated with the 245a strain. The concentration of chlorophyll a at the budding stage in plants inoculated with the RRL9 strain was higher than that of control and 245a inoculated strain plants. Treatment of pea seeds by local and 245a strains did not affect the anthocyanin concentration in leaves over the whole ontogenesis period of the pea plants. At the stage of 4-5 leaves in pea plants inoculated with RRL8 and 245а strains starch content was lower than that in control. Maximum pea grain crop was observed in plants inoculated with the RRL8 bacterial strain. It can be concluded, that pea nodule bacteria form an effective legume-rhizobium symbiosis and use of the local strains gives an increase in harvest under local climatic and soil conditions, which are the natural ecological niche for those bacterial strains.