Studies On The Wild Legume Herbage Rhizobia And Nitrogen Fixation Ability

From the northeast saline lands meadow, we gather different periods' M.sativa,Mcdilotus albus,V.acpium, Astragalus adsurgens Pall,Lathyrus pilosus and so on,seven specials of legume pastures nodule samples, They were tested infecting in 7 species as host. The main results obtained from this work are as follows:1.Although at the different physiology periods ,the legume pastures have different nodule quantity and nodule activity, but in total the Mcdilotus albus, M.sativa, nodule amount > Lathyrus pilosus, V.acpium nodule amount > Astragalus adsurgens Pall nodule amount.2.Physio-biochemistry characteristics of the strains were systematically studied, through Congo red medium experiment, beef-extract peptone medium experiment,3 keto-letose medium experiment, citrate medium experiment? Rizobium and other Agrobacterium which can be easily confused with Rizobium are separated. For BTB-reaction , M.sativa, Mcdilotus albus, V.acpium rhizobia were acid producing , Astragalus adsurgens Pall were alkali producing. As for the reactions on litmus milk , M.sativa, Mcdilotus albus, V.acpium rhizobia were acid, producing , Astragalus adsurgens Pall were alkali producing. So, M.sativa, Mcdilotus albus, V.acpium rhizobia can be divided to Rhizobium , Astragalus adsurgens Pall can be divided to Bradyrhizobiura.3.Through the salt tolerance experiment and alkali resistance experiment, finding out that the specials of rhizobia, which were separated from the northeast saline lands meadow can grow in 10%-15% salt-concentration, seven specials of rhizobia strain all can grow in a wide PH-scope. Especially they were antibase. 4. The azotase activity of seven legume pastures nodule specials are generally low, Mcdilotus albus is the highest, reached 16.40 umolC₂h₄/g· h on July. The azotase activity's whole change tendency is May > June > July. The reasons which influence the azotase activity are a lot, but arid and hypothermy maybe the main reasons. Arid soil impaired the development of root hair to make infection confined. Besides, the ability of every plant to resist adversity is different , so the difference of azotase activity of legume pastures nodule between every plant is exist. Adopting the radicalsoil of the legume pasture to determine the siitrogen content, results show that the azotification ability of the legume pasture are stronger than the non-legume pasture, among them, Mcdilotus albus is the most strongest, Astragalus adsurgens Pall, M.sativa are the next in order, V.acpium, Lathyrus pilosus are poor. Under natural conditions, with the difference of plant's life habit, their nodule vigor are also different. But even the same kind of plant and the same life habits, their nodule vigor are also different with different distribution sitesoTherefore, azotification ability of the nodule is close with environmental conditions and comparatively weak contact with life habits of plants.