STUDIES ON SYMBIOTIC NITROGEN FIXATION OF NON-LEGUMINOUS PLANTS Ⅱ. ISOLATION AND INOCULATION OF ROOT NODULE ENDOPHYTE FROM HIPPOPHAE RHAMNOIDES
Du Dazhi;Wang Yiyan;Cui Guoliang Shanxi Institute of Biology, Taiyuan
A number of strains of actinomyceteswith sporangia have been isolated from theroot nodules of Hippophae rhamnoides L.by tissue culture. Their mycelia are sep-tate, branched, and swollen into millet -ear-like sporangia. These sporangia release sphe-ricle or elliptical sprangiospores during rup-ture. During bursting, the mycelia becomebacteroid-like cells of varied shapes, whichare much like the endophyte observed bythe smearing method of root nodules. Backinoculation experiments demonstrated itsability of infecting young roots of H. rham-noides. The root nodules were formedfrom 8 days to 6 months after inoculation.The nodules were formed on all testedplants. Microscope and scanning electronmicroscope observation proved that the rootnodules and the endophyte both were similarto the natural ones. The nitrogenase activi-ty reached to 36.23 n mol C_2H_4/g.f.wt./min.The height of plants increased by 47.2%,branching number increased by 1.8 times,weight of dry substance above ground inc-reased nearly by three times, and the contentof nitrogen increased by 77.9%. As compar-ed with the uninoculated plants as control itis therefore concluded that the strain HR104 is a true endophyte of H. rhamnoides.