REPRODUCTIVE CAPACITY OF BACTEROIDS Ⅱ. IN NODULES OF GLYCINE MAX (L.)MERR.
Zhou Jun chu
Reproductive growth of bacteroids from protoplasts, as well as fromsuspsions of crushed nodules of soybean, was regularly observed directly inmicrochamber and determined as colony-forming ability (CFA) on labora-ory media. 1. Immaturc bacteroids (2 weeks after inoculation) with very low CFAare long thin rods, mature (5-week old nodule) with changeable CFA aresimilar to cultured brady-rhizobia. 2. Bacteroids from mature nodules were able to reproduce, their CFAincreased with the age of nodule and conditions of isolation. 3. The favourable conditions for bacteroid growth are distilled water orPDB-(as diluting solution), BMM(as medium) and pH 5.0-7.0. 4. A heat-hbile extract from soybean nodules and roots-increased therecovery of bacteroids marketly. Yeast extract and 5 vitamins did not showthis effect. 5. Osmoprotection(provided by the concentration of mannitol either 37g/lin BMM or 0.5M/l in PDB) Was not beneficial and even detrimental for thegrowth of bacteroids. 6. The growth from bacteroids was followed and recorded by microcham-ber incubation with video recording. Generation time of bacteroids was progre-ssively reduced and became identical with the cultured bradyrhizobium afterlst divition. 7. The identity of nodule bacteroids and isolates with the tested strainwas proved by fluorescent antibody technique.