几种非豆科植物根瘤内生菌侵染特征的研究

自不同科、属、种的非豆科植物根瘤分离内生菌，对其寄主植物进行了交叉侵染，结果表明，这些Frankia菌对不同寄主的侵染没有明显的专一性，供试菌可以进行跨越科、属、种的侵染，但有的菌株对于某些植物的侵染，可能存在一些特殊情况，相同菌株对不同植物的侵染能力，以及不同菌株对同一寄主的侵染能力是有差异的。从同一种植物根瘤中分离的不同菌株，侵染能力也有高低之分，供试菌随寄主植物的改变，侵染能力及所建立的共生系统固氮活性有所降低，侵染原寄主植物所形成的根瘤固氮活性较高的菌株，在改变寄主后所形成的根瘤固氮活性也比较高，在一定条件下，寄主植物的结瘤量与根瘤固氮活性呈正相关，而侵染不同寄主后，根瘤中菌体孢子的表面结构也发生了一定变化。

STUDY ON INFECTIVITY OF THE NODULE ENDOPHYTE OF SOME NON-LEGUMINOUS N_2-FIXING PLANTS

Cross inoculations were made with Frankia spp.from the nodules of non-leguminous plants belonging to different families,genera and species.The results showed that there are no ap- parent host specificity in these strains.Under general cases,many strains can nodulate plants in different families,genera and species,but there also are some special results.Both infec- tive ability of the same strains on diffierent host and the different strains on the same host are different.Different isolates from the same host plant were found in certain cases to have various degrees of infectivity.If the original host plant was replaced by others,both these Frankia' infective ability and nitrogenase activity in new symbiotic system were lower.The strains that are higher N_2-fixing activity in the nodules of the original host also possess stron- ger N_2-fixing activity in the nodules of other hosts.Under test condition,there are positive corrlation between the number of the nodules of host plants and N_2-fixing activity of the root nodules.The morphology of the spores of the strains in the nodules of new host plant also change more or less.