<正>为探讨外生菌根的形态及根毛生长状况对宿主生长的影响，分别对黑松接种3种不同外生菌根菌进行研究，观察菌根形态，并对菌根根段进行透明染色后观察根毛的生长发育程度及菌套、哈氏网的分布状况。结果表明：黑松与不同外生菌根菌形成的菌根形态各异，黄色须腹菌（R1）和彩色豆马勃（Pt，）的菌根以多头状分支、二又分支、多级二叉分支为主，美味牛肝菌（Be）的菌根多见二叉分支和顶端明显膨大的棒状。菌根的形态与黑松生长状态似无明显相关性。黑松不同外生菌根根段上均可观察到根毛，且根毛的生长发育状态与菌根菌对黑松的促生作用具有一定相关性。在生长较好的Rl和Pt2菌根化松苗中具根毛的菌根段所占比例较高，且在根毛生长区可同时观察到较多哈氏网菌丝；而在Be菌根苗和对照菌根中，具根毛的菌根段相对较少，在根毛生长区很难观察到根内哈氏网，且杂菌较多。

To study and make full use of Rhizobium diversity in east-area of China, the full length 16S rDNA sequences of 23 Rhizobium strains isolated from leguminosae woody plants in east China area were tested. At the same time, those of selected strains downloaded from GenBank were compared. The phylogenetic tree was therefore constructed. The analysis result was consistent with those from morphology. The taxonomic position of 23 Rhizobium strains was determined.