The Genetic Stability of Frankia after Cross Inoculation

The Frankia-actinorhizal plant root symbiosis occurs in 8 families of angiosperms.Phylogenetic analyses show that Frankia can be defined as 4 chades and a close relationship appears between the hosts and Frankia clades.Though there have been many studies on cross inoculation of Frankia,no reports showed gene variation after inocuation.Nodules of A.nepalensis from Dali were inoculated to Alnus nepalensis seedlings from Kunming and Wuding,the nodules were collected and reinoculated to new seedlings for several times.seedlings nodules of A.nepalensis and A.ferdinandi-coburgii from Wuding were done the same inoculation in the experiment.After inoculation,Frankia 16 S rRNA genes in seedlings nodules were amplified,and analyzed with ARDRA technique.The results show that the ARDRA band pattern of Frankia 16 S rRNA gene in inoculating nodules was the same as in the original seedlings nodules.