Genetic Diversity Of Frankia In Fujian

Frankia is a kind of actinomycete which has ability to fix nitrogen and form nodules on the roots of many non-leguminous woody plants. It can infect host plants of different families, genera and species, and it has a unique mechanism of preventing nitrogenase far from oxygen. So the symbiotic nitrogen fixation system was sugested to have more superior than symbion of rhizobia-legume plants.The classification above genera of Frankia has been confirmed, but it keeps confusing under genera's level. The study on genetic diversity of Frankia will improve the utilization of this nitrogen fixation symbiotic system.In this thesis, genetic diversity of Frankia strains and endophyte co-exist in the nodules were discussed from both morphology and DNA molecular polymorphism. The result indicated that Frankia in Fujian had a wide genetic diversity.The genetic diversity of Frankia has no relation to host origin and the site. Analysis of DNA molecular polymorphism has more superior than morphology in distinguishing of Frankia.