Hybrid Origin Of Camellia Reticulata Based On Multiple DNA Fragments

Camellia reticulata has a long history of cultivation in China, is the famous ornamenta plant belongs to the sect Camellia, which as famous as the Camellia japonica. Therefore, clarified the origin of the C. reticulata could enriched the theory of hybrid species of angiosperms and promoted the usage of C. retiulata. In this paper, we selected C. reticulata and related species as samples and tried to elucidate the relationships between C. reticulata and its related species based on molecular markers including several DNA fragments. Besides, we optimized the amplified fragment length polymorphism (AFLP) reaction system.The main results were as follows:1. ITS copies existence of a high degree of intra-genomic polymorphism and includes the pseudogenes in Camellia. ITS pseudogenes displaying lower GC content and unstable secondary structure were preferentially amplified under normal PCR conditions. Functional ITS copies were successfully obtained under the modified PCR conditions.2. A further analysis of the functional ITS copies, we proved that C. reticulata were originated from hybridization between C. pitardii and C. saluenensis, and closely related to Cmairei and C. polyodonta.3. There are three types of waxy sequences in genome of C. reticualta (hexaploid), may be derived from C. reticulata (diploid) and C. pitardii and C. saluenensis respectively.4. Chloroplast sequences (trnL-F and matK) were used to infer the origins of the C. reticualta (hexaploid). We had further evidence that different individual of C.reticualta (hexaploid) had different maternal origin.5. AFLP (amplified fragment length polymorphism) analysis system of suitable for C. reticulata was established. The establishment of AFLP reaction system would provid a foundation for the diversity research of C. reticulata.