Sequence characterized amplified region (SCAR) markers-based rapid molecular typing and identification of unninghamia lanceolata
Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) is the main timber and afforestation tree species in South China. C. lanceolata clones, with similar morphological characteristics, make their exact identification very difficult. A simple and effective method is required to distinguish these clones in the clonal selection and breeding of C. lanceolata. However, C. lanceolata clones have so far been identified only through traditional phenotypic analysis. In the present study, 20 C. lanceolata clones from different geographic provenances were collected and analyzed using randomly amplified polymorphic DNA (RAPD) technique. Nine polymorphic RAPD bands were cloned and sequenced. Six stable informative dominant sequence characterized amplified region (SCAR) markers were developed by designing six pairs of specific SCAR primers from six sequenced polymorphic RAPD bands, respectively. On the basis of the differences in SCAR phenotypes detected among the 20 C. lanceolata clones, 10 individual clones were identified from 20 studied clones at first, and the other 10 clones were divided into 4 distinguishable groups. Some C. lanceolata clones from the same geographic provenances were also distinguished from one another. The experiment was the first report that SCAR markers-based molecular method was used in the research on molecular identification of C. lanceolata. By developing and jointly using specific useful SCAR makers, rapid molecular typing of C. lanceolata clones was accomplished, which could be used as a tool for the identification of C. lanceolata clones.
Key words: Chinese fir, Cunninghamia lanceolata, tree breeding, SCAR markers, molecular typing, identification.