|Joung, Young hee|
Submitted to: Forest Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/8/2005
Publication Date: 12/15/2005
Citation: Joung, Y.H. and Roh, M.S. 2005. Mapping characterization of Pinus sylvestris var. sylvestriformis based on chloroplast DNA microsatellite markers. Forest Genetics. 12:89-98. Interpretive Summary: The genus Pinus, which includes approximately 100 species, is one of the most widely distributed genera in the Northern hemisphere. Pinus sylvestris (Ps) var. sylvestriformis occurs in a very limited region around Baihe, Jilin Province, China where it grows mostly at elevations of 800m, partly overlap with Ps. var. sylvestris which has the most extensive continuous range of all species in this genus. Pinus sylvestris L. var. sylvestriformis (Taken.) is often treated as an intermediate between Ps var. mongolica Litvinov and P. densiflora (var. densiflora) Sieb. et Zucc. Some variations in branch forming characteristics were observed from about 300-year old plants, one group of plants resembling P. densiflora var. densiflora while others Ps var. sylvestris. Using DNA fingerprinting techniques, such as random amplified polymorphic DNA (RAPD) and chloroplast DNAs simple sequence, existence of genetic variability in Ps var. sylvestriformis population was documented and it is suggested that both P. densiflora var. densiflora and Ps var. sylvestris are considered as the paternal source. Consequently, Ps var. sylvestriformis are referred to as P. densiflora x sylvestris, rather than an infraspecific taxon of either one or the other parental species.
Technical Abstract: Molecular markers generated by random amplified polymorphic DNA (RAPD) and chloroplast DNA simple sequence repeats (cpDNA SSR) were used to document polymorphisms in Pinus sylvestris (Ps) var. sylvestriformis and to identify putative parental species that include P. densiflora (Pd) var. densiflora collected from Korea (Pd-K) and from China (Pd-C), and Ps var. sylvestris and Ps var. mongolica. Pinus sylvestris var. sylvestriformis had the species specific RAPD markers of Pd-K. Dendrogram constructed using RAPD markers showed that Pd var. densiflora (Pd-K and Pd-C) and Ps var. sylvestriformis grouped together in the major cluster and all other varieties of P. sylvestris clustered separately. Ps var. sylvestriformis showed a close affinity to Pd-K, rather than to Pd-C. In cpDNA SSR analysis, polymorphisms at nine loci (Pt1254, 15169, 26081, 30204, 36480, 45002, 63718, 71936, and 102584) were detected from all species. Most marker sizes overlapped between Pd-K and Ps var. sylvestris except loci at Pt15169 and Pt30204. Therefore, these two cpDNA SSR markers were used for paternity test of Ps var. sylvestriformis. The sequence analysis of cpDNA SSR at loci Pt15169 and 30204 revealed that that pollen source of Ps var. sylvestriformis are composed of Pd-K which has polyT-C-polyA-polyG type cpDNA SSR and of Ps var. sylvestris which has polyT-polyA-polyG type without C between polyT and polyA and CTAT in SSR. This is the first report which confirms the existence of genetic variability in Ps var. sylvestriformis population based on the sequence analysis. It is suggested that both Pd-K and Ps var. sylvestris are considered as the paternal source. Consequently, Ps var. sylvestriformis are referred to as P. densiflora x sylvestris, rather than an infraspecific taxon of either one or the other parental species.