Chloroplast DNA typing by PCR-SSCP in the Pinus pumila-P Parviflora var pentaphylla complex (Pinaceae)

Pinus hakkodensis has been considered as a hybrid between P. pumila and P. parviflora var, pentaphylla, Chloroplast DNA typing of this putative hybrid and hypothesized parental species in the Tanigawa Mountains, Japan, was conducted by PCR and single-strand conformation polymorphism (SSCP) of the intergenic spacer between trnL(UAA)3'exon and trnF(GAA) of cpDNA, Each of the hypothesized parental species collected from other mountain regions displayed a diagnostic SSCP pattern, whereas all morphological intermediates sampled in the Tanigawa Mountains had the SSCP pattern of P. parviflora var. pentaphylla. Furthermore, some individuals classified on the basis of needle morphology as belonging to P, pumila in this mountain region showed the SSCP pattern of P. parviflora var, pentaphylla. This may suggest that pollen-mediated uni-directional introgression from P. parviflora var, pentaphylla to P. pumila occurs in the Tanigawa Mountains.