ALLOZYME VARIATION AND PHYLOGENETIC RELATIONSHIPS IN TWO-NEEDLE PINES OF THE RUSSIAN FAR EAST

摘要

Genetic variation and differentiation in four Scots pine natural populations (Pinus sylvestris L.), five funeral pine populations (P.funebris Kom.) and two Japanese red pine populations (P. densiflom Sieb. et Zucc.) occurring in the Russian Far East were studied on the basis of analysis for 24 allozyme loci. The genetic distances separating P. sylvestris, P. funebris and P. densiflora show close relation P. funebris and P. densiflora (mean D_N= 0.033). Funeral pine had admixtures of allozymes from both P. sylvestris and P. densiflora. The present results suggest that funeral pine can be regarded as a Japanese red pine variety of hybrid origin. The intrapopulati on genetic variation values exhibited by marginal populations of the Far Eastern two-needle pines were lower than those exhibited by the populations from the central segments of the pines' distribution areas. This was supported by the data on the marginal coniferous populations obtained earlier. The level of genetic variation exhibited only by the two northern hybrid populations located in close proximity to the P. sylvestris' range appeared to be in general higher than those exhibited by the both parent species. Lower levels of intrapopulation variation in the southern hybrid populations in comparison with those in the northern ones may be explained by gene drift and limited gene flow due to small sizes and scattered distributions of the hybrid populations assayed.