Allozyme investigations on the genetic differentiation between closely related pines - Pinus sylvestris, P-mugo, P-uncinata, and P-uliginosa (Pinaceae)

In eight natural European populations of four closely related taxa of pines (Pinus sylvestris, P. mugo, P. uncinata, and P. uliginosa) starch-gel elec trophoreses revealed altogether 58 alleles at 15 loci from nine enzyme syst ems. With Nei's genetic distance (D) the largest mean genetic distance (D = 0.171) was found between P. sylvestris and P. mugo, a distance correspondi ng to that between other closely related pine species. Mean genetic distanc es between the other taxa were less than half that value and characteristic for subspecies or varieties rather than for species. On the basis of our r esults we suggest that both, P. uliginosa and P. uncinata, could be the res ult of the ancient hybridization between P, sylvestris and P. mugo.