Differences Between Georgian and French Wild Cherry Populations and Consequence for Wild Cherry Breeding Programmes

摘要

For the first time, the diversity of wild cherry in Caucasia was sampled: 5 populations of Georgia, together with 11 French populations. 23 alleles from 7 isozyme loci were scored, among them 6 new alleles in Georgia. Though the total number of alleles was higher in Georgia (A = 2.4) than in France (A = 2.0), the diversity was higher in France (H_e = 0.324) than in Georgia (H_e = 0.284). A higher level of differentiation was found in France (F_st = 0.094) than in Georgia (F_st = 0.057), and the total F_st was even higher (0.108). Mean pairwise distances inside the French group, the Georgian group and between the two groups were 0.054, 0.037 and 0.094, respectively. The Pearson’s correlation coefficient between genetic and geographical distances was 0.58 (p = 0.014) between France and Georgia, which indicated a moderate pattern of isolation by distance. The number of migrants after correction of size was high among the French populations (Nm= 7.6) and even higher among the four nearby Georgian populations (Nm= 32), but it was very low between the pooled French populations and the pooled Georgian populations (Nm= 0.33). Georgia in Caucasia, as an extreme country in the distribution area, can be considered as a source of neutral gene diversity for wild cherry, and thus may also be one for adaptative gene diversity we could use to increase the genetic base of our western country wild cherry breeding populations.