Bayesian phylogenetic tree of the PR-10 sequences from B. pendula. Bayesian phylogenetic tree of the PR-10 sequences from B. pendula 'Schneverdinger Goldbirke' (Sv), 'Tristis' (Tr), and the B. pendula alleles from 'Long Trunk' (Lt). The 'Long Trunk' alleles that belong to the unknown parental species are not included in this figure. Numbers on the branches represent posterior probabilities after running a Markov chain Monte Carlo search for 1,000,000 generations. Sequences of PR-10 genes from Malus domestica (apple, X83672, Z72425, Z72427), Prunus armeniaca (apricot, AF020784), P. avium (cherry, U66076), and Pyrus communis (pear, AF057030) were used as outgroup. Each cluster that is identified as a putative gene has maximally two alleles per cultivar. Genes are classified into five major groups. The intron length is indicated on the right. If multiple introns of the same length exist within one group, the different types are shown between brackets. *1 PR-10.03B02.01 from 'Tristis' was an in vivo recombination of the PR-10.03D gene and the original PR-10.03B gene.