2.4 Phylogenetic analysis
The chloroplast genomes of the eight species of Chinese Cyatheaceae were
compared globally, and the phylogenetic trees were constructed with four
methods (ML, BI, MP, and NJ) using Cibotium barometz (Linn.) J.
Sm. as an outgroup, as shown in Figure 2. The topologies of the four
trees were consistent, except that the support rate of the branches of
the Alsophila denticulata and Alsophila gigantea was lower
(the bootstrap values of ML, MP, and NJ were 55%, 59.2%, 99%,
respectively, and the posterior probability of BI was 0.935). The
support rate of the other branches was higher (the bootstrap values of
ML, MP, and NJ were all 100%, and the posterior probability of BI was
1.00). Closely related Sphaeropteris brunoniana andSphaeropteris lepifera were clustered into one branch, which was
located at the base of the phylogenetic tree. That means they were an
earlier-diverged group in this family. Alsophila denticulata ,Alsophila podophylla , Alsophila gigantea , andAlsophila metteniana were clustered into one branch, which was
located inside the branch of Sphaeropteris brunoniana andSphaeropteris lepifera and was a sister group of the branch
formed by Alsophila spinulosa and Alsophila costularis .