Molecular phylogenetics of bromeliaceae:: Evidence from trnL(UAA) intron sequences of the chloroplast genome

Phylogenetic relationships within Bromeliaceae were assessed by comparative sequencing of chloroplast trnL(UAA) intronic DNA. Sixty-seven taxa were analyzed, encompassing 62 species, hive subspecies and two varieties from 32 bromeliad genera. One representative of Rapateaceae and two of Velloziaceae were used as outgroups. Introns were amplified by the polymerase chain reaction and conserved flanking primers. Amplification products were sequenced directly. Of 700 base pairs total trnL (UAA) intron size, 551 bp could be unambiguously aligned. Sequence divergence among ingroup taxa ranged From zero to 4.6%. Phylogenetic reconstruction by parsimony analysis of 73 informative base substitutions yielded 1092 most parsimonious trees. The topology of the resulting strict consensus tree was only partially consistent with current classification schemes. Brocchinia and Ayensua grouped close together and formed a well-supported basal clade, suggesting a sister group relationship of both to the remainder of the family. The remaining ingroup species were divided into an unresolved polytomy of three lineages, comprising (1) all members of subfamily Tillandsioideae, (2) the three investigated Hechtia species, and (3) all Bromelioideae and the remaining Pitcairnioideae (except Brocchinia, Ayensua and Hechtia). The latter clade was split into another polytomy of five sublineages, one of which comprised all Brometioideae. Whereas monophyly of Tillandsioideae and Bromelioideae was supported by trnL intron data, Pitcairnioideae as traditionally circumscribed are clearly polyphyletic. There is evidence that the genera Tillandsia, Vriesea, Guzmania, Abromeitiella. Deuterocohnia, Dyckia, Pitcairnia and Aechmea in the present circumscription are not monophyletic.