Phylogenetic analysis of Petunia sensu Jussieu (Solanaceae) using chloroplast DNA RFLP.
OBJECTIVE
The phylogenetic relationships of Petunia sensu Jussieu (Petunia sensu Wijsman plus Calibrachoa) are unclear. This study aimed to resolve this uncertainty using molecular evidence.


METHODS
Phylogenetic trees of 52 taxa of Petunia sensu Jussieu were constructed using restriction fragment length polymorphism (RFLP) of chloroplast DNA digested with 19 restriction enzymes and hybridized with 12 cloned Nicotiana chloroplast DNA fragments as probes.


RESULTS
In all, 89 phylogenetically informative RFLPs were detected and one 50 % majority consensus tree was obtained, using the maximum parsimony method, and one distance matrix tree, using the neighbour joining method. Petunia sensu Wijsman and Calibrachoa were monophyletic sister clades in both trees. Calibrachoa parviflora and C. pygmaea, previously thought to differ from the other species in terms of their cross-compatibility, seed morphology, and nuclear DNA content, formed a basal clade that was sister to the remainder of Calibrachoa. Several clades found in the phylogenetic trees corresponded to their distribution ranges, suggesting that recent speciation in the genus Petunia sensu Jussieu occurred independently in several different regions.


CONCLUSIONS
The separation of Petunia sensu Wijsman and Calibrachoa was supported by chloroplast DNA analysis. Two groups in the Calibrachoa were also recognized with a high degree of confidence.
Ando
Toshio
T
Faculty of Horticulture, Chiba University, 648 Matsudo, Matsudo, Chiba 271-8510, Japan. andot@faculty.chiba-u.jp
Kokubun
Hisashi
H
Watanabe
Hitoshi
H
Tanaka
Norio
N
Yukawa
Tomohisa
T
Hashimoto
Goro
G
Marchesi
Eduardo
E
Suárez
Enrique
E
Basualdo
Isabel L
IL
D018742:DNA, Chloroplast / Q000235:genetics*; D005843:Geography; D009154:Mutation; D032306:Petunia / Q000235:genetics*; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D013020:South America
D018742:DNA, Chloroplast