Molecular Systematics Of Ficus Sect. Ficus(Moraceae) In China

Ficus, one of the largest and most diverse genera of flowering plants, is the key member of tropical and subtropical flora in Asia, Africa and Neotropic, and also the largest genus of Moraceae. All species in Ficus are easily distinguished from other species by the characters of its distinctive inflorescence, ringlike scar of stipules and latex. But the subdivision of Ficus has been problematic. Section Ficus belonging to subgenus Ficus comprises worldwidely distributed35species of which27can be found in China. This study sampled22species and73samples representing sect. Ficus, and37species and41samples representing other sections in Ficus as ingroups, as well as two taxa, Antiaris toxicaria Lesch. and Artocarpus altilis (Park.) Fosb., as outgroups. Three plastid regions, trnH-psbA, psbK-psbl and atpF-atpH, and one nuclear ribosomal DNA region, ITS, were amplified (including380sequences,25of which were retrieved from GenBank). Three analytical methods were used to reconstruct phylogenentic relationships of section Ficus. The major conclusions are as follows:1. Section Ficus is not monophyletic and its two subsections are not close relatives. Subsection Ficus is closely related with section Conosycea belonging to subg. Urostigma; subsection Frutescentiae, excluding two species (F. pedunculosa and F. neriifolia) still needing reconfirmation by further study, is monophyletic, but infrasubsectional relationship is not consistent with morphological classification, namely that the F. deltoidea-group is paraphyletic with F. pedunculosa-group.2. F. tuphapensis has been included in sect. Eriosycea. This study indicates that F. tuphapensis obviously belongs to subsect. Frutescentiae(sect. Ficus), gaining support from morphological characters.3. F. tikoua shows sister relationship with species belonging to subg. Sycomorus and its position of fig occurring is homologous to the character of subg. Sycomorus. So we suggest that F. tikoua should be transferred to subg. Sycomorus. 4. Corner (1965) put F. henryi and F. subincisa in sect. Ficus. But Berg (2003e) transferred them to subg. Sycidium based on characters of the staminate flowers, distichous leaves and the not fully amplexicaul stipules. This study confirms Berg’s taxonomic deposition.5. Corner (1965) put F. langkokensis in sect. Ficus. This study is in accordance with Berg’s taxonomic idea (Berg&Corner,2005) that F. langkokensis could be transferred to sect. Eriosycea based on the diagnostic occurrence of cystoliths in the laminas.