Phylogeny of inferred from nine chloroplast, mitochondrial and nuclear loci

LI-BING ZHANG and SUSANNE S. RENNER. Department of Biology, University of Missouri-St. Louis, St. Louis, MO 63121. Email: [email protected]; [email protected]

Based on rbcL (Setoguchi et al. 1999; Schwarzbach & Ricklefs 2000), Cucurbitales comprise Anisophylleaceae, Begoniaceae, Coriariaceae, Corynocarpaceae, , Datiscaceae, and . To further investigate the position of Anisophylleaceae and to approp- riately root a large molecular phylogeny of Cucurbitaceae, we are investigating family relationships in Cucurbitales. Previous molecular data have identified Fagales as the sister clade to Cucurbitales, but prior to our project, Anisophylleaceae had been weakly sampled and only sequenced for rbcL, which provided limited support for the monophyly of Cucurbitales. We have combined nuclear 18S, the chloroplast genes atpB, matK, ndhF, and rbcL, the trnL intron, the rpl20-rps12 and trnL-trnF spacers, and the mitochondrial nad1 b/c intron (together 9302 aligned bp) for 25 representatives of the ingroup families and two fagalean outgroups. Cucurbitales are strongly monophyletic, and Anisophylleaceae are sister to the remaining families, which form a Marah fabaceus trichotomy of (1) Cucurbitaceae, (2) Coriariaceae and Corynocarpaceae, and (3) Begoniaceae fallax (Datiscaceae, Tetramelaceae). The relationship between the last three families has also been addressed with restriction site and ITS data (Rieseberg et al., 1992; Swensen et al., 1998),as well as morphology, which indicated a close relationship of Datiscaceae and Tetramelaceae. With the exception of a few Coriariaceae and Corynocarpaceae, Cucurbitales all have unisexual , and are usually monoecious, with repeated shifts to dioecy in Begonia, Cucurbitaceae, cannabina, and Tetramelaceae. Because molecular data do not yet resolve family

Photo: G. E. Schatz Photo: P. Endress relationships in the Cucurbitales, it is unclear whether the few perfect- flowered Coriariaceae / Corynocarpaceae represent lines or reversals from unisexual to perfect flowers. The latter is exceedingly rare, and we are currently exploring additional DNA markers specifically to resolve their position in the order. Juglans nigra Anisophylleaceae Cucurbitaceae Fagus grandifolia

94 Anisophyllea corneri Corynocarpus laevigatus 95 Anisophyllea obtusifolia Begonia evansii Anisophylleaceae 100 Anisophyllea fallax

Combretocarpus rotundatus

100 Begonia herbacea 100 Begonia oxyloba Begoniaceae Hillebrandia sandwicensis 100 100 Datiscaceae

Photo: G. C. Linney sumatrana 100 Tetramelaceae Photo: B. Glick nudiflora

Coriaria ruscifolia 100 Coriariaceae 100 Coriaria sarmentosa

Corynocarpus laevigatus Corynocarpaceae

Coccinia sessilifolia 100 Begoniaceae Corynocarpaceae Lagenaria brevifolia

Dendrosicyos socotranus

100 Gurania megistantha 100 100 Seyrigia humbertii Datisca cannabina Ecballium elaterium Cucurbitaceae

Marah macrocarpus

100 96 Schizopepon bryoniifolius

50 changes 98 Gynostemma pentaphyllum Neoalsomitra sarcophylla 88 Xerosicyos danguyi

(Single most parsimonious , CI = 0.72 RI =0.79 bootstraps at branches from 100 replicates)

Photo: G. Gerlach & P. Endress Photo: P. Endress Octomeles sumatrana

Coriariaceae Photo: W. Takeuchi Tetramelaceae Datiscaceae