Cucumber (Cucumis sativus) and melon (C. melo) have numerous wild relatives in Asia and Australia, and the sister species of melon is from Australia MO, and approved June 16, 2010 (received for review April 19, 2010) Among the fundamental questions regarding cultivated plants is their geographic origin and region of domestication. The genus Cucumis, which includes cucumber (Cucumis sativus) and melon (Cucumis melo), has numerous wild African species, and it has therefore been assumed that melon originated in Africa. For cucumber, this seemed less likely because wild cucumbers exist in India and a closely related species lives in the Eastern Himalayas. Using DNA sequences from plastid and nuclear markers for some 100 Cucumis accessions from Africa, Australia, and Asia, we show here that melon and cucumber are of Asian origin and have numerous previously overlooked species-level relatives in Australia and around the Indian Ocean. The wild progenitor of C. melo occurs in India, and our data confirm that the Southeast Asian Cucumis hystrix is the closest relative of cucumber. Most surprisingly, the closest relative of melon is Cucumis picrocarpus from Australia. C. melo diverged from this Australian sister species approximately 3 Ma, and both diverged from the remaining Asian/Australian species approximately 10 Ma. The Asian/Australian Cucumis clade comprises at least 25 species, nine of them new to science, and diverged from its African relatives in the Miocene, approximately 12 Ma. Range reconstruction under maximum likelihood suggests Asia as the ancestral area for the most recent common ancestor of melon and cucumber, fitting with both having progenitor populations in the Himalayan region and high genetic diversity of C. melo landraces in India and China. Future investigations of wild species related to melon and cucumber should concentrate on Asia and Australia.ancestral areas | crops | economic plants | wild progenitors A mong the most fundamental and debated questions regarding the evolution of cultivated plants is their geographic origin and region of domestication (1). Recent phylogeographic and phylogenetic work on cassava, pumpkin, corn, potato, and rice (2-6) has uncovered the likely places of origin and domestication of these crops. Although many premolecular hypotheses about the domestication of particular species still require testing, it is clear that the Indo-Chinese region has produced a particularly long list of crops. These include rice (Oryza sativa), millets (Setaria spp.), beans (Vigna mungo; Vigna radiata), angled loofah (Luffa acutangula), yams (Dioscorea spp.), and taro (Colocasia esculenta) (7-9). Archaeological evidence from northern India documents these Neolithic crops from 7,000 BC onward, and by the early second millennium, there is evidence of Western crops arriving in India through trade, such as wheat, barley, lentils, grasspea, and peas (7).One of the crops domesticated in the Indo-Gangetic plain is cucumber, Cucumis sativus. Evidence for this consists in the occurrence there ...

Following a phylogenetic analysis using morphology, Pittosporum is here monographed and recircumscribed as a monophyletic genus, by including the small genus Citriobatus and by excluding a new genus, described in the accompanying paper as Auranticarpa. Within Australia and its associated territories, 20 species are now recognised in Pittosporum, including the four from Citriobatus, three of which are given new combinations (P. spinescens, P. lancifolium and P. multiflorum). Citriobatus linearis requires a new name (P. viscidum). Four species are reinstated or confirmed at species level (P. angustifolium, P. ligustrifolium, P. nativitatis and P. wingii), and P. trilobum is described for the first time.

Previous estimates of phylogeny in the Phyllanthaceae, Phyllantheae, have been hampered by undersampling of species from morphologically distinctive groups and using too few gene regions. To increase the phylogenetic resolution, sequences of two nuclear (ITS1–5.8S–ITS2) and Phytochrome C (PHYC)) and two non-coding chloroplast (accD–psaI, trnS–trnG) DNA markers were analysed using maximum parsimony and Bayesian inference with expanded sampling in Breynia, Glochidion, Sauropus and Synostemon. Our results supported reinstatement of Synostemon, previously included in Sauropus s.str., to generic rank, and provided evidence towards its future infrageneric classification. The results also indicated expansion of Breynia to include Sauropus s.str.; this combined monophyletic group consists of two strongly supported clades. Finally, we showed monophyly for Glochidion, which is sister to Phyllanthus subg. Phyllanthodendron, both still remaining undersampled. Morphological features characteristic of Breynia, Sauropus and Synostemon are discussed, as well as the desirability of dividing Phyllanthus into smaller genera.

The genus Phyllanthus is paraphyletic as currently circumscribed, with the genera Breynia, Glochidion and Synostemon nested within it. A phylogeny based on nuclear (ITS, PHYC) and chloroplast (matK, accD-psaI, trnS-trnG) markers is presented, including 18/18 subgenera and 53/70 sections. Differences in habit, branching type, floral and fruit characters are discussed, and we find indications for shifts in pollination and dispersal strategies possibly underlying the convergent evolution of these characters in multiple clades. Several taxonomic issues were found in the subgeneric classification of Phyllanthus that will require new transfers and rank changes. Phyllanthus subg. Anesonemoides, subg. Conami, subg. Emblica, subg. Gomphidium, subg. Kirganelia and subg. Phyllanthus are polyphyletic, and several sections appear to be paraphyletic (e.g., P. sect. Anisonema, sect. Emblicastrum, sect. Pseudoactephila, sect. Swartziani, and sect. Xylophylla); P. subg. Phyllanthodendron is furthermore paraphyletic with the genus Glochidion nested within. To create a classification of tribe Phyllantheae that comprises exclusively monophyletic taxa, it is necessary to treat several clades at the same taxonomic rank as the genera Breynia, Glochidion and Synostemon. Since combining all genera would lead to one giant heterogeneous genus that is difficult to define, we recommend dividing Phyllanthus into several monophyletic genera, which have previously been recognized and often possess diagnostic (combinations of) morphological characters. This new classification is forthcoming.

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