The major evolutionary lineages of the coffee family (Rubiaceae, angiosperms): combined analysis (nDNA and cpDNA) to infer the position of **Coptosapelta** and **Luculia**, and supertree construction based on **rbcL, rps 16, trnL-trnF** and **atpB-rbcL** data. A new classification in two subfamilies, Cinchonoideae and Rubioideae

Abstract

Two analyses are carried out for a reconstruction of the phylogeny of the large angiosperm family Rubiaceae. The position of Luculia and Coptosapelta, unresolved or sister to all other Rubiaceae in most of the recently published results, is reanalysed by using five plastid and three nuclear DNA regions sequenced for selected Rubiaceae taxa. A supertree is constructed for more than 500 species in 300 genera, i.e. ca. 50% of the genera known in the family. The supertree is derived from four source trees based on rbcL, rps16, trnL-trnF and atpB-rbcL, the latter with 106 newly generated sequences. The results are confronted with the morphological, anatomical and biogeographical knowledge of the family and discussed in the light of other molecular phylogenies. It is proposed to recognize only two subfamilies, Cinchonoideae (raphides mostly absent; secondary pollen presentation common) and Rubioideae (raphides present; heterostyly common). Luculia and Coptosapelta are found to be basal to the rest of the Cinchonoideae, which are divided in two newly recognized supertribes, Ixoridinae and Cinchonidinae. Also in the subfamily Rubioideae, two major clades may be distinguished and are recognized as supertribes Psychotriidinae (predominantly woody) and Rubiidinae (predominantly herbaceous); the genus Colletoecema and the tribes Urophylleae, Ophiorrhizeae, Lasiantheae and Coussareeae are basal Rubioideae falling outside these two supertribes. Four alliances are spotted as groups for which major problems exist with regard to relationships and tribal delimitation: three neotropical groups, viz. the Calycophylleae/Condamineeae alliance, the Catesbaeeeae/Chiococceae complex and the Rondeletieae alliance, and the pantropical Spermacoceae s.lat. The cladogenesis of Rubiaceae depicted by the supertree is strongly correlated with the present geographical distribution of taxa. The results are summarized in a conspectus of the family enumerating the tribes and listing all their genera for which the inclusion is corroborated by DNA sequences. Newly recognized tibes and subtribes are the Henriquezieae-Posoqueriinae, the Palicoureeae and the Rubieae-Theligoninae and -Kelloggiinae. Some tribes are reduced to subtribes, viz. Virectarieae (subtribe of Sabiceeae), Bertiereae (subtribe of Coffeeae) and Isertieae (subtribe of Cinchoneae). Novel positions are proposed for the genera Aulacocalyx, Calycosiphonia, Cremaspora, Crossopteryx and Morelia.