Chilean Pitavia more closely related to Oceania and Old World Rutaceae than to Neotropical groups: evidence from two cpDNA non-coding regions, with a new subfamilial classification of the family

Abstract

The position of the plant genus Pitavia within an infrafamilial phylogeny of Rutaceae (rue, or orange family) was investigated with the use of two non-coding regions from cpDNA, the trnL-trnF region and the rps16 intron. The only species of the genus, Pitavia punctata Molina, is restricted to the temperate forests of the Coastal Cordillera of Central-Southern Chile and threatened by loss of habitat. The genus traditionally has been treated as part of tribe Zanthoxyleae (subfamily Rutoideae) where it constitutes the monogeneric tribe Pitaviinae. This tribe and genus are characterized by fruits of 1 to 4 fleshy drupelets, unlike the dehiscent fruits typical of the subfamily. Fifty-five taxa of Rutaceae, representing 53 genera (nearly one-third of those in the family) and all subfamilies, tribes, and almost all subtribes of the family were included. Parsimony and Bayesian inference were used to infer the phylogeny; six taxa of Meliaceae, Sapindaceae, and Simaroubaceae, all members of Sapindales, were also used as out-groups. Results from both analyses were congruent and showed Pitavia as sister to Flindersia and Lunasia, both genera with species scattered through Australia, Philippines, Moluccas, New Guinea and the Malayan region, and phylogenetically far from other Neotropical Rutaceae, such as the Galipeinae (Galipeeae, Rutoideae) and Pteleinae (Toddalieae, former Toddalioideae). Additionally, a new circumscription of the subfamilies of Rutaceae is presented and discussed. Only two subfamilies (both monophyletic) are recognized: Cneoroideae (including Dictyolomatoideae, Spathelioideae, Cneoraceae, and Ptaeroxylaceae) and Rutoideae (including not only traditional Rutoideae but also Aurantioideae, Flindersioideae, and Toddalioideae). As a consequence, Aurantioideae (Citrus and allies) is reduced to tribal rank as Aurantieae.

Phytochemistry of the genus Skimmia (Rutaceae)

“…The close relation to Dictamnus was confirmed in a study by Groppo et al (2012). Groppo et al (2012) furthermore propose a new subfamilial structure of the Rutaceae with only two subfamilies, Cneoroideae and Rutoideae. According to this re-classification, Skimmia now belongs to the subfamily Rutoideae while it was formerly placed in Toddalioideae.…”

“…Both genera together form a well-supported clade with the genus Dictamnus (Salvo et al, 2008). The close relation to Dictamnus was confirmed in a study by Groppo et al (2012). Groppo et al (2012) furthermore propose a new subfamilial structure of the Rutaceae with only two subfamilies, Cneoroideae and Rutoideae.…”

Molecular phylogeny and biogeography of the SouthAmerican genus Metrodorea (Rutaceae)

“…In the studies by Groppo et al (2012), although focused mainly on subfamily and tribe levels, only one species of Metrodorea was included and it emerged as sister to Esenbeckia, and conformed a clade with the other two sister genera Balfourodendron and Helietta. In the present study, however, Esenbeckia was not found as sister to Metrodorea.…”

“…All 6 species of Metrodorea were included in our analyses. Out-groups (Nixon and Carpenter, 1993) were selected based on previous studies (Engler, 1931;Groppo et al, 2012) from i) all other genera of the same subtribe Pilocarpinae (Esenbeckia, Pilocarpus, and Raulinoa), ii) a genus of another subtribe (Galipeinae) in the same tribe Galipeeae (Galipea), and iii) three genera of other subfamilies (Balfourodendron, Helietta, and Zanthoxylum). We included one species for each genus represented in outgroups based on previous studies (Engler, 1931;.…”

“…From a phylogenetic standpoint, in a previous study of the family by Groppo et al (2012), Metrodorea emerged as sister to Esenbeckia Kunth (of the same subtribe Pilocarpinae) within a strongly supported clade composed also of Balfourodendron Mello ex Oliv. and Helietta Tul., although these two genera were ascribed to a different subfamily by Engler (1931).…”