0000000001094680
AUTHOR
Nadine Bobon
Phylogeny, biogeography and systematics of Dysphanieae (Amaranthaceae)
After a rather turbulent taxonomic history, Dysphanieae (Chenopodioideae, Amaranthaceae) were established to contain five genera, four of which are monospecific (Cycloloma, Neomonolepis, Suckleya, Teloxys) and geographically restricted, and the fifth genus, Dysphania, having a nearly worldwide distribution and comprising ca. 50 species. This study investigates the phylogeny, biogeography and taxonomy of Dysphanieae. We studied specimens from 32 herbaria to infer morphological differences and distribution areas of the species and sampled 121 accessions representing 39 accepted species of the tribe for molecular phylogenetic analyses. The molecular phylogeny tested generic relationships of th…
Carbon isotope composition of plant photosynthetic tissues reflects a Crassulacean Acid Metabolism (CAM) continuum in the majority of CAM lineages
Abstract The stable carbon isotope composition of plant tissues, commonly expressed as δ13C, holds a wealth of information about photosynthetic pathway, water relations and stress physiology. Crassulacean acid metabolism (CAM) is a derived form of photosynthesis that allows plants to fix carbon at a higher water-use efficiency compared to the ancestral C3 photosynthesis. While the central carbon-fixing enzyme of C3 plants, Rubisco, strongly discriminates against the heavy 13C isotope, CAM is characterized by a dual use of Rubisco and the much less discriminating PEP carboxylase as carbon-fixing enzymes, causing the δ13C values of CAM plant tissues to be generally less negative than those fo…