Evolution of the Flavonoid System in Asteraceae
In addition to examination of presence and absence and frequencies of occurrence of flavonoid data in Asteraceae for purposes of testing subfamilial, tribal, and subtribal delimitations (Chapters 18–20), which comprised essentially a phenetic perspective, it is also appropriate to consider the data in a phylogenetic context. Use of flavonoids to interpret phylogeny has received numerous comments over many decades (e.g., Harborne, 1977a; Gornall and Bohm, 1978). Several workers have also considered use of secondary products in a cladistic context (Estabrook, 1980; Humphries and Richadson, 1980; Richardson, 1983a, 1983b; Seaman and Funk, 1983; Richardson and Young, 1982; Stuessy and Crawford, 1983). Our approach is to view the patterns in a phyletic context, attempting to gain maximum evolutionary insights from the data (Stuessy and Crawford, 1983; Stuessy, 1990). For these considerations, we will use data from Table 18-1, concepts of biosynthesis of major structural types (Chapter 5), and discussion of particular structural adornments. The existence of this sizeable data base at the tribal level for the entire family, recent identification of the basal group of Asteraceae (subfamily Barnadesioideae; Jansen and Palmer, 1987b), acceptance of Calyceraceae as sister family to Asteraceae (DeVore and Stuessy, 1995; Gustaffson and Bremer, 1995), recent studies of flavonoids of both these taxa (Barnadesioideae, Bohm and Stuessy, 1995; Calyceraceae, Bohm et al., 1995), and recent morphological (Bremer, 1994, 1996), and macromolecular (Jansen et al., 1990; Jansen and Kim, 1996; Bayer and Starr, 1998) cladograms among tribes of Asteraceae (see Figs. 2-3 to 2-8), all argue for attempts at phyletic interpretations of the evolution of flavonoids within the family.
KeywordsSecondary Product Phylogenetic Context Flavonoid Profile Primitive Tribe Evolutionary Affinity
Unable to display preview. Download preview PDF.