Phylogeny and Androecial Evolution in Schisandraceae, Inferred from Sequences of Nuclear Ribosomal DNA ITS and Chloroplast DNAtrnL‐F Regions

Abstract

Sequences of nuclear ribosomal DNA ITS and chloroplast trnL-F regions were used to construct a phylogeny of Schisandraceae. The results show that there are two major clades in Schisandraceae. One is composed entirely of Schisandra species; the other contains a mixture of Schisandra and Kadsura species. Molecular data place Smith's sect. Sphaerostema of Schisandra prominently within Kadsura, and thus neither Schisandra nor Kadsura is monophyletic, refuting the traditional division of the family into two genera based on morphological characters of mature fruits. The sister relationship between S. glabra (North America) and S. bicolor (China) and the monophyly of sect. Sphaerostema and sect. Kadsura are strongly supported. The trnL-F and combined data sets yield phylogenetic trees that are well resolved and concordant with androecial types of staminate flowers; however, they do not support the evolutionary pathways for androecia constructed by previous authors for Kadsura and Schisandra. The new alignment of species in Schisandraceae indicates that morphological characters traditionally used to construct phylogenetic relationships and evolutionary pathways, e.g., habit (deciduous vs. evergreen or semievergreen), fruit type (bacceta vs. separated apocarps), arrangement of flowers (solitary vs. paired or in glomerules), and pollen (3-colpate vs. 6-colpate), evolved more than once in the family. Preliminary observations suggest that the pentagonal androecium and gynoecium of S. glabra are thermogenic and that heat may play a role in the reproductive biology of S. glabra to enhance floral odor or simulate the temperature of brood sites for many types of insects.

Ancestral traits and specializations in the flowers of the basal grade of living angiosperms

“…ex Juss., and Illici aceae, with the single genus Illicium. Kadsura may be nested within Schisandra, but this has not been resolved (Liu & al., 2006). A conspicuous increase in number of floral organs, especially in the androecium and gynoecium, occurs in part of the family.…”

Palynological data on Illiciaceae and Schisandraceae confirm phylogenetic relationships within these two basally-branching angiosperm families

“…To infer the character evolution of the pollen of Illiciaceae and Schisandraceae, based on the data from 21 currently studied and 16 additional taxa from previous studies (Lan, 1984;Lin, 1989;Liu and Yang, 1989;Praglowski, 1976;Sun, 2000), pollen characters were optimized on a reconstruction of recent phylogenetic hypotheses for these taxa following Hao et al (2000) and Liu et al (2006). In particular, aperture and exine sculpture were plotted onto the molecular trees, using the computer program MacClade version 4.07 (Maddison and Maddison, 2005).…”

“…The pollen characters described in the current and previous studies were optimized and mapped on the molecular trees of Hao et al (2000) and Liu et al (2006). In the current study, eight of the taxa examined (I. burmanicum, I. cambodianum, I. pachyphyllum, I. petelotii, I. simonsii, I. tsaii, S. elongata and S. lancifolia) were unable to be used in this part of the study, because they were excluded from the molecular trees used.…”

“…The two other species (S. glabra and S. bicolor), being disjunct in east Asia and eastern North America, have lumina smaller in size, and form a subclade. Liu et al (2006).…”

“…Infra-generic classifications in Schisandraceae are unstable and vary between authors (Law, 1996;Saunders, 1998Saunders, , 2000Smith, 1947), while phylogenetic relationships and the boundaries among some species remain to be resolved. However, recent molecular studies concluded that neither Schisandra nor Kadsura is monophyletic (Hao et al, 2001;Liu et al, 2000Liu et al, , 2006. Denk and Oh (2006) studied seed morphology and leaf epidermal characters of 22 species of Schisandraceae, and found that the division of the family into Schisandra and Kadsura based on fruit morphological characters was not supported.…”