Molecular evolution and phylogenetic implications of internal transcribed spacer sequences of Ribosomal DNA in Winteraceae

Abstract

The internal transcribed spacers and the 5.8S coding region of nuclear ribosomal DNA were sequenced and analyzed to address questions of generic relationships in Winteraceae. The molecular data generated a single tree that is congruent with one based on morphological data. The sequences of ITS 1 in the family range from 235 to 252 bases in size and of ITS 2 from 213 to 226 bases. The size of the 5.8S coding region is 164 bases. The range of ITS 1 and ITS 2 sequence divergence between pairs of genera within Winteraceae is relatively low in comparison to other plant families. Two types of ITS 1 and ITS 2 sequences were observed in the same individual for some taxa. Sequence variations between the two arrays are 4.7%–6.3% for ITS 1 and 5.1%–7.0% for ITS 2. Both arrays of sequences, however, generate the same phylogenetic relationships. Rates of nucleotide substitutions for the internal transcribed spacers are 3.2–5.2 × 10‐10 substitution per site per year estimated in ITS 1 and 3.6–5.7 × 10‐10 in ITS 2.

Phylogenetic Relationships Among Chilean Species of Drimys (Wtnteraceae) Based on Its Sequences and Insertion/Deletion Events

“…2) shows all species of Drimys as a monophyletic group supported by a bootstrap value of 100%. In spite of an unresolved Drimys branch, relationships among the remainder of Winteraceae are well resolved and consistent with those obtained by Suh et al (1993), Karol et al (2000) and Doust & Drinnan (2004).…”

“…In the present work no variation was found among the varieties of D. winteri. However, we found few differences with those obtained by Suh et al (1993). To align Drimys and Pseudowintera sequences, it was necessary to infer 18 indels.…”

“…However, these studies are of limited utility for examining patterns of evolution in Drimys, because only one (Suh et al 1993, Karol et al 2000 or two (Doust & Drinnan 2004) DNA EXTRACTION, AMPLIFICATION AND SEQUENCING Total DNA was extracted from young leaf tissue using the CTAB method of Doyle & Doyle (1987). Doublestranded DNA of the complete region (ITS-1, 5.8S and ITS-2) was amplified by a symmetric PCR using White's universal ITS primers (1990): ITS 2 and 5, and ITS 3 with ITS 4 when necessary.…”

“…The indel data were coded as presence/absence (0 = absent, 1 = present) following Simmons & Ocheterena (2000) and added to the matrix for maximum parsimony (MP) analysis. These results were subsequently compared to previous results where indels were only mapped onto the phylogeny (Suh et al 1993, Karol et al 2000, Doust & Drinnan 2004. To estimate phylogeny within Drimys, a new matrix including five species of Drimys (including the two varieties of D. winteri) and two species of Pseudowintera Dandy as outgroup was constructed and analyzed using MP.…”

Evolutionary trends in Winteraceae pollen

“…A, a tetrad fossil from the Early Cretaceous (Aptian/Albian) of Israel ( Walker et al 1983 ) Winteraceae. Compared to the outgroup Canellaceae these character states are reversals.…”