MOLECULAR PHYLOGENETICS OF CALYCADENIA (COMPOSITAE) BASED ON ITS SEQUENCES OF NUCLEAR RIBOSOMAL DNA: CHROMOSOMAL AND MORPHOLOGICAL EVOLUTION REEXAMINED

摘要: Phylogenetic patterns within Calycadenia were estimated from 1 8-26S nuclear ribosomal DNA sequences of the internal transcribed spacer (ITS) region in 19 representatives all species Calycadenia, including Osmadenia (C.) tenella, and two outgroup species. In pairwise comparisons among sequences, divergence ranged 0 to 11.2% nucleotides ITS 8.6% 2. Of 62 nucleotide sites with potential phylogenetic information, 51.6% 1, 46.8% 2, 1.6% 5.8S subunit. A highly resolved, strict consensus tree Wagner parsimony analysis these data agrees well morphological cytological evidence. This suggests that: 1) monotypic tenella is sister-group Calycadenia; 2) base chromosome number n = 7, which other numbers derived; 3) multiple T-glands on cylindrical bracts 5 or 6 (or 7 C. oppositifolia) form a monophyletic group derived an similar identical genomic structure hooveri villosa; 4) spicata (n product independent dysploid reduction 7; 5) multiglandulosa pauciflora, sensu Keck, are not taxa; 6) loss chromosomal homology between species, as reflected by meiotic association hybrids, positively correlated time since evolutionary divergence. These results offer little evidence homoplasy phenotypic characters provide further support for utility plant sequences.