Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2004
Publication Date: 8/11/2004
Citation: Rodriguez, Spooner, D.M. 2004. Nitrate reductase based phylogeny of wild potatoes (Solanum section Petota). Meeting Abstract. p. 541. Interpretive Summary:
Technical Abstract: Nitrate reductase (NIA) catalyzes NAD(P)H reduction of nitrate to nitrite, which is the first step of nitrate assimilation. The gene expressing this protein has been isolated from fungi, algae, and higher plants. NIA has three intron regions and has been shown to be single-copy in some plants, where it is useful for low-level phylogenetic analyses. NIA has been used in phylogenetic studies for Antirrhinum, Hordeum, Memecylon, Scaevola, and Tilia. We designed primers from a published (GenBank) NIA sequence of tomato (5309 bases) and 2 cDNA sequences in potato (3049 and 3066 bases). These primers flanked the three NIA introns (74 bases, 847 bases, and 436 bases respectively). To date we have sequenced nitrate reductase from cloned sequences from individual plants from introns 1 and 2 and the intervening exon, for twenty diploid (2n = 2x = 24) and one putative allopolyploid (2n = 4x = 48) species of potato (Solanum section Petota), and outgroups (Solanum section Etuberosum, Solanum section Lycopersicon), representing the previously determined cladistic diversity of the section. Aligned sequences of these species are insertion/deletion (indel) rich, with phylogenetically informative variation in both base pairs and in variable intron lengths. The results show many points of concordance to other gene phylogenies (chloroplast DNA restriction site phylogenies, GBSSI or waxy phylogenies) of section Petota is supporting chloroplast DNA clades 1 + 2, 3, and 4. As well, variation in cloned products of the polyploid supports its allopolyploid origin.