Asparagales are a diverse monophyletic order that has numerous species (ca. 50% of monocots) including important crop plants such as Allium, Asparagus, and Vanilla, and a host of ornamentals such as irises, hyacinths, and orchids. Historically, Asparagales have been of interest partly because of their fascinating chromosomal evolution. We examine the evolutionary dynamics of Asparagales genomes in an updated phylogenetic framework that combines analyses of seven gene regions (atp1, atpB, matK, ndhF, rbcL, trnL intron, and trnL-F intergenic spacer) for 79 taxa of Asparagales and outgroups. Asparagales genomes are evolutionarily labile for many characters, including chromosome number and genome size. The history and causes of variation in chromosome number and genome size remain unclear, primarily because of the lack of data in small clades in the phylogenetic tree and the lack of comparative genetic maps, apart from Allium and Asparagus. Genomic tools such as bacterial artificial chromosome (BAC) libraries should be developed, as both molecular cytogenetic markers and a source of nuclear genes that can be widely used by evolutionary biologists and plant breeders alike to decipher mechanisms of chromosomal evolution.
Pires, J. Chris; Maureira, Ivan J.; Givnish, Thomas J.; Systma, Kenneth J.; Seberg, Ole; Peterson, Gitte; Davis, Jerrold I.; Stevenson, Dennis W.; Rudall, Paula J.; Fay, Michael F.; and Chase, Mark W.
"Phylogeny, Genome Size, and Chromosome Evolution of Asparagales,"
Aliso: A Journal of Systematic and Evolutionary Botany:
1, Article 24.
Available at: http://scholarship.claremont.edu/aliso/vol22/iss1/24
© 2006 J. Chris Pires, Ivan J. Maureria, Thomas J. Givnish, Kenneth J. Sytsma, Ole Seberg, Gitte Petersen, Jerrold I. Davis, Dennis W. Stevenson, Paula J. Rudall, Michael F. Fay, Mark W. Chase
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