Buckler E S, Holtsford T P
Division of Biological Sciences, University of Missouri, Columbia 63211, USA. buckler/biosci.mbp.missouri.edu
Mol Biol Evol. 1996 Apr;13(4):612-22. doi: 10.1093/oxfordjournals.molbev.a025621.
Ribosomal internal transcribed spacer (ITS) sequences were used to evaluate the phylogenetics of Zea and Tripsacum. Maximum likelihood and polymorphism parsimony were used for phylogenetic reconstructions. Zea ITS nucleotide diversity was high compared to other plant species, but approximately equivalent to other maize loci. Coalescence of ITS alleles was rapid relative to other nuclear loci; however, there was still much diversity within populations. Zea and Tripsacum form a clade clearly differentiated from all other Poaceae. Four Zea ITS pseudogenes were identified by phylogenetic position and nucleotide composition. The phylogenetic position of Z. mays ssp. huehuetenangensis was clearly established as basal to the other Z. mays. The ITS phylogeny disfavored a Z. luxurians and Z. diploperennis clade, which conflicted with some previous studies. The introgression of Z. mays alleles into Z. perennis and Z. diploperennis was also established. The ITS data indicated a near contemporary divergence of domesticated maize and its two closest wild relatives.
核糖体内部转录间隔区（ITS）序列被用于评估玉米属（Zea）和摩擦禾属（Tripsacum）的系统发育。最大似然法和多态简约法被用于系统发育重建。与其他植物物种相比，玉米ITS核苷酸多样性较高，但与其他玉米基因座大致相当。相对于其他核基因座，ITS等位基因的合并速度较快；然而，种群内部仍存在大量多样性。玉米属和摩擦禾属形成一个明显区别于所有其他禾本科植物的分支。通过系统发育位置和核苷酸组成鉴定出四个玉米ITS假基因。玉米（Zea mays）亚种韦韦特南戈玉米（Z. mays ssp. huehuetenangensis）的系统发育位置被明确确定为其他玉米的基部。ITS系统发育不支持繁茂玉米（Z. luxurians）和二倍体多年生玉米（Z. diploperennis）分支，这与之前的一些研究相冲突。也确定了玉米等位基因渗入多年生玉米（Z. perennis）和二倍体多年生玉米。ITS数据表明驯化玉米与其两个最亲近的野生近缘种几乎是同时分化的。
