Maize Research Institute, Sichuan Agricultural University, Ya'an, Sichuan, China.
PLoS One. 2011 Apr 15;6(4):e16728. doi: 10.1371/journal.pone.0016728.
Genetic relationship of a newly discovered teosinte from Nicaragua, Zea nicaraguensis with waterlogging tolerance, was determined based on randomly amplified polymorphic DNA (RAPD) markers and the internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA using 14 accessions from Zea species. RAPD analysis showed that a total of 5,303 fragments were produced by 136 random decamer primers, of which 84.86% bands were polymorphic. RAPD-based UPGMA analysis demonstrated that the genus Zea can be divided into section Luxuriantes including Zea diploperennis, Zea luxurians, Zea perennis and Zea nicaraguensis, and section Zea including Zea mays ssp. mexicana, Zea mays ssp. parviglumis, Zea mays ssp. huehuetenangensis and Zea mays ssp. mays. ITS sequence analysis showed the lengths of the entire ITS region of the 14 taxa in Zea varied from 597 to 605 bp. The average GC content was 67.8%. In addition to the insertion/deletions, 78 variable sites were recorded in the total ITS region with 47 in ITS1, 5 in 5.8S, and 26 in ITS2. Sequences of these taxa were analyzed with neighbor-joining (NJ) and maximum parsimony (MP) methods to construct the phylogenetic trees, selecting Tripsacum dactyloides L. as the outgroup. The phylogenetic relationships of Zea species inferred from the ITS sequences are highly concordant with the RAPD evidence that resolved two major subgenus clades. Both RAPD and ITS sequence analyses indicate that Zea nicaraguensis is more closely related to Zea luxurians than the other teosintes and cultivated maize, which should be regarded as a section Luxuriantes species.
利用来自玉米属的 14 个材料，基于随机扩增多态性 DNA（RAPD）标记和核核糖体 DNA 内部转录间隔区（ITS）序列，对新发现的来自尼加拉瓜的耐淹胁迫的甜高粱——珍珠高粱的遗传关系进行了确定。RAPD 分析表明，136 个随机十聚体引物共产生了 5303 个片段，其中 84.86%的条带是多态的。基于 RAPD 的 UPGMA 分析表明，玉米属可分为 Luxuriantes 节，包括珍珠高粱、华丽玉米、多年生玉米和尼加拉瓜甜高粱，以及 Zea 节，包括墨西哥玉米、小穗玉米、瓦哈卡玉米和普通玉米。ITS 序列分析表明，在 Zea 的 14 个分类群中，整个 ITS 区的长度从 597 到 605bp 不等。平均 GC 含量为 67.8%。除了插入/缺失外，在整个 ITS 区共记录了 78 个可变位点，ITS1 中有 47 个，5.8S 中有 5 个，ITS2 中有 26 个。用邻接法（NJ）和最大简约法（MP）对这些分类群的序列进行分析，选择大刍草作为外类群。从 ITS 序列推断的玉米属种的系统发育关系与 RAPD 证据高度一致，该证据解决了两个主要的亚属分支。RAPD 和 ITS 序列分析都表明，珍珠高粱与华丽玉米的亲缘关系比其他的甜高粱和栽培玉米更近，应被视为 Luxuriantes 节的一个种。
