Phylogeny of Agavaceae based on ITS rDNA sequence variation
Phylogeny of Agavaceae based on ITS rDNA sequence variation
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DOI：
10.2307/2446206
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发表时间：
1996-09-01
影响因子：
3
通讯作者：
Simpson, BB
中科院分区：
文献类型：
--
作者：
Bogler, DJ;Simpson, BB
对龙舌兰科植物已提出了几种分类系统。独特的双峰型核型以及果实和种子的相似性有力地支持了丝兰、Hesperaloe Besclneria、FurCraea、龙舌兰、Manfreda、Polianths、Prochnyanths以及可能还有Hosta之间的密切关系。然而，Dasylirion、Beucarnea、Nolina、Calibanus、Dracaena和Sansevieria在细胞学和形态特征上有很大的不同，许多人认为它们应该被排除在龙舌兰科之外，并划分为两个科：Nolinaceae和Dracaenaceae。叶绿体DNA限制酶切位点数据支持这些分离，表明诺林科和龙血竭与旋花科(菊科、旋花科、蜘蛛抱蛋属、山麦冬属等)的亲缘关系非常近。本文报道了龙舌兰目龙舌兰科及其近缘类群40个类群的ITS rDNA测序结果。使用一致性指数、保留指数和重新调整的一致性指数对序列比对进行优化，以找到同源性最小的比对。我们的研究结果与细胞学、免疫学、cpDNA和rbcL研究得出的结论是一致的，这些结论支持对龙舌兰科的狭义解释，以及藤科、龙血竭和萝卜科之间的密切关系。此外，ITS序列数据为这些家族之间的一些有趣的关系提供了证据。
Several systems of classification have been proposed for the family Agavaceae. A distinctive bimodal karyotype and similarities of fruits and seeds strongly support close relationships among Yucca, Hesperaloe Beschorneria, Furcraea, Agave, Manfreda, Polianthes, Prochnyanthes, and perhaps Hosta. However, Dasylirion, Beaucarnea, Nolina, Calibanus, Dracaena, and Sansevieria differ in so many cytological and morphological features that many have concluded they should be excluded from Agavaceae and separated into two families, Nolinaceae and Dracaenaceae. Chloroplast DNA restriction site data support these separations and indicate that Nolinaceae and Dracaenaceae are very close to Convallariaceae (Maianthemum, Convallaria, Aspidistra, Liriope, etc.). In this paper we report the results of an ITS rDNA sequencing study of 40 taxa in Agavaceae sensu late and related groups in the order Asparagales. Sequence alignments were optimized using the Consistency Index, Retention Index, and Rescaled Consistency Index to find the alignment that exhibited the least amount of homoplasy. The results of our study are congruent with the conclusions drawn from cytological, immunological, cpDNA, and rbcL studies, which support a narrow interpretation of Agavaceae and a close relationship among Convallariaceae, Dracaenaceae, and Nolinaceae. In addition, the ITS sequence data provide evidence for some interesting relationships within these families.