Department of Ecology and Evolutionary Biology, and Natural History Museum and Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045-7600, USA.
Am J Bot. 2011 Jul;98(7):1222-5. doi: 10.3732/ajb.1100028. Epub 2011 Jun 23.
Although root suckering and other types of sprouting are well studied in extant woody plants, little is known about the distribution of these traits at a macroevolutionary scale. Anatomically preserved fossil plants represent an excellent but understudied source of information of the distribution of sprouting behavior through time and across taxa.
A block of silicified peat collected in the Middle Triassic Fremouw Formation at the Fremouw Peak locality, Central Transantarctic Mountains, Antarctica, contains a group of anatomically preserved roots of the fossil conifer Notophytum krauselii that bear young shoots. The specimen was prepared using the standard acetate peel technique and studied in reflected and transmitted light.
Young sucker shoots bearing well-preserved leaves are produced in groups in some areas of the Notophytum roots.
The production of root suckers in Notophytum indicates that some of the trees growing in polar forests during the Triassic could respond to environmental stresses by regenerating their vegetative structures and had the potential to reproduce vegetatively. The specimens also represent the first anatomical evidence of root suckering in any fossil seed plant, and its occurrence in an early putative podocarp supports the idea that this trait might be ancestral in at least some extant conifer families.
尽管现存木本植物的根蘖和其他类型的萌芽已得到充分研究，但对于这些特征在宏观进化尺度上的分布情况知之甚少。保存下来的化石植物代表了一个极好但研究不足的信息来源，可以了解萌芽行为在时间和分类群上的分布情况。
在南极洲的南极中央横贯山脉的 Fremouw 峰地点的中三叠世 Fremouw 组中采集到的一块硅化泥炭块，其中包含一组保存完好的化石针叶树 Notophytum krauselii 的根，这些根上带有幼芽。该标本采用标准的醋酸盐剥离技术进行制备，并在反射光和透射光下进行研究。
在 Notophytum 的一些根部区域，幼芽以群体的形式产生，每个芽上都带有保存完好的叶子。
Notophytum 产生根蘖表明，在三叠纪期间生长在极地森林中的一些树木可以通过再生其营养结构来应对环境压力，并且具有营养繁殖的潜力。这些标本也代表了任何化石种子植物中根蘖的第一个解剖学证据，并且它在一个早期的拟苏铁中出现，这表明这种特征可能在至少一些现存的针叶树科中是祖先的。
