School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand.
J Hered. 2012 Sep-Oct;103(5):711-9. doi: 10.1093/jhered/ess049. Epub 2012 Sep 3.
The genus Plantago (Plantaginaceae) in New Zealand comprises species that can be difficult to delimit and contains a wide range of ploidy levels from diploid to 16-ploid. To investigate whether there have been changes in genome size associated with polyploid events and whether pollen and guard cell size can be used as an initial guide to identify polyploids, we have used flow cytometry with propidium iodide as the stain to measure the genome size (DNA C-value) in a range of Plantago species with different ploidy levels. Light microscopy was used to measure pollen diameter and guard cell length in these plants to see whether these could be used for ploidy level identification. Large differences in C-value were observed between species but the extent of changes associated with different polyploid events was highly variable. Pollen diameter was correlated with C-value but not necessarily with ploidy level. Guard cell lengths were different between diploids and polyploids but not between the different polyploid species. The significance of the changes in genome size and its relationship to pollen and stomatal guard cell size is discussed.
新西兰车前属（车前科）包含了一些难以界定的物种，其倍性水平从二倍体到 16 倍体不等。为了研究多倍体事件是否与基因组大小的变化有关，以及花粉和保卫细胞大小是否可以作为识别多倍体的初步指南，我们使用碘化丙啶作为染色剂的流式细胞术来测量一系列不同倍性水平的车前属植物的基因组大小（DNA C 值）。利用光学显微镜测量这些植物的花粉直径和保卫细胞长度，以观察它们是否可用于鉴定倍性水平。在物种之间观察到 C 值存在较大差异，但不同多倍体事件相关的变化程度高度可变。花粉直径与 C 值相关，但不一定与倍性水平相关。保卫细胞长度在二倍体和多倍体之间存在差异，但在不同的多倍体物种之间没有差异。本文讨论了基因组大小的变化及其与花粉和气孔保卫细胞大小的关系的意义。
