Suda Jan, Kyncl Tomas, Freiova Radka
Department of Botany, Charles University, Benátská 2, Prague 2, 128 01, Czech Republic.
Ann Bot. 2003 Jul;92(1):153-64. doi: 10.1093/aob/mcg104.
Nuclear DNA contents for 104 Macaronesian angiosperms, with particular attention on Canary Islands endemics, were analysed using propidium iodide flow cytometry. Prime estimates for more than one-sixth of the whole Canarian endemic flora (including representatives of 11 endemic genera) were obtained. The resulting 1C DNA values ranged from 0.19 to 7.21 pg for Descurainia bourgeauana and Argyranthemum frutescens, respectively (about 38-fold difference). The majority of species, however, possessed (very) small genomes, with C-values <1.6 pg. The tendency towards small nuclear DNA contents and genome sizes was confirmed by comparing average values for Macaronesian and non-Macaronesian representatives of individual families, genera and major phylogenetic lineages. Our data support the hypothesis that the insular selection pressures in Macaronesia favour small C-values and genome sizes. Both positive and negative correlations between infrageneric nuclear DNA amount variation and environmental conditions on Tenerife were also found in several genera.
使用碘化丙啶流式细胞术分析了104种马卡罗尼西亚被子植物的核DNA含量，特别关注了加那利群岛的特有植物。获得了超过六分之一的加那利群岛特有植物区系（包括11个特有属的代表）的初步估计值。结果显示，Descurainia bourgeauana和Argyranthemum frutescens的1C DNA值分别为0.19至7.21皮克（相差约38倍）。然而，大多数物种拥有（非常）小的基因组，C值<1.6皮克。通过比较各个科、属和主要系统发育谱系的马卡罗尼西亚和非马卡罗尼西亚代表的平均值，证实了核DNA含量和基因组大小倾向于变小的趋势。我们的数据支持这样的假设，即马卡罗尼西亚的岛屿选择压力有利于小的C值和基因组大小。在几个属中还发现了属内核DNA量变异与特内里费岛环境条件之间的正相关和负相关。
