Kentucky Tobacco Research and Development Center, 1401 University Drive, University of Kentucky, Lexington, KY 40546, USA.
Genome. 2010 Dec;53(12):1066-82. doi: 10.1139/G10-077.
The Gesneriaceae (Lamiales) is a family of flowering plants comprising >3000 species of mainly tropical origin, the most familiar of which is the cultivated African violet (Saintpaulia spp.). Species of Gesneriaceae are poorly represented in the lists of taxa sampled for genome size estimation; measurements are available for three species of Ramonda and one each of Haberlea, Saintpaulia, and Streptocarpus, all species of Old World origin. We report here nuclear genome size estimates for 10 species of Sinningia, a neotropical genus largely restricted to Brazil. Flow cytometry of leaf cell nuclei showed that holoploid genome size in Sinningia is very small (approximately two times the size of the Arabidopsis genome), and is small compared to the other six species of Gesneriaceae with genome size estimates. We also documented intraspecific genome size variation of 21%-26% within a group of wild Sinningia speciosa (Lodd.) Hiern collections. In addition, we analyzed 1210 genome survey sequences from S. speciosa to characterize basic features of the nuclear genome such as guanine-cytosine content, types of repetitive elements, numbers of protein-coding sequences, and sequences unique to S. speciosa. We included several other angiosperm species as genome size standards, one of which was the snapdragon (Antirrhinum majus L.; Veronicaceae, Lamiales). Multiple measurements on three accessions indicated that the genome size of A. majus is ~633 × 10⁶ base pairs, which is approximately 40% of the previously published estimate.
苦苣苔科（Lamiales）是一个开花植物科，包含超过 3000 种主要来自热带地区的物种，其中最著名的是栽培的非洲堇（Saintpaulia 属）。在用于基因组大小估计的分类群样本列表中，苦苣苔科的物种代表性较差；目前已有三个 Ramonda 物种、一个 Haberlea、一个 Saintpaulia 和一个 Streptocarpus 的基因组大小测量值，这些物种均来自旧世界。我们在这里报告了 10 种新热带属 Sinningia 的核基因组大小估计值，该属主要局限于巴西。叶细胞核的流式细胞术表明，Sinningia 的全基因组大小非常小（大约是拟南芥基因组大小的两倍），与其他具有基因组大小估计值的六个苦苣苔科物种相比，其基因组大小也较小。我们还记录了一组野生 Sinningia speciosa（Lodd.）Hiern 收集物的种内基因组大小变异，范围为 21%-26%。此外，我们分析了来自 S. speciosa 的 1210 个基因组调查序列，以表征核基因组的基本特征，如鸟嘌呤-胞嘧啶含量、重复元件类型、编码序列数量以及 S. speciosa 特有的序列。我们包括了其他几个被子植物物种作为基因组大小标准，其中之一是金鱼草（Antirrhinum majus L.；玄参科，Lamiales）。对三个品系的多次测量表明，金鱼草的基因组大小约为 633×10⁶ 碱基对，大约是之前发表的估计值的 40%。
