Institute for Agricultural and Fisheries Research (ILVO), Plant Sciences Unit, Caritasstraat 21, 9090 Melle, Belgium.
Genome. 2009 Oct;52(10):829-38. doi: 10.1139/g09-056.
The genome sizes of a Begonia collection comprising 37 species and 23 hybrids of African, Asiatic, Middle American, and South American origin were screened using flow cytometry. Within the collection, 1C values varied between 0.23 and 1.46 pg DNA. Genome sizes were, in most cases, not positively correlated with chromosome number, but with pollen size. A 12-fold difference in mean chromosome size was found between the genotypes with the largest and smallest chromosomes. In general, chromosomes from South American genotypes were smaller than chromosomes of African, Asian, or Middle American genotypes, except for B. boliviensis and B. pearcei. Cytological chromosome studies in different genotypes showed variable chromosome numbers, length, width, and total chromosome volume, which confirmed the diversity in genome size. Large secondary constrictions were present in several investigated genotypes. These data show that chromosome number and structure exhibit a great deal of variation within the genus Begonia, and likely help to explain the large number of taxa found within the genus.
使用流式细胞术对一个由非洲、亚洲、中美洲和南美洲起源的 37 个种和 23 个杂种组成的秋海棠属植物进行了基因组大小筛选。在该属中，1C 值在 0.23 到 1.46 pg DNA 之间变化。基因组大小与染色体数目大多没有正相关关系，但与花粉大小有关。在具有最大和最小染色体的基因型之间发现了平均染色体大小的 12 倍差异。一般来说，除了 B. boliviensis 和 B. pearcei 外，来自南美洲基因型的染色体比非洲、亚洲或中美洲基因型的染色体小。不同基因型的细胞学染色体研究显示染色体数量、长度、宽度和总染色体体积存在可变性，这证实了基因组大小的多样性。在几个研究的基因型中存在大的次级缢痕。这些数据表明，秋海棠属内的染色体数目和结构存在很大的变异性，这可能有助于解释该属内发现的大量分类群。
