Schwencke J, Bureau J-M, Crosnier M-T, Brown S
Biotechnologie des Symbioses Forestières Tropicales (ORSTOM-CIRAD-Forêt), 45 bis Av. de la Belle Gabrielle, F-94376 Nogent-sur-Marne, France, , , , , , FR.
Institut des Sciences Végétales, CNRS, UPR40, F-91198 Gif-sur-Yvette, France, , , , , , FR.
Plant Cell Rep. 1998 Dec;18(3-4):346-349. doi: 10.1007/s002990050584.
The genome size and base composition of diploid plant species from three genera of the Casuarinaceae family were determined by flow cytometry. Casuarina glauca Sieb. ex Spring. and Gymnostoma deplancheana (Miq.) L. Johnson showed a small genome with 2C = 0.70 pg, 58.6% AT, 40.5% GC for the first species and 2C = 0.75 pg, 58.7% AT, 40.5% GC for the second. Allocasuarina verticillata (Lam.) L. Johnson had a larger genome: 2C = 1.90 pg, 59.3% AT, 41.1% GC. One haploid genome of C. glauca is therefore about 340×10 base pairs. In leaves, roots or bark of these three species, polysomaty was virtually absent: a maximum frequency of 4C nuclei of only 0.08 was found in bark of C. glauca. The genome sizes of C. glauca and G. deplancheana are among the smallest described for higher plants. Small genome size, diploidy and the absence of polysomaty are advantageous traits for facilitating molecular approaches to improvement of these actinorhizal plants and developing the study of their symbiotic interactions with Frankia.
通过流式细胞术测定了木麻黄科三个属的二倍体植物物种的基因组大小和碱基组成。海滨木麻黄（Casuarina glauca Sieb. ex Spring.）和光裸木麻黄（Gymnostoma deplancheana (Miq.) L. Johnson）显示出较小的基因组，第一个物种的2C = 0.70 pg，AT含量为58.6%，GC含量为40.5%；第二个物种的2C = 0.75 pg，AT含量为58.7%，GC含量为40.5%。轮叶木麻黄（Allocasuarina verticillata (Lam.) L. Johnson）的基因组较大：2C = 1.90 pg，AT含量为59.3%，GC含量为41.1%。因此，海滨木麻黄的一个单倍体基因组约为340×10个碱基对。在这三个物种的叶、根或树皮中，几乎不存在多体现象：在海滨木麻黄的树皮中仅发现4C核的最大频率为0.08。海滨木麻黄和光裸木麻黄的基因组大小是已报道的高等植物中最小的。小基因组大小、二倍体以及不存在多体现象是有利于促进对这些放线菌根植物进行分子改良以及开展其与弗兰克氏菌共生相互作用研究的有利性状。
