摘要
对云南山茶(Camellia reticulata)8个品种的核核糖体DNA内转录间隔区(nrDNA ITS)进行克隆测序,将获得的ITS序列进行GC含量、5.8S区二级结构的稳定性、替代模式、核苷酸多样性及系统发育关系的相关分析。实验结果显示,云南山茶8个品种的ITS序列存在丰富的基因组内多态性,同时包含中性进化的假基因,表明其ITS序列逃离了一致性进化。云南山茶ITS序列多态性的原因可能来自广泛的种间杂交,以及rDNA位点在基因组中有不确定的物理位置。ITS假基因为品种的物种形成研究提供了更全面的遗传证据,同时也提示了利用ITS假基因进行系统发育分析可能会对其真实的系统关系造成影响。
In this study, nrDNA ITS copies from Camellia retioulata were cloned and se- quenced. Complementary analyses were performed including GC content,estimated seconda- ry structure stability of the 5.8S region, pattern of base substitutions, nucleotide diversity, and phylogenetic reconstruction. The ITS copies showed a high degree of polymorphism including pseudogenes in C. reticulata,suggesting an incomplete concerted evolution of the ITS region that may have resulted from hybridization events and dispersed distribution of rDNA loci a- mong chromosomes. Diversity of the pseudogenes can help in understanding the origin of the cultivar C. reticulata. However,great caution should be shown when using these pseudogenes to reconstruct phvloclenetic tress.
出处
《植物科学学报》
CAS
CSCD
北大核心
2013年第1期1-10,共10页
Plant Science Journal
基金
国家质检总局科技计划项目:云南出口花卉物种信息平台建立及分子生物学检测技术研究(2010IK273)