【摘要】 利用Codon W等软件,对木薯叶绿体基因组55条蛋白编码序列的密码子进行了分析。发现木薯叶绿体基因组密码子的GC分布不均匀，平均含量为37.81%，其中GC1、GC2、GC3的含量分别为46.64%、39.19%和27.58%;GC3s的平均含量为24.46%，表明木薯叶绿体密码子中A或T的使用频率高于G和C。有效密码子数（ENC）的平均值为47.57，说明木薯叶绿体基因组密码子的偏好性较弱。中性绘图、ENC-plot和PR2-plot分析结果表明木薯叶绿体基因组密码子的使用偏好主要受选择的影响。RSCU> 1的密码子共有30个，其中97%的密码子以A或T结尾，再次证明木薯偏爱使用以A或T结尾的密码子。筛选出最优密码子9个，分别是TTG、TCA、CCA、CAT、AAT、GAT、CGA、AGA、GGA。更多还原

【Abstract】 Codon usages of 55 chloroplast genes in cassava were analyzed by the Codon W and related software. The results showed that average GC content of the cassava chloroplast genes was 37.81%, and the average GC content of three positions of the gene codons was 46.64%, 39.19% and 27.58%. GC3s content of gene condons was 24.46%, indicating that synonymous codons in chloroplast genome tend to end with A/T. The average ENC was 47.57, indicating that the condon bias was weak.Neutral mapping analysis, PR2-plot and ENC-plot analysis demonstrated that the codon preference of cassava chloroplast genome was mainly affected by selection. There were 30 codons with RSCU>1, 97% of which ended in A or T, again indicating that synonymous codons in chloroplast genome tend to end with A/T. Nine optimal codons were finally determined, which were TTG, TCA, CCA, CAT, AAT, GAT, CGA, AGA and GGA.更多还原