OBJECTIVETo analyze the codon usage of chloroplast genome and the influencing factor in Eleutherococcus senticosus.

METHODCodon of 52 genes, which were selected from the chloroplast genome sequence of E. senticosus, was multivariate statistical and correspondence analyzed using CodonW and SPSS software.

RESULTGC content at the three position of codons by turns was 46.46%, 38.26%, 29.88%, whereas GC1 and GC2 had a significant correlation coefficient (P < 0.01). The correlation coefficient with GC12, and GC3 was 0.205 and was not significant correlated. There were 30 codons which relative synonymous codon usage was greater than 1 and 29 codons end with A and T. In the corresponding analysis, the first axis shows 10.35% variation. And there was significant correlation coefficient between ENC and GC3. The correlation coefficients with GC3 and ENC were -0.288 and 0.353, respectively. We defined 16 codons from 16 amino acids as the major preference codons in chloroplast genome of E. senticosus.

CONCLUSIONThe third positions for all codon are preferred to ending with A and T. The codon usage bias is formed under effect of mutation and selection, as well as other factors. But the selection will have a far greater impact than others.