Characterization and phylogenetic analysis of the chloroplast genome of endangered Impatiens chishuiensis

[Objective] The chloroplast genome structure and phylogenetic location of Impatiens chishuiensis were studied in order to provide scientific basis for the conservation of plant germplasm resources, genetic diversity, and phylogeny of I. chishuiensis. [Methods] Based on the chloroplast genome sequence of I. chishuiensis, an endemic species in China, the assembly, annotation, gene characterization, sequence repetition and phylogenetic analysis of chloroplast genome were performed by bioinformatic softwares. [Results] (1) The chloroplast genome of I. chishuiensis has a typical tetrameric structure with a total GC content of 37% and a length of 152 892 bp. It encodes a total of 120 genes, including 95 protein-coding genes, 8 rRNA genes, and 17 tRNA genes. (2) A total of 87 SSR sequences was detected. 20 327 codons were detected, with leucine (Leu) being the most abundant and tryptophan (Trp) being the least. (3) Impatiens was divided into two subgenera, including subg. Clavicarpa and subg. Impatiens. I. chishuiensis is a species of subg. Clavicarpa and is the closest with I. alpicola. [Conclusion] I. chishuiensis has a typical tetrad structure, and the SSR sequence is mainly formed by A/T single base. Phylogenetic analyses place it in the subg. Clavicarpa.