**1. Introduction**

*Pyrus* belongs to the *Pyrus* ssp. of the Maloideae subfamily (Rosaceae), which mainly includes temperate fruit trees. There are more than 30 species in this genus, and 13 species are present in China [1,2]. The pear has been cultivated for over 3000 years in China. It is the third most commonly cultivated fruit tree after apple and citrus. China is the world's largest pear producer, accounting for 71.2% of the world's total pear area. Wild resources of *Pyrus* are extremely precious. They are mostly distributed in the valleys, hillsides, and forest margins, and are characterized by cold resistance, drought resistance, disease resistance, barren tolerance, saline–alkali tolerance, and strong adaptability. They provide material for screening quality rootstocks and for molecular breeding. The flowers, leaves, and fruit also have high ornamental value. The fruit of the pear is rich in fruit acids, vitamins, sugars, and many mineral elements essential for human life. It is sweet and refreshing and can be used to make dried and preserved pears, wine, and other products. Furthermore, it is regarded as having a high medicinal value and is used to reduce fevers, moisten the lungs, provide cough relief, and eliminate phlegm. Therefore, *Pyrus* is a valuable wild resource with a high exploitation value.

*P. hopeiensis* is a rare wild resource of the genus *Pyrus* in the subfamily Rosaceae [3,4], which has been listed as one of the "wild plants with a tiny population" in China. It can be found at the edges of hillside jungles at 100–800 m above sea level. At present, only a few genotypes have been found in Changli, Hebei Province. So far, there have been few studies about *P. hopeiensis*. Successful sequencing of the chloroplast genome of *P. hopeiensis* in our study provides a foundation for further study of its chloroplast molecular biology and can effectively promote genetic breeding and help clarify the molecular evolution of *P. hopeiensis*. It also provides some basis for the evolutionary analysis and classification of the genus *Pyrus*. What is more, this study gives a systematic review of *P. hopeiensis* that is useful for the conservation and restoration of wild *P. hopeiensis* resources.

Chloroplasts are the main site of photosynthesis, where fatty acids, starch, pigments, and other materials are synthesized [5]. They are independent of the plant nuclei and have a highly conserved genomic structure. Chloroplast DNA (cpDNA) has the beneficial characteristics of multiple copies, low molecular weight, and simple structure. Unlike the nuclear genome, which contains more repetitive sequences, and the mitochondrial genome, which is frequently rearranged, the chloroplast genome is rather conservative. The main mutation types are substitution and base insertion or deletion, and the mutation rate is low. Additionally, the chloroplast genome is of moderate size, making it easier to sequence than complex nuclear genomes. The chloroplast genome is maternally inherited in angiosperms with an independent evolutionary route [6]. Phylogenetic trees can be constructed using cpDNA data only, and the chloroplast genome shows good collinearity among plant groups. Sequencing data are relatively easy to analyze and the chloroplast genome structure sequence information can be used to study the species origin, evolution, and relationships between different species. In recent years, with the development of high-throughput sequencing technology, more chloroplast genomes of Rosaceae have been sequenced. In this study, the chloroplast genomes of two genotypes of *P. hopeiensis* and three other *Pyrus* (*P. ussuriensis* Maxin. cv. Jingbaili, *P. communis* L. cv. Early Red Comice, and *P. betulifolia*) were sequenced and compared with other Rosaceae plants. The genome structure and phylogeny of *Pyrus* were elucidated.
