Cannabis sativa is an annual erect herb that typically reaches a height ranging from 1 to 3 m. Its branches bear longitudinal grooves and are densely covered with gray-white appressed hairs. The leaves are palmately divided, with the lobes being lanceolate or linear-lanceolate in shape. The male flowers are yellow-green in color, and their pedicels are slender and drooping. The achenes are flat on one side and are encircled by persistent yellowish-brown bracts. The pericarp is brittle and features a fine reticulated pattern. The seeds are flat, while the endosperm is fleshy. The embryos are curved, and the cotyledons are thick and fleshy as well. The leaves of Heilongjiang hemp in this study were sourced from the Heilongjiang Academy of Agricultural Sciences (longitude: 126.621016, latitude: 45.685433). Extract total genomic DNA using an improved CTAB method [3]. The specimens are stored in the specimen room of Heilongjiang University of Traditional Chinese Medicine in Heilongjiang Province (HLJDA20240328001). The whole genome of the chloroplast of Cannabis sativa was sequenced using the Illumina NovaSeq 6000 platform [5]. The resultant original data amounted to approximately 4.7GB, with a GC content accounting for 37 %. The size of its chloroplast genome is 153,871 bp.The chloroplast genome exhibits a circular structure. This circular genome is composed of two copies of reverse repeats (designated as IRa and IRb, each with a length of 26,010 bp), which are separated by two distinct regions: the large single copy region (abbreviated as LSC, measuring 84,038 bp) and the small single copy region (referred to as SSC, with a length of 17,813 bp) (Fig. 2). Compared with previous studies on cannabis chloroplasts, our latest research shows that the genome of Yunnan Yunma 7 in China contains 74 protein coding genes, while the Korean non-drug variety, Cheungsam, the African variety, Yoruba Nigeria The genome contains 86 protein coding genes, suggesting that different protein coding genes may affect different genetic traits. However, Heilongjiang hemp is superior to Yunnan hemp Yunma 7 in China the Korean non-drug variety, Cheungsam, the African variety, Yoruba Nigeria [6], Italian, “Carmagnola” and Russian‘‘Dagestani’’ The total length of chloroplast genomes is almost the same. Especially with the same duplicated genes as Yunma 7 in Yunnan, China (ndhB, rps7, rps12, rps19, rpl2, rpl23, ycf1, ycf2, rrn4.5, rrn5, rrn16, and rrn23) [3]. From this, it can be inferred that the genetic background of cannabis from Heilongjiang and Yunnan provinces in China is similar, which will be beneficial for future research on chloroplasts in the cannabis genus (Table 1).

From the center going outward, the first circle indicates that Cannabis sativa. has 86 genes with a length of 153871 bp and a GC content of 38 %. The next circle displays the positions of the large single copy gene region (LSC), small single copy gene region (SSC), and reverse repeat regions (IRA and IRB). The third circle represents the content of GC. The genes located outside the fourth circle are transcribed counterclockwise. As shown in the figure, genes from different functional groups are color coded. The classification of gene functions is shown in the bottom left corner.

Among these 86 genes, eight genes, specifically trnA-UGC, trnI-CAU, trnI-GAU, trnL-CAA, trnN-GUU, trnR-ACG, trnS-GCU, and trnV-GAC, are duplicated. Moreover, 16 genes, namely trnK-UUU, rps16, trnG-UCC, atpF, rpoC1, trnL-UAA, trnV-UAC, petB, petD, rpl16, rpl2, ndhB, trnI-GAU, trnA-UGC, ndhA, and trnI-GAU, are found to contain an intron. In addition, two particular genes, namely ycf3 and clpP, have been found to incorporate two introns each.

A total of 241 simple sequence repeats (SSRs) were identified through the application of MicroSAtellite (MISA) technology.Six types of SSRs were identified using the relevant detection methods: 165 single nucleotides, 55 dinucleotides, 7 trinucleotides, 10 tetranucleotides, 2 pentanucleotides, and 2 hexanucleotides. Fig. 3 presents the types and quantities of the SSRs that have been determined (Fig. 3A). For the purpose of investigating the phylogenetic position of cannabis, the cp genome sequences of cannabis and five members of the Cannabaceae family, for which complete cp genome sequences can be obtained from the NCBI, were aligned, and a phylogenetic tree was constructed. The phylogenetic analysis demonstrated that Humulus scandens was closely affiliated with cannabis (Fig. 3B).