Chloroplast genome of the invasive Pyrus calleryana underscores the high molecular diversity of the species

Abstract

The complete chloroplast genome of Pyrus calleryana (GenBank OM541581.1) was developed by de novo assembly from whole-genome sequencing data. Reference-guided (P. phaeocarpa) read mapping and assembly were followed by annotation and phylogenetic comparisons. The 159,965 bp P. calleryana chloroplast genome represented 36.56% GC content with a classical quadripartite architecture and two inverted repeats regions (IRs; each 26,392 bp) separating the large single-copy region (LSC; 87,942 bp) and the small single-copy region (SSC; 19.239 bp). In total, 125 unique features were annotated in that genome, including 83 protein coding genes, 38 tRNA coding genes, and 4 rRNA coding genes. Phylogenetic analyses based on the whole chloroplast genome sequences placed the P. calleryana among other Rosaceae plants, specifically among the Asian species of Pyrus.

Morphological Characteristics and Comparative Chloroplast Genome Analyses between Red and White Flower Phenotypes of Pyracantha fortuneana (Maxim.) Li (Rosaceae), with Implications for Taxonomy and Phylogeny

“…Moreover, the location of the IR/SC boundaries were nearly identical either within P. fortuneana or in comparison to P. atalantioides , P. coccinea , and P. angustifolia , and no gene arrangements were detected in Pyracantha chloroplast genomes ( Figure 3 and Figure S3 ). At a broader taxonomic scale, the genome size, GC content, and gene number of Pyracantha chloroplast genomes also resembled those of previously published Maleae species [ 55 , 56 ]. As an example, the gene for the translation initiation factor, infA , which was found to be lost in Pyracantha chloroplast genomes, was also widely absent in the chloroplast genomes of the tribe Maleae and Fabaceae and may have been transferred to the nuclear genome or replaced with other related genes [ 57 ].…”

Invasion by Callery pear (Pyrus calleryana) does not affect understory abundance or diversity in early-successional meadows

“…The prevalence of P. calleryana throughout the eastern United States is associated with the introduction of new cultivars and the practice of grafting, which together provide the trees with sufficient genetic variation to overcome self-incompatibility and form self-sustaining populations, alongside occasional hybridization with other Pyrus species (Connolly and Boutiette 2020; Culley et al 2011; Hardiman and Culley 2010; Vincent 2005). Indeed, P. calleryana across the United States is characterized by high genetic diversity, high gene flow, and a structured population (Nowicki et al 2022; Sapkota et al 2021).…”