RESUMEN
Prunus discoidea is a unique cherry blossom germplasm resource native to China. It is widely distributed across the provinces of Anhui, Zhejiang, Jiangxi, Jiangsu, and Henan, with significant variation. We employed phylogeographic analysis to reveal the evolutionary history of P. discoidea to better understand its genetic diversity and structure. This study provides more accurate molecular insights for the effective conservation and utilization of this germplasm resource. We conducted a phylogeographic analysis of 348 individual plants from 13 natural populations using three fragments (rpoB, rps16, and trnD-E) of chloroplast DNA (cpDNA) and one fragment (ITS) of ribosomal DNA. The results revealed that P. discoidea demonstrates a significant level of genetic diversity (Hd = 0.782; Rd = 0.478). Gene flow among populations was limited, and the variation within populations was the main source of genetic diversity in P. discoidea (among populations: 34.26%, within populations: 65.74%). Regarding genetic differences among populations, Nst (0.401) showed greater differences than Gst (0.308; p < 0.05), demonstrating that there was a significant geographical structure of lineage. One lineage was the central region of Anhui and the western region of Hubei. The other lineage was the Jiangsu region and the Zhejiang region. P. discoidea diverged from Prunus campanulata approximately 1.5 million years ago, during the Pleistocene epoch. This study provides a scientific theoretical basis for the conservation and utilization of germplasm resources of P. discoidea.
RESUMEN
Prunus conradinae (subgenus Cerasus, Rosaceae) is a significant germplasm resource of wild cherry blossom in China. To ensure the comprehensiveness of this study, we used a large sample size (12 populations comprising 244 individuals) which involved the fresh leaves of P. conradinae in Eastern, Central, and Southwestern China. We combined morphological and molecular evidence (three chloroplast DNA (cpDNA) sequences and one nuclear DNA (nr DNA) sequence) to examine the population of P. conradinae variation and differentiation. Our results revealed that Central, East, and Southwest China are important regions for the conservation of P. conradinae to ensure adequate germplasm resources in the future. We also found support for a new variant, P. conradinae var. rubrum. We observed high genetic diversity within P. conradinae (haplotype diversity [Hd] = 0.830; ribotype diversity [Rd] = 0.798), with novel genetic variation and a distinct genealogical structure among populations. There was genetic variation among populations and phylogeographic structure among populations and three geographical groups (Central, East, and Southwest China). The genetic differentiation coefficient was the lowest in the Southwest region and the gene exchange was obvious, while the differentiation was obvious in Central China. In the three geographic groups, we identified two distinct lineages: an East China lineage (Central China and East China) and a Southwest China lineage ((Central China and Southwest China) and East China). These two lineages originated approximately 4.38 million years ago (Mya) in the early Pliocene due to geographic isolation. P. conradinae expanded from Central China to East China at 3.32 Mya (95% HPD: 1.12-5.17 Mya) in the Pliocene. The population of P. conradinae spread from East China to Southwest China, and the differentiation time was 2.17 Mya (95% (HPD: 0.47-4.54 Mya), suggesting that the population of P. conradinae differentiated first in Central and East China. The population of P. conradinae experienced differentiation from Central China to Southwest China around 1.10 Mya (95% HPD: 0.11-2.85 Mya) during the early Pleistocene of the Quaternary period. The southeastern region of East China, near Mount Wuyi, likely serves as a refuge for P. conradinae. This study establishes a theoretical foundation for the classification, identification, conservation, and exploitation of germplasm resources of P. conradinae.
RESUMEN
Prunustongmuensis, a new species of cherry blossom, is described and illustrated from Wuyishan National Park, southeast China. This species is characterized by its tubular to nearly bottle-shaped receptacles and dark purple drupes. It can be distinguished from other wild cherry trees by its flowers and leaves, reddish brown young leaves, presence of 1-2 glands at the base of leaves, petioles densely covered with yellowish brown villi, longer pedicels (0.6-2.5 cm), villous pistil, and dark purple drupes. In the present study, we conducted a comprehensive morphological study based on specimens of the new species and its morphologically close species, field observations, and examination of pollen morphology. In addition, our phylogenetic analysis based on the complete plastid genome sequences further confirms the status of the new species and indicates that it is closely related to Prunusclarofolia, however, it notably differs in leaf shape, size, petiole villus color, gland location, timing of flower and leaf openings, and reflexed or spread sepals, as well as drupe color.