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Summary China is the origin and evolutionary centre of Oriental pears. Pyrus betuleafolia is a wild species native to China and distributed in the northern region, and it is widely used as rootstock. Here, we report the de novo assembly of the genome of P. betuleafolia‐Shanxi Duli using an integrated strategy that combines PacBio sequencing, BioNano mapping and chromosome conformation capture (Hi‐C) sequencing. The genome assembly size was 532.7 Mb, with a contig N50 of 1.57 Mb. A total of 59 552 protein‐coding genes and 247.4 Mb of repetitive sequences were annotated for this genome. The expansion genes in P. betuleafolia were significantly enriched in secondary metabolism, which may account for the organism's considerable environmental adaptability. An alignment analysis of orthologous genes showed that fruit size, sugar metabolism and transport, and photosynthetic efficiency were positively selected in Oriental pear during domestication. A total of 573 nucleotide‐binding site (NBS)‐type resistance gene analogues (RGAs) were identified in the P. betuleafolia genome, 150 of which are TIR‐NBS‐LRR (TNL)‐type genes, which represented the greatest number of TNL‐type genes among the published Rosaceae genomes and explained the strong disease resistance of this wild species. The study of flavour metabolism‐related genes showed that the anthocyanidin reductase (ANR) metabolic pathway affected the astringency of pear fruit and that sorbitol transporter (SOT) transmembrane transport may be the main factor affecting the accumulation of soluble organic matter. This high‐quality P. betuleafolia genome provides a valuable resource for the utilization of wild pear in fundamental pear studies and breeding.

Background Pyrus ussuriensis Maxim. are rich in nutrients, with a pleasant aroma and postharvest softening properties. Postharvest softening influences shelf life of fruit and fruit quality. Melatonin is a natural and safe preservative, which can effectively maintain fruit quality after harvesting, and delay softening of fruit. The aim of study was to elucidate mechanism of pear fruit softening and fruit aroma during postharvest storage and effect of melatonin. Results Ethylene production rate, respiration rate, weight loss of fruit, soluble solid content, titratable acidity were assessed, and transmission electron microscopy, metabolite profiling, and whole-transcriptome RNA-sequencing were performed. Four important pathways that pentose and glucuronate interconversion, galactose metabolism, sphingolipid metabolism and the starch and sucrose metabolism pathway were involved in pear fruit softening. Ethylene production pathway-related genes, such as ACS and ACO were involved in pear fruit softening and expression of that under exogenous melatonin treatment were slightly inhibited. Fruit aroma changed after storage mainly through lipoxygenase pathway under ddH 2 O treatment and exogenous melatonin treatment changed composition of volatile organic compounds. CeRNA networks associated with pear softening and aroma were established. Mdm-miR159a, mdm-miR396a/b-p3 and mdm-miR408a were found to modulate both fruit softening and aroma formation through ceRNA analysis. Mdm-miR10988-p3 was functionally diverse and as major regulatory components in ceRNA network. Conclusions This study indicated that degradation of cell wall caused pear fruit softening, lipoxygenase pathway mainly affected change of fruit aroma during postharvest storage and exogenous melatonin treatment could improve fruit firmness after storage and alter pear's aroma. The mechanism underlying these effects was elucidated, providing theoretical basis for study of pear fruit softening and preservation technology.

Biochar-based fertilizers (BF) have emerged as a promising strategy to improve soil physicochemical and biological properties, thereby enhancing tea yield and quality. A field experiment was conducted using two types of BF- ordinary BF (BF1, containing 15% biochar) and optimized BF (BF2, containing 30% biochar)- applied for either 1 or 2 years. The effects on the soil nutrients, tea plant growth, tea quality, and metabolomics profiles were assessed. Results showed that BF application significantly increased soil pH and nutrient availability, as well as the bud length and hundred-bud weight ( < 0.05). Notably, BF2 applied for 2 years significantly increased the content of free amino acids, total flavonoids, soluble sugar, while reduced the phenol-ammonia ratio ( < 0.05), thereby improving tea quality. Further metabolomics analysis revealed that BF2 treatment significantly elevated the levels of amino acids, including theanine, threonine, proline, valine, and glutamic acid, while decreasing catechins including C, EC, and EGCG, thus leading to reduced bitterness and astringency and enhanced freshness. Besides, differential metabolites were mainly involved in amino acid and flavonoid biosynthesis pathway. Taken together, prolonged BF2 application significantly improved soil fertility, promoted tea growth, and enriched flavor-related metabolites, offering valuable insights for optimizing fertilization strategies in tea plantations.

Background Pear is one of the most popular and widely cultivated fruits globally, with rich cultivar diversity. Pyrus species are characterized by self-incompatibility and the absence of reproductive barriers between species, leading to extensive gene flow and genetic recombination among different types of cultivars. As a result, cultivar identification technologies have considerable practical significance in pear production. Multiple nucleotide polymorphism (MNP) technology, which combines multiplex PCR amplification and high-throughput sequencing, offers high efficiency and accuracy in pear cultivar identification, and meets the needs of cultivar innovation and industry development. Results We applied MNP technology to pear cultivar identification for the first time, establishing fingerprints for major pear cultivars and exploring the feasibility of MNP markers for pear population structure analysis. Based on genomic resequencing data from 143 pear accessions, 558 marker loci were initially developed, and 310 core markers were retained after screening. The 310 MNP markers showed high polymorphism, with an average of 18.14 alleles per marker locus and PIC values ranging from 0.57 to 0.99. Validation using 76 representative pear cultivars demonstrated reproducibility and accuracy rates exceeding 99% for the 310 MNP markers. A total of 2,850 pairwise comparisons among the 76 cultivars showed an average genetic differentiation of 90.89%. Population structure analyses based on MNP markers effectively reflected the classification relationships among the 76 cultivars, clearly distinguishing European from Asian pears. Conclusion In summary, the developed pear MNP markers possess high polymorphism, stability, and cultivar-discrimination capability, promising extensive future applications in pear cultivar identification and population genetic research.

Flesh texture is an important quality trait and is related to people’s preference for fruit, especially for crisp pears. Puncture tests were carried out on 156 crisp pear fruit germplasm samples to analyze the diversity level of texture traits, to clarify the correlation between sensory description evaluation and instrumental traits, and to explore the effects of fruit ripening, size, and shelf life on the change in flesh texture. The results showed that puncture parameters were significantly different between crisp pear cultivars, and the work associated with the flesh limit compression force had the highest coefficient of variation (0.281). There was a significant correlation between puncture parameters and sensory evaluation scores. The correlation between sensory score and flesh firmness was the highest, with a correlation coefficient of 0.708, indicating that hardness can significantly influence the sensory evaluation of texture. Cluster analysis based on sensory evaluation and puncture determination could divide the germplasm resources of crisp pear into five texture categories: loosen, crunchy, crisp, tight–crisp, and dense. A comprehensive texture score model, constructed by principal component analysis, showed consistency with sensory evaluation scores and proved that the combination of a puncture test and sensory evaluation is the best way to identify and evaluate the texture of crisp pear. Further analysis of the influencing factors of flesh texture showed that fruit maturity and shelf life had significant effects on flesh quality. This study provides an important reference for the standardization, evaluation, and utilization of crisp pear variety resources.

Wild Ussurian Pear germplasm resource has rich genetic diversity, which is the basis for genetic improvement of pear varieties. Accurately and efficiently identifying wild Ussurian Pear accession is a prerequisite for germplasm conservation and utilization. We proposed YOLOv10n-MCS, an improved model featuring: (1) Mixed Local Channel Attention (MLCA) module for enhanced feature extraction, (2) Simplified Spatial Pyramid Pooling-Fast (SimSPPF) for multi-scale feature capture, and (3) C2f_SCConv backbone to reduce computational redundancy. The model was trained on a self-made dataset of 16,079 wild Ussurian Pear leaves images. Experiment results demonstrate that the precision, recall, mAP50, parameters, FLOPs, and model size of YOLOv10n-MCS reached 97.7(95% CI: 97.18 to 98.16)%, 93.5(95% CI: 92.57 to 94.36)%, 98.8(95% CI: 98.57 to 99.03)%, 2.52M, 8.2G, and 5.4MB, respectively. The precision, recall, and mAP50 are significant improved of 2.9%, 2.3%, and 1.5% respectively over the YOLOv10n model (p<0.05). Comparative experiments confirmed its advantages in precision, model complexity, model size, and other aspects. This lightweight model enables real-time wild Ussurian Pear identification in natural environments, providing technical support for germplasm conservation and crop variety identification.

Pears are popular among consumers for their juicy and delicious taste. In this study, the sugar and organic acid compositions of pear fruits with different texture types during development were determined by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), and fruit texture traits were determined by a texture analyzer. The results showed that the dominant sugar in soft and crispy types of pear fruits was fructose. The main difference between pears was the second-highest sugar component; glucose content was higher in crispy-flesh pear fruits while sucrose content was higher in soft-flesh pear fruits. The composition of organic acid components in both texture types of pear fruits was similar. The turning points of changes in the content of sucrose, sorbitol, glucose and quinic acid were different between different-textured pear varieties. A Pearson correlation analysis showed that sugar and organic acid components were significantly correlated with single fruit weight and soluble solid contents (SSCs), respectively. There was a high correlation among texture traits, individual sugars and organic acids. A partial least squares discriminant analysis (PLS-DA) VIP score plot showed that the differential traits with scores greater than 1 were total soluble sugars/total organic acids (TSSs/TAs), fracture and malic acid/citric acid (MA/CA), which could distinguish pear fruits of different texture types better and reflect the uneven quality differences among pear fruits adapted to different origins. The comprehensive analysis results of the flesh texture parameters and sugar and organic acid components are in line with objective reality and will provide a reference for quantitative indicators of the sensory evaluation of pear varieties as well as for molecular mechanism research on trait differences.

Aroma is an important sensory factor in evaluating the quality of pear fruits. This study used headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS) to analyze the volatile organic compounds (VOCs) of three crispy pears and five soft pears during shelf life, and the changes in soluble solids content (SSC) were analyzed. The results showed that the SSC of the soft pears such as Nanguoli, Jingbaili and Louis was always higher than that of the crispy pears throughout shelf life. A total of 160 VOCs were detected in the eight pear varieties. Orthogonal partial least squares discriminant analysis (OPLS-DA) and hierarchical cluster analysis (HCA) combined with predictor variable importance projection (VIP) showed that the eight pear varieties could be obviously classified into six groups according to the differences in their VOCs, and 31 differential VOCs were screened out, which could be used to differentiate between pears with different flesh textures. The results of clustering heat map analysis showed that, with the extension of shelf life, the content of each different VOC did not change much in crispy pears, whereas the difference in soft pears was larger. This study confirmed the potential of determining the optimal shelf life of different pear varieties about aroma evaluation and studying the mechanism of differences in VOCs in the future.

As the third most important temperate fruit, Pear ( Pyrus spp.) exhibits a remarkable genetic diversity and is classified into two mainly categories known as Asian pear and European pear. Although several pear genomes are available, most of the released versions are fragmented and not chromosome-level high-quality. In this study, we report two high-quality genomes for Pyrus bretschneideri Rhed. cv. ‘Danshansuli’ (DS) and Pyrus communis L. cv. ‘Conference’ (KFL), which represent the predominant Asian and European cultivars, respectively, with nearly telomere-to-telomere (T2T) gap-free level. The finally assembled genome sizes for DS and KFL were 510.98 Mb and 510.71 Mb, respectively, with Contig N50 of 29.47 Mb and 30.47 Mb, where each chromosome was represented by a single contig. The DS and KFL genomes yielded a total of 46,394 and 44,702 protein-coding genes, respectively. Among these genes, the functional annotation accounted for 96.47% and 96.46% in the DS and KFL genomes. The two novels nearly T2T genomic information offers an invaluable resource for comparative genomics, genetic diversity analysis, molecular breeding strategies, and functional exploration.

Located in the southwestern region of China, the Yunnan–Kweichow Plateau, is closely related to the origins of Pyrus L. Despite this important status, there has been relatively little population genetics research focused on the wild Pyrus species in this area. To address this gap in knowledge, the present study was conducted investigating wild Pyrus species distributions in the Yunnan–Kweichow Plateau region. These analyses entailed the collection of 80 accessions, whole-genome resequencing, and the detection of variants including SNPs, InDels, SVs, and CNVs. Genetic structure analyses revealed clear differences between P. pashia and P. calleryana, where the former was additionally subdivided into five groups. The genetic structure of these accessions was closely aligned with their geographic distribution, highlighting the fragmented nature of wild Pyrus populations on the Yunnan–Kweichow Plateau. Analyses of genetic diversity suggested that the central and easter portions of Yunnan Province are key centers of Pyrus diversity on the Yunnan–Kweichow Plateau, whereas the highest degree of differentiation was observed for wild Pyrus in the southwest and northwest regions. Demographic analyses indicated that wild Pyrus populations on the Yunnan–Kweichow Plateau are currently in a state of population contraction, with evidence of migration events between these populations.