Molecular characterization of PSEUDO RESPONSE REGULATOR family in Rosaceae and function of PbPRR59a and PbPRR59b in flowering regulation.

BACKGROUND: PSEUDO RESPONSE REGULATOR (PRR) genes are essential components of circadian clock, playing vital roles in multiple processes including plant growth, flowering and stress response. Nonetheless, little is known about the evolution and function of PRR family in Rosaceae species. RESULTS: In this study, a total of 43 PRR genes in seven Rosaceae species were identified through comprehensive analysis. The evolutionary relationships were analyzed with phylogenetic tree, duplication events and synteny. PRR genes were classified into three groups (PRR1, PRR5/9, PRR3/7). The expansion of PRR family was mainly derived from dispersed and whole-genome duplication events. Purifying selection was the major force for PRR family evolution. Synteny analysis indicated the existence of multiple orthologous PRR gene pairs between pear and other Rosaceae species. Moreover, the conserved motifs of eight PbPRR proteins supported the phylogenetic relationship. PRR genes showed diverse expression pattern in various tissues of pear (Pyrus bretschneideri). Transcript analysis under 12-h light/ dark cycle and constant light conditions revealed that PRR genes exhibited distinct rhythmic oscillations in pear. PbPRR59a and PbPRR59b highly homologous to AtPRR5 and AtPRR9 were cloned for further functional verification. PbPRR59a and PbPRR59b proteins were localized in the nucleus. The ectopic overexpression of PbPRR59a and PbPRR59b significantly delayed flowering in Arabidopsis transgenic plants by repress the expression of AtGI, AtCO and AtFT under long-day conditions. CONCLUSIONS: These results provide information for exploring the evolution of PRR genes in plants, and contribute to the subsequent functional studies of PRR genes in pear and other Rosaceae species.

A high-quality genome assembly of the shrubby cinquefoil (Dasiphora fruticosa).

Dasiphora fruticosa (Rosaceae), commonly known as shrubby cinquefoil, is a flowering shrub of high ornamental value yet underutilized in East Asian landscapes. Given its broad elevational distribution range, D. fruticosa serves as an ideal model for studying genetic adaptations and speciation along elevation gradients. Here, we present a high-quality chromosome-scale assembly of D. fruticosa with a genome size of 249.23 Mb and a contig N50 length of 14.01 Mb. The genome sequence contains 32,613 protein-coding genes, of which 30,643 (93.96%) were functionally annotated. Compared to the published D. fruticosa genome sequence, our assembly demonstrates higher completeness and continuity. Furthermore, comparative genomic analyses provide insights into the phylogenetic relationship and high-altitude adaptation of D. fruticosa. Overall, our study offers a valuable genetic resource for both molecular and evolutionary research on shrubby cinquefoil.

Reversed phase HPLC with UHPLC benefits for the determination of tocochromanols in the seeds of edible fruits in the Rosaceae family.

Rosaceae family includes several edible fruit species processed in vast quantities and generates large amounts of seeds valuable in tocopherols. In the present study, the composition of tocochromanols in the seeds of 141 samples was determined by reversed phase high-performance liquid chromatography (RPLC) with diode array detector (DAD), fluorescence detector (FLD) and confirmed by mass detector (MS). The thirteen species belonging to the Rosaceae family were classified by multivariate statistical analysis, hierarchical cluster analysis (HCA) and principal component analysis (PCA) into two groups based on tocochromanols content. Group 'A' includes pears (Pyrus communis), sweet cherry (Prunus avium), sour cherry (Prunus cerasus), apricots (Prunus armeniaca), hexaploid plums (Prunus domestica), diploid plums (Prunus cerasifera), raspberry (Rubus idaeus), and rose hip (Rosa rugosa); while group 'B' quince (Cydonia oblonga), Japanese quince (Chaenomeles japonica), strawberry (Fragaria × ananassa), dessert apples (Malus domestica), and crab apples (Malus spp.). Two rapid (6-7 min) and low pressure (7.2-8.1 MPa) separation methods were developed and validated using two core-shell columns (i) C18 and (ii) F5. The F5 achieved a separation of ß and γ isomers while the C18 column did not.

Recent Advances in Polysaccharides from Chaenomeles speciosa (Sweet) Nakai.: Extraction, Purification, Structural Characteristics, Health Benefits, and Applications.

This article systematically reviews the extraction and purification methods, structural characteristics, structure-activity relationship, and health benefits of C. speciosa polysaccharides, and their potential application in food, medicine, functional products, and feed, in order to provide a useful reference for future research. Chaenomeles speciosa (Sweet) Nakai. has attracted the attention of health consumers and medical researchers as a traditional Chinese medicine with edible, medicinal, and nutritional benefits. According to this study, C. speciosa polysaccharides have significant health benefits, such as anti-diaetic, anti-inflammatory and analgesic, anti-tumor, and immunomodulatory effects. Researchers determined the molecular weight, structural characteristics, and monosaccharide composition and ratio of C. speciosa polysaccharides by water extraction and alcohol precipitation. This study will lay a solid foundation for further optimization of the extraction process of C. speciosa polysaccharides and the development of their products. As an active ingredient with high value, C. speciosa polysaccharides are worthy of further study and full development. C. speciosa polysaccharides should be further explored in the future, to innovate their extraction methods, enrich their types and biological activities, and lay a solid foundation for further research and development of products containing polysaccharides that are beneficial to the human body.

Morphological and physiological investigations reveal the regulatory effect of exogenous paclobutrazol on flowering promotion by winter warming in Chaenomeles speciosa 'Changshouguan'.

The application of exogenous paclobutrazol (PP333) can improve the ability of winter warming to promote flowering in Chaenomeles speciosa, but the underlying mechanism is unclear. In this study, the cultivar 'Changshouguan' was sprayed with different concentrations of PP333 during flower bud differentiation, and the changes in the anatomical structures and physiological characteristics of the flower buds during the differentiation process, as well as the growth state of the flower buds and the effect on flowering promotion after winter warming treatment, were comprehensively investigated. The results showed that different concentrations of PP333 could advance the flowering time of 'Changshouguan' by 15-24 d under the warming treatment and increase the flowering duration to 17 d compared with those under the warming treatment alone (CK), and 1000 mg/L was the best treatment. Compared with the CK treatment, the PP333 treatment decreased the contents of indole acetic acid (IAA) and gibberellic acid (GAs) and increased the contents of zeatin ribosides (ZRs) and abscisic acid (ABA), thus changing the balance of hormones during flower bud differentiation. The inflection point (low point) of the curve shapes of the ZRs/GAs and ZRs/IAA ratios appeared significantly earlier, which showed a pattern consistent with soluble sugar and protein content and antioxidant activity. Interestingly, the above changes also corresponded to earlier flowering times during the warming process. Taken together, these results indicate that spraying an appropriate concentration of PP333 in the early stage of 'Changshouguan' flower bud differentiation promotes the early differentiation of flower buds and early flowering under winter warming treatment by altering their endogenous hormone content and homeostasis and changing their physiological state. The key to maintaining a relatively long flowering period in plants in the PP333 treatment group after flowering promotion was the increased accumulation of sugars and proteins.

Antidepressant-like Effects of Chinese Quince (Chaenomeles sinensis) Fruit Based on In Vivo and Molecular Docking Studies.

In this study, we examined the potential antidepressant-like effects of Chinese quince fruit extract (Chaenomeles sinensis fruit extract, CSFE) in an in vivo model induced by repeated injection of corticosterone (CORT)-induced depression. HPLC analysis determined that chlorogenic acid (CGA), neo-chlorogenic acid (neo-CGA), and rutin (RT) compounds were major constituents in CSFE. Male ICR mice (5 weeks old) were orally administered various doses (30, 100, and 300 mg/kg) of CSFE and selegiline (10 mg/kg), a monoamine oxidase B (MAO-B) inhibitor, as a positive control following daily intraperitoneal injections of CORT (40 mg/kg) for 21 days. In our results, mice treated with CSFE exhibited significant improvements in depressive-like behaviors induced by CORT. This was evidenced by reduced immobility times in the tail suspension test and forced swim test, as well as increased step-through latency times in the passive avoidance test. Indeed, mice treated with CSFE also exhibited a significant decrease in anxiety-like behaviors as measured by the elevated plus maze test. Moreover, molecular docking analysis indicated that CGA and neo-CGA from CSFE had stronger binding to the active site of MAO-B. Our results indicate that CSFE has potential antidepressant effects in a mouse model of repeated injections of CORT-induced depression.

Research on Application of Japanese Quince (Chaenomeles L.) and Pork Collagen in Dark Chocolate-Benefits in Prevention of Inflammation In Vitro Model.

In the present study, the effect of the addition of quince and collagen type I and III to dessert chocolate on its functional properties was determined. The study evaluated the antioxidant potential of the tested formulations using the FRAP method and the linoleic acid oxidation test and beta-carotene bleaching test. The tested samples were also evaluated for inhibitory activity against enzymes important in preventive health (inflammation and neurodegenerative disorders) namely: AChE, BChE, GR, GPx, COX, and SOD. The addition of quince and collagen to the chocolate samples resulted in higher activity compared to the control sample, as indicated by the FRAP test. The experiment highlighted the impact of including quince fruit on the antioxidant activity of the chocolate samples. Interestingly, merely increasing the quince fruit amount did not consistently enhance antioxidant potential. Specifically, chocolate samples with a lower proportion of quince fruit (2 g/100 g) exhibited greater antioxidant activity when supplemented with collagen I. Conversely, in samples with higher quince percentages (3 g and 4 g), those enriched with collagen III showed higher antioxidant activity. Similar correlations were observed in the linoleic acid oxidation test. Notably, samples containing 3 g and 4 g of quince and type III collagen demonstrated statistically similar highest antioxidant properties. Regardless of the collagen type used, there was no observed increase in activity towards the tested enzymes for samples with the lowest percentage of quince fruit. Both collagen types exhibited the highest activity in the inhibition assay against acetylcholinesterase and butyrylcholinesterase when combined with 3 g and 4 g of quince. Overall, the experimental incorporation of both fruit and collagen enhanced the chocolates' activity. Similarly to the antioxidant activity findings, chocolates with lower quince fruit quantities showed increased activity when supplemented with collagen III, while those with higher quince content (3 g and 4 g) displayed higher activity with collagen I. Bitter chocolate by itself is an attractive food product, rich in many bioactive compounds. However, enriching it with other attractive raw materials can make its properties and taste even more attractive.

Stimuli-responsive glucuronoxylan polysaccharide from quince seeds for biomedical, food packaging, and environmental applications.

Mucilage is a gelatinous mixture of polysaccharides secreted from the seed coat and/or pericarp of many plant seeds when soaked in water. Mucilage affected seed germination while maintaining hydration levels during scarcity. Cydonia oblonga (quince) seeds are natural hydrocolloids extruding biocompatible mucilage mainly composed of polysaccharides. Quince seed mucilage (QSM) has fascinated researchers due to its applications in the food and pharmaceutical industries. On a commercial scale, QSM preserved the sensory and physiochemical properties of various products such as yogurt, desserts, cakes, and burgers. QSM is responsive to salts, pH, and solvents and is mainly investigated as edible coatings in the food industry. In tablet formulations, modified and unmodified QSM as a binder sustained the release of various drugs such as cefixime, capecitabine, diclofenac sodium, theophylline, levosulpiride, diphenhydramine, metoprolol tartrate, and acyclovir sodium. QSM acted as a reducing and capping agent to prepare nanoparticles for good antimicrobial resistance, photocatalytic characteristics, and wound-healing potential. The present review discussed the extraction optimization, chemical composition, stimuli-responsiveness, and viscoelastic properties of mucilage. The potential of mucilage in edible films, tissue engineering, and water purification will also be discussed.

Identification of PP2Cs in six rosaceae species highlights RcPP2C24 as a negative regulator in rose drought tolerance.

Drought is a major environmental stress that limits plant growth, so it's important to identify drought-responsive genes to understand the mechanism of drought response and breed drought-tolerant roses. Protein phosphatase 2C (PP2C) plays a crucial role in plant abiotic stress response. In this study, we identified 412 putative PP2Cs from six Rosaceae species. These genes were divided into twelve clades, with clade A containing the largest number of PP2Cs (14.1%). Clade A PP2Cs are known for their important role in ABA-mediated drought stress response; therefore, the analysis focused on these specific genes. Conserved motif analysis revealed that clade A PP2Cs in these six Rosaceae species shared conserved C-terminal catalytic domains. Collinearity analysis indicated that segmental duplication events played a significant role in the evolution of clade A PP2Cs in Rosaceae. Analysis of the expression of 11 clade A RcPP2Cs showed that approximately 60% of these genes responded to drought, high temperature, and salt stress. Among them, RcPP2C24 exhibited the highest responsiveness to both drought and ABA. Furthermore, overexpression of RcPP2C24 significantly reduced drought tolerance in transgenic tobacco by increasing stomatal aperture after exposure to drought stress. The transient overexpression of RcPP2C24 weakened the dehydration tolerance of rose petal discs, while its silencing increased their dehydration tolerance. In summary, our study identified PP2Cs in six Rosaceae species and highlighted the negative role of RcPP2C24 on rose's drought tolerance by inhibiting stomatal closure. Our findings provide valuable insights into understanding the mechanism behind rose's response to drought.

Chromosome-level genome assembly of a cliff plant Taihangia rupestris var. ciliata provides insights into its adaptation and demographic history.

BACKGROUND: Cliffs are recognized as one of the most challenging environments for plants, characterized by harsh conditions such as drought, infertile soil, and steep terrain. However, they surprisingly host ancient and diverse plant communities and play a crucial role in protecting biodiversity. The Taihang Mountains, which act as a natural boundary in eastern China, support a rich variety of plant species, including many unique to cliff habitats. However, it is little known how cliff plants adapt to harsh habitats and the demographic history in this region. RESULTS: To better understand the demographic history and adaptation of cliff plants in this area, we analyzed the chromosome-level genome of a representative cliff plant, T. rupestris var. ciliata, which has a genome size of 769.5 Mb, with a scaffold N50 of 104.92 Mb. The rapid expansion of transposable elements may have contributed to the increasing genome and its ability to adapt to unique and challenging cliff habitats. Comparative analysis of the genome evolution between Taihangia and non-cliff plants in Rosaceae revealed a significant expansion of gene families associated with oxidative phosphorylation, which is likely a response to the abiotic stresses faced by cliff plants. This expansion may explain the long-term adaptation of Taihangia to harsh cliff environments. The effective population size of the two varieties has continuously decreased due to climatic fluctuations during the Quaternary period. Furthermore, significant differences in gene expression between the two varieties may explain the varied leaf phenotypes and adaptations to harsh conditions in different natural distributions. CONCLUSION: Our study highlights the extraordinary adaptation of T. rupestris var. ciliata, shedding light on the evolution of cliff plants worldwide.

Steady and dynamic shear rheology of aqueous solutions of quince seed gum combinations with locust bean or xanthan gums.

This study presents the rheological properties of quince seed gum (Q) solution in comparison with xanthan gum (X) and locust bean gums (L) and the polymeric interactions of different ratios of Q:X and Q:L blends (1:1, 1:3 and 3:1). Q exhibits greater and stronger elastic properties than X and L. The frequency and temperature stability of Q and X are both higher than that of L. The viscoelastic properties of Q:X and Q:L solutions were found to be higher than those of the individual solutions. The higher polymer entanglements observed in Q:L blends resulted in enhanced synergistic interactions and thixotropy compared to Q:X. 3QX exhibited an enhanced elastic structure, but the best synergism was observed for 3QL due to the establishment of a stronger intermolecular bond for gelling. The lower tan δ observed with increasing Q indicate a Q-induced synergistic interaction with L. At all temperatures, 3QL showed the highest thixotropy. The combination of Q and L resulted in the formation of a true gel, with the higher gel strength being observed for QL and 3QL. This study shows that Q:L and Q:X combinations can yield desired flow properties. In particular, L provides a firmer gel network with Q.

Mimosa/quince seed mucilage-co-poly (methacrylate) hydrogels for controlled delivery of capecitabine: Simulation studies, characterization and toxicological evaluation.

This research focused on developing pH-regulated intelligent networks using quince and mimosa seed mucilage through aqueous polymerization to sustain Capecitabine release while overcoming issues like short half-life, high dosing frequency, and low bioavailability. The resulting MSM/QSM-co-poly(MAA) hydrogel was evaluated for several parameters, including complex structure formation, stability, pH sensitivity, morphology, and elemental composition. FTIR, DSC, and TGA analyses confirmed the formation of a stable, complex cross-linked network, demonstrating excellent stability at elevated temperatures. SEM analysis revealed the hydrogels' smooth, fine texture with porous surfaces. PXRD and EDX results indicated the amorphous dispersion of Capecitabine within the network. The QMM9 formulation achieved an optimal Capecitabine loading of 87.17 %. The gel content of the developed formulations ranged from 65.21 % to 90.23 %. All formulations exhibited excellent swelling behavior, with ratios between 65.91 % and 91.93 % at alkaline pH. In vitro dissolution studies indicated that up to 98 % of Capecitabine was released after 24 h at pH 7.4, demonstrating the potential for sustained release. Furthermore, toxicological evaluation in healthy rabbits confirmed the system's safety, non-toxicity, and biocompatibility.

Characterization and performance evaluation of colorimetric pH-sensitive indicator based on Ò -carrageenan/quince seed mucilage hydrogel as freshness/spoilage monitoring of rainbow trout fillet.

The aim of research was to fabricate a novel indicator by using κ-carrageenan and quince seed mucilage (QSM) hydrogels and red cabbage anthocyanin. The porosity of the hydrogel was controlled using different ratios of κ-carrageenan(C):QSM(Q) (C90:Q10, C70:Q30, and C50:Q50). The hardness of hydrogels decreased from 28.6 ± 0.3 N for C90Q10 to 11.0 ± 1.0 N for C50Q50 sample. However, according to field emission scanning electron microscopy (FE-SEM) analysis, the C50R50 sample had the best morphology with smooth surface and uniform interconnected porous network. Hydrogen bonding interactions among anthocyanins, QSM, and κ-carrageenan were confirmed by Fourier transforms infrared (FT-IR) spectroscopy. The indicator showed a color variation from red to yellow over the pH range of 2-12. Also, the indicator exhibited high sensitivity to ammonia vapors (SRGB = 115%) and good color stability. The C50QRA indicator was used for monitoring rainbow trout fillet spoilage and revealed a visually-detectable color change from red to green upon detecting total volatile basic nitrogen (TVB-N) content produced throughout storage at 4 °C. Generally, the halochromic hydrogel developed in this research can be suggested as a more sensitive and accurate freshness indicator than conventional indicator solid supports.

Anoplophora glabripennis, an invasive longhorned beetle, has the potential to damage fruit trees in Japan.

Invasive Anoplophora glabripennis recently became established in Japan and has caused heavy damage to several street-tree species. Overseas, A. glabripennis infests trees of the genera Acer and Populus as common host plants, and Malus, Pyrus, and Prunus (Rosaceae), including apple, pear, and plum trees; it therefore poses a potential risk to the production of economically valuable fruits in Japan. Fruit farms in areas already invaded by A. glabripennis are now threatened with tree infestation. We aimed to determine the potential damage to major fruit species in Japan. In the laboratory, we determined if the adult beetle is attracted to the odor of each of these tree species' branches; two confirmed host plant species and five Rosaceae fruit species, as well as its feeding preferences among branches of one host plant and the five fruit trees and its oviposition preferences among them. Among the fruit species, cherry branch had the highest rate of odor orientation by males. The feeding-preference assay showed that, besides the host plant, Japanese pear was the most consumed among the fruit trees. The potential risk of A. glabripennis laying eggs on fruit-tree branches was high for Japanese pear and above zero for plum, apple, and cherry branches.

Ecofriendly Controlled-Release Insecticide Carrier: pH-/Temperature-Responsive Rosin-Derived Hydrogels for Avermectin Delivery against Mythimna separata (Walker).

The exploration of environmentally friendly, less toxic, sustained-release insecticide is increasing with the growing demand for food to meet the requirements of the expanding population. As a sustained-release carrier, the unique, environmentally friendly intelligent responsive hydrogel system is an important factor in improving the efficiency of insecticide utilization and accurate release. In this study, we developed a facile approach for incorporating the natural compound rosin (dehydroabietic acid, DA) and zinc ions (Zn2+) into a poly(N-isopropylacrylamide) (PNIPAM) hydrogel network to construct a controlled-release hydrogel carrier (DA-PNIPAM-Zn2+). Then, the model insecticide avermectin (AVM) was encapsulated in the carrier at a drug loading rate of 36.32% to form AVM@DA-PNIPAM-Zn2+. Surprisingly, the smart controlled carrier exhibited environmental responsiveness, strongly enhanced mechanical properties, self-healing ability, hydrophobicity, and photostability to ensure a balance between environmental friendliness and the precision of the drug release. The release experiments showed that the carboxyl and amide groups in the polymer chains alter the intermolecular forces within the hydrogel meshes and ingredient diffusion by changing temperatures (25 and 40 °C) and pH values (5.8, 7.4, and 8.5), leading to different release behaviors. The insecticidal activity of the AVM@DA-PNIPAM-Zn2+ against oriental armyworms was good, with an effective minimum toxicity toward aquatic animals. Therefore, AVM@DA-PNIPAM-Zn2+ is an effective drug delivery system against oriental armyworms. We anticipate that this ecofriendly, sustainable, smart-response carrier may broaden the utilization rosin and its possible applications in the agricultural sector.

Effect of free and bound proanthocyanidins from Chinese quince on heterocyclic aromatic amine formation and quality in fried chicken.

The abilities of Chinese quince free proanthocyanidins (FP) and bound proanthocyanidins (BP) at different levels (0.1%, 0.15%, and 0.3%) to mitigate heterocyclic aromatic amine (HAA) formation in fried chicken patties were investigated for the first time and compared with vitamin C (Vc). FP and BP reduced HAAs in a dose-dependent manner. Significantly, high concentrations of FP (0.3%) resulted in a reduction of PhIP, harman, and norharman levels by 59.84%, 22.91%, and 38.21%, respectively, in chicken patties. The addition of proanthocyanidins significantly (p < 0.05) reduced the weight loss of fried chicken patties. Furthermore, a positive correlation was observed among pH, weight loss, and total HAA formation in all three groups (FP, BP, and Vc). Multivariate analysis showed that FP had a more pronounced effect than BP from the perspective of enhancing the quality of fried chicken patties and reducing the formation of HAAs. These results indicate that proanthocyanidins, both BP and FP, but especially FP, from Chinese quince can inhibit the formation of carcinogenic HAAs when added to protein-rich foods that are subsequently fried.

Comparing RT-PCR of Individual Samples with High-Throughput Sequencing of Pooled Plant Samples for Field-Level Surveillance of Viruses in Blackberry and Wild Rubus.

Blackberry production is increasing in the Southeastern United States with the availability of new cultivars. In addition to high production costs, growers are challenged by virus diseases. Blackberry yellow vein disease (BYVD) significantly limits blackberry production. BYVD is associated with the crinivirus blackberry yellow vein-associated virus in mixed infections with other viruses. The specific disease etiology and ecological factors underlying BYVD are not well understood and rely on the effective diagnosis of several viruses involved in the complex. In 2021, we collected samples from blackberry plants showing BYVD symptoms, asymptomatic blackberry plants, and wild Rosaceae spp. from nine farms across South Carolina, for a total of 372 individual plant samples. RNA from individual samples was isolated and pooled into sample groups (i.e., symptomatic, asymptomatic, and wild) from each farm for a total of 24 pooled samples. We sequenced the pooled RNA using Illumina and analyzed sequence profiles using the Virtool bioinformatics application. We also tested each plant for six viruses by reverse transcriptase PCR or reverse transcriptase quantitative PCR and compared plant (PCR)-level and field (high-throughput sequencing [HTS])-level data. Virtool detected 17 known viruses in the pooled samples, including 11 blackberry viruses. PCR testing was mostly consistent with HTS, with some notable disagreements for specific viruses. Our study demonstrates that HTS could be used as an efficient tool to detect viruses in bulked samples in blackberry fields, although limitations to using HTS for field-level surveillance are also discussed here.

Chromosome-scale genome assembly and annotation of Cotoneaster glaucophyllus.

Cotoneaster glaucophyllus is a semi-evergreen plant that blossoms in late summer, producing dense, attractive, fragrant white flowers with significant ornamental and ecological value. Here, a chromosome-scale genome assembly was obtained by integrating PacBio and Illumina sequencing data with the aid of Hi-C technology. The genome assembly was 563.3 Mb in length, with contig N50 and scaffold N50 values of ~6 Mb and ~31 Mb, respectively. Most (95.59%) of the sequences were anchored onto 17 pseudochromosomes (538.4 Mb). We predicted 35,856 protein-coding genes, 1,401 miRNAs, 655 tRNAs, 425 rRNAs, and 795 snRNAs. The functions of 34,967 genes (97.52%) were predicted. The availability of this chromosome-level genome will provide valuable resources for molecular studies of this species, facilitating future research on speciation, functional genomics, and comparative genomics within the Rosaceae family.

Introduction of a diverse genetic background of Pyrus into Malus through intergeneric hybridization.

Wide hybridizations across species and genera have been employed to enhance agriculturally important traits in crops. Within the tribe Maleae of the Rosaceae family, different genera and species exhibit several traits useful for increasing diversity and gene pool through hybridization. This study aimed to develop and characterize intergeneric hybrid individuals between Malus and Pyrus. Through seed germination, shoot multiplication, and rooting in vitro, acclimatized seedlings showing vegetative growth on their own roots were obtained from crosses of Malus × domestica pollinated by Pyrus communis, P. bretschneideri, and the Pyrus interspecific hybrid (P. communis × P. pyrifolia). Comparative analysis of leaf morphology, flow cytometry, and molecular genotyping confirmed the hybrid status of the individuals. Genome-wide genotyping revealed that all the hybrid individuals inherited genomic fragments symmetrically from the Malus and Pyrus parents. To the best of our knowledge, this is the first report on the development of intergeneric hybrid seedlings between Malus × domestica and P. bretschneideri. Furthermore, the Pyrus interspecific hybrid individual served as a bridge plant for introducing the genetic background of P. pyrifolia into Malus × domestica. The results of this study provided a crucial foundation for breeding through intergeneric hybridization between Malus and Pyrus, facilitating the incorporation of valuable traits from diverse gene pools.

Flower opening dynamics, pollen-ovule ratio, stigma receptivity and stigmatic pollen germination (in-vivo) in Chaenomeles speciosa (Sweet) Nakai.

Although Chaenomeles is widely used in horticulture, traditional Chinese medicine and landscape greening, insufficient research has hindered its breeding and seed selection. This study investigated the floral phenology, floral organ characteristics, palynology, and breeding systems of Chaenomeles speciosa (Sweet) Nakai. The floral characteristics of C. speciosa were observed both visually and stereoscopically. The microstructures of the flower organs were observed using scanning electron microscopy. Pollen stainability was determined using triphenyl tetrazolium chloride staining. Stigma receptivity was determined using the benzidine-H2O2 method and the post-artificial pollination pollen germination method. The breeding system was assessed based on the outcrossing index and pollen-ovule ratio. The flowers of C. speciosa were bisexual with a flowering period from March to April. The flowering periods of single flowers ranged from 8 to 19 d, and those of single plants lasted 18-20 d. The anthers were cylindrical, with the base attached to the filament, and were split longitudinally to release pollen. The flower had five styles, with a connate base. The ovaries had five carpels and five compartments. The inverted ovules were arranged in two rows on the placental axis. The stigma of C. speciosa was dry and had many papillary protrusions. In the early flowering stage (1-2 d of flowering), the pollen exhibited high stainability (up to 84.24%), but all stainability was lost at 7 d of flowering. Storage at - 20 °C effectively delayed pollen inactivation. The stigma receptivity of C. speciosa lasted for approximately 7 days, and the breeding system was classified as outcrossing with partial self-compatibility.