Fruit texture and storage properties of various apple varieties exhibit significant variation. The rate of fruit softening post-harvest plays a crucial role in determining fruit quality and shelf life. This research utilized four apple varieties as test subjects to investigate the internal factors influencing fruit texture changes among different varieties. By monitoring changes in relevant physiological indicators during the post-harvest texture softening process, the study examined fruit quality, cell wall material content, hydrolase activity, and gene transcription levels during storage of ‘Orin’, ‘RX’, ‘RXH’, and ‘Envy’ apples. Initial fruit softening was primarily linked to heightened post-harvest fruit respiration intensity, ethylene production, and rapid amylase activity. Subsequent softening was associated with increased activity of water-soluble pectin (WSP), cellulose (CEL), and other hydrolases. With the extension of the storage period, the fruit cells of the four varieties became more loosely arranged, resulting in larger intercellular gaps. Variations in WSP and cellulose content, CEL activity, and relative expression of Mdβ-gal were observed among the different apple varieties, potentially accounting for the disparities in fruit texture.

Background Kobreisa littledalei, belonging to the Cyperaceae family is the first Kobresia species with a reference genome and the most dominant species in Qinghai-Tibet Plateau alpine meadows. It has several resistance genes which could be used to breed improved crop varieties. Reverse Transcription Quantitative Real-Time Polymerase Chain Reaction (RT-qPCR) is a popular and accurate gene expression analysis method. Its reliability depends on the expression levels of reference genes, which vary by species, tissues and environments. However, K.littledalei lacks a stable and normalized reference gene for RT-qPCR analysis. Results The stability of 13 potential reference genes was tested and the stable reference genes were selected for RT-qPCR normalization for the expression analysis in the different tissues of K. littledalei under two abiotic stresses (salt and drought) and two hormonal treatments (abscisic acid (ABA) and gibberellin (GA)). Five algorithms were used to assess the stability of putative reference genes. The results showed a variation amongst the methods, and the same reference genes showed tissue expression differences under the same conditions. The stability of combining two reference genes was better than a single one. The expression levels of ACTIN were stable in leaves and stems under normal conditions, in leaves under drought stress and in roots under ABA treatment. The expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression was stable in the roots under the control conditions and salt stress and in stems exposed to drought stress. Expression levels of superoxide dismutase (SOD) were stable in stems of ABA-treated plants and in the roots under drought stress. Moreover, RPL6 expression was stable in the leaves and stems under salt stress and in the stems of the GA-treated plants. EF1-alpha expression was stable in leaves under ABA and GA treatments. The expression levels of 28 S were stable in the roots under GA treatment. In general, ACTIN and GAPDH could be employed as housekeeping genes for K. littledalei under different treatments. Conclusion This study identified the best RT-qPCR reference genes for different K. littledalei tissues under five experimental conditions. ACTIN and GAPDH genes can be employed as the ideal housekeeping genes for expression analysis under different conditions. This is the first study to investigate the stable reference genes for normalized gene expression analysis of K. littledalei under different conditions. The results could aid molecular biology and gene function research on Kobresia and other related species.

Polygonati Rhizoma, as a traditional medicinal herb, possesses pharmacological effects enhancing physical strength and immunity. In this study, a systematic analysis of the monosaccharide and non-polysaccharides components in Polygonati Rhizoma was conducted using pre-column derivatization high-performance liquid chromatography (HPLC-DAD) and liquid chromatography coupled to electrostatic orbitrap high-resolution mass spectrometry (LC-Orbitrap-MS) techniques. The polysaccharides from Polygonati Rhizoma were initially extracted, hydrolyzed, and derivatized with 1-phenyl-3-methyl-5-pyrazolone (PMP), resulting in the successful detection of five monosaccharides. The high sensitivity and specificity of the HPLC-DAD method were confirmed. Furthermore, by comparing the external standard method (ESM) and the quantitative analysis of multi-components by single-marker (QAMS) revealed that D-mannose is the most abundant monosaccharide in Polygonati Rhizoma. The LC-Orbitrap-MS analysis of Polygonati Rhizoma led to the identification of 53 compounds, including organic acids, amino acids, amides, saponins, alkaloids, esters, and others. This research provided significant data for the chemical composition analysis and the pharmacological basis study of Polygonati Rhizoma.

Seedless watermelon production relies on triploid cultivation or the application of plant growth regulators. However, challenges such as chromosomal imbalances in triploid varieties and concerns about food safety with growth regulator application impede progress. To tackle these challenges, we developed a sexually and vegetatively reproducible inducer line of diploid seedless watermelon by disrupting the double fertilization process. This innovative approach has enabled the successful induction of diploid seedless watermelon across diverse varieties.

Torenia fournieri Lind. is an ornamental plant that is popular for its numerous flowers and variety of colors. However, its genomic evolutionary history and the genetic and metabolic bases of flower color formation remain poorly understood. Here, we report the first T. fournieri reference genome, which was resolved to the chromosome scale and was 164.4 Mb in size. Phylogenetic analyses clarified relationships with other plant species, and a comparative genomic analysis indicated that the shared ancestor of T. fournieri and Antirrhinum majus underwent a whole genome duplication event. Joint transcriptomic and metabolomic analyses identified many metabolites related to pelargonidin, peonidin, and naringenin production in rose (TfR)-colored flowers. Samples with blue (TfB) and deep blue (TfD) colors contained numerous derivatives of petunidin, cyanidin, quercetin, and malvidin; differences in the abundances of these metabolites and expression levels of the associated genes were hypothesized to be responsible for variety-specific differences in flower color. Furthermore, the genes encoding flavonoid 3-hydroxylase, anthocyanin synthase, and anthocyanin reductase were differentially expressed between flowers of different colors. Overall, we successfully identified key genes and metabolites involved in T. fournieri flower color formation. The data provided by the chromosome-scale genome assembly establish a basis for understanding the differentiation of this species and will facilitate future genetic studies and genomic-assisted breeding.

Flower scent is one of the main ornamental characteristics of herbaceous peony, and the improvement of flower fragrance is a vital objective of herbaceous peony breeding. In this study, 87 herbaceous peony cultivars were divided into three groups (no/light fragrance, medium fragrance, and strong fragrance) based on their sensory evaluation scores, and 16 strong fragrance cultivars and one no fragrance cultivar were selected for subsequent analysis. Sixty-eight volatile components were detected in these 17 cultivars based on solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS), and 26 types were identified as important scent components. They were composed of terpenoids, benzenoids/phenylpropanoids, and fatty acid derivatives. According to the content and odor threshold of these main aroma components, the characteristic aroma substances of herbaceous peony were identified, including linalool, geraniol, citronellol, and phenylethyl alcohol (2-PE). The cultivars of strong scented herbaceous peony were divided into three types: rose scent, lily scent, and mixed scent. We explored the possible key genes of characteristic aroma substances in herbaceous peony petals with different odors through the qRT-PCR. The key genes encoding monoterpene biosynthesis were found to be PlDXS2, PlDXR1, PlMDS1, PlHDR1, PlGPPS3, and PlGPPS4. In addition, the linalool synthase (LIS) gene and the geraniol synthase (GES) gene were also found. PlAADC1, PlPAR1, and PlMAO1, related to the biosynthesis of 2-PE were detected, and the synthetic pathway of 2-PE was speculated. In conclusion, these findings revealed that the difference in gene expression of monoterpene and 2-PE synthesis pathway was related to the difference in the fragrance of herbaceous peony. This study explored the releasing pathway of herbaceous peony characteristic aroma substances and provided key genetic resources for fragrance improvement.

The leaves of Zanthoxylum bungeanum Maxim. are important in traditional Chinese medicine and are a valuable nutritional source and flavoring agent. Although they are rich in phenolic compounds, the characterization of phenolic chemotypes of Zanthoxylum bungeanum has not been reported yet. Here, the profiles, accumulation kinetics, and tissue localization of phenolic compounds were analyzed in the leaves of 11 cultivars of Zanthoxylum bungeanum during growth and development. Twenty-seven phenolic compounds were identified, among which isoquercitrin, hyperoside, chlorogenic acid, quercitrin, myricetin, and ferulic acid existed in all cultivars, with ferulic acid and quercitrin being the most abundant. Chemometric analysis showed that the 11 cultivars were characterized by four chemotypes: 1) isoquercitrin, 2) rutin and hyperoside, 3) quercitrin, and 4) chlorogenic acid and quercitrin. Additionally, the accumulation dynamics of its main components were explored and the optimal harvest period for Zanthoxylum bungeanum leaves (early August) was determined. Moreover, anatomy and histochemical analysis results showed that the phenolics mainly accumulated in the epidermis, palisade tissue, and parenchyma cells. However, differences in the dimensions of these structures accounted for variations in phenolic accumulation, thus determining the different chemotypes. The classification of Zanthoxylum bungeanum chemotypes, and accumulation patterns of major chemical components, is valuable for the effective utilization of agricultural resources, quality evaluation, directional breeding, product multipurpose utilization, and development of plants.

Zanthoxylum bungeanum Maxim., an important spice plant, is rich in volatile components and has formed several cultivars in China. Genetic variation among different cultivars has significant effects on volatile components. In this study, a total of 52 volatile compounds were detected from 11 cultivars of Z. bungeanum, among which palmitic acid, (+)-limonene, phytol, β-caryophyllene, and terpinyl acetate were screened as characteristic compounds, with palmitic acid and phytol contributing the most to the volatile composition. Combined with the results of chemometric and content analyses, three Z. bungeanum chemotypes were identified: (+)-limonene, β-caryophyllene + terpinyl acetate, and palmitic acid + phytol. In addition, the dynamics of the accumulation of its main components were explored, and the optimal harvest period for Z. bungeanum leaves (late July or early August) was clarified. Moreover, histochemical analysis results showed that terpenoids were mainly accumulated in the oil cells of Z. bungeanum leaves, and there were some differences in the number of oil cells in different chemotypes of Z. bungeanum, which might affect the yield and quality of volatile components. The results showed that the differences of chemical composition among diverse chemotypes of Z. bungeanum might be an important factor leading to the quality differences of the same planting resources. Accordingly, the study on the classification of Z. bungeanum chemotypes and the accumulation patterns of major chemical components is of great theoretical significance and practical value as a favorable guarantee for the development and utilization of Z. bungeanum resources and quality control.

Species interactions are often context-dependent and complex, such as the grasshopper community and phytoecommunity. The adaption of grasshopper abundance and plant community were determined by topographical heterogeneity. However, it remains vague about how vegetation community, such as coverage, abundance and height, influence the spatial distribution pattern of grasshopper abundance at the altitude gradient. The geostatistical methods were used in natural grassland of the upper reaches of Heihe River to quantify the relationship of spatial correlation. A 5-years investigation shown that 3149 of grasshoppers was collected，belonging to 3 families, 10 genera, and 13 species. The semivariable function of grasshopper abundance and vegetation community followed a nonlinear model. Meanwhile, horizontal distribution of two communities was a clear flaky and plaque distribution pattern, especially at the altitude gradient. The abundance of grasshoppers is opposite to the height and coverage of vegetation and the overall follow ability of coverage, while the local following is consistent. Such as grasshopper abundance, the above 2750m sample with the opposite trend, the following areas were consistent. The grasshoppers exhibited the varieties on vegetation characters among all directions. On the different habits, the spatial distribution formed uniform trends; meanwhile, on the same, the trends diversified with altitude gradient, formed embedded striped patches structure.

Understanding the impact of the heterogeneity of the ecological environment on biodiversity is a key issue in ecology. Topographical heterogeneity was potentially important in grassland systems to create or change habitats for grasshopper settlement and foraging. Yet, there was little knowledge of how grasshopper communities respond to plant communities along the altitude gradient. We investigated the role of plant communities on grasshopper diversity with geostatistical methods to test the effects of heterogeneity in the natural grassland on the upper reaches of the Heihe River, Qilian Mountains. To aim the goal of the study, nonreturn experiments were used to collect the grasshoppers' diversity and populations, and the plant's community was sampled at the same location. The results showed that the semivariograms of grasshopper abundance and plant communities were both nonlinear models, while the grasshopper abundance typically produces heterogeneity with a larger range and nuggets than plant communities (except the plant coverage range in the model, range <1.5 m). The two communities presented the spatial distribution pattern of aggregated distribution, and the spatial trend is more intense in the northeast-southwest direction than in the northwest-southeast. The grasshopper species developed a good selection on microenvironment to habitat and the distribution consistent with plants, forming the horizontal distribution with a flaky and plaque distribution pattern. The relationship between grasshoppers and plants was highly dependent on the altitude, and grasshopper abundance has a positive correlation with plant richness (F = 0.68) and plant coverage (F = 0.32) and has a negative correlation with plant height (F = 0.13). In summary, the spatial distribution and correlation characteristics of plant communities and grasshoppers formed a plaque heterogeneity structure under the altitude gradients.

Eucommia ulmoides (Tu-chung) is an economically and ecologically important tree species which has attracted worldwide attention due to its application in pharmacology, landscaping, wind sheltering and sand fixation. Molecular marker technologies can elucidate the genetic mechanism and substantially improve the breeding efficiency of E. ulmoides. The current research updated the original linkage map, and quantitative trait loci (QTL) analysis was performed on tree growth traits measured over 10 consecutive years in an E. ulmoides F1 population (“Xiaoye” × “Qinzhong No.1”). In total, 452 polymorphic markers were scored from 365 simple sequence repeat (SSR) primers, with an average of 1.24 polymorphic markers per primer combination. The integrated map was 1913.29 cM (centimorgan) long, covering 94.10% of the estimated genome and with an average marker density of 2.20 cM. A total of 869 markers were mapped into 19 major independent linkage groups. Growth-related traits measured over 10 consecutive years showed a significant correlation, and 89 hypothetical QTLs were forecasted and divided into 27 distinct loci. Three traits for tree height, ground diameter and crown diameter detected 25 QTLs (13 loci), 32 QTLs (17 loci) and 15 QTLs (10 loci), respectively. Based on BLASTX search results in the NCBI database, six candidate genes were obtained. It is important to explore the growth-related genetic mechanism and lay the foundation for the genetic improvement of E. ulmoides at the molecular level.

Trans-polyisoprene rubber is produced in the tissues of leaves, bark, and fruit of Eucommia ulmoides and is considered an important energy source. Transcript profiles of two tissues from E. ulmoides cv. Qinzhong No. 3, leaf and fruit, were analysed using the Illumina HiSeq 2000 system. In total, 104 million clean reads were obtained and assembled into 58,863 unigenes. Through gene functional classification, 28,091 unigenes (47.72%) were annotated and 65 unigenes have been hypothesized to encode proteins involved in terpenoid biosynthesis. In addition, 10,041 unigenes were detected as differentially expressed unigenes, and 29 of them were putatively related to terpenoid biosynthesis. The synthesis of trans-polyisoprene rubbers in E. ulmoides was hypothesised to be dominated by the mevalonate pathway. Farnesyl diphosphate synthase 2 (FPPS2) was considered a key component in the biosynthesis of trans-polyprenyl diphosphate. Rubber elongation factor 3 (REF3) might be involved in stabilising the membrane of rubber particles in E. ulmoides. To date, 351 simple sequence repeats (SSRs) were validated as polymorphisms from eight E. ulmoides plants (two parent plants and six F1 individuals), and these could act as molecular markers for genetic map density increase and breeding improvement of E. ulmoides.

This work aims to evaluate the quality of seven varieties of Zanthoxylum bungeanum peels based on phenolic compounds, bioactivity, and HPLC fingerprint combined with chemometrics analysis, and pick out the key chemical compounds. As a result, S2 (Fengxian Dahongpao) showed the highest content of total phenolic and rutin, as well as the strongest antioxidant activity, followed by S6 (Hancheng Shizitou). From HPLC fingerprint, eight common characteristic peaks were selected and proved to be effective in controlling the quality of Z. bungeanum peels with the total contribution of 92.775%. The similarity values of each sample ranged between 0.696 and 0.970. In addition, hyperoside was identified as another key chemical indicator for quality evaluation of Z. bungeanum peels by PCA. Accordingly, seven varieties of Z. bungeanum were classified into four groups, among which group 4 (Fengxian Dahongpao, S2) was considered as an outstanding variety, followed by group 1 (S5, S6, and S7) and group 3 (S3 and S4), and group 2 (Fugu late-maturing, S1) was the last one. These results will be helpful to establish an effective and comprehensive evaluation system of Z. bungeanum. PRACTICAL APPLICATION: This study not only provides another index for quality evaluation of Z. bungeanum peels, but it also expects to be a theoretical basis for high-quality germplasm cultivation and the development of Z. bungeanum peels as food additives, pharmaceutical, or health care products.

Background The SWEET proteins are a group of sugar transporters that play a role in sugar efflux during a range of biological processes, including stress responses. However, there has been no comprehensive analysis of the SWEET family genes in Brassica oleracea ( BoSWEET ), and the evolutionary pattern, phylogenetic relationship, gene characteristics of BoSWEET genes and their expression patterns under biotic and abiotic stresses remain largely unexplored. Results A total of 30 BoSWEET genes were identified and divided into four clades in B. oleracea . Phylogenetic analysis of the BoSWEET proteins indicated that clade II formed first, followed by clade I, clade IV and clade III, successively. Clade III, the newest clade, shows signs of rapid expansion. The Ks values of the orthologous SWEET gene pairs between B. oleracea and Arabidopsis thaliana ranged from 0.30 to 0.45, which estimated that B. oleracea diverged from A. thaliana approximately 10 to 15 million years ago. Prediction of transmembrane regions showed that eight BoSWEET proteins contain one characteristic MtN3_slv domain, twenty-one contain two, and one has four. Quantitative reverse transcription-PCR (qRT-PCR) analysis revealed that five BoSWEET genes from clades III and IV exhibited reduced expression levels under chilling stress. Additionally, the expression levels of six BoSWEET genes were up-regulated in roots of a clubroot-susceptible cabbage cultivar (CS-JF1) at 7 days after inoculation with Plasmodiophora brassicae compared with uninoculated plants, indicating that these genes may play important roles in transporting sugars into sink roots associated with P. brassicae colonization in CS-JF1. Subcellular localization analysis of a subset of BoSWEET proteins indicated that they are localized in the plasma membrane. Conclusions This study provides important insights into the evolution of the SWEET gene family in B. oleracea and other species, and represents the first study to characterize phylogenetic relationship, gene structures and expression patterns of the BoSWEET genes. These findings provide new insights into the complex transcriptional regulation of BoSWEET genes, as well as potential candidate BoSWEET genes that promote sugar transport to enhance chilling tolerance and clubroot disease resistance in cabbage.

Zanthoxylum bungeanum (Rutaceae), a popular food flavoring and traditional Chinese medicine ingredient, is an important cash crop. Its leaves are rich in flavonoids with multiple bioactivities. However, the transcriptional sequencing has not been investigated, and the molecular basis for the flavonoid biosynthesis remains unclear in this plant. This paper, the key flavonoids (epicatechin, rutin, hyperoside, trifolin, quercitrin, and afzelin) contents were determined in the leaves of 10 Z. bungeanum varieties from a common garden. Results show the leaves of Z. bungeanum mainly contained hyperoside (11.410-21.721 mg/g) and quercitrin (9.401-18.016 mg/g). The total content of these key components was the highest in Fengxian Dahongpao (66.012 mg/g) and the lowest in Fugu (32.223 mg/g). Three varieties (Hancheng stingless, Fugu, and Fengxian Dahongpao) with significant differences in the total content of key flavonoids were selected for transcriptome analysis to obtain flavonoid biosynthesis-related genes. In total, 83 522 unigenes were obtained, 40 668 (48.69%) unigenes were annotated, and 6656 differentially expressed genes (DEGs) were identified. Comparison of the other two varieties, Fugu had many differentially expressed genes indicating the particularity of its variety. Flavonoid-related DEGs of 22 structural genes, including three PALs, one CYP73A, three 4CLs, six CHSs, one CHI, one F3H, one DFR, two ANSs, one ANR, one FLS, and two CYP75B1s, as well as nine MYBs were obtained. These structural genes had different expression patterns in different Z. bungeanum varieties. It is worth noting that the genes expressing the flavonoid 3'5 hydroxylase are absent in Z. bungeanum. Furthermore, quantitative real-time PCR experiment showed consistent results in transcriptome analysis. The RNA-Seq data set of this study sheds lights on the molecular mechanism of flavonoid biosynthesis in Z. bungeanum, provides valuable information for the metabolic regulation of flavonoids, and may serve as a guide for future breeding programs.

Idesia polycarpa Maxim. is a promising plant for biodiesel in China. We have reported the flowering phenology, breeding system and parental effect on fruit characters of this species distributed in Qinling-Bashan Mountain (Shaanxi Province) nature reserve. As a dioecious plant, the male and female flowered almost synchronously. The anthesis was from around 10th of May and proceeded until the end of May or the beginning of June at population level. To determine the breeding system of I. polycarpa, three pollination treatments were carried out on every three female plants: natural pollination (NP), apomixy (AP) and cross pollination (CP). Reproductive success of apoximy treatment indicated that, as a dioecious plant, I. polycarpa could also reproduce by apomixis. However, the mean fruit set under apomixy treatment was markerly lower (3.6-13.33%) than that of two pollination treatments (>65.69%). Fruit quality (fruit length, fruit width, 100 fruit weight, seed production and seed germination) of the cross pollination treatment was greater than the other two treatments, suggested that pollen competition in cross pollination treatment was the most intense in three treatments. To study parental effect on fruit characters, cross pollination was carried out with three female plants and three male plants. The result showed that maternal parents (P<0.001) and parental interaction significantly affected all the fruit characters (including 100 fruit weight, pulp/fruit ratio, oil content and seed germination) while paternal parents showed significant effects on 100 fruit weight, pulp/fruit ratio and seed germination. Fruit set was only significantly affected by maternal parents (P = 0.001). Our findings will facilitate future breeding programs of I. polycarpa in parental selection.

Eucommia ulmoides is cultivated for the production of eucommia rubber and Chinese herbal drugs. Molecular breeding methods, such as marker-assisted selection (MAS), have the potential to improve the efficiency of E. ulmoides breeding. Quantitative trait locus (QTL) analysis was applied to identify marker-trait associations for E. ulmoides using an F1 mapping population of 152 individuals derived from a cross between the wild genotype Xiaoye and the cultivar Qinzhong No. 1. A total of 78 QTLs were identified for 12 leaf traits involving morphology, yield, and secondary metabolites. Phenotypic variance explained by individual QTLs ranged from 10.4 to 53.3%. Fifteen QTL clusters, each harboring loci controlling at least two leaf traits, were detected across nine linkage groups. Co-location of these QTLs may be due to pleiotropy or linkage. Three main QTL regions for secondary metabolites were consistently identified each year. QTL information from this study furthers our understanding of the genetic architecture of these economically important traits and of MAS in E. ulmoides breeding.

Eucommia ulmoides is an economically important tree species for both herbal medicine and organic chemical industry. Effort to breed varieties with improved yield and quality is limited by the lack of knowledge on the genetic basis of the traits. A genetic linkage map of E. ulmoides was constructed from a full-sib family using sequence-related amplified polymorphism, amplified fragment length polymorphism, inter-simple sequence repeat and simple sequence repeat markers. In total, 706 markers were mapped in 25 linkage groups covering 2133 cM. The genetic linkage map covered approximately 89% of the estimated E. ulmoides genome with an average of 3.1 cM between adjacent markers. The present genetic linkage map was used to identify quantitative trait loci (QTL) affecting growth-related traits. Eighteen QTLs were found to explain 12.4%–33.3% of the phenotypic variance. This genetic linkage map provides a tool for marker-assisted selection and for studies of genome in E. ulmoides.