[Objective]To characterize the dynamic changes in sugar and organic acid composition across three key developmental stages in 14 major blueberry cultivars currently cultivated in China,which differ markedly in ripening period and flavor profile,and to elucidate the relationship between PEPC and organic acid metabolism in blueberry fruit,thereby providing theoretical support for blueberry production and flavor quality improvement.[Method]Fruits of 14 blueberry cultivars at three key ripening stages(green,pink,and blue)were used as materials.Soluble sugar and organic acid components were determined by HPLC,and the expression patterns of the PEPC gene were analyzed by qRT-PCR.[Result]During fruit ripening,the accumulation dynamics of TA and TSS varied among different blueberry cultivars and could be classified into three acid-accumulation patterns(continuous decline,stable-decline,and increase-decline)and three sugar-accumulation patterns(continuous increase,stable-increase,and decline-increase).Glucose and fructose were the major soluble sugar components in blueberry fruits,whereas citric acid,quinic acid,and malic acid were the predominant organic acids.Among them,quinic acid exhibited a relatively high coefficient of variation.Cluster analysis based on sugar and organic acid composition divided the 14 cultivars into four groups.In four cultivars,the major organic acids were citric acid,quinic acid,and malic acid;seven cultivars were dominated by citric acid and malic acid;and one cultivar was characterized primarily by citric acid and quinic acid.In these 12 cultivars,the proportions of glucose and fructose were relatively balanced.In contrast,the remaining two cultivars showed a clear predominance of quinic acid,with fructose content significantly higher than that of glucose.Total sugar content in blueberry fruits was significantly positively correlated with glucose and fructose contents,while total organic acid content was extremely significantly positively correlated with the contents of citric acid,quinic acid,oxalic acid,and lactic acid.In the three blueberry cultivars representing different acid-accumulation patterns,PEPC expression increased from the green fruit stage to the pink fruit stage,but was downregulated from the pink fruit stage to the blue fruit stage.During this latter period,the contents of malic acid and citric acid in the fruits also decreased correspondingly.[Conclusion]During blueberry fruit development,the variation patterns of TA and TSS were closely associated with cultivar characteristics.The major soluble sugar components were glucose and fructose,while the predominant organic acids were citric acid,quinic acid,and malic acid.Based on organic acid composition,the cultivars could be categorized into two types:high-citric-acid and high-quinic-acid types.In three blueberry cultivars representing different acid-accumulation patterns,PEPC expression was downregulated from the pink fruit stage to the blue fruit stage,which was consistent with the declining trends of malic acid and citric acid contents,indicating that PEPC is involved in the metabolism of organic acids in blueberry fruits.

[Objective] Pollen is the genetic carrier of the male parent in plant sexual reproduction. Pollen germination on the stigma of female flower and fertilization is the prerequisite for successful reproduction for plants. Therefore, the determination of pollen morphological differences is the basis for plant hybridization and breeding. According to morphology, pomegranate flowers are divided into two types: bisexual flowers and functional male flowers. Bisexual flowers, also known as “tubular flowers”, have normal pistil and eventually develop into fruit. Functional male flowers, which also known as “bell-shaped flowers”, have aborted pistil and will fall off eventually. Pollen characteristics plays a critical role in pomegranate production, influencing the fruit sets. The objectives of this study were to explore the effects of anther quality and different culture conditions on pollen germination rate of bisexual flowers and functionally male flowers in different pomegranate varieties, which will provide reference for pollen selection and preservation for pomegranate breeding. [Methods] Pollen samples were collected from the National Horticultural Germplasm Resource Center. The number of anthers of bisexual flowers and functionally male flowers were collected in cultivars including Suanmeiren, Mollar, Tianshihong, Zhongshiliu 4, Huaguang and Turkmenistan. On June 8th, 2022, at the initial period of the flowering, 50 flower buds of uniform size that were about to open were selected and sampled. The anthers were peeled in a dry carton indoors and the filaments were removed. They were put in a place at room temperature with dark ventilation to allow cracking of the anthers. The pollen grains were completely released and packed into a dry small glass bottle and sealed for later analyses. Anther quality and pollen germination rate of bisexual flowers and functionally male flowers of different pomegranate varieties were analyzed. The differences in anther number, single anther yield, stigma, pollen tube and pollen germination rate between bisexual flowers and functionally male flowers were compared. The effects of sucrose concentration on germination rate and storage temperature on pollen viability were also analyzed. [Results] When the sucrose concentration was 300 g·L-1, the pollen germination rate reached 83.5%, exhibiting no significant difference when compared to the treatment with a sucrose concentration of 250 g·L-1. Sucrose at concentrations of 250 g·L-1 and 300 g·L-1 was beneficial for the germination of pomegranate pollen. There was no significant difference in the number of stamens between bisexual flowers and functionally male flowers in the same cultivar. The number of stamens of Turkmenistan in fertile flowers was significantly lower than that of Suanmeiren, Mollar, Tianshihong, Zhongshiliu 4 and Huaguang (p<0.05). The pollen number in each anther of the bisexual flowers (31-48) was significantly lower than that of the functionally male flowers (85-91). Otherwise, the pollen germination rate of the bisexual flowers (90%-93%) was significantly higher than that of the functionally male flowers (41%-43%). Pollen tube growth of the bisexual flowers was faster than that of the functionally male flowers, and the length of pollen tube was higher than that of the functionally male flowers. There was no correlation between the number of stamens, the number of pollens produced by anthers and the pollen germination rate in the bisexual flowers and the functionally male flowers. Pollen from the bisexual flowers began to germinate 12 hours after pollination, and the number of germinated pollens was small at 24 hours, and some of the pollen tubes had grown into the pistil. By 36 hours, pollen from the bisexual flowers had germinated in large quantities and pollen tubes had extended in the pistil. In contrast, germination of the pollen from the functionally male was not observed until 36 h, when only partial pollen germination was observed on the stigma surface, and only a very small number of pollen was able to protrude into the pistil. Although the functionally male flowers could accept pollen and the pollen on the stigma surface could germinate, only a few pollens could germinate with pollen tube successfully growing into the pistil. The massive germination of pollen from the bisexual flowers at 36 h post-pollination indicates that pollen needs at least 36 h of contact time to fully interact with the stigma for successful and reliable pollination. Storage temperatures had an effect on pomegranate pollen activity, and the pollen germination rate was significantly higher at -20 ℃ than at 4 ℃ and 25 ℃. The pollen was completely inactivated after 3 days of storage at 25 ℃, but it could maintain pollen viability for a longer time when stored at -20 ℃. The pollen germination rate of different varieties was different, with the highest germination rate observed in Tianshihong pollen (93.3%) and the lowest in Zhongshiliu 4 (82.7%). [Conclusion] There were differences in anther quality and pollen germination rate between the bisexual flowers and the functionally male flowers in different cultivars. But there was no significant difference in the number of stamens between the two flower types in the same cultivar. The functionally male flowers have a large amount of pollen but a low germination rate. The storage conditions of -20 ℃ could maintain high pollen viability.

[Objective]Pomegranate(Punica granatum L.)is highly valued for its nutritional and cultur-al significance.However,its production is often constrained by soil quality issues,such as soil desertifi-cation,which can result in reduced yield,leaf chlorosis,and smaller arils.To mitigate these impacts,in-creased water and fertilizer inputs are commonly employed in pomegranate seedling cultivation.How-ever,the excessive application of chemical fertilizers is one of the main causes of soil salinization and alkalinization.Microbial fertilizers,a specialized bio-formulation containing beneficial microbial strains,enhance nutrient uptake efficiency and suppress soil-borne diseases.Additionally,they improve soil quality by activating organic matter and increasing soil enzyme activity,thereby supporting sustain-able soil development.This study compared the effects of different types of microbial fertilizers on seedling growth and soil quality,identifying the most effective fertilizer for promoting pomegranate seedling development.[Methods]Two-year-old cuttings of Huaguan cultivar(P.granatum L.)from the National Horticultural Germplasm Repository(Zhengzhou)were used as experimental materials.A con-trol group(CK)without microbial fertilizer was established,alongside five microbial fertilizer treat-ments:Vigorous Source(T1,incorporation),Trichoderma harzianum(T2,fertigation),microbial inocu-lant(powder form,T3,incorporation),microbial inoculant(granular form,T4,incorporation),and soil activator(T5,fertigation).Each treatment consisted of 10 replicates.The effects of different microbial fertilizer on the growth and development of seedlings were studied.Plant height,stem diameter,and the number of new shoots were measured on each seedling under each treatment.After leaf shedding,the fresh weight of the plants was measured with three biological replicates for each treatment.Fresh leaves were collected from each treatment to measure chlorophyll a,chlorophyll b,carotenoid,and total chloro-phyll contents,with three biological replicates for each measurement.Fully expanded leaves from each treatment were selected to determine photosynthetic parameters,including net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),intercellular CO2 concentration(Ci),and water use effi-ciency(WUE).Each measurement included three biological replicates and two technical replicates.Af-ter leaf shedding,the pH of different treated substrates was measured with three biological replicates for each treatment.The experimental results provided a comprehensive evaluation of seedling growth and photosynthetic performance under different microbial fertilizer treatments.[Results]We revealed that the application of microbial fertilizers significantly affected the growth and development of seedlings,with the T1 demonstrating the most pronounced effects.In June,the plant height of seedlings with T1 and T3 was significantly higher than that of CK,with increases of 25.82％and 15.89％,respectively.Stem diameter with Tl,T2,T3,and T4 was higher than CK,and the number of new shoots increased across all treatments compared to CK.In July,there were no significant differences in plant height among treatments,but the stem diameter with T1,T2,and T3 was significantly higher than CK,with in-creases of 69.06％,30.94％,and 43.17％,respectively.The number of new shoots with T1 was signifi-cantly higher than CK,with an increase of 46.88％.Leaf chlorophyll a,chlorophyll b,carotenoid,and total chlorophyll contents increased across all treatments compared to CK.Chlorophyll a and total chlo-rophyll contents were significantly higher in all treatments,with T1 showing the highest values.Photo-synthetic parameters(Pn,Tr,Gs,C,and WUE)were also influenced by microbial fertilizer application.In the T1,Gs at 8:00 was significantly higher than CK,with no significant reductions at other time points.Ci at 14:00 was significantly lower than CK,with no significant increases at other time points.WUE at 14:00 was significantly higher than CK at the 0.05 level,with no significant reductions at other time points.[Conclusion]Different microbial fertilizer treatments had varying effects on the growth and development of P.granatum L.seedlings.The efficacy of these treatments was significantly influ-enced by the active components and microbial strains in the fertilizer.Vigorous Source was identified as the optimal microbial fertilizer,demonstrating the most significant promotion of plant height,stem di-ameter,number of new shoots,chlorophyll content,and photosynthetic efficiency during the growth and development stages.The application of Vigorous Source can accelerate the cultivation of high-quali-ty pomegranate seedlings through a well-optimized fertilization strategy.

Pomegranate is an important perennial fruit tree distributed worldwide. Reference genomes with gaps and limit gene identification controlling important agronomic traits hinder its functional genomics and genetic improvements. Here, we reported a telomere-to-telomere (T2T) gap-free genome assembly of the distinctive cultivar 'Moshiliu'. The Moshiliu reference genome was assembled into eight chromosomes without gaps, totalling ~366.71 Mb, with 32 158 predicted protein-coding genes. All 16 telomeres and eight centromeres were characterized; combined with FISH analysis, we revealed the atypical telomere units in pomegranate as TTTTAGGG. Furthermore, a total of 16 loci associated with 15 important agronomic traits were identified based on GWAS of 146 accessions. Gene editing and biochemical experiments demonstrated that a 37.2-Kb unique chromosome translocation disrupting the coding domain sequence of PgANS was responsible for anthocyanin-less, knockout of PgANS in pomegranate exhibited a defect in anthocyanin production; a unique repeat expansion in the promoter of PgANR may affected its expression, resulting in black peel; notably, the G → A transversion located at the 166-bp coding domain of PgNST3, which caused a E56K mutation in the PgNST3 protein, closely linked with soft-seed trait. Overexpression of PgNST3A in tomato presented smaller and softer seed coats. The E56K mutation in PgNST3 protein, eliminated the binding ability of PgNST3 to the PgMYB46 promoter, which subsequently affected the thickness of the inner seed coat of soft-seeded pomegranates. Collectively, the validated gap-free genome, the identified genes controlling important traits and the CRISPR-Cas9-mediated gene knockout system all provided invaluable resources for pomegranate precise breeding.

Seed hardness is a unique trait for edibility and an important breeding target for pomegranates. We compared changes in hormones during the development of soft- and hard-seeded varieties in order to identify key hormones and developmental stages that affect seed lignin synthesis and accumulation. During the development of pomegranate seeds, lignin accumulates significantly in the stereid layer, and the degree of lignification is higher in Shandazi than in Huazi cultivars. The results showed that the accumulation of lignin in the stereid layer of the outer pomegranate seed coat is the reason for the differences in seed hardness between the soft-seeded variety and the hard-seeded variety. The hardness of pomegranate seeds was positively correlated with endogenous indole-3-acetic acid (IAA) and jasmonic acid (JA), while it was negatively correlated with cytokinins (CTKs), abscisic acid (ABA), gibberellins (GAs), salicylic acid (SA), and strigolactones (SLs). The highest contents of IAA and JA were 8.615 ng·g−1 and 4.5869 ng·g−1, respectively, in the hard-seeded variety. In the soft-seeded variety, the maximum values of dihydrozeatin (DZ), dihydrozeatin-7-glucoside (DHZ7G), ABA, gibberellin A1 (GA1), SA, and 5-deoxystrigol (5-DS) were 281.82 ng·g−1, 1542.889 ng·g−1, 61.273 ng·g−1, 5.2556 ng·g−1, 21.15 ng·g−1, and 0.4494 ng·g−1, respectively. IAA, CTKs, ABA, GA1, and SA play major roles in the formation of lignin in pomegranate seeds, collectively determining seed hardness.

The walnut (Juglans regia L.) is a typical and an economically important tree species for nut production with heterodichogamy. The absence of female and male flowering periods seriously affects both the pollination and fruit setting rates of walnuts, thereby affecting the yield and quality. Therefore, studying the characteristics and processes of flower bud differentiation helps in gaining a deeper understanding of the regularity of the mechanism of heterodichogamy in walnuts. In this study, a total of 3540 proteins were detected in walnut and 885 unique differentially expressed proteins (DEPs) were identified using the isobaric tags for the relative and absolute quantitation (iTRAQ)-labeling method. Among all DEPs, 12 common proteins were detected in all four of the obtained contrasts. GO and KEGG analyses of 12 common DEPs showed that their functions are distributed in the cytoplasm metabolic pathways, photosynthesis, glyoxylate and dicarboxylate metabolism, and the biosynthesis of secondary metabolites, which are involved in energy production and conversion, synthesis, and the breakdown of proteomes. In addition, a function analysis was performed, whereby the DEPs were classified as involved in photosynthesis, morphogenesis, metabolism, or the stress response. A total of eight proteins were identified as associated with the morphogenesis of stamen development, such as stamen-specific protein FIL1-like (XP_018830780.1), putative leucine-rich repeat receptor-like serine/threonine-protein kinase At2g24130 (XP_018822513.1), cytochrome P450 704B1-like isoform X2 (XP_018845266.1), ervatamin-B-like (XP_018824181.1), probable glucan endo-1,3-beta-glucosidase A6 (XP_018844051.1), pathogenesis-related protein 5-like (XP_018835774.1), GDSL esterase/lipase At5g22810-like (XP_018833146.1), and fatty acyl-CoA reductase 2 (XP_018848853.1). Our results predict several crucial proteins and deepen the understanding of the biochemical mechanism that regulates the formation of male and female flower buds in walnuts.

Piercing/sucking insects such as green peach aphid (GPA) (Myzus persicae) cause direct damage by obtaining phloem nutrients and indirect damage by spreading plant viruses. To investigate the response of peach trees (Prunus persica) to aphids, the leaf transcriptome and metabolome of two genotypes with different sensitivities to GPA were studied. The gene expression of aphid-susceptible plants infested with aphids was similar to that of control plants, whereas the gene expression of aphid-resistant plants infested with aphids showed strong induced changes in gene expression compared with control plants. Furthermore, gene transcripts in defense-related pathways, including plant-pathogen interaction, MAPK signaling, and several metabolic pathways, were strongly enriched upon aphid infestation. Untargeted secondary metabolite profiling confirmed that aphid infestation induced larger changes in aphid-resistant than in aphid-susceptible peaches. Consistent with transcriptomic alterations, nine triterpenoids showed highly significant GPA-induced accumulation in aphid-resistant peaches, whereas triterpenoid abundance remained predominantly unchanged or undetected in aphid-susceptible peaches. Furthermore, some types of transcription factors (including WRKYs, ERFs, and NACs) were strongly induced upon GPA infestation in aphid-resistant, but not in aphid-susceptible peaches. These results suggested that the accumulation of specialized triterpenoids and the corresponding pathway transcripts may play a key role in peach GPA resistance.

The whitefly Bemisia tabaci is critical global pest threatening crops and leading to agricultural losses. Wolbachia is an intracellular symbiotic bacterium in insects, which can regulate the growth and development of the host through various ways. In a prior study, Wolbachia was found to be transferred to whitefly and induce fitness changes. However, little is known about the underlying mechanisms of host-Wolbachia interactions in B. tabaci. In this study, a Wolbachia strain wStri was isolated from the small brown planthopper, Laodelphex striatellus, and transferred to B. tabaci. The distribution of Wolbachia in whiteflies was determined using fluorescence in situ hybridization. Reciprocal crossing experiments demonstrated that wStri did not induce cytoplasmic incompatibility phenotypes in B. tabaci, but prolonged the developmental duration of the offspring. We performed transcriptomic analysis of Wolbachia-infected female and male adults using Illumina-based RNA-Seq. A total of 843 differentially expressed genes (DEGs) were identified in infected females, among them 141 were significantly up-regulated and 702 were down-regulated by Wolbachia infection. In infected males, of 511 gene sets, 279 host genes were significantly up-regulated, and 232 were down-regulated by Wolbachia infection. KEGG analysis of DEGs demonstrated significant differences in gene pathway distribution between up-regulated and downregulated genes. These genes are involved in various biological processes, including, but not limited to, detoxification, oxidation-reduction, metabolic processes, and immunity. The transcriptomic profiling of this study offers valuable information on the differential expression of genes in whiteflies following Wolbachia infection, and enhances our understanding of this host-symbiotic interaction.

The pomegranate fruit is valued for its nutritional and medicinal properties, and the composition and content of primary and secondary metabolites are the main factors impacting its nutritional and medicinal properties. However, a deep understanding of metabolites in different parts of fruit is still lacking. Here, the peel, aril, and seed of mature pomegranate fruits were analyzed separately to compare metabolic component differences using UPLC/MS-MS. A total of 858 metabolites belonging to 11 classes were identified, of which flavonoids, such as delphinidin-3-O-glucoside and cyanidin-3-O-glucoside; tannins, such as ellagic acid and punicalin; and terpenoids, such as corosolic acid and madasiatic acid, were upregulated in the peel. Lipids, such as punicic acid, methyl linolenate, and linoleic acid; alkaloids, such as indole and choline; nucleotides and derivatives mainly including 2-deoxyribose-1-phosphate and 9-(arabinosyl)-hypoxanthine, were upregulated in seeds. Phenolic acids, such as 1-O-galloyl-4,6-(S)-HHDP-beta-D-glucose and 1,7-di-O-galloyl-D-sedoheptulose, and flavonoids, such as cyanidin-3-O-glucoside, cyanidin-3-O-(2 ''-O-xylosyl) galactoside, and delphinidin-3-O-glucoside, were upregulated in aril. The flavone and flavonol biosynthesis (ko00944) pathways were significantly enriched between the peel and seed, as were the anthocyanin biosynthesis (ko00944) pathways between the aril and seed and the flavonoid biosynthesis (ko00941) pathways between the peel and aril. Additionally, functional antioxidants, such as 10,16-dihydroxypalmitic acid, 3-O-methylellagic acid, and 3,3'-O-dimethylellagic acid, were first identified in pomegranate fruits. Our results revealed the composition and abundance of primary and secondary metabolites in pomegranate fruit, which can lay the foundation for further elucidation of its nutritional and medicinal properties. A total of 858 metabolites belonging to 11 classes were identified in pomegranate peel, seed, and aril, of which 647 metabolites showed statistically significant differences between the groups. Flavonoids were mainly upregulated in peel and aril; as were phenolic acids and amino acids in aril; tannins and terpenoids in peel; and lipids and alkaloids in seed. Some functional antioxidants, such as 10,16-dihydroxypalmitic acid, 3-O-methylellagic acid, and 3,3 '-O-dimethylellagic acid, were first identified in pomegranate fruits.image

植物生长过程中,时刻面对植食性昆虫的威胁,如营养生长以及生殖生长、叶子和嫩枝.昆虫对于寄主植物的直接伤害来自对寄主植物取食,分为吸取植物汁液和咀嚼植物组织2种方式.此外,昆虫取食会对植物造成多种疾病,从而导致间接植物受损.为应对昆虫的攻击,植物会产生一些生物活性化合物(包括三萜皂苷),以增强它们对食草昆虫的防御能力.萜类是植物代谢物中种类最多的一类,在植物生长和发育中,它们被广泛用于维持各种基本功能,很多数萜类化合物,如三萜皂苷,在植物应对非生物和生物胁迫过程中行使特定的保护作用.本文阐述了植物中三萜皂苷代谢产物在抵御昆虫危害过程中的最重要功能,并概述了对三萜皂苷类代谢途径、调节和多样化理解的最新进展.因此,植物生物活性化合物的研究有助于不同生态系统中的害虫综合治理.

Flat peach [Prunus persica (L.) Batsch var. platycarpa] is a variant of ordinary peach with a unique flat shape. It is well known for its shape and delicious fruits (Miao et al. 2022). Although flat peach has a long history of cultivation in China, until the beginning of the 20th century, flat peach was only distributed as a minor variety in the main peach-producing areas of China. In terms of flat peach cultivars, only 46 of the 709 peach cultivars listed in Peach Genetic Resource in China (Wang et al. 2012) are flat peach cultivars, and most of them are flat landraces. Several problems have been noted previously in flat peach cultivars, including poor closure of the blossom end (blossom-end scarring in mild cases and cracking in severe cases), cracked stone in some cultivars (loss of commercial value in severe cases), nonsymmetrical fruit shape, small flesh, and low yield (Wang 2021). Many of the shortcomings of flat peach cultivars are intrinsic problems of the cultivars, which are difficult to improve through cultivation measures. This is the key factor limiting the large-scale promotion of flat peach cultivation in China. For many years, peach breeders in China have been devoted to the genetic improvement of flat peach, and some improved flat peach cultivars have been released, for instance, ‘Pocket Zaoban’ (Jiang et al. 2007) and ‘124 Pantao’ (Ma et al. 2003). However, problems persist in these cultivars, including small fruits, soft flesh, and blossom-end cracks. Only a few flat peach cultivars have good overall performance. In recent years, the Zhengzhou Fruit Research Institute (ZFRI), Chinese Academy of Agricultural Sciences (CAAS), identified genetic sources of flat peach with slow or nonmelting flesh, a wellclosed blossom end, and little or no cracking. They were hybridized with high-quality peach and nectarine cultivars or selections. After multiple generations of improvement, breakthroughs were made in early flat peach breeding, and a series of flat peach cultivars with excellent comprehensive traits have been produced. These cultivars are favored by fruit farmers in the main peach-producing areas in China. Hence, the main problems in flat peach cultivation are expected to be solved, which will help expand the cultivation area of flat peach. ‘ZhongPan 101’ and ‘ZhongPan 102’ are two yellow-flesh flat peach cultivars 45 released from the ZFRI, CAAS. These two cultivars produce large, well-shaped, high-quality fruits with a completely closed stylar end and high yield. Three years of evaluation has confirmed that the peach trees of the two cultivars are stable. ‘ZhongPan 101’ and ‘ZhongPan 102’ were well adapted to climate of the middle and lower reaches of the Yellow River; have performed well in Henan, Jiangsu, and Anhui Provinces; and are suggested for trial wherever ‘ZhongYouPan 9’ is grown.

The chemical compositions of juice and peel from 37 cultivars of pomegranates grown in China were identified using UPLC-Q TOF MS. The total phenolic contents and antioxidant activities of pomegranate juice and peel samples were also determined to make comparisons of their potential nutraceutical values. A total of 20 and 25 compounds were tentatively identified from the juice and peel samples. For the antioxidant activities of juice samples, No. 32 from Italy showed greatest abilities in scavenging DPPH and ABTS free radicals, and a registered novel cultivar No. 24 showed greatest value in scavenging oxygen radical. For the peel samples, No. 8 from Anhui Province of China showed generally greater values in all the three assays. All these results showed that different cultivars of pomegranate have different amounts of bioactive components and antioxidant activities, and development about the byproduct of these pomegranates after industrial processing should be focused in the future.

Flat peach is a variety of Prunus persica and characterized with flat fruit shape. The production of flat peach has been restricted in very limited regions in China for a very long time, due to cracking fruit, not well-closed fruit top and so on. Some new flat peach/nectarines were released in recent 20years, and attractive to the consumers, such as Zhongpan 11, Jinxia Youpan, and Zhongyoupan 9. These cultivars have made a great progress in their comprehensive traits, especially in fruit size, fruit cracking and fruit shape. however, early maturing cultivar is still rare. In 2011, a cross was made between Zhongyou 15 and 02-77-3. 11 seedlings were finally obtained and planted in the field in 2012. The seedlings began to flower and bear fruit in 2014. After 3 consecutive fruiting years observation, the seedling numbered 7-4-29 was selected for early ripening, perfect appearance and high fruit quality. The regional trials began in 2017. It was named as Zhong Pan 101 and authorized to release in Henan province in2021. The fruit of Zhong Pan 101 is flat with concave fruit apex, the suture is shallow and symmetrical.The fruit size is middle to large with average fruit mass 164 g. The background color of the fruit skin is light green-yellow, and more than 90% of the fruit surface is covered with rose-red color when maturing. The fruit peel is medium in thickness and difficult to tear off. The flesh is yellow, with less anthocyanins under the pericarp at maturity and no anthocyanins near the nucleus. The flesh texture is fine, with less fiber. The fruit is melting and juicy with very good flavor. The content of soluble solids in fruit juice（w） is 13.0%-14.9%. The stone is cling. The pit is small, flat and light brown. The flower is showy with 5 pink petals. The inner wall of the calyx tube is orange yellow. It is fertile with middle to high yield. In Zhengzhou, the bud of Zhong Pan 101 breaks in late February and blooms in middle to late March. The fruit ripens in mid-June, and the fruit development period is about 80 days. The leaves begin to fall in early November, and the annual growth period is about 230 d. Zhong Pan 101 is suitable to cultivate in open field or in protected cultivation condition in Northern China.

[目的]评价不同石榴种质资源籽粒硬度及抗寒性,筛选可能参与调控石榴抗寒性的MAPK家族基因.[方法]以31份石榴种质资源为试材,进行抗寒性及籽粒硬度评价;基于全基因组筛选石榴MAPK家族基因,对其进行进化、基因结构和蛋白理化性质分析,同时利用实时荧光定量PCR(real-time quantitative PCR,qRT-PCR)分析冷胁迫对石榴MAPK家族基因表达模式的影响.[结果]31个石榴品种籽粒硬度及半致死温度测定结果表明,峄城粉红牡丹、淮北六棱甜和鲁白榴2号等硬籽石榴抗寒性较强,华紫、以3和玛丽斯等软籽石榴抗寒性较弱.基于石榴全基因组鉴定出17个MAPK家族基因,广泛分布于8条染色体上;MAPK家族所有成员主要分为3个亚类,其中,A和B亚类成员主要包含PKc_MAPKK_plant_like和PTZ00024结构域,C亚类主要包含PLN00034结构域,所有成员均具有S_TKc结构域;各成员氨基酸残基数量分布在314～860 aa,外显子数目1～18个,蛋白分子质量为34910.05～97965.26 u,等电点4.94～9.35;PgMKK2、PgMPK6、PgMPK9、PgMPK16和PgMPK13在峄城粉红牡丹响应冷胁迫过程中表现为显著上调,PgM-KK8、PgMPK1-1和PgMKK4在玛丽斯响应冷胁迫过程中表现为显著上调;PgMKK2、PgMPK6、PgMPK9、PgMPK16和PgMPK13在峄城粉红牡丹响应冷胁迫过程中的表达量显著高于玛丽斯,PgMKK8和PgMPK1-1在玛丽斯响应冷胁迫过程中的表达量显著性高于峄城粉红牡丹;PgMKK3在峄城粉红牡丹不同时间均未检测到表达,在玛丽斯中表现为先升高后降低的趋势;PgMPK12-2在玛丽斯不同时间均未检测到表达,在峄城粉红牡丹中表现为逐渐升高的趋势.[结论]石榴MAPK家族基因响应冷胁迫信号,其中,PgMKK2、PgMPK6、PgMPK12-2和PgMPK9可能参与正调控石榴的抗寒性.

Peach (Prunus persica L.) is prone to chilling injury as exhibited by inhibition of the ethylene production, failure in softening, and the manifestation of internal browning. The basic leucine zipper (bZIP) transcription factors play an essential role in regulatory networks that control many processes associated with physiological, abiotic and biotic stress responses in fruits. Formerly, the underlying molecular and regulatory mechanism of (bZIP) transcription factors responsive to chilling injury in peach fruit is still elusive. In the current experiment, the solute peach ‘Zhongyou Peach No. 13’ was used as the test material and cold storage at low temperature (4 °C). It was found that long-term low-temperature storage induced the production of ethylene, the hardness of the pulp decreased, and the low temperature also induced ABA accumulation. The changes of ABA and ethylene in peach fruits during low-temperature storage were clarified. Since the bZIP transcription factor is involved in the regulation of downstream pathways of ABA signals, 47 peach bZIP transcription factor family genes were identified through bioinformatics analysis. Further based on RT-qPCR analysis, 18 PpbZIP genes were discovered to be expressed in refrigerated peach fruits. Among them, the expression of PpbZIP23 and PpbZIP25 was significantly reduced during the refrigeration process, the promoter analysis of these genes found that this region contains the MYC/MYB/ABRES binding element, but not the DRES/CBFS element, indicating that the expression may be regulated by the ABA-dependent cold induction pathway, thereby responding to chilling injury in peach fruit. Over investigation will provide new insights for further postharvest protocols related to molecular changes during cold storage and will prove a better cope for chilling injury.

【Objective】The objective of this study is to clarify the underlying biochemical mechanisms related to the resistance and susceptibility of peach towards Myzus persicae, and to identify the key secondary metabolites of peach responding to the M. persicae infection.【Method】New shoots of resistant (‘96-5-1’ (9651), ZaoYouTao (ZYT)) and susceptible (Zhong You 13 (CN13), Zhong Nong Jin Hui (ZNJH)) peach trees were inoculated with M. persicae for 3 days and used for secondary metabolite extraction and UPLC-MS/MS analysis. Differentially altered metabolites (DAMs) were screened with |log2 fold change|≥1, P-value≤0.01 as threshold. The VIP value of the OPLS-DA model was used to perform differences between resistant and susceptible peach.【Result】To illustrate the biochemical mechanisms of M. persicae resistance in peach, aphid-resistant/aphid-susceptible peach varieties infested with M. persicae for 3 days. A total of 528 metabolites were identified in the treated samples through widely targeted metabolomics analysis. Using principal component analysis (PCA), hierarchical cluster analysis (HCA) and Venn diagram analysis, it was found that 7 DAMs were identified from the susceptible variety CN13, and 2 of them were significantly decreased, 5 of them were significantly increased. 7 DAMs were identified from the susceptible variety ZNJH, and 3 of them were significantly decreased, 4 of them were significantly increased. 33 DAMs were identified from the resistant variety ‘96-5-1’, and 1 of them was significantly decreased, 32 of them were significantly increased. 55 DAMs were identified from the resistant variety ZYT, and 12 of them were significantly decreased, 43 of them were significantly increased. The majority of the DAMs were identified from the two resistant varieties, and the overall magnitude of change was greater in the resistant varieties than that in the susceptible varieties. Finally, 15 secondary metabolites (6 amino acids and their derivatives, 5 phenolic acids, 3 nucleotides and their derivatives, and 1 organic acid) were considered to be involved in M. persicae resistance of ‘Shou xing tao’.【Conclusion】The significantly up-regulated secondary metabolites obtained in M. persicae-resistant peach varieties were mainly involved in the response to M. persicae feeding. The regulation of these secondary metabolites (amino acids and their derivatives, phenolic acids, nucleotides and their derivatives, organic acid) is the important mechanism of defense reaction to M. persicae.

Additional file 1: Table S1. Candidate region of SNP_index.

Additional file 2: Table S2. Genome-wide Delta_SNP_index.

中油蟠36-3是以油蟠桃单株97-3-21为母本、早熟油桃品种中油桃5号为父本,经胚挽救后选育而成的早熟、白肉油蟠桃品种.该品种果形扁平,较对称,平均单果质量80～120g,最大150g左右.果皮底色浅绿白,成熟时大部分果面着鲜红色,美观,果顶有少量果锈.果肉白色,硬熟时脆甜,完熟后多汁,可溶性固形物含量(w)13.5％～16.9％,浓甜,品质优.黏核.花铃型,花瓣5枚,花粉多.自花结实,丰产.在郑州地区,一般年份2月底萌芽,3月中下旬始花,果实6月中旬成熟,果实发育期80 d左右,11月中旬左右完全落叶.适宜在北方露地及设施促早栽培,南方地区可尝试避雨栽培.

The green peach aphid (GPA), Myzus persicae, is a polyphagous, sap-sucking aphid and a vector of many plant viruses. In peach, Prunus persica, three individual dominant GPA resistance loci have been genetically defined (Rm1-3), but knowledge of the underlying genes is limited. In this study, we focused on the Rm3 locus. Bulk segregant analysis (BSA) mapping in segregating progeny populations delimited Rm3 to an interval spanning 160 kb containing 21 genes on chromosome 1. RNA-seq data provided no evidence of candidate genes, but chromosomal structural variations were predicted around a nucleotide-binding site-leucine-rich repeat (NLR) gene (ppa000596m) within the Rm3 fine-mapping interval. Following bacterial artificial chromosome (BAC) library construction for a GPA-resistant peach cultivar and the sequencing of three target BAC clones, a chromosomal structural variation encompassing two novel TIR-NLR-class disease resistance (R) protein-coding genes was identified, and the expressed NLR gene (NLR1) was identified as a candidate for M. persicae resistance. Consistent with its proposed role in controlling GPA resistance, NLR1 was only expressed in the leaves of resistant peach phenotypes. A molecular marker that was designed based on the NLR1 sequence co-segregated with the GPA-resistant phenotype in four segregating populations, 162 peach cultivars, and 14 wild relatives, demonstrating the dominant inheritance of the Rm3 locus. Our findings can be exploited to facilitate future breeding for GPA-resistance in peach.