Flavonoids are a class of secondary metabolites with ‘flavan’ skeleton and thousands of derivatives. The biosynthetic pathways of flavonoids are complicated，and some of them and related enzymes have been analyzed. Flavonoids play important roles in the growth and development of plants and the formation of flowers and fruits. Studies revealed that flavonoids can response to stresses and improve the tolerance and resistance of plants. This article reviews the biosynthetic pathways and molecular regulation mechanism of flavonoids in plants，the response of flavonoid pathways to different stresses，the main roles and mechanisms of flavonoids，and the future research directions. Thus，this article is expected to providing theoretical support for the targeted cultivation of horticultural crop varieties with highly resistant，deep processing，and product development.

‘Zhejiao 10’，a new late maturing double-harvest water bamboo cultivar developed by systematic selection from‘Suozijiao’mutants after 10 years，has a luxuriant growth. The harvest period of ‘Zhejiao 10’is about 13 days later than that of‘Suozijiao’in fall. Gross harvested weight of‘Zhejiao 10’in fall is 136.8 g per each，net weight is 90.6 g per each，and the average yield is 23 460 kg · hm^-2. The harvest period of‘Zhejiao 10’is about 6 days later than that of ‘Suozijiao’in summer. Gross harvested weight of‘Zhejiao 10’in summer is 151.8 g per each，net weight is 103.3 g per each，and the average yield is 40 020 kg · hm^-2. The succulent stem has 3-5 joints，and the bud is white. It has glossy surface，fine and tender quality. The cultivar was suitable for planted in Zhejiang Province.

In this study，ninety apple cultivars were used as experimental materials to evaluate cold tolerance by a relative electrical conductivity test. Genome-wide association analysis was conducted on 1 247 162 SNPs detected in apple accessions by genome resequencing technology，and candidate genes significantly associated with cold tolerance were selected. Three cultivars with the strongest cold tolerance were identified，and their relative electrical conductivity was all less than 40%，which were‘Jinhong’，‘Ederbostdorf’and‘Haralson’. Based on the association analysis using 1 247 162 high-quality SNPs and index of relative electrical conductivity characterizing cold tolerance，five significant correlated loci related to cold tolerance were identified，which were distributed on chromosome 4，15，and 16，respectively. Three candidate genes TIF3B1（MD04G1241100），COR47（MD15G1003900），and MD16G1069900 closely related to cold stress tolerance were identified.

This review briefly describes the carotenoid metabolic pathway and main flux-controlling steps for carotenoid accumulation in plants. It highlights our recent understanding of the regulatory mechanisms underlying carotenoid accumulation at transcriptional，post-transcriptional，post-translational and epigenetic levels.

To explore the functions of SAUR（Small Auxin-up RNA）gene family in plant growth and development，bioinformatics methods were used to identify the SAUR genes in peach（Prunus persica）. The chromosome location，gene structure，evolutionary relationship and gene expression were analyzed，and the function of PpSAUR5 was verified through transgenic method. A total of 80 PpSAUR members were identified and divided into 12 subgroups，which were unevenly distributed on the eight chromosomes. The analysis of gene structure showed that 75 PpSAUR genes contained only one exon，and five genes contained two to three exons. Eighteen SAUR genes were found to be associated with tree growth through RNA-seq analysis. These genes exhibited different expression patterns in response to exogenous hormone.Among them，PpSAUR5 was induced by both IAA and GA. PpSAUR5 transgenic Arabidopsis exhibited longer petiole，hypocotyl，root，and less sensitivity to NAA and 2,4-D treatment than wild-type. The results indicated that PpSAUR5 functioned to promote organ elongation.

The relationship among 5-aminolevulinic acid（ALA），abscisic acid（ABA）and auxin （IAA）in strawberry roots growth were discussed. It was found that exogenous ABA treatment significantly inhibited strawberry root growth，while ALA alleviated the inhibitory effect by ABA. ABA reduced the endogenous IAA content in the root tips of strawberry，while ALA promoted endogenous ABA content. The expressions of NCED1，NCED2 and CYP707A，referring to ABA biosynthesis and catabolism，respectively，were not different among treatments，whereas that of PYL4 and PYL8，both coding ABA receptors，and SnRK2.1，SnRK2.2，SnRK2.3，SnRK2.4，SnRK2.5 and SnRK2.6，which code the protein kinases in ABA signaling pathway were up-regulated by ABA but not mediated by ALA. These results suggested that the genes in ABA signaling route were not involved in ALA-ABA regulating root growth of strawberry. On the other hand，ABA down-regulated expressions of YUC2，YUC3（referring to IAA synthesis） and AUX1（coding auxin influx carrier）. However，the down-regulation of gene expressions by ABA were not reversed by ALA. This also means that these genes are not so important in ALA-ABA-regulated root growth of strawberry. Nevertheless，the expression of PIN1，which codes IAA exporter carrier，was down-regulated by ABA，and ALA reversed the down-regulation，suggesting that PIN1 may be involved in ALA-ABA regulating root growth of strawberry. In a transgenic Arabidopsis carrying the green fluorescent protein gene（GFP），it was found that AtPIN1-GFP expression was inhibited by ABA and reversed by ALA. Bioinformatic analysis showed that the amino acid sequence of FaPIN1 in the cultivated strawberry is high homology with many Rosaceous plants，with several transmembrane regions located at both ends of the polypeptide. When FaPIN1-GFP was transferred into tobacco （Nicotiana benthamiana），the fluorescence was distributed in the plasma membrane. When the cloned FaPIN1 was constructed into an estradiol-induced expression vector and transformed into Arabidopsis，the root growth of the transgenic plants was less sensitive to ABA treatment，and the ALA mitigation was also less significant. These results suggest that FaPIN1 is an important factor during ALA-ABA regulating root growth，and the alleviation of ALA on ABA-inhibiting root growth may be dependent on the promotion of IAA polar transport in the root tip of strawberry.

A new emerging banana leaf spot disease was found during a disease survey in the banana-producing area of Maoming City，Guangdong Province. The pathogen was isolated and tested for pathogenicity according to Koch's postulate，and the pathogen was identified based on morphological characteristics and sequence analyses of ITS，β-tubulin and tef1 genes. The results showed that strain MM3-2z9 could infect banana leaves and induce similar symptoms as in the field. The colony of strain MM3-2z9 on the PDA medium was white，producing obvious concentric ring patterns. The conidia were fusoid with 4-septate，three median cells versicoloured，apical cell hyaline，pyramidal，with two to four filiform apical appendages（mostly three），and basal cell with appendage single was centric and hyaline. Sequence homology analysis indicated that the ITS，β-tubulin and tef1 sequences of three single-conidial strains of MM3-2z9 were more than 98% identical to the corresponding sequences of Neopestalotiopsis musae stains. The phylogenetic tree constructed by the three fragments showed that strain MM3-2z9 was most closely related to N. musae. Therefore，strain MM3-2z9 was identified as N. musae based on morphological analysis and phylogenetic tree analysis. In addition to damaging banana（Musa AAA Cavendish）leaves，the pathogen could also quickly infect the leaves of M. × paradisiaca ABB and Musa ABB Pisang Awak‘Fenza 1’.

Sugar is an important factor that determines fruit quality of citrus. Illustrating the characteristic and regulation mechanism of citrus fruit sugar metabolism and transport will greatly contribute to regulating sugar accumulation accurately. In this paper，the mechanisms underlying sugar accumulation were comprehensively reviewed，we also summarized the differences of fruit sugar accumulation in various citrus varieties，the characteristics of sugar accumulation with fruit development and the relationship between sugar and the related enzyme activities. Subsequently，a model of metabolic differences between sucrose accumulation type and hexose accumulation type was mapped in citrus. Moreover，the storage process of sucrose from leaf（source organ）to fruit（sink organ）was described systematically，including phloem loading，unloading，transport and sucrose storage in fruit vacuole. Finally，a model of sugar transport from source to sink was constructed in citrus.

MLO is a plant specific recessive resistance gene family. It is widely believed that it has a negative regulatory effect on powdery mildew. Many powdery mildew resistance MLO genes have been found in both monocotyledon and dicotyledon. However，there are few studies on the mechanism of upstream regulator of MLO genes. In this study，a cDNA library of apple rootstock‘Qingzhen 1’leaf was constructed with a titer of about 4 × 10⁹ cfu · mL^-1，and the recombination rate was 100%. Bioinformatics analysis of apple MLO gene family promoter region showed that there were 38 kinds of cis-acting elements，including hormone，stress defense response as well as growth and development response elements，etc. TCA and TC-rich repeats cis-acting elements were selected as bait sequences and constructed bait vectors named Bait-TCA and Bait-TC for yeast one-hybrid，respectively. The results showed that the Bait-TCA had self-activation and could not be used for screening. Among the Bait-TC obtained 30 sequences，six sequences were involved in plant anti-stress defense response. It suggested that they might be involved in the response of apple to powdery mildew through regulating the expression of MLO genes.

In this study，apple whole-genome data were used to identify and conduct a biological analysis of the MdTOPP gene family. A total of 44 TOPP genes were systematically identified from apple genome，and they distributed on 15 chromosomes. The phylogenetic tree analysis showed that MdTOPP，PpTOPP and AtTOPP were highly homologous；the gene structure and conserved domain analysis showed that 1-2 exons，0-20 introns and 10 conserved motifs were in MdTOPP genes. The promoter cis-acting element analysis showed that the MdTOPP genes were not only affected by the external environment such as light and heat，but also comprehensively regulated by multiple hormones. All the MdTOPP genes have distinctive expression patterns in different apple tissues. MdTOPP13 and MdTOPP28 were identified from the transcriptome data of exogenous cytokinin（6-BA and TDZ）induced apple axillary bud outgrowth，and cloning sequence alignment showed high homology. Using quantitative real-time PCR，the expressions of MdTOPP13 and MdTOPP28 were upregulated after exogenous 6-BA or TDZ applied on the axillary buds of apple rootstock‘SH40’. In summary，MdTOPP13 and MdTOPP28 may play an important role in mediating cytokinin regulation of axillary bud outgrowth.

The objective of this research is to provide reference for the new germplasms creating，new cultivar breeding and regions of peach with low chilling requirement through clarifying the impact of air temperature change on the adaptability. Based on the air temperature data of 12 regions with different geographical locations and climate types in China from 2011 to 2021，this paper evaluates the chilling accumulation of the tested regions for breaking peach dormancy，and counts the chilling requirement of 589 peach resources by 0-7.2 ℃ model. Then，this study analyzes the air temperature change in the studied regions and its impact on the chilling accumulation to judge the peach adaptability challenge and point out some strategies. The results show that the temperature in the regions increased year by year with an average increase of 2 ℃ in 10 years，during the period of peach chilling accumulation from early November to the end of March of the following year，but some great fluctuation of the temperature in some years. There are significant differences of chilling accumulation in various regions. As the reduced latitude （from North to South），the start date of chilling accumulation changes from early to late，and the end date changes from late to early，and days of the chilling accumulation gradually decreased. The average chilling accumulation in each region varies from 4.5 to 1 315 h in 10 years. There is an obvious downward trend of the chilling accumulation year by year in each region with the lower the latitude，the more lowering tendency. In addition，the climate type also affects the chilling accumulation. The decrease of chilling accumulation in each region had a slight or moderate or severe impact on the peach adaptability with different chilling requirement. Based on these results，the range of peach chilling requirement in tested regions is predicted. The range of peach cold requirements for growth in different regions was predicted as follows：< 1 000 h for Beijing，Mengyin，Zhengzhou and Nanjing，600-700 h for Shanghai and Hangzhou，< 400 h for Guilin，< 200 h for Wenshan and Gutian（400 h adaption for some high-altitude areas in Gutian），< 100 h for Fuzhou and < 50 h for Guangzhou. There is non-dormant and evergreen peach in Hainan Province. In the future，the development of peach industry needs to increase the creating and breeding new germplasms and varieties with low chilling requirement，and also optimize the variety layout，and reasonably formulate the south extension cultivation plan.

‘Zaofeng’wampee and‘Jixin’wampee cultivars were respectively selected as materials representing for sweet and sour wampees. The components and contents of soluble sugars，organic acids and polyphenolics at young fruit stage，color changing stage and ripening stage were measured；antioxidant activities at three different stages were analyzed by ORAC and CAA assay. Results showed that soluble sugars were continuously accumulated during fruit development in both‘Zaofeng’and‘Jixin’wampee cultivars. At ripening stage，the contents of fructose and glucose in‘Zaofeng’wampee were higher than sucrose，while the sucrose content was higher than fructose and glucose in‘Jixin’wampee. The contents of organic acids in‘Zaofeng’wampee and‘Jixin’wampee varied greatly during fruit development. There was little difference between them at young fruit stage，however，organic acids were almost not detected in ‘Zaofeng’wampee at color changing and ripening stages. While the content of citric acid increased sharply at color changing stage and then decreased at ripening stage in‘Jixin’wampee fruit. The contents of total phenolics and phenolic compounds in‘Zaofeng’and‘Jixin’wampee decreased during fruit development. The content of total phenolic in‘Jixin’wampee was 13.6 times higher than that in‘Zaofeng’wampee at young fruit stage，and was about eight times higher than that in‘Zaofeng’wampee at color changing and mature stages. Six phenolic compounds were detected in wampee fruit，in which rutin was the main component，while syringin was the differential component between‘Zaofeng’and‘Jixin’wampees. The young fruit showed the highest antioxidant activity both in‘Zaofeng’and‘Jixin’wampees as measured by ORAC and CAA methods，and then the antioxidant activity decreased during fruit development. The antioxidant activities of‘Jixin’wampee fruit significantly higher than that of‘Zaofeng’wampee fruit.

In this review，recent studies on the relationship between fruit sugar accumulation and sugar transporters （mainly includes sucrose transporter SUT related to sucrose accumulation，hexose transporter STP related to hexose accumulation，tonoplast sugar transporter TST that is highly related to vacuolar sugar accumulation，early response to dehydration six like protein ERDL6 related to vacuolar glucose efflux，sugar transporter SWEET newly identified in plants in recent years，and sorbitol transporter SOT，which is unique to Rosaceae plants，etc）in horticultural crops were summarized，and discussed prospects for future research directions on sugar transporters and the molecular biology method for fruit quality improvement.

Fruit chloroplast quantity and function have a direct impact on fruit quality. Fruit chloroplasts function as assimilation organs before ripening，synthesizing amounts of assimilates for fruit development and quality-related metabolites synthesis，and transform into chromoplasts during ripening，storing nutrients and flavor substances synthesized by different metabolic pathways driven by photosynthesis in the early stage. As a result，increasing fruit quality by controlling chloroplast development has been a research emphasis，and significant progress has been made in the study of fruit chloroplast developmental regulation in tomatos an essential fruit vegetable and model plant. This manuscript reviewed the progress of tomato fruit chloroplast development regulation in terms of transcription factors，light signals，hormone signals，and oxidative stress signals，as well as the challenges and future research directions，to clarify the specific regulation mechanism of fruit chloroplast development and provide new ideas for fruit quality improvement of tomato and other crops.

Crassulacean acid metabolism photosynthetic pathway is a kind of carbon concentrating mechanism that evolved from C3 photosynthesis and it is characterized by nocturnal CO₂ fixation and high water use efficiency. Currently，there are growing interests in improving WUE to enhance drought resistance by“transferring”CAM pathway into C₃ crops，also called‘CAM engineering’. CAM engineering has significant application potential in agriculture，while systematical investigations of CAM photosynthetic pathway / plants are a prerequisite to its progression. The wide applications of multi-omics and molecular biology methods have extensively promoted CAM plants related studies. CAM pathway-related key genes and their functions are being gradually revealed，and many CAM plant genomes have been published. Diverse mechanisms are involved in the regulation of the CAM pathway, including transcription factors，hormones，miRNA，lncRNA，alternative splicing，and DNA methylation This article mainly focuses on the latest progress of molecular biology and omics studies on CAM plants. In addtion，future research prospective and study interests are also discussed to guide further investigations on CAM plants.

Orchid senescence caused by the external factors，the metabolic changes of internal organization during the senescence process，and the molecular mechanism of ethylene synthesis and signal transduction pathway regulating orchid senescence were reviewed. The common commercially popular fresh-keeping treatment technologies for cut and potted orchids and their application effects after treatment，and the improvement of orchid senescence-related genes were summarized. Additionally，modern genetic engineering technologies to delay the orchids senescence process and prolong the ornamental time by regulating functional genes were prospected.

With diploid and tetraploid Hedychium coronarium as test material，the developmental process of cut flowers were observed. Micrographic changes of the flower stem base，corolla tube and petals were identified by scanning and transmission electron microscopy. With the bent neck of corolla tube and initial wilting of petal as markers，the developmental process of florets was divided into six stages：bracts cracking stage，initial opening stage，blooming stage，neck bending stage，initial wilting stage，and wilting stage. Neck bending of the floret corolla tube preceded petal wilting，and the senescence of corolla tube cells arose earlier than the petal cells. The diameter of the corolla tube of the tetraploid was extremely significantly more than that of the diploid，and the ratio of the corolla tube length out of bracts to the total length of the tetraploid was significantly less than that of the diploid. During the whole vase life，the cut flowers of tetraploid were in the state of net water absorption for longer time and the basal vessel of cut flower stem were blocked more slightly than those of the diploid. The neck bending of the tetraploid floret arose later than that of the diploid，and damages of mitochondria of corolla tube and petal cells were posterior to those of the diploid. In total，neck bending of the corolla tube was the landmark for the beginning of senescence of H. coronarium floret. The significant longer longevity of the tetraploid cut flowers may be due to the thicker corolla tube and stronger support from bracts to florets，the postponed senescence of corolla tube and petal cells，and stronger water absorption and anti-blocking ability of the flower stems.

In order to explore the effects of abscisic acid（ABA）on monoterpene synthesis in grape berries，this study used table grape species‘Jingxiangyu'with muscat flavor as experimental material，and soaked the clusters with 300 mg · L^-1 ABA twice at one week before and during veraison. The contents of free monoterpenoids at 7，14，21，28 and 35 days after first treatment were analyzed qualitatively and quantitatively by GC-MS. The results showed that 28 kinds of monoterpenes were detected in berries，most of which accumulated during ripening. The total contents of free monoterpenoids in treated berries at maturity was 45.20% higher than that in the control，and the substance that changed most strongly was linalool. To investigate how ABA regulate monoterpenes synthesis，quantitative real-time PCR was used. The results indicated that the expression of ABA synthesis genes（VvNCED1 and VvGT）was much stronger than that of the control. The relative expression of VvβG1 increased after ABA treatment constantly. The transcriptional levels of ABA receptor VvPYL1 and signal transduction related genes VvPP2C2，VvSnRK2.1 and VvABI5 were distinctly higher than the control on 21 and 35 days after treatment respectively. The expression levels of upstream genes about monoterpene synthesis（VvDXS2，VvDXS3，VvDXR，VvGPPS）and monoterpene synthase gene VvPNLinNer was significantly higher. According to the above results，it’s suggested that exogenous ABA enhance ABA signal transduction in berries，which lead to the increase of monoterpene substrate level and facilitate monoterpene synthesis，finally improve the quality of rose flavor grapes.

The experimental materials were five-year-old vines of‘Summer Black’grape in the eastern Henan region. The experiment was conducted from 2018 to 2019. The mineral nutrient contents of soil and grape leaves，and the fruit quality at maturity were analyzed. The functional model of fruit comprehensive quality and soil and leaf mineral nutrients was established by the method of component nutritional diagnosis（CND），then the nutritional diagnosis analysis of soil and leaf was carried out to obtain the diagnostic criteria of soil and leaf nutrition. The main results showed that the contents of available N，P，K，Ca，and Mg in soil were at the rich level or above，the contents of available Cu，Fe and Mn were at the very rich level，the contents of available B and Zn were also at the rich level，the content of available Mo was at a low level. The variation range of each trace element caused by soil layer difference was small，the coefficient of variation was also at a medium level. Four high-quality plots were divided by soil nutrition diagnosis，which the range of available N，P，K，Fe，Mn，Cu，Zn，B，and Mo contents in all soil samples were 39.23 to 205.20，11.47 to 31.53，106.38 to 436.62，162.32 to 220.87，86.52 to 93.89，2.18 to 2.54，1.15 to 1.91，1.03 to 1.29，and 0.13 to 0.14 mg · kg^-1，respectively. The change in exchangeable Ca contents ranged from 6 599.83 to 7 513.33 mg · kg^-1，and exchangeable Mg content ranged from 550.52 to 592.15 mg · kg^-1. Five high-quality plots were divided by the leaf nutrition diagnosis，which the range of available N，P，K，Fe，Mn，Cu，Zn，B，and Mo contents in all leaves samples were 18.46 to 23.33 g · kg^-1，4.19 to 5.85 g · kg^-1，10.91 to 12.46 g · kg^-1，198.58 to 382.25 mg · kg^-1，67.23 to 119.25 mg · kg^-1，93.23 to 231.67 mg · kg^-1，29.16 to 52.13 mg · kg^-1，22.14 to 33.88 mg · kg^-1，0.71 to 1.11 mg · kg^-1，respectively. The change in exchangeable Ca contents ranged from 20.85 to 25.95 g · kg^-1，and exchangeable Mg content ranged from 3.68 to 4.30 g · kg^-1. In summary，conventional fertilization can be used for the diagnosed high-quality plots，and the fertilization suggestion for the corresponding low-quality plots are that for the elements with low contents such as B，Fe and Mo，are firstly considered to supplement with soil application when applying base fertilizer in early autumn. Mg should be management as conventional fertilization in soil，and foliar fertilizer should be applied less or no. Mn should be sprayed on the leaves during the main growth period of grapes. For P，K，Ca，Zn and other elements，the amount of fertilizer should be appropriately controlled in cultivation management.

The cytokinin response regulator VlRRA1 and its promoter were cloned from‘Kyoho’grape. The expression characteristics of VlRRA1 and the activity of VlRRA1 promoter were analyzed. The results showed that the full-length cDNA of VlRRA1 was 666 bp and encoded 221 amino acids. Conservative domain analysis showed that the gene contained only one phosphoacceptor receiver domain（REC），which belongs to type-A RR genes and can only accept phosphate groups;phylogenetic relationships showed that VlRRA1 was closely related to type-A RR in other species. The yeast self-activation assay illustrates that VlRRA1 has no transcriptional activation activity in agreement with other A-type RR genes and does not have a function similar to that of the B-type RR transcription factor. The results of qRT-PCR showed that VlRRA1 had tissue-specific expression and was mainly expressed in stems，leaves and young fruit，slightly lower expression in inflorescence and ripe fruit，suggesting that VlRRA1 may play an important role in the process of fruit set;exogenous cytokinin forchlorfenuron（CPPU）can promote VlRRA1 expression，while the cytokinin biosynthesis inhibitor lovastatin（LOV）inhibits VlRRA1 transcription. Many elements related to abiotic stress and hormone response were found in VlRRA1 promoter. The results of GUS tissue staining showed that VlRRA1 promoter had promoter activity and could respond to a variety of hormone signals，including three plant hormones related to fruit setting，cytokinin，auxin and gibberellin. These results suggest that VlRRA1 plays an important role in grape fruit setting and young fruit development mediated by cytokinin.