Taking apple Honglu/M9-T337 as experimental material,container seedlings were cultivated in containers of small,medium and large sizes with upper diameter of 10 cm,20 cm and 30 cm,lower diameter of 8 cm,16 cm and 24 cm,and height of 30 cm,respectively. The container seedlings were transplanted into 25-year-old apple orchards together with substrates. Bare root seedlings were used as control. The growth of seedlings and soil environmental characteristics of root zone were observed after six months and 18 months. The results showed that the three kinds of container seedlings improved the soil environment and promoted the growth of saplings in different degrees,and the effect of large container seedlings with substrate was the most significant,followed by medium container seedlings with substrate. In September 2019,the plant height,ground diameter,fresh weight and dry weight increased by 210.3%,52.5%,189.6%,171.8% and 111.3%,25.1%,85.3%,82.8% respectively compared with the bare root seedlings;The root length,root surface area and root volume of medium container seedlings and large container seedlings transplanted with substrate were increased;The activities of SOD,POD,and CAT were increased;At the same time,it increased the content of chlorophyll and promoted the photosynthesis of leaves;The activities of urease,invertase,phosphatase and catalase in root zone soil were increased,and the gene copy numbers of Fusarium oxysporum and F. solani were decreased. The trend in September 2020 is consistent with that in September 2019. In conclusion,the three specifications of container seedlings can optimize the replant soil environment and promote the growth of young trees,and the large container seedlings with substrate have the best effect,which can effectively alleviate the apple replant obstacles. However,with the increase of container specifications,the cost of seedling raising increases significantly. Therefore,the medium container seedlings with substrate should be selected according to the situation in the old orchard and the new orchard.
Using Satsuma mandarin fruits at enlargement stage as the material,three stress treatments with the substrate relative water content 40%,30% and 20% were set. Afterward,fruit quality changes and expression patterns of transcription factors regulating citrate accumulation were studied under drought conditions. Using deuterium water（D2O）tracer method,the law of water transportation and distribution in citrus tree after re-watering could be cleared. Drought stress at fruit enlargement stage inhibited fruit growth and fruit size severely. After ten days drought stress,fruit transverse diameter,longitudinal diameter and single fruit weight decreased significantly. After constant drought for 40 days,fruit diameter in treatment groups decreased by 18.33% to 23.82% comparing to the control nd single fruit weight decreased by 45.17% to 48.67%. No significant difference was found in fruit size between different drought-treatment groups. After 40 days of drought stress in each treatment,fruit total solid soluble increased significantly by 47.7% to 59.3% and fructose increased drastically by 63.25% to 78.77%,but sucrose and glucose in fruit did not change. No significant difference was found in fruit sugar components between different drought-treatment groups. Citrate content in control fruits decreased gradually with fruit development,but that increased significantly after 20 days drought stress with 1 fold higher to control at the peak. Fruit malate content was higher than that in control by 14.70% to 33.82% after drought stress. No significant difference was found in fruit acid components between different drought-treatment groups. Transcription factors CitPH3（WRKY）,CitPH4（MYB）and CitAN1（bHLH）which regulate citrate accumulaiton in citrus fruit expressed with up-regulation under drought stress. After rehydration,citrus roots absorbed water quickly in four to eight hours. Deuterium water content in main stems and perennial stems reached the highest in 24 hours. The water absorption of the fruit tended to be stable during 24 to 48 hours. In this experiment,drought duration affects fruit quality significantly while drought degree does slightly. The up-regulated expression of CitPH3,CitPH4,and CitAN1 under drought stress promotes the accumulation of citric acid,which may be an important reason for the acidification of citrus fruits. Orchard soil being moist for 24 to 48 hours after continuous drought is necessary for water reaching fruit massly.
Current studies have shown that a number of microRNA（miRNA）families are involved in plant flowering time regulation and phase transition,etc. Therefore,it is very instructive for the phase transition regulation of fruit trees to gain insight into microRNA family associated with phase transition in jujube tree. In this study,the new shoots at different development stages（nodes）of jujube progenies were used as materials. Firstly,27 miRNA families with 58 known miRNAs and 23 novel miRNAs were identified by small RNA sequencing analysis in the three different development stages of juvenile,transition and adult period. Among them,44 miRNAs were differentially expressed,including 32 known miRNAs and 12 novel miRNAs. Afterward,six miRNAs（zjmiR156a-5p,zjmiR156j,zjmiR172c,zjmiRmir172e-3p,zjmiRnovel-16 and zjmiRnovel-71）with obviously differential expression in the three development stages were screened out. Their 15 key target genes were also predicted through TargetFinder software,and they are mainly involved in flowering,transcriptional regulation and biosynthesis. Finally,the differential expression of the above-mentioned 12 miRNAs and their 15 key target genes during phase transition were verified by qRT-PCR,and they had positive or negative regulatory relationships. Moreover,the two newly discovered miRNAs（zjmiRnovel-16 and zjmiRnovel-71）may affect the phase transition through photoperiod pathway and glucose metabolism pathway,respectively.
EC（embryogenic callus）,ICpEC（incomplete embryogenic compact structures）and GE（globular embryos）of the early somatic embryogenesis（SE）of Dimocarpus longan Lour.‘Honghezi’were used as experimental materials. Using bioinformatic methods identified and analyzed the members and its molecular evolutionary characteristic of longan chromatin remodeling factor DlSnf2 family,and the expression patterns of DlSnf2 gene family were analyzed through transcriptome data and real-time quantitative PCR（qRT-PCR）. The longan DlSnf2 family contains 35 members,and expansion of the family is mainly driven by whole-genomic or segmental duplication events. 31 members of containing SNF2_N and HELICc domains were selected and divided into 19 subfamilies under six categories depending on the evolutionary characteristics. Protein interaction,microRNA and promoter prediction showed that partial members can interact each other,almost all genes may be potentially regulated by microRNA and exist a large number of cis-acting elements related to hormone,stress,light,growth and development;Transcriptome and qRT-PCR analysis showed that most genes were highly expressed in ICpEC,and the expressions of DlCHR18,DlCHR24,DlCHR25,DlCHR29 and DlCHR31a were gradually decreased from EC to GE,while DlCHR4,DlCHR15 and DlCHR42 gradually increased;The analysis exhibited that DlSnf2 family genes responded to 2,4-D,ABA,ethrel,Methyl jasmonate,4 ℃ and 40 ℃. Expressions of DlCHR10 and DlCHR11 are up regulated by ethrel,while DlCHR28b and DlCHR36 are down regulated. DlCHR11 is down regulated by ABA and high temperature,DlCHR10 is down regulated by Methyl Jasmonate,DlCHR36 is down regulated by low temperature,and DlCHR24 and DlCHR35 are down regulated by high temperature. The Snf2 gene family may have relatively conservative functions and certain species specificity during plant evolution. Under plant growth regulator and temperature treatments,longan DlSnf2 family members may be involved in regulating somatic embryogenesis and resisting high and low temperature stress,and it is speculated that other epigenetic regulatory mechanisms such as DNA methylation,microRNA and histone modification are involved in the process.
In order to study the molecular mechanism of floral axis waxiness in Chinese cabbage,a comparative transcriptome analysis was carried out on a pair of near isogenic lines with difference in floral axis waxiness. In total,7 237 differentially expressed genes（DEGs）were identified between waxy material （RHL065_1）and non-waxy material（RHL065_2）,mainly enriched in carbohydrate biological processes,cellular components of plasma membrane and tetrapyrrole binding molecular functions. Combined with gene function annotation,17 DEGs,involved in wax synthesis MAH1,CYTB5-B （Bra022898,Bra021809）,KCS6/CER6/CUT1,KCS9,FAR3/CER4,KCS1,CER2,KCD/PAS2,CYTB5-C（Bra039268,Bra004518）,CER2-LIKE,wax transport LTPG1（Bra010912,Bra030067）and transcription factors WIN1/SHINE1,MYB30,DEWAX were proposed to contribute to surface waxiness formation in Chinese cabbage floral axis. A further qRT-PCR analysis was used to verify the transcriptome analysis and survey the expression pattern of DEGs. These results will be helpful for further gene cloning,developing functional molecular markers and understanding the genetic architecture for waxiness.
In order to study the aging mechanism of Hibiscus esculentus fruit,the changes of cellulose content were measured during fruit development and postharvest period,and the distribution of cell structures were observed by microscope. The results showed that during the aging process of H. esculentus fruit,the content of cellulose increased greatly. It was suggested that the increase of cellulose was the main factor of fruit aging. Moreover,nine fragments annotated as CESA gene family were screened from the RNA-seq database of H. esculentus fruit,then the full-length cDNA sequences of CESA1,CESA2,CESA3,CESA4,CESA6,CESA7,CESA8 genes and CESA5and CESA9 gene fragments were cloned. Expression of these nine genes of cellulose synthase gene family in H. esculentus was analyzed by fluorescence quantitative PCR. The results showed HeCESA1,HeCESA3 and HeCESA6had the same expression pattern
and conserved sequences CQIC and SVICEXWF motifs of primary cell wall specific CESAs. HeCESA4,HeCESA8 and HeCESA7 had the same expression pattern,and their expression levels were significantly up-regulated during fruit development and postharvest storage when cellulose increased significantly,which was much higher than that of other CESA genes at the same period. It can be inferred that HeCESA4,HeCESA8and HeCESA7 play an important role in cellulose synthesis of H. esculentus fruit during senescence.
In 190 Paeonia rockii（flare tree peony）cultivars,the colorimeter was used to measure the flower color parameters in the full bloom period for two consecutive years,and the measured L*,a*,and b* values were converted into H（Hue）,V（Value）and C（Chroma）values of the Munsell Color System. Then,according to the systematic clustering analysis of L*,a*,and b* values combined with the ISCC-NBS Method,each petal sample’s color was described qualitatively. The result showed：the color classification by cluster analysis on the L*,a*,and b* values can more accurately reflected the true color of flare tree peony than that by the ISCC-NBS Method,so that the flower colors can be classified into six color systems,including five colors like white,pink,red,purplish red and black red,and one blended color that can be identified directly by eyes. In such the newly-established color classification system of flare tree peony,the quantitative classification range of five color systems and the measurement value on the flower of each cultivar were obtained to realize the quantitative description of distinct color systems. These results supply important experimental data for the classification, identification and breeding of flare tree peony.
TIFY transcription factors are unique transcription factors of terrestrial plants. They are divided into four sub-families TIFY,PPD,JAZ,ZML according to structural domain characteristics,and regulate the growth and development of plants. In this paper,the TIFY transcription factor of tea plant is the research object. A total of 22 members of the CsTIFY transcription factor family have been identified from the tea plant genome database,all of which contain the TIFY domain. Gene structure analysis found that most of the CsTIFY family members have exons between five and 12,and the same subfamily contains similar numbers of motifs and exons. The results of the phylogenetic tree showed that the 122 genes of six species were divided into four groups,among which tea trees were more closely related to grapes and poplars. Analysis of promoter cis-acting elements found that the CsTIFY family contains a large number of phytohormones and abiotic stress response elements such as SA,ABA,low temperature and drought. The results of subcellular localization experiments showed that CsTIFY1,CsJAZ1 and CsJAZ5 were localized in the nucleus. The tissue expression analysis of different tea cultivars showed that most CsTIFY gene family members had higher relative expression levels in mature leaves,roots and fruits. In addition,the expression of most CsJAZ genes was increased and the expression of CsZML was decreased under the treatments of exogenous hormones ABA,SA and MeJA. The expression of CsZML1 was significantly increased under both low temperature and drought treatments.
The purpose of this study was to explore the effect of exogenous brassinolides（2,4- Epibrassinolide,EBR）on sugar metabolism of Merlot grape berries. 10-year-old grape Vitis vinifera ‘Merlot’was used as the test material,and different concentrations of EBR（0.2,0.4,0.6 mg · L-1）solutions were sprayed in the eighth week after anthesis,with distilled water as the control. Using chemical analysis,HPLC,Enzyme-linked Immunosorbent assay,and transcription analysis to study the effects of EBR treatment on the sugar components,key sugar metabolism enzymes and related gene expression during the ripening process of‘Merlot’grapes. Compared with the control,0.6 mg · L-1 EBR treatment can significantly promote the accumulation of glucose and fructose in grape berries,the contents were respectively increased by 16.95% and 39.31%. At maturation,the activities of acid invertase（AI）and sucrose phosphate synthase（SPS）were significantly higher than the control. The 0.6 mg · L-1 EBR significantly up-regulated the transcription levels of cell wall acid invertase（VvcwINV）,sucrose transporter（VvSUC12）,and sucrose synthetase（VvSS）during the process of grape color transformation to maturity. The expression of VvSS gene was 2.75 times that of the control. Correlation analysis showed that hexose was significantly positively correlated with SS and AI under 0.6 mg · L-1 EBR treatment. 0.6 mg · L-1 EBR treatment improves the activity of SS and AI,and promotes the expression of VvSS,VvcwINV gene and sucrose transporter VvSUC12 gene,thereby increasing the content of glucose and fructose. 0.6 mg · L-1 EBR treatment has the best effect.
To clarify the taxonomy of the pathogen causing Allium ascalonicum anthracnose in Guangdong, diseased plant samples of A. ascalonicum showing anthracnose symptoms from Huizhou and Shaoguan in Guangdong were collected as test materials. Strains were isolated and purified by conidial suspension dilution method. The pathogenicity of these strains was determined by the Koch’s postulates with in vivo or in vitro inoculation of conidial suspension on plants of A. ascalonicum. The pathogen was identified based on morphological characteristics,combined with polygene sequence analysis and phylogenetic analysis method using partial sequences of internal ribosome transcribed spacer（ITS）,actin （ACT）,chitin synthase 1（CHS1）,glyceraldehyde-3-phosphate dehydrogenase（GAPDH）and β-tublin （TUB2）. Results showed that 23 single-conidium-isolates with similar morphological characteristics were obtained from diseased plant samples of A. ascalonicum showing anthracnose symptoms. Artificial in vivo and in vitro inoculation results showed that the tested isolate could infect A. ascalonicum and cause typical anthracnose symptoms both at 20 ℃ and 25 ℃. Old leaves were more susceptible than young leaves. On PDA medium,the colony was gray,and mycelia of the tested isolate grew evenly and fast at 20 ℃. But it grew abnormally and slowly,the colony showing petal-like shape at 25 ℃ and 28 ℃. Conidiomata in orange color were formed on the surface of the colony. Conidiophores were hyaline with conidia on the top. Conidia were hyaline,single-spore,slightly curved,13.1-19.6 µm × 3.2-3.9 µm. Appressoria were dark brown,irregular shapes,11.7-25.5 µm × 5.0-14.3 µm. Setae were light brown to dark brown,with enlarged base and pointy or rounded tip,44.5 to 106.4 µm in length. These morphological characteristics were similar with Colletotrichum spaethianum. Sequence identities of partial sequences of ITS,ACT,CHS1,GAPDH and TUB2 genes of representative isolates were 99.46% to 100% identical to the ex-holotype strain CBS 167.49. The phylogenetic tree showed that two representative isolates were grouped together with three C. spaethianum strains to form a single clade. This study clarified that the pathogen causing A. ascalonicum anthracnose in Guangdong was determined as C. spaethianum and reported for the first time that C. spaethianum could cause A. ascalonicum anthracnose.
The 77 tomato leaves suspected to be infected by lettuce chlorosis virus（LCV）were sampled in Yunnan Province,China. The reverse transcriptional（RT）-PCR amplified near full length of minor coat protein gene（CPm）of LCV,which was sequenced by Sanger sequencing method. The genetic evolution was analyzed based on the sequences of near full length CPm genes. The results showed that the specific 1.38 kb fragment was amplified by RT-PCR,and 12.99% LCV-positive samples were detected in the 77 tomato leaf samples. The sequences of near full length CPm genes of Yunnan Province,China,shared the highest nucleotide sequence identity of 99.27%-99.78% with LCV Shandong isolate（MK370741）. Phylogenetic analysis indicated that all of LCV isolates were divided into three subclusters with region-dependent,LCV Yunnan isolates grouped into same subcluster with other LCV isolates of China,and America isolates and European isolates grouped into other two subclusters separately. Genetic evolution analysis revealed one recombinant event exiting in LCV Yunnan isolate YN58,and the highest nucleotide substitution of 25.25 occurring in pyrimidine C/T,which shown LCV had the tendency of independent evolution and expedited diffusion in China. This is the first report of LCV in Yunnan Province.
The mycelium and sclerotium of Pleurotus tuber-regium（Fr.）Singer were used as materials,the methylation levels were analyzed by MSAP technology,and the differentially methylated fragments were recovered and sequenced to explore the relationship between the growth of P. tuber-regium and DNA whole genome methylation.The results showed that the DNA methylation rates of mycelium and sclerotium were 7.94% and 9.54%,respectively;the hemi-methylation rates were 4.50% and 4.09%,and the fully methylation rates were 3.44% and 5.45%,respectively.That is,the formation of sclerotium was accompanied by an increase in the methylation level,the full methylation level was more representative of the overall methylation status.Partially methylated differential fragments were recovered,cloned and sequenced.The NCBI homology comparison showed that the homologous genes or proteins are mainly related to metabolism,cell growth,and stress resistance.It is speculated that P. tuber-regium might regulate the expression of these genes or proteins through methylation to form sclerotium to adapt to environmental changes.
In Rosa chinensis‘Slater’s Crimson China’and Rosa sp.‘2015-58-20’,the fluorescence microscope observation of pollen tubes in both self-pollinated and cross-pollinated styles indicated that rose is a typical gametophyte self-incompatible plant. The full-length sequence of RcS1-RNase and RcS2-RNase cDNA and DNA have been identified in the‘Slater’s Crimson China’. Sequence analysis showed that RcS1-RNase and RcS2-RNase have five conserved domains（C1,C2,C3,RC4 and C5）and a hypervariable region. Phylogenetic analysis found that RcS-RNase has high homology with S-RNase proteins in other Rosaceae plants. Tissue specific expression analysis indicated that RcS1-RNase and RcS2-RNase genes are solely expressed in styles.
In order to improve callus induction quality,and establish highly efficient regeneration system of Paeonia ostii‘Fengdan’,the immature embryo collecting time,technical treatments of immature embryos,basic medium selection,and different concentrations and combinations of plant growth regulators and H2O2 were optimized. The results showed that the best collection time for immature embryos callus induction was 60 days after pollination. Compared with four technical treatments of immature embryos,thoroughly divided embryos（slices）were produced better callus with low callus browning rate than that with whole embryos,halved embryos,and broken into quarters embryos. MS basic medium with 0.162 μmol · L-1 H2O2 can improve the callus induction rate of immature embryo,and it can also increases the callus browning rate. Different concentration of H2O2 adding in WPM basic medium could not be improved the callus induction rate. WPM basic medium is better than MS basic medium for immature embryo callus induction. The combination of WPM + 2.5 mg · L-1 2,4-D + 0.1 mg · L-1 6-BA can obtain higher callus induction rate（93.33% ± 3.53%）with lower callus browning rate（25.33% ± 4.81%）. The best hormone combinations for adventitious bud and root induction were WPM + 0.5 mg · L-1 GA3 + 0.5 mg · L-1 6-BA,1/2 WPM + 2.0 mg · L-1 IBA + 1.0 mg · L-1 IAA,respectively.
The phenotypic characteristics of sepal color,petal color,lip color,leaf art,petal type and lip spot of 311 Cymbidium ensifolium germplasms were recorded,and the traits were assigned and statistically analyzed. Twenty-two pairs of SSR fluorescent primers were used to perform PCR amplification on 311 C. ensifolium germplasm resources in order to conduct genetic diversity analysis. Use Structure software to analyze the population structure of C. ensifolium germplasm resources,and principal component analysis and cluster analysis were employed for verification. Core collection was analyzed and screened by using Core Finder software and t-test. The results showed that the phenotypic genetic diversity of the six quality traits of 311 C. ensifolium germplasm resources were all greater than 0.5,indicating that the phenotype of C. ensifolium germplasm resources had abundant genetic variations. A total of 171 alleles（Na）were detected by 22 pairs of SSR fluorescent primers,the average of Ne was 2.729. High genetic diversity was revealed in the germplasm resources of C. ensifolium（I = 1.026）. Structure software analysis results showed that the optimal population number K was three,and there is a small amount of germplasm mixing among the populations. The population structure analysis divided C. ensifolium germplasm resources into three groups. Principal component analysis and cluster analysis further verified the reliability of its classification. In this study,51 core collections of C. ensifolium were constructed,accounting for 16.4% of the initial collection,with the retention rate of Na,Ne,and I were 100%,130% and 124%,respectively. Through t-test and principal coordinate analysis showed that there was no significant difference between the genetic diversity of the core collection and initial collection. The 51 core collections constructed could represent the genetic diversity of C. ensifolium germplasm resources to the greatest extent.
In order to explore the chloroplasts genomic characteristics of Forsythia suspensa and the phylogenetic development of this genus,high-throughput sequencing technology was used to sequence and functionally annotate the chloroplast genomes of long and short style type in F. suspensa. PCR was used to confirm the sequencing results. The results showed that the chloroplast genomes of the long and short styles type were 156 386 bp,which was a typical four-segment structure in F. suspensa. A total of 114 unique genes were annotated,including 80 protein-coding genes,30 tRNA,and four rRNA. Analysis of 56 simple sequence repeats（SSRs）showed that it mainly composes of A and T bases. In addition,the coding region of the chloroplast genome of F. suspensa prefers to use A and T bases,but the overall codon preference is weak,which is mainly reflected by the difference of Arg and Ser. Based on the chloroplast genome sequence of the heterostyly and 32 plants’ chloroplast genome sequences（including 14 species of Forsythia）published the phylogenetic relationship is analyzed. And the results showed that the chloroplast genome of heterostyly was highly homologous to F. suspensa in Zezhou,Shanxi. It is possible that heterostyly also evolved from the homostyly flowers in F. suspensa.
Glucosinolates（GSL）are a group of nitrogen- and sulfur-containing secondary metabolites found almost exclusively in the Brassicaceae family,which play an important role in plant defense and environment stress. This review summarized the GSL participate in a variety of abiotic stress response patterns,mechanism and signal transduction. Meanwhile,the problems and research prospects of GSL mediated stress responses are prospected. This will provide a theoretical reference for studying on molecular mechanism of GSL mediated abiotic stress responses.
In this review,we reviewed the recent progresses of the genome editing technology and its application in tomato. We summarized successful examples in fruit storage tolerance and ripening regulation,nutrient composition and fruit color,male sterility and parthenocarpy,stress response,plant architecture,inflorescencetype and de novo domestication of wild tomato species. We further stated the technical innovations of the CRISPR/Cas-based genome editing,such as single-base editing,DNA-free editing and the improvement of homologous recombination efficiency. We finally showed the prospects and challenges in applying the genome editing technology in tomato genetic improvement and new variety breeding.
‘Mihuangli’ is a new mid-late ripening plum cultivar with suborbicular fruit shape,yellow pericarp,deep yellow,crisp and juicy flesh. The average fruit weight is 43.0 g. The soluble solids,soluble sugar and vitamin C content are 15.0%,6.84% and 21.5 μg · g-1,respectively. The tree is extremely adaptable to chilling and freezing injuries,the production of five years old tree is 31.7 t · hm-2,and it can be cultivated in the northwest of Guangxi.
The new Castanea henryi cultivar‘Huali 1’was selected from the natural C. henryi seedlings. It displays following excellent characteristics such as early maturity,large fruit,high yield and resistance to pest and disease. It ripens in late August,25-30 days earlier than that of the‘Youzhen’. The average nut weight is 12.12 g,sugar content is 9.80%,starch content is 36.35%,protein content is 4.39%,fat content is 0.99% and vitamin C content is 322.90 mg · kg-1. The flesh of nut is fine and smooth and the nuts are perfect for table. Its fruiting age is the second year after grafting,the yield at full fruiting period is up to 4 639.95 kg · hm-2. It is suitable to plant in mountains and hills in Hunan Province.