Litchi chinensis Sonn.is an important economic fruit tree in tropical and subtropical regions.Regrettably,the efficiency of plant regeneration via somatic embryogenesis in litchi is typically low due to the poor conve...Litchi chinensis Sonn.is an important economic fruit tree in tropical and subtropical regions.Regrettably,the efficiency of plant regeneration via somatic embryogenesis in litchi is typically low due to the poor conversion of embryos to plants.The purpose of this study was to establish a regeneration system via somatic embryogenesis from immature embryos explants in‘Heiye'cultivar of litchi.Our results demonstrated that MS medium supplemented with 2.0 mg L^(-1)2,4-D was optimal for callus induction.For somatic embryo(SE)induction,MS medium containing0.5 g L^(-1) activated charcoal(AC)was the most effective,while the use of zeatin(ZT)and thidiazuron(TDZ)resulted in abnormal somatic embryos.The rooting and regeneration rate of 2.15%and 17.5%,respectively,were achieved using MS medium supplemented with 0.5 g L^(-1) AC.Furthermore,transcriptome analysis was performed on embryogenic callus(EC),globular embryo(GE),and heart embryo(HE)to explore the molecular mechanisms of early somatic embryogenesis.2,587 common differentially expressed genes(DEGs)between EC_vs_GE and EC_vs_HE were identified,and the expression patterns of these common DEGs were separated into twelve major clusters.GO annotation and KEGG pathway analysis revealed that these common DEGs were implicated in plant hormone signal transduction,auxin-activated signaling pathway,and other biological processes.Additionally,differentially expressed transcription factors were identified,and the function of LcBBM2 which is specifically highly expressed during early somatic embryogenesis was verified.Overexpression of LcBBM2 in tomato promotes callus and shoot formation.Therefore,this study can provide a theoretical basis and technical support for genetic breeding improvement of litchi.展开更多
Litchi has great economic significance as a global fruit crop.However,the advancement of litchi functional genomics has encountered substantial obstacles due to its recalcitrance to stable transformation.Here,we prese...Litchi has great economic significance as a global fruit crop.However,the advancement of litchi functional genomics has encountered substantial obstacles due to its recalcitrance to stable transformation.Here,we present an efficacious Agrobacterium tumefaciens-mediated transformation system in somatic embryos of‘Heiye'litchi.This system was developed through the optimization of key variables encompassing explant selection,A.tumefaciens strain delineation,bacterium concentration,infection duration,and infection methodology.The subsequent validation of the transformation technique in litchi was realized through the ectopic expression of LcMYB1,resulting in the generation of transgenic calli.However,the differentiation of transgenic calli into somatic embryos encountered substantial challenges.To delineate the intricate molecular underpinnings of LcMYB1's inhibitory role in somatic embryo induction,a comprehensive transcriptome analysis was conducted that encompassed embryogenic calli(C),globular embryos(G),and transgenic calli(TC).A total of 1,166 common differentially expressed genes(DEGs)were identified between C-vs.-G and C-vs.-TC.Gene Ontology(GO)annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis revealed that these common DEGs were mostly related to plant hormone signal transduction pathways.Furthermore,RT-qPCR corroborated the pronounced down-regulation of numerous genes that are associated with somatic embryo induction within the transgenic calli.The development of this transformation system provides valuable support for functional genomics research in litchi.展开更多
Litchi(Litchi chinensis Sonn.),an important fruit tree in tropical and subtropical regions,possesses substantial economic value.The branchand leaf-related traits of litchi have a significant impact on litchi yield and...Litchi(Litchi chinensis Sonn.),an important fruit tree in tropical and subtropical regions,possesses substantial economic value.The branchand leaf-related traits of litchi have a significant impact on litchi yield and quality.However,due to limitations such as the density of the genetic linkage map,there have been few studies on mapping QTLs of branch-and leaf-related traits.In this study,a high-density genetic map was constructed by next-generation sequencing(NGS)using an F_(1) population of 264 progenies,derived from the cross between the cultivars‘Sanyuehong'and‘Ziniangxi'.A total of 2574 high-quality BINs(binomial intervals)were obtained,and a genetic linkage map was constructed with a total length of 1753.3 cM and an average marker distance of 0.68 cM.With the genetic map and the phenotyping of single leaf length(SLL),single leaf width(SLW),leaf shape index(LSI),weight of specific leaf(WSL),petiole length(PL)and compound leaf length(CLL)measured in three seasons,11,9,9,10,9 and 12 QTLs were detected for SLL,SLW,WSL,LSI,PL and CLL traits,respectively.Among these QTLs,five QTLs were consistently detected in two seasons and 12 pleiotropic QTLs were identified for at least two traits.These findings will provide new insights for the gene cloning for branch-and leaf-related traits as well as marker-assisted selection(MAS).展开更多
This paper focused on the effect of spraying chitosan and salicylic acid to Litchi under low temperature stress conditions.The physiology and biochemistry of litchi were studied as well.Results showed that the appropr...This paper focused on the effect of spraying chitosan and salicylic acid to Litchi under low temperature stress conditions.The physiology and biochemistry of litchi were studied as well.Results showed that the appropriate concentration of chitosan and salicylic acid treatment could effectively reduce injury caused by low temperature to litchi,compared with water control,chlorophyll,proline,soluble protein content of litchi after treatment and the activity of protective enzyme increasing significantly.However,the accumulation of resistance could significantly be improved.Furthermore,when 1 000 mg/L chitosan combined with 50 mg/L salicylic acid,the litchi acquired the best cold resistance capability.展开更多
[Objective] This study aimed to investigate the effect of spraying the mixture of paclobutrazol and ethephon on the endogenous hormones and carbon and nitrogen nutrients in litchi variety ＇Feizixiao＇.[Method] [Resul...[Objective] This study aimed to investigate the effect of spraying the mixture of paclobutrazol and ethephon on the endogenous hormones and carbon and nitrogen nutrients in litchi variety ＇Feizixiao＇.[Method] [Result] The results showed that foliar spraying of the mixture of paclobutrazol and ethephon could effectively inhibit litchi variety ＇Feizixiao＇ to produce winter shoots,promote the flower bud differentiation and improve flower formation rate; meanwhile,this treatment could also increase the contents of ABA and ZR,and the ratios of ABA/IAA,ABA/GA3,ZR/IAA,ZR/GA3,and decrease the contents of IAA and GA3; additionally,it could increase the contents of soluble sugar,starch and total nitrogen,and raise C/N ratio,thus improving the flower formation rate.[Conclusion] Foliar spraying of the mixture of paclobutrazol and ethephon is an effective pathway for solving warmth damage to litchi.展开更多
A total RNA extraction method for young embryo of seedless litchi was introduced. CTAB, Phenol （saturated with water）, chloroform, Guanidine isothioeyanate were used as main extraction reagents. Polyphenolie compoun...A total RNA extraction method for young embryo of seedless litchi was introduced. CTAB, Phenol （saturated with water）, chloroform, Guanidine isothioeyanate were used as main extraction reagents. Polyphenolie compounds were removed effectively by added PVP into the extraction buffer solution. RNA was purified intensively by phenol, chloroform extraction, and ethanol deposition after deposited by LiCl. Both the results of formaldehyde denatured agarose gel eleetrophoresis and ultraviolet spectrophotometer analysis showed high integrity and purity of RNA. So the quality of extracted RNA could meet the demand of most molecular biology experiments that require higher quality RNA.展开更多
[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determ...[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.展开更多
Phenolic inhibitors were preliminarily isolated from the normal and abortive litchi (Litchi chinensis Sonn.) ovules with a series of solvents, and then separated and purified by thin-layer chromatography (TLC), furthe...Phenolic inhibitors were preliminarily isolated from the normal and abortive litchi (Litchi chinensis Sonn.) ovules with a series of solvents, and then separated and purified by thin-layer chromatography (TLC), further isolated and identified with GC-MS, and finally checked with standards. p-Hydroxybenzoic acid (p-HBA) was isolated and identified from litchi ovules in this experiment for the first time. Determination of its biological activity showed that p-HBA was a very strong growth inhibitory substance. In abortive ovules, p-HBA content and IAA oxidase activity were much higher; IAA content was much lower than those in normal ovules (P<0.01). It is suggested that p-HBA may be involved in the regulation of litchi embryo development; high content of p-HBA may accelerate IAA oxidation and affect the balance of growth promoting and inhibitory substances, causing embryo abortion.展开更多
[Objective] To lay the foundation for the classification and breeding of Litchi （Litchi chinensis Sonn.） through RAPD （Random Amplification Polymorphic DNA） analysis of the Litchi cultivars with different origins....[Objective] To lay the foundation for the classification and breeding of Litchi （Litchi chinensis Sonn.） through RAPD （Random Amplification Polymorphic DNA） analysis of the Litchi cultivars with different origins. [Method] 5 Litchi cultivars from Sichuan, Guangxi, Guangdong, Fujian and Hainan were used as experimental materials to extract genomic DNA by modified CTAB method. Twenty primers with well reproducibility were randomly selected to conduct RAPD amplification to analyze the polymorphism and genetic relationship of the five cultivars. [Result] The polymor- phism of the five Litchi cultivars was 61%, with the similarity coefficient of 0.571 4- 0.803 6. The similarity coefficient of those from Guangdong and Guangxi was the largest of 0.803 6, and from Sichuan and Hainan was the lowest of 0.571 4. The resolution and production of RAPD was significantly improved by appropriately pro- longing the ramp time from annealing to extension to 0.3℃/s. [Conclusion] This study provided theoretical basis for the classification and breeding of Litchi.展开更多
In this paper,we reviewed the advances in the quality and functions of several exogenous plant growth regulators widely used on litchi,and in the applications of exogenous plant growth regulators on litchi production ...In this paper,we reviewed the advances in the quality and functions of several exogenous plant growth regulators widely used on litchi,and in the applications of exogenous plant growth regulators on litchi production and fresh keeping of litchi,aiming at providing reference for future litchi production and improvement in litchi quality.展开更多
[Objective] The aim was to screen litchi varieties suitable for local production in Vietnam. [Method] The fruit botanical and quality characteristics of the seven litchi varieties introduced into Northern Mountainous ...[Objective] The aim was to screen litchi varieties suitable for local production in Vietnam. [Method] The fruit botanical and quality characteristics of the seven litchi varieties introduced into Northern Mountainous Agriculture and Forestry Science Institute of Vietnam Academy of Agriculture Sciences were compared and analyzed. [Result] Three varieties with good general qualities including Lai Phu Ho,Thach Binh and Hung Long which were suitable to be cultivated in the local area were selected. In addition,Phu Dong was the available,early-maturing germplasm resource. [Conclusion] This research will provide reference for litchi production and breeding in northern mountainous area.展开更多
Litchi(Litchi chinensis Sonn.)is a type of commercially prevalent subtropical and tropical fruit.Since litchi has a highly heterozygous genetic background and a long reproductive cycle,conventional breeding methods(su...Litchi(Litchi chinensis Sonn.)is a type of commercially prevalent subtropical and tropical fruit.Since litchi has a highly heterozygous genetic background and a long reproductive cycle,conventional breeding methods(such as hybridization)have limited ability to nurture new litchi cultivars.Here,an efficient and stable Agrobacterium tumefaciens-mediated genetic transformation of embryogenic callus was established in‘Feizixiao’litchi.Transgenic materials were verified using polymerase chain reaction(PCR)analysis,β-glucuronidase(GUS)assay,and green fluorescent protein(GFP)assay.To implement the technology of the Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)/associated protein 9(CRISPR/Cas9)technology in‘Feizixiao’litchi and verify the validity of these transformation systems,the litchi polyphenol oxidase gene(LcPPO,JF926153)was knocked out.Various categories of mutations,covering base insertions,deletions,and substitutions,were found in transgenic materials via sequence analysis.The transformation system achieved high feasibility and efficiency,and the system of CRISPR/Cas9 was successfully employed to edit genes in‘Feizixiao’litchi.This work provides an essential foundation for investigating the functions of genes and accelerating litchi genetic improvement.展开更多
Litchi(Litchi chinensis Sonn.)and longan(Dimocarpus longan Lour.)fruits have a succulent and white aril with a brown seed and are becoming popular worldwide.The two fruits have been used in traditional Chinese medicin...Litchi(Litchi chinensis Sonn.)and longan(Dimocarpus longan Lour.)fruits have a succulent and white aril with a brown seed and are becoming popular worldwide.The two fruits have been used in traditional Chinese medicine as popular herbs in the treatment of neural pain,swelling,and cardiovascular disease.The pericarp and seed portions as the by-products of litchi and longan fruits are estimated to be approximately 30%of the dry weight of the whole fruit and are rich in bioactive constituents.In the recent years,many biological activities,such as tyrosinase inhibitory,antioxidant,anti-inflammatory,immunomodulatory,anti-glycated,and anti-cancer activities,as well as memory-increasing effects,have been reported for the litchi and longan pericarp and seed extracts,indicating a potentially significant contribution to human health.With the increasing production of litchi and longan fruits,enhanced utilization of the two fruit by-products for their inherent bioactive constituents in relation to pharmacological effects is urgently needed.This paper reviews the current advances in the extraction,processing,identification,and biological and pharmacological activities of constituents from litchi and longan by-products.Potential utilization of litchi and longan pericarps and seeds in relation to further research is also discussed.展开更多
The regulatory role of calcium in fertility of pollen and pistil under simulated acid rain was investigated. The germination percentage of pollen treated with acid rain of pH 4.5 was 9.42% lower than that of control, ...The regulatory role of calcium in fertility of pollen and pistil under simulated acid rain was investigated. The germination percentage of pollen treated with acid rain of pH 4.5 was 9.42% lower than that of control, and that of pH 3.5, pH 2.5 and pH 1.5 were 22.47%, 45.49% and 71.62%, respectively. Simultaneously, the injury character of pollen was obviously observed when flowers were treated with acid rain of pH 3.5. The difference in fruit setting rate between the female flower treated with acid rain of pH 4.0 and the control was significant at p 〈 0.05. Ca（NO3 ）5 of 0.2-0.4 mmol/L could promote pollen germination under the stress of acid rain. The beneficial function was reduced when calcium concentration surpassed 0.8 mmol/L. Spraying 2 mmol/L Ca（NO3 ）5 reduced the injury of acid rain to pistil and increased fruit-setting rate significantly. The physiological importance of calcium during pollen germination and pistil development was also discussed.展开更多
Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-E...Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-Exp1 and Lc-Exp2 , were cloned. Lc-Exp1 and Lc-Exp2 was respectively composed of 531 bp encoding 177 amino acids and 537 bp encoding 179 amino acids. Eight cysteine residues and three tryp-tophan residues, which is supposed to be the characteristics of expansins, are conserved in both Lc-Exp1 and c-Exp2. In addition, the homology between the two expansins is 71. 6% at nucleotide acid sequences and 76.3% at amino acid sequences. The homology of Lc-Exp1 with Fa-Exp2 or Pp-Exp1 was 92.7% or 92.1%, but that of Lc-Exp2 with Fa-Exp2 or Pp-Exp1 was only 77. 4% or 76.3% at amino acid sequences.展开更多
Sucrose synthase(SUS,EC 2.4.1.13)is widely considered as a key enzyme involved in plant sucrose metabolism,and the gene family encoding different SUS isozymes has been identified and characterized in several plant spe...Sucrose synthase(SUS,EC 2.4.1.13)is widely considered as a key enzyme involved in plant sucrose metabolism,and the gene family encoding different SUS isozymes has been identified and characterized in several plant species.However,to date scant information about the SUS genes is available in Litchi chinensis Sonn.Here,we identified five SUS genes in litchi.These Lc SUSs shared high levels of similarity in both nucleotide and amino acid sequences.Their gene structure,phylogenetic relationships,and expression profiles were characterized.Gene structure analysis indicated that the Lc SUSs have similar exon-intron structures.Phylogenetic analysis revealed that the five members could be classified into three groups(LcSUS1 and LcSUS2 in SUSⅡ,LcSUS4 and LcSUS5 in SUSⅢ,and LcSUS3 in SUSⅠ),demonstrating evolutionary conservation in the SUS family across litchi and other plant species.The expression levels of Lc SUSs were investigated via real-time PCR in various tissues and different developmental stages of aril.For tissues and organs,Lc SUSs exhibited distinct but partially redundant expression profiles in litchi,being predominantly expressed in young leaves(sink).During aril development,the expression pattern of LcSUS1 was consistent with the trend of sugar accumulation,indicating it may play important roles in determination of sink strength in aril.Moreover,transcript levels of LcSUS2,LcSUS4,and LcSUS5 varied between cultivars with different hexose/sucrose ratios,which may regulate the sugar composition in aril.Our results provide insights into physiological functions of SUS genes in litchi,especially roles in regulating sugar accumulation in aril.展开更多
Litchi chinensis Sonn is widely cultivated in subtropical regions and has an important economic value.A high-density genetic map is a valuable tool for mapping quantitative trait loci(QTL)and marker-assisted breeding ...Litchi chinensis Sonn is widely cultivated in subtropical regions and has an important economic value.A high-density genetic map is a valuable tool for mapping quantitative trait loci(QTL)and marker-assisted breeding programs.In this study,a single nucleotide polymorphism(SNP)-based high-density linkage map was constructed by a genotyping-by-sequencing(GBS)protocol using an F1 population of 178 progenies between two commercial litchi cultivars,‘Ziniangxi’(dwarf)and‘Feizixiao’(vigorous).The genetic map consisted of 3027 SNP markers with a total length of 1711.97 cM in 15 linkage groups(LGs)and an average marker distance of 0.57 cM.Based on this high-density linkage map and three years of phenotyping,a total of 37 QTLs were detected for eight dwarf-related traits,including length of new branch(LNB),diameter of new branch(DNB),length of common petiole(LCP),diameter of common petiole(DCP),length of internode(LI),length of single leaf(LSL),width of single leaf(WSL),and plant height(PH).These QTLs could explain 8.0 to 14.7%(mean=9.7%)of the phenotypic variation.Among them,several QTL clusters were observed,particularly on LG04 and LG11,which might show enrichment for genes regulating the dwarf-related traits in litchi.There were 126 candidate genes identified within the QTL regions,55 of which are differentially expressed genes by RNA-seq analysis between‘Ziniangxi’and‘Feizixiao’.These DEGs were found to participate in the regulation of cell development,material transportation,signal transduction,and plant morphogenesis,so they might play important roles in regulating plant dwarf-related traits.The high-density genetic map and QTLs identification related to dwarf traits can provide a valuable genetic resource and a basis for marker-assisted selection and genomic studies of litchi.展开更多
基金supported by the National Natural Science Fund of China(Grant Nos.31872066 and 32272663)the Science and Technology Planning Project of Guangzhou(Grant No.2023B01J2002)+1 种基金the Key Research and Development Program of Hainan(Grant No.ZDYF2023XDNY052)the Seed Industry Engineering Project of Ministry of Agriculture and Rural Affairs of Guangdong(Grant Nos.2022-NPY-00-004 and 2022-NBH-00-001)。
文摘Litchi chinensis Sonn.is an important economic fruit tree in tropical and subtropical regions.Regrettably,the efficiency of plant regeneration via somatic embryogenesis in litchi is typically low due to the poor conversion of embryos to plants.The purpose of this study was to establish a regeneration system via somatic embryogenesis from immature embryos explants in‘Heiye'cultivar of litchi.Our results demonstrated that MS medium supplemented with 2.0 mg L^(-1)2,4-D was optimal for callus induction.For somatic embryo(SE)induction,MS medium containing0.5 g L^(-1) activated charcoal(AC)was the most effective,while the use of zeatin(ZT)and thidiazuron(TDZ)resulted in abnormal somatic embryos.The rooting and regeneration rate of 2.15%and 17.5%,respectively,were achieved using MS medium supplemented with 0.5 g L^(-1) AC.Furthermore,transcriptome analysis was performed on embryogenic callus(EC),globular embryo(GE),and heart embryo(HE)to explore the molecular mechanisms of early somatic embryogenesis.2,587 common differentially expressed genes(DEGs)between EC_vs_GE and EC_vs_HE were identified,and the expression patterns of these common DEGs were separated into twelve major clusters.GO annotation and KEGG pathway analysis revealed that these common DEGs were implicated in plant hormone signal transduction,auxin-activated signaling pathway,and other biological processes.Additionally,differentially expressed transcription factors were identified,and the function of LcBBM2 which is specifically highly expressed during early somatic embryogenesis was verified.Overexpression of LcBBM2 in tomato promotes callus and shoot formation.Therefore,this study can provide a theoretical basis and technical support for genetic breeding improvement of litchi.
基金supported by the National Natural Science Foundation of China(31872066 and 32272663)the Science and Technology Planning Project of Guangzhou,China(2023B01J2002)+2 种基金the Key Research and Development Program of Hainan,China(ZDYF2023XDNY052)the Seed Industry Engineering Project of Department of Agriculture and Rural Affairs of Guangdong,China(2022-NPY-00-004 and 2022-NBH00-001)the Litchi Industry Science and Technology Special Mission of Yunnan,China(202204BI090021)。
文摘Litchi has great economic significance as a global fruit crop.However,the advancement of litchi functional genomics has encountered substantial obstacles due to its recalcitrance to stable transformation.Here,we present an efficacious Agrobacterium tumefaciens-mediated transformation system in somatic embryos of‘Heiye'litchi.This system was developed through the optimization of key variables encompassing explant selection,A.tumefaciens strain delineation,bacterium concentration,infection duration,and infection methodology.The subsequent validation of the transformation technique in litchi was realized through the ectopic expression of LcMYB1,resulting in the generation of transgenic calli.However,the differentiation of transgenic calli into somatic embryos encountered substantial challenges.To delineate the intricate molecular underpinnings of LcMYB1's inhibitory role in somatic embryo induction,a comprehensive transcriptome analysis was conducted that encompassed embryogenic calli(C),globular embryos(G),and transgenic calli(TC).A total of 1,166 common differentially expressed genes(DEGs)were identified between C-vs.-G and C-vs.-TC.Gene Ontology(GO)annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis revealed that these common DEGs were mostly related to plant hormone signal transduction pathways.Furthermore,RT-qPCR corroborated the pronounced down-regulation of numerous genes that are associated with somatic embryo induction within the transgenic calli.The development of this transformation system provides valuable support for functional genomics research in litchi.
基金supported by the Science and Technology Special Fund of Hainan Province(Grant Nos.ZDYF2021XDNY159 and ZDYF2021XDNY156)the Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Science(Grant No.1630032022007)China Agricultural Research System of MOF and MARA(Grant No.CARS-32-01)。
文摘Litchi(Litchi chinensis Sonn.),an important fruit tree in tropical and subtropical regions,possesses substantial economic value.The branchand leaf-related traits of litchi have a significant impact on litchi yield and quality.However,due to limitations such as the density of the genetic linkage map,there have been few studies on mapping QTLs of branch-and leaf-related traits.In this study,a high-density genetic map was constructed by next-generation sequencing(NGS)using an F_(1) population of 264 progenies,derived from the cross between the cultivars‘Sanyuehong'and‘Ziniangxi'.A total of 2574 high-quality BINs(binomial intervals)were obtained,and a genetic linkage map was constructed with a total length of 1753.3 cM and an average marker distance of 0.68 cM.With the genetic map and the phenotyping of single leaf length(SLL),single leaf width(SLW),leaf shape index(LSI),weight of specific leaf(WSL),petiole length(PL)and compound leaf length(CLL)measured in three seasons,11,9,9,10,9 and 12 QTLs were detected for SLL,SLW,WSL,LSI,PL and CLL traits,respectively.Among these QTLs,five QTLs were consistently detected in two seasons and 12 pleiotropic QTLs were identified for at least two traits.These findings will provide new insights for the gene cloning for branch-and leaf-related traits as well as marker-assisted selection(MAS).
文摘This paper focused on the effect of spraying chitosan and salicylic acid to Litchi under low temperature stress conditions.The physiology and biochemistry of litchi were studied as well.Results showed that the appropriate concentration of chitosan and salicylic acid treatment could effectively reduce injury caused by low temperature to litchi,compared with water control,chlorophyll,proline,soluble protein content of litchi after treatment and the activity of protective enzyme increasing significantly.However,the accumulation of resistance could significantly be improved.Furthermore,when 1 000 mg/L chitosan combined with 50 mg/L salicylic acid,the litchi acquired the best cold resistance capability.
文摘[Objective] This study aimed to investigate the effect of spraying the mixture of paclobutrazol and ethephon on the endogenous hormones and carbon and nitrogen nutrients in litchi variety ＇Feizixiao＇.[Method] [Result] The results showed that foliar spraying of the mixture of paclobutrazol and ethephon could effectively inhibit litchi variety ＇Feizixiao＇ to produce winter shoots,promote the flower bud differentiation and improve flower formation rate; meanwhile,this treatment could also increase the contents of ABA and ZR,and the ratios of ABA/IAA,ABA/GA3,ZR/IAA,ZR/GA3,and decrease the contents of IAA and GA3; additionally,it could increase the contents of soluble sugar,starch and total nitrogen,and raise C/N ratio,thus improving the flower formation rate.[Conclusion] Foliar spraying of the mixture of paclobutrazol and ethephon is an effective pathway for solving warmth damage to litchi.
基金Supported by the National“863”Import Program(AA001380)~~
文摘A total RNA extraction method for young embryo of seedless litchi was introduced. CTAB, Phenol （saturated with water）, chloroform, Guanidine isothioeyanate were used as main extraction reagents. Polyphenolie compounds were removed effectively by added PVP into the extraction buffer solution. RNA was purified intensively by phenol, chloroform extraction, and ethanol deposition after deposited by LiCl. Both the results of formaldehyde denatured agarose gel eleetrophoresis and ultraviolet spectrophotometer analysis showed high integrity and purity of RNA. So the quality of extracted RNA could meet the demand of most molecular biology experiments that require higher quality RNA.
基金Supported by National Science Foundation of China ( GrantNo.30460085, 30960233)Open Foundation of Provincial Key Laboratory for Fruit and Vegetable Preservation of Hainan ( GrantNo. CH001)National Non-profit Institute Grant (ITBBZD2007-3-1)~~
文摘[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.
文摘Phenolic inhibitors were preliminarily isolated from the normal and abortive litchi (Litchi chinensis Sonn.) ovules with a series of solvents, and then separated and purified by thin-layer chromatography (TLC), further isolated and identified with GC-MS, and finally checked with standards. p-Hydroxybenzoic acid (p-HBA) was isolated and identified from litchi ovules in this experiment for the first time. Determination of its biological activity showed that p-HBA was a very strong growth inhibitory substance. In abortive ovules, p-HBA content and IAA oxidase activity were much higher; IAA content was much lower than those in normal ovules (P<0.01). It is suggested that p-HBA may be involved in the regulation of litchi embryo development; high content of p-HBA may accelerate IAA oxidation and affect the balance of growth promoting and inhibitory substances, causing embryo abortion.
文摘[Objective] To lay the foundation for the classification and breeding of Litchi （Litchi chinensis Sonn.） through RAPD （Random Amplification Polymorphic DNA） analysis of the Litchi cultivars with different origins. [Method] 5 Litchi cultivars from Sichuan, Guangxi, Guangdong, Fujian and Hainan were used as experimental materials to extract genomic DNA by modified CTAB method. Twenty primers with well reproducibility were randomly selected to conduct RAPD amplification to analyze the polymorphism and genetic relationship of the five cultivars. [Result] The polymor- phism of the five Litchi cultivars was 61%, with the similarity coefficient of 0.571 4- 0.803 6. The similarity coefficient of those from Guangdong and Guangxi was the largest of 0.803 6, and from Sichuan and Hainan was the lowest of 0.571 4. The resolution and production of RAPD was significantly improved by appropriately pro- longing the ramp time from annealing to extension to 0.3℃/s. [Conclusion] This study provided theoretical basis for the classification and breeding of Litchi.
文摘In this paper,we reviewed the advances in the quality and functions of several exogenous plant growth regulators widely used on litchi,and in the applications of exogenous plant growth regulators on litchi production and fresh keeping of litchi,aiming at providing reference for future litchi production and improvement in litchi quality.
基金Supported by Introduction of Overseas Tropic Crop Germplasm Resources (948 Program of China)(2010-G2-08)a Grant from Modern Agricultural Industry Technology System Construction Program(nycytx-32-17)~~
文摘[Objective] The aim was to screen litchi varieties suitable for local production in Vietnam. [Method] The fruit botanical and quality characteristics of the seven litchi varieties introduced into Northern Mountainous Agriculture and Forestry Science Institute of Vietnam Academy of Agriculture Sciences were compared and analyzed. [Result] Three varieties with good general qualities including Lai Phu Ho,Thach Binh and Hung Long which were suitable to be cultivated in the local area were selected. In addition,Phu Dong was the available,early-maturing germplasm resource. [Conclusion] This research will provide reference for litchi production and breeding in northern mountainous area.
基金supported by grants from the National Key R&D Program of China(Grant No.2019YFD1000900)the Hainan Province Science and Technology Special Fund(Grant No.ZDYF2022XDNY253)the earmarked fund for CARS(Grant No.CARS-32-01)。
文摘Litchi(Litchi chinensis Sonn.)is a type of commercially prevalent subtropical and tropical fruit.Since litchi has a highly heterozygous genetic background and a long reproductive cycle,conventional breeding methods(such as hybridization)have limited ability to nurture new litchi cultivars.Here,an efficient and stable Agrobacterium tumefaciens-mediated genetic transformation of embryogenic callus was established in‘Feizixiao’litchi.Transgenic materials were verified using polymerase chain reaction(PCR)analysis,β-glucuronidase(GUS)assay,and green fluorescent protein(GFP)assay.To implement the technology of the Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)/associated protein 9(CRISPR/Cas9)technology in‘Feizixiao’litchi and verify the validity of these transformation systems,the litchi polyphenol oxidase gene(LcPPO,JF926153)was knocked out.Various categories of mutations,covering base insertions,deletions,and substitutions,were found in transgenic materials via sequence analysis.The transformation system achieved high feasibility and efficiency,and the system of CRISPR/Cas9 was successfully employed to edit genes in‘Feizixiao’litchi.This work provides an essential foundation for investigating the functions of genes and accelerating litchi genetic improvement.
基金supported by the National Natural Science Foundation of China(No.31770726)the National Key Research and Development Program of China(No.2016YFD0400904)
文摘Litchi(Litchi chinensis Sonn.)and longan(Dimocarpus longan Lour.)fruits have a succulent and white aril with a brown seed and are becoming popular worldwide.The two fruits have been used in traditional Chinese medicine as popular herbs in the treatment of neural pain,swelling,and cardiovascular disease.The pericarp and seed portions as the by-products of litchi and longan fruits are estimated to be approximately 30%of the dry weight of the whole fruit and are rich in bioactive constituents.In the recent years,many biological activities,such as tyrosinase inhibitory,antioxidant,anti-inflammatory,immunomodulatory,anti-glycated,and anti-cancer activities,as well as memory-increasing effects,have been reported for the litchi and longan pericarp and seed extracts,indicating a potentially significant contribution to human health.With the increasing production of litchi and longan fruits,enhanced utilization of the two fruit by-products for their inherent bioactive constituents in relation to pharmacological effects is urgently needed.This paper reviews the current advances in the extraction,processing,identification,and biological and pharmacological activities of constituents from litchi and longan by-products.Potential utilization of litchi and longan pericarps and seeds in relation to further research is also discussed.
文摘The regulatory role of calcium in fertility of pollen and pistil under simulated acid rain was investigated. The germination percentage of pollen treated with acid rain of pH 4.5 was 9.42% lower than that of control, and that of pH 3.5, pH 2.5 and pH 1.5 were 22.47%, 45.49% and 71.62%, respectively. Simultaneously, the injury character of pollen was obviously observed when flowers were treated with acid rain of pH 3.5. The difference in fruit setting rate between the female flower treated with acid rain of pH 4.0 and the control was significant at p 〈 0.05. Ca（NO3 ）5 of 0.2-0.4 mmol/L could promote pollen germination under the stress of acid rain. The beneficial function was reduced when calcium concentration surpassed 0.8 mmol/L. Spraying 2 mmol/L Ca（NO3 ）5 reduced the injury of acid rain to pistil and increased fruit-setting rate significantly. The physiological importance of calcium during pollen germination and pistil development was also discussed.
文摘Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-Exp1 and Lc-Exp2 , were cloned. Lc-Exp1 and Lc-Exp2 was respectively composed of 531 bp encoding 177 amino acids and 537 bp encoding 179 amino acids. Eight cysteine residues and three tryp-tophan residues, which is supposed to be the characteristics of expansins, are conserved in both Lc-Exp1 and c-Exp2. In addition, the homology between the two expansins is 71. 6% at nucleotide acid sequences and 76.3% at amino acid sequences. The homology of Lc-Exp1 with Fa-Exp2 or Pp-Exp1 was 92.7% or 92.1%, but that of Lc-Exp2 with Fa-Exp2 or Pp-Exp1 was only 77. 4% or 76.3% at amino acid sequences.
基金the Key-Area of Research and Development Program of Guangdong Province(Grant No.2018B020202011)the China Litchi and Longan Industry Technology Research System(Grant No.CARS-32-05)Yang Fan Innovative&Entrepreneurial Research Team Project(Grant No.2014YT02H013)。
文摘Sucrose synthase(SUS,EC 2.4.1.13)is widely considered as a key enzyme involved in plant sucrose metabolism,and the gene family encoding different SUS isozymes has been identified and characterized in several plant species.However,to date scant information about the SUS genes is available in Litchi chinensis Sonn.Here,we identified five SUS genes in litchi.These Lc SUSs shared high levels of similarity in both nucleotide and amino acid sequences.Their gene structure,phylogenetic relationships,and expression profiles were characterized.Gene structure analysis indicated that the Lc SUSs have similar exon-intron structures.Phylogenetic analysis revealed that the five members could be classified into three groups(LcSUS1 and LcSUS2 in SUSⅡ,LcSUS4 and LcSUS5 in SUSⅢ,and LcSUS3 in SUSⅠ),demonstrating evolutionary conservation in the SUS family across litchi and other plant species.The expression levels of Lc SUSs were investigated via real-time PCR in various tissues and different developmental stages of aril.For tissues and organs,Lc SUSs exhibited distinct but partially redundant expression profiles in litchi,being predominantly expressed in young leaves(sink).During aril development,the expression pattern of LcSUS1 was consistent with the trend of sugar accumulation,indicating it may play important roles in determination of sink strength in aril.Moreover,transcript levels of LcSUS2,LcSUS4,and LcSUS5 varied between cultivars with different hexose/sucrose ratios,which may regulate the sugar composition in aril.Our results provide insights into physiological functions of SUS genes in litchi,especially roles in regulating sugar accumulation in aril.
基金funded by the Key-Area of Research and Development Program of Guangdong Province,China(2018B020202011)the National Natural Science Foundation of China(31701885)+2 种基金the China Agriculture Research System of MOF and MARA(CARS-32-05)the State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources,China(SKLCUSA-b201716)the YangFan Innovative&Entrepreneurial Research Team Project,China(2014YT02H013)。
文摘Litchi chinensis Sonn is widely cultivated in subtropical regions and has an important economic value.A high-density genetic map is a valuable tool for mapping quantitative trait loci(QTL)and marker-assisted breeding programs.In this study,a single nucleotide polymorphism(SNP)-based high-density linkage map was constructed by a genotyping-by-sequencing(GBS)protocol using an F1 population of 178 progenies between two commercial litchi cultivars,‘Ziniangxi’(dwarf)and‘Feizixiao’(vigorous).The genetic map consisted of 3027 SNP markers with a total length of 1711.97 cM in 15 linkage groups(LGs)and an average marker distance of 0.57 cM.Based on this high-density linkage map and three years of phenotyping,a total of 37 QTLs were detected for eight dwarf-related traits,including length of new branch(LNB),diameter of new branch(DNB),length of common petiole(LCP),diameter of common petiole(DCP),length of internode(LI),length of single leaf(LSL),width of single leaf(WSL),and plant height(PH).These QTLs could explain 8.0 to 14.7%(mean=9.7%)of the phenotypic variation.Among them,several QTL clusters were observed,particularly on LG04 and LG11,which might show enrichment for genes regulating the dwarf-related traits in litchi.There were 126 candidate genes identified within the QTL regions,55 of which are differentially expressed genes by RNA-seq analysis between‘Ziniangxi’and‘Feizixiao’.These DEGs were found to participate in the regulation of cell development,material transportation,signal transduction,and plant morphogenesis,so they might play important roles in regulating plant dwarf-related traits.The high-density genetic map and QTLs identification related to dwarf traits can provide a valuable genetic resource and a basis for marker-assisted selection and genomic studies of litchi.
