In order to study the role of apple ELO gene family in wax synthesis and cold resistance,bioinformatics methods were used to identify and analyze the ELO family members in the whole apple genome. The results showed that the MdELO gene family consisted of seven members,which were unevenly distributed on three apple chromosomes(Chr2,Chr8 and Chr15). The MdELO protein contains 211-305 amino acid residues with isoelectric points ranging from 9.43 to 11.62. The results of subcellular localization showed that MdELO protein was distributed in the nucleus,cell membrane and chloroplast. The analysis of cis-acting elements showed that the 2 000 bp sequences upstream of the seven MdELO promoters were distributed with response elements such as hormones,environmental adaptability and stress induction. The wax content in different apple cultivars was further determined,and the results showed that the wax content of‘Oregon Spur Delicious’was significantly higher than that of‘Miyazaki’;On the other hand,from the it perspective of wax morphology and cuticle morphology,the wax of‘Oregon Spur Delicious’was needle-like and closely distributed,and the cuticle structure of its branches was close and smooth,while the wax of‘Miyazaki’was loose and lumpy,and the cuticle structure of its branches was loose and the surface was rough. Additionally,the proline,relative electrical conductivity and starch phosphorylase of the two apple branches increased firstly and then decreased with the extension of the overwintering period,and the amylase increased gradually,among which the content and activity of all indexes of‘Oregon Spur Delicious’were higher than that of‘Miyazaki’. The changes of the above indexes showed that the cold resistance of‘Oregon Spur Delicious’was significantly higher than that of‘Miyazaki’. It was found that the expression of ELO family members can be detected in the roots and leaves through qRT-PCR analysis,and the expression level displayeded certain differences. Most of them showed a trend of rising first and then falling,and the expression level is the highest at 12 h or 24 h,indicating that this family members may play an important role in low temperature stress.
Dof genes in pear genome were identified by BLAST software based on Dof genes from domestic apple and Arabidopsis thaliana. TBtools,MEME and MEGA-X software were used for bioinformatics analysis of Dof protein and gene sequences. The results showed that a total of 51 PbDof genes were identified,which belong to nine subfamilies. Structural analysis showed that the number of introns in PbDof gene varies from one to three. The promoter region contains five cis-regulatory elements related to stress response and nine cis-regulatory elements related to plant hormones. Synteny analysis of PbDof genes showed that PbDof was mainly affected by purification selection in the process of species evolution. To provide theoretical basis for understanding what roles the Dof genes play in calyx persistence and abscission of pear,the qRT-PCR method was used to detect the relative expression of Dof genes in ovary and sepals after sprayed with distilled water,PP333 and GA3 at full bloom stage. qRT-PCR analysis revealed that the expression levels of PbDof34 and PbDof51 after GA3 treatment were significantly higher than those after PP333 treatment,and the expression levels of PbDof34 were significantly higher than those after distilled water treatment(control) in calyxes on 9 d. The expression levels of PbDof16,PbDof19 and PbDof44 after GA3 treatment were all lower than those after PP333 treatment in calyxes on 9 d. The expression levels of PbDof16 and PbDof44 after PP333 treatment was significantly lower than those of control in calyxes on 9 d. We speculated that PbDof34 and PbDof51 may promote the calyxes persistence whereas PbDof16,PbDof19 and PbDof44 may promote the calyxes abscission in‘Korla Fragrant Pear’.
In this study,eight CslD genes were characterized in pineapple genome. Chromosomal mapping showed that they were distributed on seven chromosomes and one scaffold. Three to five exons were identified in these genes. Three subgroups were divided according to the phylogenetic analysis,and the number of Group Ⅲ was significantly increased in pineapple. The potential biological functions of the pineapple CslD gene family members were further predicted,basing on the collinearity and gene expression analysis. The full length cDNA sequence of AcoCslD2a was cloned and the subcellular localization analysis indicated that its encoding protein was localized in Golgi apparatus. Two expression vector for AcoCslD2a gene,which were driven by the promoters including ProAtUbq10 and ProAtCslD3,respectively,were constructed and transformed into the Arabidopsis atcsld3 root hair deficient mutant,mediated by Agrobacterium tumefaciens GV3101. The phenotype analysis for the transgenic lines of different expression vectors both indicated that the defect root hair number phenotype of mutant could be recovered to the wild-type phenotype by AcoCslD2a,while the defect root hair length phenotype could be partially recovered.
Two UDP-rhamnose synthase(RHM)genes(FcRHM1 and FcRHM2)were cloned from Fortunella crassifolia. The open reading frame(ORF)of FcRHM1 gene was 2 007 bp,encoding protein consisting of 668 amino acids with 75.3 kD,and FcRHM2 was 2 031 bp encoding 676 amino acids with 76.2 kD. In vitro experiments showed that FcRHM1 and FcRHM2 could function in converting UDP-glucose into UDP-rhamnose(UDP-Rha). Tissue-specific expressions revealed that the relative expression levels of FcRHM1 and FcRHM2 are different in different tissues. Combination with accumulation patterns of UDP-Rha,we concluded that both FcRHM1 and FcRHM2 were involved in the biosynthesis of UDP-Rha. Among them,FcRHM1 might be more critical in UDP-Rha of flowers and fruits,whereas FcRHM2 is mainly responsible for leaves and buds.
In order to provide data basis and theory reference for the protection,development and utilization of Yanshan chestnut resources. The diversity of 28 leaf phenotypic traits(five quality traits and 23 quantitative traits)of 149 germplasm resources from 11 Yanshan populations was studied. The results showed that:(1)There were significant differences(P < 0.01)in 28 leaves quantitative traits within the population,and only four quantitative traits had significant or extremely significant differences among populations. There were no significant differences in five quality traits among populations,indicated that the phenotypic variation of Yanshan chestnut leaves was at a low level among populations,and there were abundant variations within populations.(2)The average of phenotypic differentiation coefficient among populations were 7.80%,which was much less than that within populations(92.20%). It showed that the variation within populations was the main source of variation.(3)The average variation coefficient(CV)and the Shannon-Wiener index(H')of leave phenotypic traits were 15.91% and 1.24,respectively. Among the five quality traits,the variation coefficient(CV)and Shannon-Wiener index(H')of leaf shape were the highest(34.44%,0.82),the variation coefficient(CV)and Shannon-Wiener index(H')of leaf margin character were the lowest(0,0). The variation coefficient(CV)of 23 quantitative traits ranged from 4.52%(Stoma width)to 28.32%(sawtooth depth),and the Shannon-Wiener index(H')ranged from 1.97(leaf length/width)to 2.09(Petiole length). The average Shannon-Wiener index(H')of physiological,appearance and anatomical structure were 2.05,2.04 and 2.04,respectively,and the average variation coefficient(CV)from high to low was 12.61%(appearance)> 12.53%(physiological)> 10.29%(anatomical structure).(4)The nine quantitative traits(leaf thickness,thickness of palisade tissue,leaf area,leaf length/width,stoma length,stoma density,leaf mass per area,the angle between sawtooth and leaf margin and sawtooth depth)contained abundant genetic information,which could be used as typical traits for phenotypic diversity analysis of Yanshan chestnut leaves.(5)Based on nine typical leaf traits,149 chestnut resources were clustered into five groups at the Euclidean distance of five.
To investigate the resistant effects of camalexin to Plasmodiophora brassicae in Chinese cabbage,treatments with five amount of camalexin were carried out by P. brassicae inoculation on a Chinese cabbage susceptible inbred line‘BJN3-1’. Results indicated that the control showed the visually susceptible symptoms. But the treatments with different amount of camalexin after 21 days treatment can significantly inhibit the invasion of P. brassicae to reduce the disease index of clubroot. The inhibition of P. brassicae infection was enhanced with the increase of camalexin application. Furthermore,the genes involved in synthesis pathways of jasmonic acid,salicylic acid,ethylene and pathogenesis-related proteins were significantly up-regulated after 14-21 days under camalexin treatment. These indicated that the application of camalexin can induce the host responses to P. brassicae invasion,and improve resistance. However,the effects of all camalexin treatments on clubroot development were reduced after 28 days treatment which may be related to the microbial detoxification activities of P. brassicae.
In the current study,the pepper(Capsicum annuum L.)cultivar‘Bola Hongshuai’was used to explore the effects of supplemental lighting on the growth,photosynthetic characteristics,carbohydrate accumulation,root colonization by arbuscular mycorrhizal fungi(AMF),and phosphorus absorption at the seedling stage. The results showed that compared with the control,supplemental red and blue light could significantly increase the biomass and seedling index of pepper seedlings;however,compared with the supplemental blue light,supplemental red light had more profound stimulating effects on the light-saturated photosynthetic rate,the accumulation of photosynthetic pigments,and the proportion of total sugar and sucrose content in the roots. Notably,red and blue light treatments were both conducive to the accumulation of strigolactones in roots but the former was more obvious. Moreover,supplementation of red and blue light during the seedling stage significantly promoted the colonization of roots by AMF and increased the dry weight,the accumulation of strigolactone content in roots,the expression of PT4 and PT5 genes,the phosphorus content and phosphorus concentration in pepper under the following condition of white light and phosphorus deficiency. However,compared with other light conditions,these responses were more profound when supplemented with red light. Taken together,the study revealed that supplementation of red light during the seedling stage was the most beneficial to the growth of pepper seedlings,and the accumulation of carbohydrates and strigolactones in the roots,which in turn promoted the colonization of roots by AMF and the phosphorus absorption in pepper seedlings.
In order to identify the function of miR396b in eggplant resistance to verticillium wilt,pri-miR396b gene was cloned from eggplant cultivar‘Suqi 1’and miR396b transgenic eggplant lines were obtained through Agrobacterium-mediated transformation. In infected eggplant,the expression level of miR396b was down-regulated by Verticillium dahliae induction. The disease resistance analysis showed that miR396b overexpression line was more sensitive to Verticillium dahliae infection compared with the control with disease index of 75.2,while miR396b antisense lines showed more resistance with disease index of 16.2-25.3. ITS quantitative analysis showed that the content of Verticillium dahliae in the vascular tissues of miR396b overexpression plants was significantly increased compared with the wild- type eggplant,while that in miR396b antisense plants was significantly reduced. Antioxidant enzyme activity analysis showed that the activities of SOD,POD and CAT in miR396b overexpression line were lower than those in the wild-type eggplant,while they were higher in antisense lines than those in the wild-type eggplant. These results showed that miR396b might play a negative role in eggplant defense response against Verticillium wilt.
In this study,based on 203 representative spray cut chrysanthemum(Chrysanthemum morifolium Ramat.)varieties,the flower opening angle of spray cut chrysanthemum was quantitatively measured by image processing at full-bloom stage and 11 flower opening angle related traits such as leaf petiole angle and inflorescence diameter were investigated. The results indicated that there was abundant variation in flower opening angle of spray cut chrysanthemums,and the coefficient of variation was 22.87%.‘Nannong Xiufengche’exhibited the smallest opening angle(62.12°),while‘Q1-79’had the largest opening angle(218.29°). The flower opening angle was significantly negatively correlated with the corolla tube length(-0.46),the corolla tube merged degree(-0.45)and ray floret length(-0.21), whereas it was significantly positively correlated with the number of ray florets whorls (0.39),ray floret width(0.35)and center disc flower diameter(0.31). The optimal regression equation for flower opening angle of spray cut chrysanthemum was obtained by multiple regression analysis: Y (flower opening angle)= 85.59 + 30.28X4(inflorescence diameter)-63.66X7(ray floret length)+ 21.78X8(ray floret width)+ 21.57X9(the corolla tube length)-62.31X10(the corolla tube merged degree) with a coefficient of determination larger than 0.69,which could be potentially used to predict flower opening angle of spray cut chrysanthemum. Principal component analysis integrated the investigated 12 traits into five principal component factors,including ray floral related traits,inflorescence size and leaf angle,etc,and the cumulative contribution rate was 89.07%. According to phenotypic clustering,the tested 203 spray cut chrysanthemum varieties were divided into four groups,displaying significant difference on flower opening angle.
The low differentiation rate of callus and the difficulty of rooting in tissue culture have always been two restrictive factors for the establishment of regeneration system in peony. Methylation Sensitive Amplification Polymorphism(MSAP)was employed to compare the DNA methylation level between in vitro non-embryogenic and embryogenic callus,as well as unrooted seedlings and rooted plantlets in tissue culture of Paeonia ostii T. Hong et J. X. Zhang‘Fengdan’. The results showed that permethylation was the main methylation type in both non-embryogenic and embryogenic calli of ‘Fengdan’,while there existed significant differences in the number of hypermethylation sites between these two callus types. Compared with non-embryogenic callus,the transition from permethylation to hypermethylation caused by embryogenic callus differentiation accounted for as much as 33.45%. Compared with unrooted tissue culture seedlings,the demethylation was the main mode in the rooting process of seedlings,accounting for 38.41%. Therefore,it is speculated that the less differentiation of embryogenic callus of‘Fengdan’may be related to the formation of hypermethylation. The formation of rooting plantlets in tissue culture may be related to the demethylation.
Melaleuca bracteata is rich in essential oil,the main component of which is methyl eugenol with the content is as high as 86.5%. Eugenol is the precursor for the synthesis of methyl eugenol,but the biosynthetic pathway of essential oil is not clear. Based on the transcriptome databases of Melaleuca bracteata,two eugenol synthase genes(MbEGS1 and MbEGS2)were identified and cloned from Melaleuca bracteata. The coding sequences(CDS)of MbEGS1 and MbEGS2 were 963 and 972 bp in length,encoding 320 and 323 amino acids,respectively. Multiple sequence alignment and phylogenetic tree analysis showed that the deduced proteins MbEGS1 and MbEGS2 had the highest similarity (65.92% and 63.89%)with CbIGS1. qRT-PCR analysis showed that MbEGS1 and MbEGS2 were expressed in flowers,leaves and stems of Melaleuca bracteata. The highest expression level was observed in flowers,followed by leaves and stems,which was similar to the eugenol content in different tissues of Melaleuca bracteata,showing a significant positive correlation between the gene expression and eugenol content. MbEGS1 was expressed in roots of Melaleuca bracteata,and the expression level was higher than that in stems and lower than that in leaves. However,MbEGS2 was not expressed in roots. When MeJA was used to treat Melaleuca bracteata,MeJA could induce the expression of MbEGS1 and MbEGS2 and eugenol synthesis,which showed a trend of first increase and then decrease. Treatment with MeJA at 0.1 mmol · L-1 had the most significant effect on gene expression,and their transcription levels were positively correlated with the eugenol content. Subcellular localization showed that MbEGS1 was mainly located in plant cell membrane and nucleus,and MbEGS2 was mainly located in plant cell membrane. Ectopic expression of MbEGS1 and MbEGS2 showed that overexpression of MbEGS1 and MbEGS2 promoted the synthesis of eugenol in Fragaria vesca(Yellow Wonder). The results show that both MbEGS1 and MbEGS2 genes are involved in eugenol biosynthesis.
In our study,the white(W),semi-red(SR_R,SR_W)and full-red(R)pericarps of winter jujube were used as materials,we analyzed components and changes of flavonoids in different coloring periods using targeted metabolomics. The phylogenetic tree of MYB family in winter jujube was constructed,and the potential MYB regulators associated with flavonoid synthesis were analyzed using transcriptomic analysis. The results showed that the differential metabolites between colored and uncolored pericarps were 291(R vs W),196(R vs SR_W),297(SR_R vs SR_W),and 201(SR_R vs W),respectively. There were 98 differential metabolites in the four comparison groups. Further analysis of KEGG revealed that the shared differential metabolites of four comparison groups mainly enriched in secondary metabolites,phenylpropanoids and flavonoid biosynthetic pathways. The 126 flavonoids were detected during the coloring period of winter jujube pericarp,including thirteen anthocyanins,fifty-three flavones,twenty-eight flavonols,eight isoflavones,five proanthocyanidins and nineteen flavanols. Along with the coloration of winter jujube pericarp,three anthocyanins,three flavones and three flavonols increased significantly,while procyanidins and flavanols(catechin,epicatechin)decreased significantly. Fourteen potential MYB regulators associated with flavonoid synthesis were screened via cluster analysis of MYB family. The analyses of transcriptome and qRT-PCR showed that twelve MYB transcription factors were down-regulated with the coloration of winter jujube pericarp,while LOC107434709 and LOC107404750 had higher expression levels in colored pericarp of winter jujube. This suggested that they might play positive roles in the coloring process of winter jujube.
The whole chloroplast genome resequencing of Carya illinoinensis cultivars‘Jinhua’‘Pawnee’and an old seedling individual were sequenced using Illumina sequencing platform,and their chloroplast genome characteristics were analyzed. The results showed that the three pecan chloroplast genomes were a typical tetrad structures with 160 819,162 611 and 160 762 bp in size,respectively. The gene sequences were highly conserved. A total of 124 genes,including 79 protein-coding genes,38 tRNA genes,and seven rRNA genes were identified from each of three pecan chloroplast genomes;repeat sequences detected were similar in categories,and 74,74 and 73 SSR loci were identified in their chloroplast genome sequence,respectively;phylogenetic analysis showed that they were most closely related to Annamocarya sinensis.
A total of 176 Passiflora edulis leaf samples showing mosaic,crinkle and deformation were collected from Sanya and Wuzhishan of Hainan Province from May to July 2020. Seven viruses were detected by PCR and RT-PCR including cucumber mosaic virus ( CMV ),cucurbit aphid-borne yellows virus ( CABYV ),East Asian Passiflora virus ( EAPV ),Telosma mosaic virus ( TeMV ),passion fruit woodiness virus ( PWV ),Passiflora mottle virus ( PaMV ) and tomato yellow leaf curl virus ( TYLCV ). The result showed that TeMV was the most prevalent virus with infection rate of 52.27%,followed by PaMV(43.75%),CMV and EAPV ( 28.98% ),PWV ( 22.73% ),TYLCV ( 9.09% ) and CABYV ( 4.55% ). TeMV,PaMV,CMV,EAPV and PWV may be the main viruses infecting P. edulis in Sanya and Wuzhishan. 78.91% of samples were detected co-infection with a total of 32 kinds of co-infection types,in which co-infection of two to four viruses commonly occurs. Three complete genome sequences of TYLCV from P. edulis were determined to be 2 781 bp and encoded six open reading frames ( ORFs ). Both the identity and phylogenetic analysis based on the complete genome showed that all the three TYLCV isolates belonged to TYLCV Israel strain with nt identity ranging from 98.85% to 99.14%,and clustered in the same branch with the four TYLCV isolates from other crops in Hainan. To our knowledge,this is the first report of TYLCV in P. edulis.
In this study,effects of silicon nutrition and grafting rootstocks on chilling tolerance of‘Xintaimici’cucumber(Cucumis sativus L.)were investigated by using hydroponic non-grafted seedlings and grafted seedlings on both strong de-blooming rootstock‘Huangchenggen 2’(Cucurbita moschata Duch)and weak de-blooming rootstock‘Yunnan Figleaf Gourd’(Cucurbita ficifolia Bouché). The results showed that,under low temperature stress,chilling injury index(CII)of non-grafted cucumber seedlings treated with silicon was significantly lower than that without silicon. The lowest CII was observed in grafted cucumber seedlings on‘Yunnan Figleaf Gourd’followed by the grafted ones on ‘Huangchenggen 2’and finally the non-grafted ones,regardless of silicon supplementation. The significant reduction in electrolyte leakage rate and malondialdehyde content,and the significant enhancement in proline content and antioxidant enzyme(SOD,POD and CAT)activities were observed in the leaves of seedlings supplemented with silicon relative to those without silicon,and in the leaves of grafted seedlings relative to the non-grafted ones,and the alterations in these tolerance-related parameters were greater for grafting treatment,in particular‘Yunnan Figleaf Gourd’used as rootstock,than silicon supplementation. Altogether,our study revealed that both rootstocks and silicon nutrition can improve the chilling tolerance of cucumber seedlings,while grafting treatment displays better performance than silicon supplementation,and for grafting treatment,‘Yunnan Figleaf Gourd’is superior to‘Huangchenggen 2’in alleviating the detrimental effects of chilling stress on cucumber seedlings.
In order to clarify the species and biological characteristics of the pathogen of the brown spot of Forsythia suspensa(Thunb.)Vahl,the pathogen was isolated by tissue separation method and was tested for its pathogenicity following Koch’s postulation. Combing morphological feature with molecular identification of the ITS,LSU and SSU sequences,the pathogen was identified as Alternaria alternata. Growth response of the pathogen to different medium,light treatments,temperature,pH,carbon sources,and nitrogen sources were also studied. The toxicities of eight fungicides against the pathogen were tested using mycelial growth rate method. The results showed that the optimal conditions for mycelial growth were 25-30 ℃ at pH 7.0 with xylitol and mannitol as the carbon sources and peptone as the nitrogen source. The optimal sporulation conditions were 25 ℃ at pH 7.0 with xylitol as the carbon source and urea as nitrogen source. The optimal conditions for conidia germination were 15-35 ℃ at pH 5-9 with xylitol as the carbon source and beef extract powder as the nitro gen source. Among eight fungicides tested in toxicity assays,Cyprodinil(EC50 = 0.032 mg · L-1)and Difenoconazole(EC50 = 0.054 mg · L-1) had stronger inhibitory effect on A. alternata.
Phenomics is a research hotspot in the postgenomic era,and needs to be supported by high-throughput phenotypic acquisition and data processing methods. Here we summarized the recent advances in phenotypic high-throughput acquisition and data analysis methods,especially on grapevine (Vitis vinifera L.). Main reviewed methods include image,optical spectrum and point clouds measurements,three-dimensional reconstruction and machine learning analyzing methods etc. These methods can be divided into two main classes based on their objectives:1)construction of smart orchard for precision viticulture and 2)precision phenotypic analysis for grape breeding. Moreover,the phenome studies of grapevine were reviewed from different scales ranging from field scale,individual plant,to individual organs,and from different traits:yield,quality and growth status. The future applications of the dynamic phenotyping and three-dimensional morphological phenotypes,and their integration with functional-structure plant models in viticulture and grapevine breeding were also discussed.
Ziziphus jujuba‘Yuhong’,a new male-sterile mid-late ripening Chinese jujube cultivar for table with high resistance to fruit cracking and fruit shrinking disease,was found and selected from Mancheng County,Hebei Province. Its fruits were cylinder with average weight of 17.04 g. The flesh is intermediate crispy,juicy and sweet. The soluble sugar content is 23.75%,the titratable acid content is 0.13%,and vitamin C content is 2.62 mg · g-1 FW.‘Yuhong’is early bearing with high and stable yield. It is easier to be managed,and this caltivar is suitable to be cultivated in Xian,Zanhuang,Xingtang Counties of Hebei Province and other regions with similar ecological conditions.
‘Jinlü 60’is a dual-use cabbage hybrid in spring and autumn derived from two self-incompatible inbred lines 01C63-1-1 as the female parent and 02C54-1-2 as the male parent. It is a mid-early maturing cultivar. It tabes about 55-60 d from planting to harvest. The head is round in shape and green in color,with average weight of 1.6 kg. The head tastes crisp and tender,with high quality. It has high tolerance to head-splitting and premature bolting,high resistance to Fusarium wilt and Peronospora brassicae,moderate resistance to black rot. It is suitable for open-field cultivation in spring and autumn in Beijing,Hebei,Gansu,Shaanxi,etc. The average yield was 77 530 and 76 690 kg · hm-2 respectively.
‘Yuejiao 8’ is an early maturing cultivar,possessing strong growth ability. The plant is 70 cm in height,with the ninth node of the first flower. The fruit is thick ox-horn shaped,weighing about 106 g per fruit and with 15 cm in fruit length,5.46 cm in width and 0.31 cm in fresh thickness. The fruit is green and slightly spicy,with smooth and glossy peel. The fruit is in good quality and tolerant to storage and transportation. ‘Yuejiao 8’shows resistance to Phytophthora,bacterial leaf spot and virus disease. The early yield is high and with average yield of 35 260 kg · hm-2.
Caladium cultivars‘Red Heart’and‘Pink Lovely’were selected from‘Freida Hemple’and‘Rose Bud’mutations in tissue culture,respecitively.‘Red Heart’has red leaves.‘Pink Lovely’has pink leaves,chilling tolerance and early germination. Compared with original materials,the plants of the two new cultivars are shorter and neater,the leave and petioles are thicker.