Abstract:In this study,a new gene encoding proline-rich protein was isolated from 12 days post anthesis(DPA) cotton fiber,and designated as GhPRP10.The ORF of the gene was 684bp encoding 228 amino acids,contained 34.6% proline.The bioinformatics analysis showed that the protein encoded by this gene belonged to the first class of PRPs,which has a signal peptide in N terminal and a proline rich conserved region.The quantitative RT-PCR results showed that GhPRP10 is preferentially expressed in cotton fiber.The transcript level increased along with fiber development and reached the highest abundance at 18DPA,after which time it gradually decreased.The plant over-expression vector was constructed using Gateway technology and then transformed into tobacco suspension BY-2 cells.The phenotype observation and cell length measurement found that the transgenic cells were significantly longer than that of the wild type.Based on the expression profile of GhPRP10 and phenotype analysis of transgenic cells,it is presumed that the gene plays an important role in the process of fiber elongation and secondary wall synthesis.

Abstract:The MYB transcription factor is one of the largest gene families in plant,involving in various physiological and biochemical processes.In this study,one new MYB gene TaMYB3-4D was isolated from the wheat cultivar ‘Gaoyuan 115’.TaMYB3-4D was close to the genes regulating anthocyanins biosynthesis in phylogenetic tree.TaMYB3-4D possessed only one intron,while the other MYB genes regulating anthocyanins biosynthesis had two introns.The deduced amino acid of TaMYB3-4D contained two consecutive MYB domains,the typical characteristic of the R2R3-MYB transcription factor.Transient expression experiments showed that TaMYB3-4D induced the white coleoptile cells of wheat cultivar Chinese Spring (CS) to synthesize anthocyanins with the help of bHLH transcription factor ZmR in light.Meanwhile,the RT-PCR analysis showed that TaMYB3-4D gene only expressed in purple seeds and red coleoptiles of ‘Gaoyuan 115’,but not in root,stems and leaves.All of these results suggested that TaMYB3-4D was a R2R3-MYB transcription factor regulating anthocyanins biosynthesis in wheat.

Abstract:It has important significance for transgenic resistance research to clone and validate endogenous inducible promoters in response to abiotic stresses,and use to construct inducible expression vectors.In this study,the sequence of the late embryogenesis abundant late gene (MGL3) promoter (pMGL3) was cloned from maize according to bioinformatics analysis.After analysis for abiotic stress-responsive elements and abiotic response by quantitative real-time PCR,we used this sequence to construct expression vector of the reporter gene GUS,and used to transform maize calli by biolistic method.The promotion activity of the pMGL3 promoter under abiotic stress was validated by GUS staining.In addition,the different cis-acting elements was removed according to promoter sequence analysis,used to construct expression vectors of the reporter gene GUS,and transform tobacco discs by Agrobacterium mediation,in order to determine the shortest active sequence of the pMGL3 promoter.The results showed that the pMGL3 promoter is 1 554 bp long,containing multiple regulatory elements in response to abiotic stress.The expression of the MGL3 gene is increased under the stress of drought,high salt and low temperature,and induction of abscisic acid and ethylene.The calli transformed by the GUS gene under control of the pMGL3 promoter showed promotion activity under high osmotic,high salt,low temperature stresses,and abscisic acid induction.However,it kept promotion activity when truncated to as short as 325 bp.These results indicated that the pMGL3 promoter has promotion activity in response to abiotic stresses,and can be applied to maize transgenic studies for abiotic tolerance after further validation for its mechanism.

Abstract:Acetohydroxyacid synthase(AHAS) is involved in the synthesis of branched-chain amino acids(BCAAs) in Arabidopsis.To investigate the effects of various domains of AHAS on the BCAAs synthesis,the point mutations harboring in the specific sites of the large and small units of AHAS were introduced by site-directed mutagenesis.The mutagened histidine-tagged units of AHAS were expressed individually in the bacterial hosts and the recombinant proteins were purified using Ni beads.The point mutated large and small units were reconstituted in vitro and the activities of holoenzymes were determined.Moreover,the effects of valine,which is one of the final end products of AHAS,on the activities of the mutated holoenzymes were also examined.The results showed that the G88D mutation in the small unit of AHAS abolished the final end product inhibition and the E305D or E482D mutation in the large unit decreased the activity of AHAS holoenzyme.The two mutations in the large unit displayed difference in the activity of AHAS and the E482D mutation presents the more effects than the E305D on the activity of AHAS.The results in this study suggest that the large unit interacts with the small unit in the AHAS and the various domains in the units of AHAS exhibit distinct functions.

Abstract:According to transcriptome data of Fagopyrum tataricum at flowering,using PCR and RT-PCR techniques,the DNA and full-length cDNA sequences of FtLSD1 gene (GenBank accession number:KP252134) were amplified from F.tataricum.The obtained sequences were analyzed by bioinformatics software,and the expression FtLSD1 gene were analysed by qPCR under UV-B,SA and 4 ℃ cold stress.The results showed that the DNA sequence of FtLSD1 gene was 2 427 bp,of which consisted 6 exons and 5 introns,in line with the principle of GU-AG splicing,and the cDNA of FtLSD1 contained a 528 bp ORF.The UV-B radiation and 2 mmol/L salicylic acid could lead to a significant increase in the expression of the FtLSD1 gene,while 4 ℃ cold stress remained stable expression levels of the gene.The results expected to lay a foundation for study the stress resistance in F.tataricum.

Abstract:To study the function of somatic embryogenesis receptor-like kinase gene (SERK) in Anthurium andraeanum’ s somatic embryogenesis,we isolated a novel AaSERK gene from the embryogenic callus of A.andraeanum by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE).The expression levels of AaSERK were analyzed by Real time-PCR.The results showed that:(1)The full-length cDNA of AaSERK was 1 949 bp with an open reading frame of 1 866 bp encoding a protein of 622 amino acid residues.(2)It was speculated that the AaSERK was a typical SERK gene with one signal peptide,one leucine zipper domain,five Leu-rich repeat(LRR) domains,one SPP motif,one transmembrane domain,the kinase domain with eleven subdomains,and one C-terminal domain.DNAMAN analysis showed that the putative AaSERK amino acid sequence had 65%-89% identity with those of the other plants.(3)In the different stages of somatic embryogenesis in vitro,the expression of AaSERK was weak or little in the inducing stage and the developmental stage,but was the highest in the embryogenic callus on the 30th day of the subculture stage.It was speculated that the AaSERK might be one of the marker genes of somatic embryogenesis in A.andraeanum.

Abstract:In order to study the relationship between of pepper cytoplasmic male sterility and energy metabolism,we cloned pepper glucose-6-phosphate dehydrogenase gene (CaG6PDH) based on the G6PDH homologous sequences of the related species tomato by the electronic cloning in this research.Real-time quantitative-PCR was used to analyze the gene expression levels in the different stages of flower development in the cytoplasmic male sterility line (9704A) and its maintainer line (9704B),and different tissues(stem,leaf,flower,pericarp,placenta and seed) in the 9704B.The results showed that there was no difference of cDNA sequences between the CaG6PDH in the 9704A and the 9704B.Sequence prediction showed that the 1 533 bp cDNA sequences represent 1 single gene,which encodes 510 amino acids.CaG6PDH gene has a different expression in the different tissues in the 9704B,the highest in the placenta and the lowest in the stem.CaG6PDH gene expression in 9704A was higher than that in 9704B during the different stages of flower development,especially in the uninucleate microspore stage and mature pollen stage.The abnormal expression level of CaG6PDH in the 9704A disturbed the balance of energy metabolism and interfered the development of microspore,then resulted male sterility in the pepper.

Abstract:In this study,the strong drought-resistant cotton variety ‘KK1543’ was used as the material.RT-PCR method was used to clone a HSP70 gene,a gene coding for GhHSP70 was isolated from cotton (Gossypium hirsutum L.).The open reading frame was 1 997 bp,encoding 648 amino acid residues with a predicted molecular mass of 70.94 kDa and a basic isoelectric point of 4.83.Homology analysis and phylogenetic tree analysis founded that GhHSP70 shared 96.4% amino acid identity with the HSP70 from Populus trichocarpa,and GhHSP70 protein is close to PtHSP70.An expression vector pGEX-4T-1-GhHSP70 was constructed.Then,the recombinant plasmid was transformed into Escherichia coli.The SDS-PAGE results displayed that the expressed protein was consistent with the anticipated size.The expressed protein quantity induced by 0.2 mmol/L IPTG treatment for 2 h at 37 ℃ is the highest.This study provide a fundamental condition supporting research on function of GhHSP70 gene.

Abstract:In the present study,DNA methylation specific PCR primers were designed according to the sequences of CpG island region throughout 12 chromosomes and the specific genomic position.In order to investigate the changes of DNA methylation level and pattern in the cold tolerance introgression lines (ILs,IL5335 and IL5423) and their parents,we used these special primers to amplify the previously digested genomic DNA by McrBC enzyme.(1)Analysis of 83 pairs of primers distributed across the 12 chromosomes of rice showed that the frequency of DNA methylation in IL5335 and IL5423 was to 46.6% and 53.8%,respectively,which was lower than that of recurrent parent (Oryza sativa L.cv.Xieqingzao B).Most of DNA methylation patterns of recurrent parent could be inherited in the ILs.At the same time,some of methylation patterns have changed including demethylation (13.3-18.1%) and hypermethylation (4.4%-6.0%).(2)In the QTLs region related to cold tolerance,the frequency of DNA methylation in IL5335 and IL5423 was 13.3%-26.7%,which was much lower than that of recurrent parent.The frequency of DNA methylation patterns changes of the two ILs in the QTLs region was mainly for demethylation (33.3%-40.0%),which was higher than that of the average variation frequency of whole-genome.(3)Further analysis on 51 pairs of primers based on two retrotransposons (Houba and Osr14) demonstrated that there was higher level of frequency of DNA methylation and lower frequency of methylation pattern changes.These results suggested that the extensive DNA methylation level and pattern changes have been happened during the interspecific hybridization and alien gene introgression,which would provide useful information for efficiently exploiting and using the interesting wild genes for rice enhancement.

Abstract:In this study,a mutant with super short primary and adventitious roots,less lateral roots and short root hairs was isolated from an EMS (ethyl methane sulfonate)-generated rice mutant library in the Kasalath background,designated as ssr1 (super short root 1).At the 8 d old stage,the length of primary and adventitious roots of ssr1 was only 8.89% and 2.29% of the wild type (WT),respectively.The initiation of adventitious roots of ssr1 was similar as WT,while the initiation and elongation of lateral roots were severely impaired and root hairs were also much shorter than that of WT.Moreover,ssr1 showed dwarf phenotype with plant height less than half of WT.Genetic analysis indicated that the mutant phenotype was controlled by a single recessive nuclear gene.Map-based cloning analysis located SSR1 to a 243 kb region between STS(sequence tagged site)markers 9g7047K and 9g7290K on chromosome 9.The region contains 39 putative genes with none reported to be related to root development of rice.This result will be helpful for the cloning of SSR1 and further characterization of molecular genetic mechanisms underlying root architecture in rice.

Abstract:A karyological study of 22 Rosa taxa,including 5 wild species,8 old garden roses and 9 modern cultivars,was performed using traditional squashing and pressing methods.There are three ploidy levels among the taxa,R.multiflora var.cathayensis is triploid with 21 chromosomes(2n=3x=21),the other wild taxa are diploid with 14 chromosomes(2n=2x=14),and the modern rose taxa are all tetraploid with 28 chromosomes(2n=4x=28),while the old garden roses contain all three ploidies.Four karyotypes(1A,2A,1B and 2B) have been found among the taxa,with 1A and 2A in wild species,1A,2A and 1B in old garden roses,and 1A,1B and 2B in modern roses.Also,the studied taxa differ from each other in the asymmetry index,centromere index,satellite position and number and constitution of relative lengths.The results indicate that karyological diversity is abundant in Rosa germplasm resources.

Abstract:The ultrastructure of secretory canals in root of Angelica dahurica and the accumulation of essential oils were investigated by transmission electron microscopy (TEM) analysis.The secretion process of the essential oil was also discussed.The results indicate that the plastid,ground substances of cytoplasm and mitochondria took part in the biosynthesis of oil or oil precursor.At latter stages of development of secretory cells,numerous different sized vesicles fused with the plasmalemma and tonoplast and released the inner materia into the lumen of secretory canals.As a result,plastid and ground substances of cytoplasm were the major synthetic site of volatile oil which secreted into the lumen by diffusion or by vesicles fusing with the plasmalemma and tonoplast.Abundant mitochondria may provide energy for the series of process.

Abstract:The morphological structure of the inner wall of the vessel elements in 14 species of Maloideae (Rosaceae) from Heilongjiang Province was studied by means of scanning electronic microscope (SEM).The result showed that:(1)The length,the width and the slope of vessel elements are various in different species;(2)All studied species have pitted vessel type,while reticulated and spiral vessel only appear in the Malus and Sorbus;(3)Helical thickening of the inner wall of the vessel elements occurs in most species except in Malus and in Crataegus maximowiczii and C.sanguinea;(4)The arrangement of pits is alternate,opposite or both in one element;(5)Simple and scalariform perforations were found on the end wall of the vessel elements in Sorbus pohuashanensis,Malus baccata and Crataegus pinnatifida var.psilosa,while other species only with simple perforations on the end wall of the vessel elements;(6)The remnants of pit membrane are common in all species.These results indicated that the morphological structure of the inner wall of the vessel elements is systematic significance for Malodieae,and the micro structure of the vessel elements is also adapted to their environment.

Abstract:In this paper,the base of mature leaves of three Chinese Isoetes are used as experimental materials.With the method of paraffin technology,we observed three Chinese Isoetes ligules in detail to build their own stereoscopic models,and analyzed the genetic relationship between them.They were compared with Central Asia and North American Isoetes ligules to discuss the evolutionary relationship.The results show that:(1)All three Chinese Isoetes ligules had tongue,glossopodium and medimoles.(2)Both Isoetes sinensis and I.orientalis ligules had side tongue like halberd-shape,oval-shape cornua and glossspodium paraller with leaf axis.Oppositely,I.yunguiensis had long nose-shape tongue without side tongue,triangular cornua and glossopodium angled with leaf axis.(3)The lateral view of I.sinensis and I.yunguiensis glossoposium were oblong,but I.orientalis was reniform.The study suggests that the genetic relationship between Isoetes sinensis and I.orientalis is close,and they two are distant with I.yunguiensis.The ligule should be coalescent form of Isoetes.With its complex structure and stable obvious difference,ligule is suggested to be a important gist in Isoetes classification.

Abstract:Based on the well developed Isoetes sinensis plants material,with method of semi-thin section,we observed the development of the root and the characteristics of root system in detail,and discussed the endogenous origin of I.sinensis roots,the structural function of the thick roots and the fine roots the biological functioning of the dichotomous and transverse partition,which provided the morphologic basis for the study about ancient vascular plants evolution and their endangered reasons.The result show that:(1)The mature plants of I.sinensis have approximately one hundred brown,hollow roots,but have not main roots,both endogenous origin and external origin ways are observed among these roots,and each root has multi-round dichotomies.(2)The happened of dichotomies general frequency of intensive and fission unequality,among the thinner root are much more earlier and frequently and for every dichotomous point,there is a permanent transverse partition including 2-3 layers of cells between each inferior branch and its superior root.Even in the old root the transverse partition is always there.(3)The epidermis cells of inferior branches are transformed directly from some cortical cells;diameters of roots tips of these two inferior branches are different.These evidences suggested that:roots of I.sinensis could be originated from both stem and rhizophore;cortical cells have special differentiation capacity;the transverse partition may be a adaptive structure formed during the geological time million years ago,with what to against the high-energy environment in that era;root system of I.sinensis obtain powerful regenerative capacity and highly complicacy.

Abstract:In order to breed new rose cultivars with flower fragrance and strong abiotic and biotic resistance,we carried out 72 interspecific hybridization combinations,using Rosa xanthina f.normalis,R.xanthina,R.primula,R.bella,R.macrophylla var.glandulifera,R.multiflora f.carnea and five R.rugosa cultivars as male parents,and eleven modern rose cultivars and R.odorata as female parents.The fruit setting,pollen shape and stigma form of the parents,as well as the pollen germination of the male parents were observed.The results showed that:(1)Except R.xanthina,all other pollen providers can be used as male parents to hybridize with modern rose cultivars.The fruiting rate and the hybrid seed germination rate were significantly different among different cross combinations.(2)The pollen and stigma shape had little effect on the fruiting rate during hybridizing;however the pollen germination rate had remarkable effect on it.Fourteen cross combinations with high fruiting rate and high hybrid seed germination rate were selected,and 4 suitable female parents (R.odorata,‘Orange Wave’,‘Goldmarie’ and ‘Pink Peace’) and 6 suitable male parents(R.xanthina f.normalis,R.primula,R.bella,R.macrophylla var.glandulifera,R.multiflora f.carnea,R.rugosa ‘Dahong Zizhi’) were recommended for interspecific hybridization.

Abstract:The pollen morphology of Camellia magniflora was investigated under scanning electronic microscope(SEM),Fresh pollen of C.magniflora was took as materials to test the pollen viability by in vitro.Effects of different store methods on the pollen viability,SOD,POD and CAT were also investigated.The results show that (1)The polar face is a equilateral triangle,the germinal aperture is wider on the polar.The exine ornamentation were mainly perforate,sulciform.The average length of polar axis is 71.05 μm,which show C.magniflora should occupy special taxonomic status in the genus Camellia.(2)The best combination for pollen germination is 150 g·L^-1 sucrose,20 mg·L^-1 boric acid,100 mg·L^-1 KNO₃,50 mg·L^-1 MgSO₄,300 mg·L^-1 Ca(NO₃)₂.The germination rate reached 68.10%.(3)-80 ℃ sealed storage is the best storage condition to keep the vitality of pollen,the germination rate of pollen reached 39.40% after 360 d storage.(4)The three kinds of enzyme activities were higher,Antioxidant,aging ability were also higher in -20 ℃ and -80 ℃ storage.The germination proportion of pollen decreased significantly when the activities of SOD,POD and CAT were around the highest levels;(5)The three enzymes had different responses to the storage temperature.SOD was a responding protection enzymes at normal temperature,POD was a responding protection enzymes at 4 ℃ and -20 ℃,while CAT was a responding protection enzymes at -80 ℃.The effect of three kinds of enzymes on pollen germination is CAT>SOD>POD.

Abstract:The purpose of the study was to determine the difference of aging time on germination and root tip cell ultrastructure of wheat cultivar,‘Xinchun 6’.Germination rate,seedling root length,seedling fresh weight,seedling dry weight,and the change in root tip skin form,cellular structure were included in this test.It was,then,easy to guess that germination rate,germination potential,germination index,seedling root length,fresh weight and dry weight were decreased sharply while MGT increase as the extension of aging time.And aging 4 d was the turning point of seed vigor drops by scanning seedling root of germination 72 h,we can find that along with the aging time,the root epidermal cells shrivel deepened/compacted,eventually.It can be caused shin burst,inside cells bared.Under the transmission electron microscopy,the degree of organelles dissolved obvious gradually,and the whole cell formation of cavity eventually.We can visibly saw that the seed gradually lost vitality may be caused by root epidermal morphology,internal changes in the cellular structure.

Abstract:In this study,taking elm(Ulmus pumila L.) seeds as materials,we combined the use of seed vigor detection technology,confocal laser scanning microscopy,protein S-nitrosylation detection technology and pharmacology of many nitric oxide inhibitors,to investigate the role and the mechanism of nitric oxide during seed ageing.The results showed that:(1)Nitric oxide donor SNP can improve seed vigor after ageing.The scavenger of nitric oxide cPTIO can suppress the seed vigor after ageing,and the suppressions can be recovered by nitric oxide donor SNP.These illustrated that nitric oxide can improve the ability of anti-ageing.(2)The substrates of nitrite reductase and nitric oxide synthase like enzyme can improve seed vigor after ageing.The inhibitors of nitrite reductase and nitric oxide synthase like enzyme can suppress the seed vigor after ageing,and the suppressions can be recovered by nitric oxide donor SNP.These illustrated that nitric oxide can be produced by nitrite reductase pathway and nitric oxide synthase like enzyme pathway.(3)Nitric oxide was first produced in cotyledon,then in radical,shoot apex and hypocotyl.The level of protein S-nitrosylation was in accordance with temporal characteristics of nitric oxide produce.In conclusion,nitric oxide can improve the ability of anti-ageing,and can be produced by nitrite reductase pathway and nitric oxide synthase like enzyme pathway.The level of S-nitrosylation was also related to nitric oxide production.

Abstract:This study overexpressed dihydroxyacetone synthase (DAS) and dihydroxyacetone kinase (DAK) genes,which are two key genes for formaldehyde (HCHO) assimilation in methylotrophic yeasts,in chloroplasts of geranium to obtain transgenic geranium with DAS/DAK HCHO assimilation pathway,The metabolites of wild type and transgenic geranium under liquid H¹³CHO stress were comparatively analyzed by ¹³C-NMR,and the physiological and biochemical indexes of wild type and transgenic geranium under 48 μg·L^-1 gaseous HCHO stress were measured.The results showed that:(1)Under 2 mmol·L^-1 liquid H¹³CHO stress,overexpression of DAS/DAK genes enhanced the role of Calvin cycle during the H¹³CHO metabolism in transgenic geranium,thereby the yield of sugars increased approximately 2.85-fold,and simultaneously changed the original HCHO metabolic pathways of geranium.(2)Under 48 μg·L^-1 gaseous HCHO stress,the contents of H₂O₂,malondialdehyde and protein carbonyl in transgenic geranium leaves were much less than those of wild type.(3)Under environment-polluted gaseous HCHO stress,the absorptive capacity of HCHO and stomata conductance in transgenic geranium leaves remained significantly higher than those of wild type.These results suggest that overexpression of DAS/DAK genes can effectively improve the ability of geranium to purify the environmental-polluted gaseous HCHO.

Abstract:Hydrogen sulfide(H₂S) has been known as a new gasotransmitter which plays a vital role in regulating plant growth and responding to stresses.For deepening the understanding of physiological mechanism on the response to chilling stress in Chinese Cabbage (Brassica rapa var.pekinensis),we analyzed the influence of the seedlings growth conditions,photosynthesis and related genes expression levels under chilling stress which pretreated with exogenous H₂S (5 μmol·L^-1 NaHS treated 24 h).The results showed that:(1)The chilling stress activated the endogenous production of H₂S,and up-regulated the expression of the cysteine desulfhydrases coding genes,LCD,DCD and DES,which were identified as the main genes for endogenous H₂S emission.These data implied the close correlation among them.(2)The cabbage seedlings pretreated with H₂S showed obvious advantages in the aerial part height,the leaf width and the relative water content under chilling stress.The proline,the soluble sugar content and the photosynthetic pigment were increased significantly,along with the great improvement of the photosynthetic rate.And,the coding genes of some light-harvesting protein,ferredoxin,thioredoxin were up-regulated dramatically after pretreated with H₂S.From all these results,it could be concluded that physiological concentrations of H₂S could raise the photosynthesis through up-regulating the photosynthesis related-genes and P_n,promote osmotic adjustment and relieve the damage caused by chilling that could maintain the growth of cabbages under chilling stress.

Abstract:‘Hanxiao’ was selected as material to study the effects of 0.5 mmol/L exogenous spermidine(Spd) on the growth and quality of pakchio seedlings under 80 mmol/L calcium nitrate stress by hydroponic culture.The results showed that:(1)The stress of 80 mmol/L Ca(NO₃)₂ significantly reduced plant growth,plant height,root length,leaf area,root volume,fresh and dry weight.Spraying 0.5 mmol/L Spd on leaf significantly promoted the growth of seedlings.(2)The stress of 80 mmol/L Ca(NO₃)₂ significantly reduced the contcents of photosynthetic pigments.Compared with CK treatment,chlorophyll content in seedlings declined 54.72% with Ca(NO₃)₂ treatment.Spraying 0.5 mmol/L Spd on leaf significantly promoted the contents of photosynthetic pigments in seedlings.Compared with Ca(NO₃)₂ treatment,carotenoid contcent in seedlings increased 53.33% with NS treatment[Ca(NO₃)₂+Spd].(3)The stress of 80 mmol/L Ca(NO₃)₂ significantly reduced photosynthesis.Compared with CK treatment,P_n of seedlings declined 34.45% with Ca(NO₃)₂ treatment.Spraying 0.5 mmol/L Spd on leaf significantly promoted P_n of seedlings.Compared with Ca(NO₃)₂ treatment,P_n of seedlings increased 28.11% with NS treatment.(4)The stress of 80 mmol/L Ca(NO₃)₂ significantly reduced quality.Compared with CK treatment,the contents of vitamin C,soluble sugar and soluble protein of seedlings significantly declined,nitrate and organic acid significantly increased with Ca(NO₃)₂ treatment.Spraying 0.5 mmol/L Spd on leaf significantly promoted seedlings above-mentioned nutritive index.These results indicated that exogenous Spd significantly promoted the growth,photosynthesis and improved the quality of pakchoi seedlings under calcium nitrate stress.

Abstract:The change rule of root growth and respiratory metabolism were analyzed under different treatment times(1,3,5,recovery 7 d) and different levels(root flooded and half submerged) in pakchoi (Brassica campestris ssp.chinensis Makino).(1)Waterlogging stress inhibited the plant roots growth of pakchoi,ruesulted in the decrease of root fresh,root length,and root activity,and the reduction of half submerged was higher than that of root flooded.(2)Comparing with the control,waterlogging stress reduced the root malate dehydrogenase (MDH) and succinte dehydrogenase (SDH) activities significantly,increased the lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH) activities.The impact of semi-submergence of plants was more serious than that of submergence of roots,and 5 d and 1 d treatments have significant difference.(3)After the waterlogging stress,the lactic acid fermentation way of ‘Xinaiqing’ was weaker than that of ‘Xinxiaqing’.By contrast,alcoholic fermentation of ‘Xinxiaqing 2’ was stonger,causing the lactic acid accumulation in the root is more than that of ‘Xinaiqing’,and the degree of cytoplasm acidification was seriously reducing the tolerance to flooding stress.Obviously,after the waterlogging stress,the aerobic respiration of pakchoi was inhibited while the anaerobic respiration was accelerated.With the extension of flood time,the degree of inhibition on root respiration metabolism was more serious,eventually lead to restrain root growth.

Abstract:By spraying different concentration of CaCl₂,gibberellin (GA₃),salicylic acid (SA) and paclobutrazol (PP₃₃₃),we studied and compared the effects of the pretreatments with four chemical regulators on chilling tolerance and photosynthetic characteristics in tobacco(Nicotiana tabacum L.) seedlings.The results showed that:(1)As compared with the control spraying distilled water,the pretreated seedlings with the four chemical regulators generally had higher dry weight,root vigor,proline content and net photosynthetic rate,and lower malondialdehyde (MDA) content,which totally enhanced the quality of tobacco seedlings.(2)When transferred to chilling stress at 10 ℃ for 20 d,as compared with the control,the pretreated seedlings with the four chemical regulators could maintain higher dry weight,relative growth rate,dry matter accumulation rate,root vigor,proline and chlorophyll content,net photosynthetic rate,intercellular CO₂ concentration,stomatal conductance and transpiration rate,reduced MDA content and lipid perioxidation,which finally enhanced chilling tolerance of the tobacco seedlings.(3)The pretreatments with the four chemical regulators all could increase chilling tolerance in tobacco seedlings to different contents,in general,SA pretreatment displayed the best effect.

Abstract:Populus cathayana,a native species,is a typical dioecious and fast-growing woody species,which extensively distributed in China,exhibiting good adaptivity to local climates.In the present study,a controlled experiment was conducted to detect differences in Pb accumulation and nutrient status between male and female cuttings of P.cathayana,when exposed to diffused levels of Pb pollution.One-year old shoots of both sexes of P.cathayana were selected as experimental materials,and each cutting was cultivated in one pot.In our study,three levels of Pb pollution (CK:20.5 mg·kg^-1;T₁:50 mg·kg^-1;T₂:100 mg·kg^-1) were set up.The experiment lasted a grown season (from June 2013 to October 2013).The result showed that:(1)The diffused levels of Pb pollution (T₁ and T₂) significantly decreased total biomass of females,but not for that of males.However,in all corresponding treatments,the total biomass of females was significantly higher than that of males.(2)Both levels of Pb pollution (T₁ and T₂) did not negatively affect N concentration in all organs of both sexes,and there was no significant difference in N concentration between the sexes.In contrast,the response of P concentration in both sexes was more obvious than that of N concentration,especially when exposed to the treatment T₂.The treatment T₂ decreased the P concentration in different organs of both sexes to some degree when compared to the control.When compared to the control,the decrease of N/P ratio in males suggested that growth of males would be restricted by shortage of P gradually.(3)When comes to accumulation capacity of Pb,the total Pb accumulation increased gradually in females,but not in males,along with increasing level of Pb pollution.In conclusion,our results indicated that males’ capacity in resistance and tolerance against lead pollution is greater than females,and there is sex-specific adaptive strategy in response to lead pollution.The higher accumulation of Pb in females might be main reason for decreasing its biomass and imbalance in nutrient status,while lower accumulation in males might be in favor for its adaptivity to Pb-contaminated environments.

Abstract:Aroma characteristics and genetic performance were analyzed in four varieties of Cucumis melo and their crossing combinations in this study.The results showed that:(1)There was great difference of aroma composition in the fruits existed among four varieties.Aroma in Charentais from var.cantalupensis was characterized by esters,closely connected with the climacteric traits.Nine-carbon aldehydes were the characteristic aromatic components in Queen (var.inodorus) which was non-climacteric accession.Aroma in Tianbao (var.makuwa) was characterized by OASPC.(2)Eleven quality traits including aroma composition were studied by principal component analysis,the result shows that the first three components contributed 77.80%.The contribution rate of PC1 was 43.37%,was significantly correlated with relative content of esters,AloPC and AIPC and the numbers of aromatic compounds.PC2 was significantly correlated with OASPC and ethylene production vate.Four different varieties of melon and their crossing combinations can be significantly distinguished by these traits.(3)The performance trends of different aroma composition were largely varied among four combinations from four different varieties of melon.The relative content of most of esters showed intermediate values in all of four combinations closed to the high parent values.AloPC,AIPC and OASPC showed values closed to the low parent values.

Abstract:Field investigation was performed on the floral syndrome,pollination characteristics,pollinator behaviors and breeding system of Heteroplexis by continuous observations,TTC method,Benzidine-H₂O₂ method,out-crossing index,pollen-ovule ratio.The result as follows:(1)Under natural conditions,the flowering stage of Heteroplexis vernonioides was about 60 days from April to June,Heteroplexis microcephala and Heteroplexis incana were about 60 days from April to August,Heteroplexis impressinervia and Heteroplexis vernonioides were about 150 days from August to December.The life span of a single flower was about 3 days and the inflorescence was 5 days.(2)Pollen had vigor after the 1-18 h of anthesis.Stigma was receptive after 48 hours of anthesis.The out-crossing index was 4,P/O was 1 450-2 250.The breeding system of five species were given priority to out-crossing,part self-compatibility,insects pollinator dependent.(3)Eristalis cerealis and vespa ducalis are effective pollinators.The visiting frequency showed triple-climax was 10:00-12:00 and the visiting time was 2-10 s per flower.

Abstract:Based on field investigation,specimen collection and relevant literature data,we compiled a list of wild seed plants of Liangyeshan Nature Reserve in Fujian province,and analyzed the composition of seed plant flora and its geographical distribution types of families and genera,and the results were compared to two neighboring nature reserves.The results showed that:(1)There were totally 1 498 natural seed plant species belonging to 662 genera and 154 families in Lingyeshan Nature Reserve,which was abundant in plant species.(2)Tropical elements were the dominant components of the flora,but a large number of temperate elements reflecting subtropical flora characteristics.At family level,85 families belonged to tropical elements and accounted for 69.67% of the total families.At genus level,371 genera belonged to tropical elements and accounted for 60.82% of the total genera.(3)Compare to two neighboring nature reserves,R/T (number of tropical elements/number of temperate elememts) ratio of genus in the region (1.66) was higher than that in the Wuyishan Nature Reserve (1.10),but lower than that in the southern subtropical rainforest in Nanjing (2.68).Floristic similarity coefficients between this region and the two neighboring nature reserves were very close.Liangyeshan Nature Reserve not only shared common temperate floristic components with Wuyishan Nature Reserve which were not found in subtropical rainforest in Nanjing,but also shared common tropical floristic components with subtropical rainforest in Nanjing which were not found in Wuyishan Nature Reserve.This indicated that flora in the region was consistent with its geographic position at southern Wuyishan Mountains,and that it was geographically a transitional area from south subtropical to mid-subtropical.

Abstract:After examining a large number of specimens and type materials,as well as field observations,we reduce Astragalus koburensis,A.ningxiaensis,A.salsugineus var.hetaoensis and A.acceptus to the synonymy of A.galactites.

Abstract:Three newly recorded species of aquatic angiosperms were reported from Hainan.They were Nechamandra alternifolia(Roxburgh ex R.Wight) Thwaites (Hydrocharitaceae),Limnophila heterophylla (Roxburgh) Bentham (Scrophulariaceae) and Acorus calamus Linnaeus (Araceae).They grew in the Yangshan wetland with unpolluted water of Haikou.Specifically,Nechamandra alternifolia and Limnophila heterophylla were rare.So they were as further evidence information to support the claim that Yangshan wetland was an important area of species distribution.

Abstract:With all the basic characteristics of all other developmental processes,stomatal development is relatively simple and easy to operate,which make it a good platform to research the mechanism how hormones integrate the environment signal and regulate development.In this paper,we reviewed the latest research progress on the signal transmission network and key components in stomatal development,and hormone(sterols,auxin,ABA,GA,Eth) function in regulation of stomatal development,and the cross interactions between hormones are summarized.