Abstract:In this study,we collected fresh flowers from Cucumis sativus around 10:00^am from June to August,isolated the generative cells (GC) of C.sativus with the method of osmotic shock,quantified its mitochondrial DNA (mtDNA) contents through employing the competitive quantitative PCR technology,and analyzed the change of mtDNA contents in GC during its development,in order to investigate the origin of the abundant mtDNA,and lay the foundation for further study on the molecular mechanism of regulation of mitochondrial DNA amplification in angiosperm.The results showed that:(1)DAPI staining represents abundant fluorescence points of organellar DNA around the nucleus of GC of C.sativus,indicating the presence of a large number of mtDNA in cytoplasm of cucumber GC.(2)The single mature GC of C.sativus averagely owns (1 037±126) mtDNA copies.(3)Compared with early GC,the mature GC upregulates the mtDNA by 14.5 times,suggesting that mtDNA in mature GC is mainly from its active amplification after GC formation.The study suggests that the active increase of mtDNA in GC is the basis of the paternal mitochondrial inheritance of C.sativus.

Abstract:To explore the effects of different temperature treatments on anthocyanin contents of postharvest pomegranate pulp,and the function of anthocyanin biosynthesisrelated gene (F3′5′H) in anthocyanin biosynthesis pathway of pomegranate pulp,taking pomegranate cultivar ‘Yushizi’ as test materials,we measured anthocyanin contents of pomegranate pulp under different temperature (0 ℃,5 ℃,10 ℃,15 ℃) treatments.At the same time a anthocyanin biosynthesisrelated gene was cloned from pomegranate pulp by RACE,named PgF3′5′H(GenBank accession:KU058892).The expression levels of PgF3′5′H in pomegranate pulp during different temperature storage periods were analyzed by RTPCR.The results showed that:(1)under different temperature treatments,anthocyanin contents of pomegranate pulp showed a rising trend as the storage time (0-56 d) went on;In the whole storage time,anthocyanin contents were the highest under 15 ℃ treatments,secondly 10 ℃,5 ℃ and 0 ℃ at lower levels;Anthocyanin contents under 15 ℃ were unstable after 14 d.(2)The fulllength cDNA of PgF3′5′H was 1 199 bp with an open reading frame of 918 bp encoding 305 amino acids.The 36th to 39th amino acids of the Nterminus of PgF3′5′H contained the characteristic conserved sequences (CYP motif “PPGP”) of the cytochrome P450 family genes;Bioinformatics showed that the amino acid sequences of PgF3′5′H had high consistency with Eucalyptus grandis EgF3′5′H2,Jatropha curcas JcF3′5′H2 and Nelumbo nucifera NnF3′5′H2 as 86%,82% and 81%,respectively.(3)The expression levels of PgF3′5′H showed a rising trend as the storage time (0-56 d) went on under 0 ℃,5 ℃ and 10 ℃ treatments,being unstable under 15 ℃;The relative expression of PgF3′5′H was significantly positively correlated with anthocyanin contents of pomegranate pulp.The research results laid the foundation for exploring the changes of anthocyanin contents in postharvest pomegranate pulp.

Abstract:In ferns,the spermatogenesis is a process of de novo formation of the motile apparatuses and the molecular mechanisms of the spermatogenesis were unclear.Centrin,a highly conservative calcium binding protein usually locating in the centrosome,was considered to be the protein that participates the formation of motile apparatuses.Cloning of the centrin gene has some significance for elucidating the molecular mechanism of spermatogenesis of ferns.The present investigation cloned the centrin gene (CtCEN) from the fern model plant,Ceratopteris thalictroides.The full length the cDNA sequence of the CtCEN gene is 1 077 bp,and the structural analysis showed that the gene belongs to be centrin gene of EFhand protein superfamily.Phylogenetic analysis indicated that the CtCEN of the algae,ferns,animal and human,all of which produce sperms with flagella,is clustered in one branch.The CtCEN of angiosperm is clustered in another branch.It is suggested that the centrin may participate the genesis of flagellum.The prokaryotic expression and Western blot analysis showed that the expressed protein of CtCEN can hybridize with the centrin protein antibody of Human,which indicated that the CtCEN belongs to the centrin family.The present studies lay a foundation for the molecular mechanism of the centrin participating formation of motile apparatuses in fern spermatogenesis.

Abstract:To understand the sibship of Notholirion and the genetic differentiation of N.bulbuliferum,the genetic diversity of 255 individuals from 24 populations was analyzed by using seven intersimple sequence repeat (ISSR) markers.(1)The results of the UPGMA analysis exhibited significant genetic differentiation between N.bulbuliferum,N.campanulatum,and N.macrophyllum,which indicated that they are separate species.(2)N.bulbuliferum×N.campanulatum clustered together with N.campanulatum,which may be a result from the matrilineal inheritance and strong asexual reproduction capacity;its low gene flow (N_m=0.216 0) implied that N.bulbuliferum×N.campanulatum may be undergoing differentiation.(3)The Mantel test showed a substantial significant correlation between genetic and geographic distances in N.bulbuliferum (r=0.410,P=0.01),and clustered four groups.(4)The analysis of molecular variance (AMOVA) revealed that the variation of N.bulbuliferum among the populations was 77.12% (P<0.01),and the variation within the population was 22.88% (P<0.01).These findings clearly evidenced the genetic relationship of Notholirion in the Hengduan Mountains.Importantly,the high diversity of N.bulbuliferum found in this study indicated that reasonable measures should be taken for the conservation and restoration for medicinal and ornamental plant species.

Abstract:In this study,the total genomic DNA were extracted with CTAB method,and then the genetic structure of the Arceuthobium sichuanense from 9 different populations was analyzed according to the sequence of internal transcribed spacer 1 (ITS1).1)Sixteen haplotypes (H1-H16) were observed from 62 ITS1 sequences,showing a low level of genetic diversity (h=0.678 5,π=0.005 9) in the populations of A.sichuanense.However,there were larger differences of the level of genetic diversity (h=0-1.000 0,π=0-0.009 4) among different populations.The AMOVA analysis showed that the genetic variation within populations of A.sichuanense,accounted for 51.37%,while the genetic variation among populations was 48.63%.2)Haplotypes of network showed that H1 and H12 were relatively original in this study.Also,two haplotypes were not shared among all of populations.H1 exists widely in six populations from Qinghai and Gansu,and H12 only exists in two populations from Sichuan.3)Population clustering based on maximum likelihood and medianjoining network based on maximum parsimony method indicated that the three populations from Sichuan are independent populations,while there is no significant differentiation between Gansu and Qinghai population.It is the first report about the genetic diversity and structure of A.sichuanense.The results will provide reference for the evolution and disease control of A.sichuanense.

Abstract:In order to screening podophyllotoxin biosynthesis related differentially express genes among podophyllin plant species,we constructed a suppression subtractive hybridization(SSH) library from root and rhizome of Dysosma tsayuensis Ying and Sinopodophyllum hexandrum (Royle) Ying.201 positive clones randomly picked from the SSH library were sequenced,and then 183 qualified sequence ESTs which represent 17 unique ESTs through preprocessing,assembling,clustering,annotation and functional classification from Dysosma tsayuensis were obtained.Among them,12 unique ESTs which annotated with database were further classified into functional groups including photosynthesis ,biosynthetic metabolism,transcriptional regulation,etc,accouted for 70.6%.5 unique ESTs were nonannotated or did not match any entry in the databases,accouted for 29.4%.These results showed that we successfully constructed a SSH library of Dysosma tsayuensis Ying and Sinopodophyllum hexandrum (Royle) Ying,which provided a foundation for revealing the podophyllotoxin biosynthetic pathway and its regulation mechanism.

Abstract:Karyological study of 8 wild populations of Lilium sargentiae Wilson from Yunnan Province was carried out by traditional squashing and pressing method.The results were the following:(1)the base number of chromosome in L.sargentiae was 12 (x=12).All of the 8 wild populations were diploid (2n=2x=24) and without B chromosome;(2)karyotypes of 8 wild populations of L.sargentiae were ‘3A’,Their first and second pairs of chromosomes were either large median chromosomes (m) or large submedian chromosomes (sm).All the first pairs of chromosomes of the 8 populations had satellite chromosomes;(3)chromosome length ratio were from 1.64 to 2.26,the mean arm ratio ranged from 6.43 to 8.22,and the karyotype asymmetry coefficient (As.K.%) of the 8 populations were from 79.82% to 81.77%.The above results indicated that the chromosome number of L.sargentiae was stable,and the chromosome variation among populations was generally coming from structure variation.The 8 populations had obvious differences 〖JP2〗in the composition of chromosomes,the number and distribution of satellite,chromosomes arm ratio,chromosome length ratio and As.K.%.There were obvious karyological variations among populations of L.sargentiae.

Abstract:In this paper,authors investigated the forming process of VAM in the root of honeysuckle.Results showed that:(1)when honeysuckle’s root was infected by VAM fungi,appressorium appeared firstly in the root epidermis,and then hyphae invaded cortical cells.There were down with linear and looped hyphae to form finaly in the cortical cells.Vesicle appeared at the end of the hyphae;In the thick hyphae,very tiny and dense mycelium appeared.It looked like a crown that was the arbuscular.some coarser hyphae could pass through two neighboring cortical cells and formed arbuscular continuously.When VAM hyphae formed arbuscular,VAM hyphae inflated and formed a emulsion bumps and then grow out of a short and thick stalk hyphae,then wiched broom.(2)There were three VAM hyphae morphological types in honeysuckle cortex cells:the stretching,hyphal coils and arbscule;honeysuckle with VAM mycorrhiza should belong to mixed mycorrhizal.(3)There were at least three types of VAM fungi spores in the honeysuckler’s rhizosphere,so honeysuckle formed a symbiotic relationship with at least three kinds of VAM fungi.(4)Available phosphorus content of the soil planting honeysuckle was 6.6 mg/kg that was significantly higher than that of the no plant soil’s (3.5 mg/kg);Impregnation rate of the VAM was 81% in the vigorous growth season (late April to midMay).

Abstract:The transmitting tissue of style is essential for the pollen tube growth.It involves pollen tube movement and has multiple roles in guidance,nutrition,adhesion.In order to study the pollination effect on the structure of style’s transmitting tissue,we observed the transmitting tissues which were pollinated or nonpollinated during the flowering of Nicotiana tabacum.The results showed that the cell death of transmitting tissue was similar to senescence in the nonpollinated style.However,the transmitting tissue had dramatic changes after pollination:the cells died rapidly.The dynamic changes of nucleus in the both pollination and nonpollination transmitting tissue were in accordance with the above.Overall,there are two different types of the death in transmitting tissue between pollination and nonpollination.

Abstract:To elucidate the relationship between reflorescence and nutrition conditions,were investigated the organic nutrition changes in shoots and flower buds from the Pyrus pyrifolia cv.Hosui during reflorescence.The results showed that:(1)along with the bud break at 6 d defoliated by hand，the budding rate was keeping low rising,and flowers opened fully at 42 d.(2)The soluble sugar was increased firstly when the tree defoliated by hand.However,the soluble sugar content was decreased at the 12 d of rapid increasing stage for budding rate.The budding rate increasing stage was consistent with starch contents reducing periods in shoots.In addition,protein content in shoots was decreased to promote rapid increasing for the free amino acid content in the flower buds.(3)The related positive or negative correlation for budding rate and starch content,soluble protein content in flower bud and shoot reached at the 1% significant level,respectively.The positive correlation for budding rate and soluble sugar content in flower bud were 0.794,reached at the 5% significant level.It was indicated the nutrition conditions played important roles in the reflorescence occurrence for Pyrus pyrifolia cv.Hosui.

Abstract:Fall shoot of Citrus(Citrus reticulata Blanco.‘Nichinan No.1’) cultured in hoagland hydroponic solution were used as experimental materials to study effects of different concentration of H₂O₂ treatments on growing state and physiological indexes of relative electric conductivity(REC),contents of malondialdehyde (MDA) and proline as well as activities of catalase(CAT),superoxide dismutase(SOD) and peroxidase(POD) in C.reticulata leaves under 4 ℃ low temperature stress.Meantime optimum H₂O₂ concentration was selected to alleviate chilling injury of C.reticulata and the mechanism of tolerance to cold in C.reticulata with exogenous H₂O₂ treated was also explored.Results showed that the degree of curl and cell membrane damage of leaf gradually increased with the extension of low temperature stress time in all treated groups of C.reticulata.Both 0.2 mmol·L^-1and 1.0 mmol·L^-1concentrations of H₂O₂applied to hydroponic solution could ease C.reticulata leaves curling and wilting caused by low temperature stress,lower the increase of REC and MDA,reduce the accumulation of H₂O₂,and increase the content of osmotic proline and activities of SOD,CAT and POD in C.reticulata leaves.The 1.0 mmol·L^-1 of H₂O₂alleviated chilling stress on C.reticulata damage more significant than that of the concentration of 0.2 mmol·L^-1.The studies confirmed that the symptoms of leaf curl,wither,fall off and cell membrane damage were caused by treatment of 4 ℃ low temperature in autumn shoots leaves of C.reticulata.And the treatment of 1.0 mmol·L^-1H₂O₂could increase the content of proline and activities of SOD,CAT and POD under low temperature stress,and effectively relieve the damage of cell membrane under low temperature in C.reticulata leaves,to enhance its cold resistance.

Abstract:Simulating the salinealkali soil environment of Daqing in northeast of China which include low,middle and high concentration,we studied the effects of different concentrations and processing time(0~25 d) on each physiological index of Miscanthus sacchariflorus seedlings which basically defined the complex saltalkali tolerance range of M.sacchariflorus seedings and provided a theoretical basis for the screen of salinealkali tolerant plants and applications in landscape of energy plants like M.sacchariflorus in the future.The results showed that:(1)with the increase of mixed salinealkali stress intensity over time,the chlorophyll content of M.sacchariflorus seedlings was constantly drop.The root activity was rising with the treatments of low concentration and middle concentration over time.While it showed decreased first and then increased and decreased in the end with the treatments of high concentration.At the same time,the relative electrical conductivity and MDA content of M.sacchariflorus seedlings were also rising over time; (2)the SOD,POD,CAT,APX,GR activities,ASA and GSH contents were rising slowly in low concentration,but in the treatment of high concentration these indexes increased at first and then decreased with time passing by.The study found that M.sacchariflorus seedlings could remove excess reactive oxygen and free radicals and protect the cell structure by regulating the activities of the protective enzymes and the accumulation of antioxidants.M.sacchariflorus seedlings could effectively resist salinealkali stress of middle and low concentrations,while they have no resistance to high concentration.

Abstract:Hydroponic experiments were conducted to investigate the effects of exogenous GSH on plant growth and root activity,as well as electrolytic leakage rate,the contents of lipid peroxidation (MDA),proline (Pro) and soluble sugar and the activities of superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) in leaves of tomato seedlings under NaCl stress.The result shows that:1)NaCl stress significantly inhibited the growth and root activity of tomato seedlings and decreased the activities of SOD,POD and CAT,and increased electrolyte leakage rate and the contents of MDA,proline (Pro) and soluble sugar in leaves of tomato seedlings.2)The application of exogenous GSH induced the upregulation of POD,SOD and CAT activities,decreased the electrolyte leakage rate and MDA contents,and returned the contents of proline and soluble sugar to control level in leaves of NaClstressed tomato seedlings.3)The application of exogenous BSO decreased root activity and POD,SOD and CAT activities,and increased proline contents in leaves of tomato seedlings under NaCl stress.4)Spraying GSH increased the root activity and SOD,POD and CAT activities,decreased the contents of MDA and Pro in combined stressed (NaCl and BSO) plants.These results suggested that GSH alleviated saltinduced growth inhabitation and enhanced salttolerance by promoting the osmotic adjustment capacity and the defense ability of antioxidant enzyme system to decrease membrane lipid peroxidation and protect the integrity of membrane structure in tomato seedlings under NaCl stress.

Abstract:Anoectochilus formosanus and Anoectochilus zhejiangensis are Anoectochilus plants,they are main original plants of Anoectochilus roxburghii that is common folk rare herbs and they are rich in polysaccharide.The study extracted polysaccharide of Anoectochilus formosanus and A.zhejiangensis using ultrasonic extraction Ⅰ,Ⅱ,solvent extraction methods to compare polysaccharide content;we use colorimetry method to compare hydroxyl free radical clearance ability of the two A.roxburghii.We use Caenorhabditis elegans as a model organism to study the effects of two A.formosanus polysaccharide on lifetime of Caenorhabditis elegans under oxidative stress,then we can evaluate antioxidant activity of A.formosanus and A.zhejiangensis.The results show that:(1)the solvent extraction method is the most effective method to extract polysaccharide of A.roxburghii,polysaccharide content of Anoectochilus zhejiangensisis significantly higher than that of A.formosanus.(2)With the increase of polysaccharide concentration,hydroxyl free radical clearance rate has a tendency to rise,the hydroxyl free radical clearance rate of Anoectochilus zhejiangensis polysaccharide is significantly higher than that of A.formosanus polysaccharide.(3)Both kinds of Anoectochilus polysaccharide can prolong the lifetime of C.elegans,but the impact of two kinds of polysaccharide to the lifetime of C.elegans is not obviously different.The results show that both kinds of Anoectochilus are rich in polysaccharide and have antioxidant activity,but the polysaccharide content and antioxidant activity of the two kinds Anoectochilus are different.The results lay a good foundation for the further study of choosing and cultivating the best origin A.roxburghii.

Abstract:Different concentrations of CdCl₂ were used to study the influence of cadmium stress on antioxidant system of Jatropha curcas seedlings.Results indicated that:1)the contents of soluble protein decreased,MDA increased.2)The activities of guaiacol peroxidase (POD),catalase (CAT),superoxide dismutase (SOD) and ascorbate specific peroxidase (APX),glutathione reductase (GR) firstly increased and then decreased.3)The antioxidants contents of ascorbic acid (ASA) and glutathione (GSH) decreased;contents of oxidized ascorbic acid (DHA) and oxidized glutathione (GSSG) increased in leaves of J.curcas seedlings under Cd²⁺ stress.The results showed that Cd²⁺ stress induced the abilities of antioxidative system increase,while the abilities were decreased and the seedlings were harmed after the prolonged treatments.

Abstract:To investigate the association between droughtinduced carbon/nitrogen imbalance and leaf senescence,we treated eight maize varieties in leaf senescence progress under drought stress with PEG to mimic the drought stress.Leaf senescence symptoms,such as photosynthesis,photosystem II photochemistry efficiency (F_v/F_m) and chlorophyll content,and the nonstructural carbohydrates (soluble sugars,starch) content and nitrogen content were determined.Then,the correlation between droughtinduced leaf senescence and carbon/nitrogen imbalance (C/N ratio) was analyzed.Our results showed that:(1)the net photosynthetic of eight maize varieties were severely suppressed,F_v/F_m has fallen dramatically and chlorophyll content decreased significantly,which indicated that drought induced maize leaf senescence.(2)Drought stress induced the maize leaf senescence accompanied with the accumulation of soluble sugar content,slightly increased starch content,decreased of total nitrogen content and increased significantly of C/N ratio,carbon and nitrogen balance were damaged.(3)Both the nonstructural carbohydrates content and carbon/nitrogen ratio showed a significant negative correlation with chlorophyll content,and there was a significant positive correlation between total nitrogen content and chlorophyll content.Therefore,carbon and nitrogen metabolisms were tightly associated with droughtinduced leaf senescence,and the carbon/nitrogen balance may involve in the regulation of droughtinduced leaf senescence.

Abstract:To investigate the effect of nitrogen forms on the growth and physiological characteristics of the Lactuca sativa L.seedlings,we treated overground parts and roots of L.sativa L.seedlings with different mixing ratios of ammonium nitrogen and nitrate nitrogen using hydroponic technique.Our results showed that:(1) with the increasing of the ratio of ammonium nitrogen in nutrient solution,the nitrate content of overground parts and roots of L.sativa L.showed a reducing trend and was up to the standard of green vegetables.(2) With the increasing of the ratio of ammonium nitrogen in nutrient solution,the overground parts showed reduced content of organic acid in the early stage but a great increase in later stage.Soluble carbohydrate content in overground parts increased when NH₄⁺increased.Soluble protein content,however,declined first and increased later.When NO₃^-∶NH₄⁺ was 5∶5,the content of organic acid in overground parts was minimum while soluble protein reached the maximum.On the contrary,organic acid content in roots exhibited the opposite trend,with an elevation in early stage and reduction in later stage.The maximum was detected when NO₃^-∶NH₄⁺ was 5∶5.Soluble carbohydrate had the highest level when NO₃^-∶NH₄⁺was 7.5∶2.5 in roots.Soluble protein content in roots had maximum level with total NO₃^--N in nutrient solution and declined when NH₄⁺increased.(3) The SOD activity of overground parts and roots of L.sativa L.increased first and declined later when NH₄⁺increased.The SOD activity in overground parts was the highest when NO₃^-∶NH₄⁺ was 5∶5 ，but it reached the maximum when NO₃^-∶NH₄⁺was 7.5∶2.5 in roots.On the contrary,the contents of MDA and proline as well as the activities of POD and CAT exhibited the opposite trend both in overground parts and in roots.(4) With the increasing of the ratio of ammonium nitrogen in nutrient solution,rootshoot ratio declined while the dry weight of both overground parts and roots increased first and declined later.When NO₃^-∶NH₄⁺ was 7.5∶2.5,the dry weight of both overground parts and roots were the highest,and rootshoot ratio was optimal.In summary,different forms of nitrogen had remarkable effect on the growth and physiological characteristics of both overground parts and roots of L.sativa L.seedlings，and roots physiological response was more sensitive.When NO₃^-∶NH₄⁺ was 7.5∶2.5 in nutrient solution,the coordinated growth of the overground parts and roots was optimal,and the degree of stress was minimum.

Abstract:In order to elucidate effect of SNP on the parameters response to drought and relate to drought resistance of cultivars and to supply the new method and theory for drought resistant cultivation in processed potato,we firstly treated droughtresistant potato cv.‘Desiree’ and droughtsensitive potato cv.‘Atlantic’ with 0 (control) and 0.01 mmol·L^-1SNP at bud,and then analyzed plant morphology,the contents of superoxide anion and H₂O₂,as well as activities of antioxidant enzymes under normal water,light waterstress,medium waterstress and heavy waterstress,respectively.The results showed that:(1) SNP treatment could maintain the normal growth of potato under heavy waterstress.(2)The contents of superoxide anion and H₂O₂,as well as activities of CAT and APX increased under water stress,but increases of superoxide anion content and H₂O₂ content were not related to the levels of stress.(3)The activity of POD rose in Desiree but lowered in Atlantic under drought stress.Compared with Atlantic drought resistant cultivar of Desiree possessed low content of superoxide anion and high activities of POD,CAT and APX under drought stress.Along with the levels of stress 0.01 mmol·L^-1 SNP treatment did not change the tendency of superoxide anion content and H₂O₂ content but changed the tendency of SOD,POD and CAT activities in Atlantic and of APX activity in Desiree.(4) The content of superoxide anion decreased in Desiree under normal water and heavy drought stress and in Atlantic under light drought stress and heavy drought stress by 0.01 mmol·L^-1 SNP.Additionally,SNP increased activities of POD and APX in both Desiree and Atlantic under drought stress.In conclusion,the parameters responsed to drought and drought resistance cultivars in potato were POD,CAT and APX activities.SNP could enhance the drought resistance of potato under drought stress.

Abstract:In order to ensure different tolerances of two Salvia plants to NaCl stress and its physiological mechanism,we used S.meiliensis and S.cavaleriei with high medicinal and ornamental value as experimental materials to analyze the variation of their growth,chlorophyll content,protective enzymes activities and their content of organic osmotic regulation substances under 0,200,300,400,500 and 600 mmol·L^-1NaCl.The results showed that:1)under each concentration of NaCl stress,S.meiliensis suffered from the salt damage more severely than S.cavaleriei.As NaCl concentrations increased.2)The chlorophyll content in the leaves of S.cavaleriei had no significant change,but those in the leaves of S.meiliensis decreased gradually.3) When NaCl concentration increased from 0 to 500 mmol·L^-1,S.cavaleriei and S.meiliensis plants responded adaptively to NaCl stress.The POD and CAT activities,as well as soluble sugar,soluble protein and proline contents gradually inceased in the leaves of S.cavaleriei and S.meiliensis.The SOD activity also increased in the leaves of S.meiliensis.4) When NaCl concentration reached to 600 mmol·L^-1,the soluble sugar,soluble protein and proline contents in the leaves of S.meiliensis continued to increase,while the SOD,POD and CAT activities started to drop,but were still significantly higher than those of the control.In contrast,at the same NaCl concentration,the POD and CAT activities in the leaves of S.cavaleriei continued to increase.The soluble sugar,soluble protein and proline contents started to drop,but were still significantly higher than those of the control.S.cavaleriei possesses higher contents of osmotic regulation substances under NaCl stress and can maintain higher protective enzymes activities with increase of NaCl concentration,it has stronger tolerance to NaCl than S.meiliensis.

Abstract:The effects of different diluted olive mill wastewater(OMWS) on the germinability and related enzyme activities of wheat and maize seeds were investigated.The germination rate,root length,and related biochemical parameters were tested using the methods of counting,weigh,and colorimetry,respectively.The results showed that the influence on the germination rate,germination vigor,and growth was based on the concentrations of OMWS.The OMWS with low dilution ratio(Original and D5) treatments were not only inhibited the seeds germination,but also delayed the growth of leafbud and root,even had more phytotoxicity.The inhibition reduced with the decreasing of OMWS concentration.However,higher dilution ratio groups(D30 and D50) promoted the seed growth behavior.The effects of OMWS on the changes in soluble protein content,catalase(CAT),peroxidase(POD),and phenylanlanine ammonia lyase(PAL) activities also displayed the tendency of inhibition under high,and induction under low concentration.There was significant positive correlation between root length and POD and PAL activities.It was concluded from the results that the influence of OMWS on the germination and growth of wheat and maize seeds had dual effects with inhibition and induction according to the dilution of OMWS.The most important effect was possibly attributed to the contents of phenolic compounds in OMWS.In view of the phytotoxicity caused by phenolics and oxidation products,we suggest to do a dilution pretreatment when OMWS used as organic fertilizer or soil conditioner.

Abstract:The plasticity of plant morphological and physiological traits is the foundation to probe species adaptation.Hence,the plasticity of growth,photosynthetic and hydraulic traits of Caragana korshinskii growing under different slope positions with different soil texture,including A:gully channel+loessial soil,B:slope+loessial soil,C:slope top+loessial soil and D:slope top+layered soil,were studied in order to explore the mechanism of the extensive distribution of this species under fragmented landscapes on the Loess Plateau.The results indicated that:(1)the soil moisture within 1-3 m and 3 m layer under habitat D and A were higher than those under habitat B and C.(2)C.korshinskii growing under habitat A and D had relatively larger canopy size,plant height and currentyear twig length and thinner leaf thickness than those plants under habitat B and C.The midday leaf water potential,net photosynthetic rate,stomatal conductance and transpirational rate were also increased,but no difference existed for specific hydraulic conductivity,Huber value and midday native embolism.(3)Among those measured plant traits,currentyear twig length,net photosynthetic rate,stomatal conductance and transpirational rate showed relative larger plasticity,indicting C.korshinskii mainly depend on variation of currentyear twig length and photosynthetic traits to adapt to different water habitats.

Abstract:In this paper,Sophora alopecuroides,Achnatherum splendens,Artermisia ordosica and Kalidium foliatum are 4 kinds of common plant communities growing in Yanchi County of Ningxia Province.They were taken as examples to study the soil microenvironment of different plant communities in desert steppe.After the study of community composition,the basic physical and chemical properties of the soil,we measured urease,catalase,phosphatase,sucrase.The results showed that:(1)the species composition of the different plant communities were various,and the frequency of occurrences of Gramineae,Compositae,Chenopodiaceae were relatively high in survey region.(2) There were differences on soil physical and chemical properties in the 4 kinds of plant communities.For example,the soil bulk density was less in S.alopecuroides community and the total nitrogen was relatively higher,the pH and organic carbon content of soil were significantly higher than others in A.splendens community.The soil moisture content and total phosphorus were lower in A.ordosica community and the salt content was higher markedly in K.foliatum community.(3) There were differences of soil enzyme activity among 4 kinds of plant communities.The urease activity of A.splendens and A.ordosica communities topsoil soil（0-10 cm）was higher;soil catalase of A.ordosica and K.foliatum communities increased as soil deepening;soil phosphatase activity of S.alopecuroides and A.splendens communities were higher and soil phosphatase activity of K.foliatum community was no significant difference in various soil layer（P>0.01）;soil sucrase activity of 4 kinds of communities was generally low,and the little difference between the soil layer.(4) The correlation of the same soil enzyme activity was different among various plant communities.In conclusion,the different plant community characteristics and soil traits,especially the correlations of soil enzyme activities among different plant communities,can predict the succession of plant communities in desert steppe,and can be used as ways of vegetation restoration of desert steppe on the other hand.That is,moderate artificial disturb can raise soil enzyme activity,then increase biomass,which make desert steppe onto positive succession.

Abstract:We implemented typical sampling method,in order to illustrate the crown architectural variation of Quercus liaotungensis saplings in different habitats and understand the response and adaptation mechanisms of plant to different environment conditions.The characteristics of lateral branch and leaf,as well as their spatial distribution for Q.liaotungensis saplings,which grew in three different habitats (under story,forest gap and forest edge) in Huanglong mountain of Loess Plateau,were investigated.The results showed that:(1)the crown morphological features of Q.liaotungensis saplings changed in response to three kinds of habitats,the crown of understory is simple and the crown of the other habitats are rich.(2)The tree height and the height under branch declined and the diameter increased from understory,forest gap to forest edge.The crown width,crown area,crown ratio of the saplings increased first and then decreased,and the variance under 3 habitats is significant.Overall bifurcation ratio,gradually branching ratio,branch diameter ratio of saplings firstly increased then decreased from understory,gaps to forest edge.(3)Under three kinds of habitats,the length,diameter and angle declined with the tree height increased,and the variance is not significant.The firstolder branches were mainly in the top area of the canopy and in the other two habitats were mainly in the middle of the canopy.(4)Leaf length,leaf width,leaf area and leaf area ratio decreased,while the average leaf number,total leaf area and LAI firstly increased and then decreased,from understory,gaps to forest edge.Compared with the other two habitats,the leaves of understory were mainly in the top of the canopy.(5)Aboveground biomass of saplings,the trunk biomass of understory accounted for 83%,branch and leaf biomass account for only 17%.Under the gaps and forest edge habitats,the biomass of various parts was different,but the proportion was basically the same.The biomass of trunk accounted for 66%,and biomass of branch and leaf accounted for about 34%.Under three habitats,the sapling architecture of forest gap was better than that of the other two habitats.In the future,appropriate thinning techniques should be used to increase the number of the forest gap and provide favorable conditions for regeneration and structure optimization of Q.liaotungensis forests.

Abstract:Wild litchi,the wild population of litchi,is an important gene bank for the betterment and innovation of litchi variety.The spatial distribution pattern,population diameter structure,static life table,and survival curve of litchi populations are studied base on the field survey of both inside and outside the natural conservation area.We revealed the population distribution and the trend of population dynamics of wild litchi,in order to provid the basis for the protection of wild litchi resources.The results show that:(1) wild litchi populations both inside and outside the natural reserve are aggregated distribution,and the aggregation degree of the nonnatural conservation area is more obvious than that of the natural conservation area.(2) According to the age structure analysis,the population structure of wild litchi is growthoriented,and its life expectancy is decremented with the age class increasing,and its survival curve is nearly linear type,which indicates that the population structure of wild litchi in the natural reserve is relatively stable;while those outside the natural reserve is of declining type.(3) The maximum of population dynamic index and random disturbance risky value of wild litchi population in the natural reserve is close to zero,but the value of the nonnatural conservation area is higher that than that of the natural conservation area.It indicates that the sensitivity of the protection zone outside is stronger than inside.That is to say,the living environment of wild litchi outside the protection zone has been seriously disturbed and the threatened by human beings.The study suggests that,in the nonnatural conservation area,the serious lack of saplings of wild litchi population is not only related to its own update mechanism,but more important is the destruction of the environment and human deforestation leading to structure change of wild litchi population and the decrease of wild litchi forest.

Abstract:There were about 816 species linolenic acid plant resources which belong to 446 genera and 116 families in China,and their oil and linolenic acid contents of seeds were higher than 10%.In this paper,distribution patterns of linolenic acid plant resources in China and its relationship with climatic and geographical factors were investigated based on flora listsin largescale,coupled with principal component analysis.The results show that:1)Labiatae,Euphorbiaceae,Fabaceae,Rosaceae,Brassicaceae and Cucurbitaceae families have abundant linolenic acid plant resource species.2)The region species richness of linolenic acid resource plants showed trend of descend around a center (the Southwestern China).3)The altitude species richness showed unimodal pattern that increased first and then decreased with the increase of altitude,with the maximum value appeared at the height of about 900 m.4)The climate factors significantly affected the distribution of linolenic acid plant resources.The relative humidity,annual average temperature and annual precipitation,were positively associated with species richness.In addition,there were negative correlations between species richness and Latitude,annual radiation quantity,mean altitude.5)China was divided into 10 distribution areas of linolenic acid resource plants by cluster analysis.Above results partly revealed the distribution characteristics of linolenic acid resource plants in China.

Abstract:Based on the investigation,collection and study of Bryophytes from Etuoke Banner and Hanggin Banner of Inner Mongolia,we firstly found two new geographic distribution records of Riccia albolimbata and Riccia setigera.R.albolimbata was discovered in Asia for the first time.It is superficially well distinguished by the colourless ventral scales,lead to thallus margins whitish.R.setigera was first found in Ordos in Inner Mongolia.The peculiar character of this species is that there are cilia on dorsal side.Morphological characteristics and geographical distribution of R.albolimbata and R.setigera are detail described.Meanwhile,compared with their related species,the illustrations are provided.The present study increased the basic data of China or even Asia moss flora.

Abstract:Ribes pulchellum Turcz.,belonging to the genus Ribes,is reported as a newly recorded plant to Shandong.Its morphological characters,leaf epidermal micromorphology and flower structure were observed and studied in detail and its floristic geography significance were discussed as well in this present paper.Results show that the distribution of R.pulchellum in Fenghuang Mountain,Zoucheng,Shandong should be the most southern east boundary toward its natural area.

Abstract:Some pteridophytes are firstly reported from Hainan Province，which include a genus (Mesopteris Ching),a variety (Pteris grevilleana var.ornata Alderw.) and seven species［Arachniodes hekiana Sa.Kurata; Coniogramme wilsonii Hieron.; Cornopteris opaca (D.Don) Tagawa; Diplazium megaphyllum (Baker) Christ;Mesopteris tonkinensis (C.Chr.) Ching; Pronephrium parishii (Bedd.) Holttum; Cyclosorus calvescens Ching］.All the specimens examined are preserved in Herbarium of Shanghai Chenshan Plant Science Research Center,Chinese Academy of Sciences (CSH).

Abstract:Because of sedentary life style,plants can not avoid bad environmental stimulus,hence need to defense and avoid environmental stress through their own defense mechanism.Epigenetic plays an important role in regulating plans response to environmental stress.This paper summarizes the current research status of epigenetic variations of plants induced by abiotic stress,including DNA methylation,histone modification,chromatin remodeling and noncoding RNA.We are expecting to exploit epigenetic changes improve the stress resistance of plants.