Abstract:The purpose of this paper is to study the expression and function of VqSTS21,VqSTS30 and VqSTS32 genes,which cloned from powdery mildew-resistant Chinese wild Vitis quinquangularis accession ‘Danfeng-2’.Sequence analysis indicated that their cDNA has equal length of 1 179 bp and encodes 392 amino acid residues (GenBank accession No.JQ868677,JQ868668 and JQ868666).qRT-PCR showed the expression patterns of VqSTS21,VqSTS30 and VqSTS32 in ‘Danfeng-2’ and powdery mildew-susceptible Cabernet Sauvignon (Vitis vinifera L.) under biotic stress (Uncinula necator) and abiotic stress (ABA,SA,MeJA,heat,low temperature and NaCl).HPLC was employed to analysis resveratrol contents of these three genes overexpressed in transgenic tobacco plants.The results showed that the expression of VqSTS32 was higher than that of other two genes in two grape germplasms tested after treated with biotic stress and heat.Compared with the VqSTS21 and VqSTS30-overexpressed lines,trans-resveratrol was the highest accumulation in the VqSTS32-overexpressed lines of transgenic tobacco plants.Our results suggested that VqSTS32 gene was involved in the resveratrol synthesis pathway in grapes,and played an important role in response to U.necator.

Abstract:The study used Cymbidium goeringii wild type and peloric mutant (two lateral petals mutated into lips) as experiment materials.In this research,a novel AGL6-3 gene was isolated from C.goeringii by RT-PCR and RACE-PCR techniques.Sequence analysis showed AGL6-3 gene sequences are same in the wild type and peloric mutant of C.goeringii.The gene contained an open reading frame of 720 bp encoding a putative protein of 239 amino acids.Phylogenetic tree analysis indicated that CgAGL6-3 belongs to AGL6 clade of AP1/AGL9 subfamily,named CgAGL6-3 (GenBank accession No.KU058679).Real-time quantitative PCR demonstrated that,in wild type CgAGL6-3 was highly expressed in lips,lower in dorsal sepal,lateral sepal,column,and very little in lateral petal.Whereas expression of CgAGL6-3 in peloric mutant was the highest in lip,lateral petal comes second,lower and close in dorsal sepal,lateral sepal and column.These results indicated that CgAGL6-3 play a important role in the process that lateral petals specialized into lips.

Abstract:The study takes normal plant and tepal natural variant which have big differences in appearance as materials from wild Anemone rivularis var.flore-minore.The class B genes were isolated from genomes of normal plant and natural variant by using conventional and Hi-Tail PCR techniques.They were proved to be AP3-3 branch of paralogs which belong to AP3 gene family from B class MADS-box genes by sequence analysis and named NArAP3-3 (in normal plant) and VArAP3-3 (in natural variant),respectively.The full length of NArAP3-3 gene was 3 795 bp whereas 3 898 bp in VArAP3-3,they both have a 666 bp open reading frame (ORF) and can encode 221 amino acids.The protein showed a typical MADS-box gene structure containing MADS domain,K domain,Ⅰ region and C terminus.The comparison result of full length sequences between NArAP3-3 and VArAP3-3 genes was found to have a 49 bp insertion in VArAP3-3 gene,and there are also 4 base mutations in ORF sequence compared with the NArAP3-3 gene.By bioinformatics analysis of the two’s full length sequences,221 amino acids and insertion sequence,we can find that there are differences in all aspects of gene promoter,basic properties of protein,structure function domain,advanced prediction structure and so on.These differences may be one of the causes of tepals variation,and this study lays the foundation for the further exploration of its variation mechanism.

Abstract:Using RT-PCR combined with RACE techniques,we cloned the chitinases gene PhCHT (GenBank accession number:KT992851) from Phalaenopsis.The full length cDNA was 1 210 bp,containing a 5′-UTR of 37 bp,a 3′-UTR of 240 bp,and an opening reading frame of 933 bp encoding 310 amino acids;The deduced protein belonged to glycoside hydrolase family 19 and may have lysozyme activity.The bioinformatics analysis indicated that this protein was predicted to be an extracellular secreted protein with a N-terminal signal peptide and a transmembrane structure;It was highly identified with the chitinase-like protein of Phoenix dactylifera,Elaeis guineensis,Setaria italica,and Arabidopsis thaliana.Phylogenetic analysis showed that PhCHT belongs to a clade with other class Ⅶ chtinase genes from Gossypium hirsutum and Saccharum spp.The PhCHT gene was expressed in vegetative and reproductive organs with a higher expression level in root than others.The expression of PhCHT was decreased by a low temperature of 13 ℃/8 ℃ for 3,6,9 and 15 d,and increased by 4 ℃ treatment for 1,2 and 4 h.Our results suggest that the PhCHT plays a crucial role in responding to the short-term cold stress.These results could provide the foundation for further study the phyletic evolution of chitinase genes and the stress resistance breeding of Phalaenopsis.

Abstract:In this study,we used island cotton (Gossypium barbadense L.) variety as experimental materials,which are ‘C6015’ and ‘Xinhai 29’,(high fiber strength experimental group);‘Ba 1248’ and ‘Bima 1’,(low fiber strength experimental group).Activity changes and expression profiles of sucrose synthase (EC 2.4.1.13,Sus) during different development periods were measured by fructose and UDPG colorimetric with qRT-PCR methods in two experimental groups,which differences of fiber strength are obvious.Analysis the relationship between activity changes,expression profiles of Sus and fiber strength.In addition,we discussed the main physiological and molecular mechanisms,which lead to form differences of fiber strength in island cotton.The results showed that:(1)the average strength of ‘C6015’ and ‘Xinhai 29’:47.5 cN·tex^-1 and 44.7 cN·tex^-1,respectively;the average strength of ‘Ba 1248’ and ‘Bima 1’:31.2 cN·tex^-1 and 32.6 cN·tex^-1,respectively.The difference was extremely significant about the average strength in two experimental groups.(2)Activity change features of Sus were all single peak curve appear in 4 island cotton varieties,as well as peak appear more early in low fiber strength experimental group.However,peak and later activity of Sus in high fiber strength experimental group were higher and reached to very significant as compared with the low fiber strength experimental group.(3)High expression of Sus genes were Sus1A,Sus1D,Sus3A,Sus3D,Sus6A,Sus6D and Sus8D,but each member of Sus genes had specific expression during fiber development in island cotton.Expression of Sus3A gene start increased to maximum then droped at initial stage of secondary wall thickening (20 days post anthesis) in two experimental groups.Showed that it emphasized on the role of this period;expression of Sus1A and Sus1D genes happened increased phenomenon at late and final period of secondary wall thickening (30-35 days post anthesis) in high fiber strength experimental group.However,expression of Sus1A and Sus1D genes were very low and did not existence this phenomenon at those periods in low fiber strength experimental group.The results showed that both of them work in these periods.(4)The obvious differences about Sus activity level,relative expression of Sus gene each member,as well as Sus activity maintain time during late stage of secondary wall thickening in two experimental groups showed as high fiber strength experimental group＞low fiber strength experimental group.Furthermore,the differences of Sus activity about high or low was synchronize with the differences of expression in Sus3A,Sus1A and Sus1D genes.Research showed that:Sus3A,Sus1A,Sus1D genes associated with formation and differences of fiber strength.They may key genes,which affect the fiber strength.

Abstract:To clarify the gene expression patterns of Eucommia ulmoides Oliver leaves in the process of development at the transcription level,this study compared and analyzed the gene expression level of ‘Huazhong 6’ leaves in different development periods from expanding (April) to falling (October) by digital gene expression profile technology.A total of 3 002 different expression genes were obtained,in which 1 764 up-regulated expression and 1 238 down-regulated expression.These mainly function referred to catalytic activity or oxidoreductase activity,and involved in metabolic process and biological process.Through further pathway enrichment analysis,we found that several related genes of phenylpropanoid biosynthesis pathway were enriched,in which six significantly different expression genes were related to chlorogenic acid synthesis.The gene expression patterns showed that these genes are highly expressed in mid-April and mid-Septemeber,which suggested that these two periods play an important role for chlorogenic acid synthesis.By real-time fluorescent quantitative PCR,6 chlorogenic acid synthesis genes and 12 randomly different expression genes were detected,and the results verified the reliability of digital gene expression profile.This study lays a solid foundation for revealing the molecular regulation mechanism of E.ulmoides Oliver leaves in different development periods,and provides the reference for further clarifying the synthesis mechanism of E.ulmoides Oliver chlorogenic acid and then improve E.ulmoides Oliver chlorogenic acid content by means of molecular breeding.

Abstract:By using sand culture,we made comparisons between the T₃ transgenic lines overexpressed a rice (Oryza sativa L.) phosphate transporter gene OsPT6 and their non-transgenic (NT) host cultivar to examine the differences in the traits of growth and development,the concentrations of available phosphorus,total phosphorus,total nitrogen,and leghemoglobin,the activities of glutamine synthetase and the contents of seed proteins in vegetable soybean under low phosphorus conditions.In addition,the relative expression levels of some genes related to the nodulation and nitrogen fixation in roots were also measured.The purpose of this research was to provide the theoretical basis for elucidating the mechanisms of nodulation and nitrogen fixation in the roots of the transgenic plants under phosphorus deficiency.The results showed that:(1)the plant height,stem diameter,numbers of flowers,pods and root nodules of the transgenic plants were significantly higher than those of the NT plants.(2)The concentrations of available phosphorus in roots,stems,leaves and nodules,the contents of phosphorus and nitrogen of the whole plant,the concentrations of leghemoglobin in the nodules and the activities of glutamine synthetase in functional leaves of the transgenic plants were significantly higher than those of the NT plants.(3)The mutually significant positive correlations were observed among the concentrations of leghemoglobin,total phosphorus,total nitrogen,and the activity of glutamine synthetase.(4)The relative expression levels of GmENOD40a,GmENOD40b,GmGS1β1,GmGS1β2 genes in transgenic plants were significantly higher than those in the NT plants.The above results indicated that the overexpression of OsPT6 gene enhances the ability of nodulation and nitrogen fixation in the transgenic vegetable soybean under low phosphorus conditions,which lays the foundations for the further studies on their regulation mechanisms.

Abstract:Elaeagnus mollis Diels is an endemic and endangered tree in China.Twenty primer pairs were selected by the combined biotin capture and identified in two populations of E.mollis.Nineteen pairs showed highly polymorphic,and were selectively neutral and the locus CGY19 was monomorphic.One locus manifested significant deviation from Hardy-Weinberg Equilibrium (P<0.01),which was probably caused by the influence of selection.No significant linkage disequilibrium was detected among pairs of loci in each pair.With a mean of 4.225,the number of alleles per locus ranged from 1 to 9.The observed and expected heterozygosity (H_O and H_E) per locus ranged from 0 to 0.900 and from 0 to 0.847,respectively.The genetic diversity levels of 2 natural populations of E.mollis were estimated by these 19 pairs of SSR markers obtained in this study.It showed that the mean genetic diversity was 97.37%,indicating that the loss of genetic diversity was not the cause of the endangerment of E.mollis.The significant fragmentation (F_ST=0.033 1) was tested between the two populations and it provided the evidence that the genetic variation mainly existed in the populations.Furthermore,due to the frequent gene flow between populations (N_m=32.081 8),it also verified the Shannon’s information index (I=genetic similarity) was very high in each population.On a long view,the new set of loci and the information of genetic diversity will be applied in the mating system and population structure of this species and provide valuable information for its sampling strategy,conservation and utilization.

Abstract:Genetic diversity and genetic relationship of 59 Pyrus pyrifolia germplasm resources distributed in Guizhou Province were analyzed using SRAP markers.The results showed that:(1)15 SRAP primer pairs generated 151 bands and 120 presented polymorphic loci.(2)A relatively high level of genetic diversity was revealed by Ne (mean observed number of alleles) 1.355 9,H(Nei’s genetic diversity) 0.216 9,I (Shannon’s information index)=0.336 2 at species level and by Ne=1.261 1,H=0.155 5,I=0.235 2 at population level.Pear resource in Qianxinan Prefecture showed the highest genetic diversity and that in Liupanshui City showed the lowest.(3)Cluster analysis with UPGMA method showed that 59 P.pyrifolia germplasms could be grouped into six groups at genetic coefficient of 0.75.The result also indicated that P.pyrifolia resources distributed in Guizhou Province had abundant genetic diversity with obvious geographical feature.The genetic diversity and genetic relationship of the P.pyrifolia germplasms could be revealed effectively by SRAP markers,which provided more genetic information in a smaller range of variation as compared to ISSR.

Abstract:We constructed an F₂ genetic segregation population crossed by parents between a flat-leaved inbred line ‘0835’ and a feathered-leaved inbred line ‘0819’in ornamental kale(Brassica oleracea var.acephala).Four feathered-leaved related traits,i.e.leaf length,leaf width,leaf index and number of serrated leaf margin,were investigated at rosette stage.The genetic segregation analysis was conducted by using four generations(P₁,P₂,F₁ and F₂) mixed major gene plus polygene inheritance model.The results showed that:(1)there are prominent helerosis in the trait of number of serrated leaf margin.Meanwhile,these four characters showed negative transgressive heterosis.(2)Genetic analysis of quantitative traits indicated that leaf length and leaf width were both compatible with E-4 model characterized by two equal additive major gene plus additive-dominant polygene.The heritabilities of major gene and polygene were 83.80% and 1.05%,respectively,in leaf length.The heritabilities of major gene and polygene were 22.28% and 61.92%,respectively,in leaf width.(3)Leaf index and number of serrated leaf margin both meet E-1 model showing two additive-dominant-epistatic major gene plus additive-dominant polygene.The heritabilities of major gene and polygene were 93.73% and 2.59%,respectively,in leaf index.The major gene heritability was 91.18% in number of serrated leaf margin trait.

Abstract:Astragalus taiyuanensis was newly found,which was only located in Shanxi and Shaanxi Province of China.Floral organogenesis and development in A.taiyuanensis were studied by means of scanning electron microscopy.Results were as followed:(1)sepals,petals,outer stamens,and inner stamens were formed unidirectionally in each whorl from the abaxial to the adaxial sides of the flower.Overlap in starting time between members of adjacent whorls occured.(2)The existence of two forms of common primordia,categorized as primary and secondary,was observed.Primary common primordia develop into antesepalous stamens and secondary common primordia.In comparison,the five secondary common primordia subdivide into a petal and an antepetalous stamen primordia respectively.(3)Filament tube had two adaxial fenestrations at base,which was adaptation to the pollinators and in favor of pollination activities.(4)Ovules were anatropous and bitegmic in A.taiyuanensis.Anatropous ovules was a result of the appearance of both inner and outer integuments.

Abstract:Flue-cured tobacco ‘Nanjiang 3’ was a kind of main cultivated varieties in Guizhou Province.Paraffin section method was employed to observe its anatomical structure of microsporogenesis,megasporogenesis and development of female and male gametophytes.The results showed that,the anther wall is defined as basic development type with glandular veriform tapetum.The cytoplasm of microspore mother cell undergoes simultaneous division and produces tetrahedral or decussate tetrad.The mature pollen belongs to 2 cell type and has three or four apertures.The ovary of flue-cured tobacco ‘Nanjiang 3’ is anatropous with thin nucellus.The archesporial cell develops to megaspore mother cell directly and has larger volume.Four megaspore cells form a linear tetrad.The development pattern of embryo sac is polygonum type,finally forms 7-cell or 8-cell nucleate mature embryo sac.Stamen develops earlier than gynoecium and the period of microsporogenesis,megasporogenesis and development of female and male gametophytes can be judged by appearance from the flower bud.

Abstract:The annual assimilating shoots of 6 Haloxylon ammodendron species were selected as experimental materials,which were gotten from arid region of northwest China according to precipitation gradient which is from east to west.9 anatomical structures were measured.We analyzed the relationship between anatomical differences and ecological factors of the assimilating shoots of H.ammodendron,to provide theoretical basis for the protection and utilization of the ecological environment and H.ammodendron resources in arid areas of China.Results showed that:(1)the anatomical structure of the assimilating shoots of H.ammodendron in the arid desert environment with continuous wreath of palisade tissue,structure,crystal cell and water storage organization structure,but the epidermis cells,cutin layer thickness,hole position under the gas chamber difference with xerophyte structure,mainly displays in the epidermal cells and corneous layer is thinner,porosity nuder half wubsidence and gas chamber is not developed.(2)9 anatomical structures of the assimilating shoots of each characteristic of 6 H.ammodendron species have significant differences by variance analysis.The variability coefficients are greater in the number of vascular bundle and cuticle thickness with the values of 22.78% and 15.20%,respectively;Correlation analysis showed that each index has different degree of correlation with eight ecological factors,which are longitude,latitude,altitude,average temperature in January and July,annual average temperature,annual precipitation and annual average relative humidity.The diameter of assimilating shoots thickness,palisade cell cut to length,water storage tissue thickness and vascular cylinder diameter have different degrees of correlation with eight ecological factors.(3)6 populations of H.ammodendron could be divided into 2 categories by cluster analysis.The results of cluster analysis were identical with the habitat types and geographical distribution of H.ammodendron;as fewer natural rainfall from east to west,the drought resistance of H.ammodendron gradually strengthened.

Abstract:Salix gordejevii and S.microstachya var.bordensis are important shrubs for soil and water conservation in Hunshandake sandland.The former is suitable for growing on flow and semi-flow sand dunes,and the latter does on dune slack.They can grow mixed,and also can form pure forest.So that they have the feature of regular distribution.Through the method of tissues segregation and micrographic technique,this paper comparatively studied on the morphological characteristics and ecological adaptability of vessel elements of S.gordejevii and S.microstachya var.bordensis.The results showed that:(1)the two species were given priority to reticulate vessels with both end walls with one tail and a tail in one wall.Both ends of their vessel elements with alternate pitting had simple perforation plates.(2)There were significant differences between the length,diameter and end wall slope angle of xylem vessels in the root of S.gordejevii and S.microstachya var.bordensis(P<0.05).The diameter of root vessel elements of the former was wider and the end wall slope angle of those was smaller than the latter’s,which showed the evolutionary features.However,the length of root vessel elements of the former was longer which showed the primitive feature.There were no significant differences between the length,diameter and end wall slope angle of xylem vessels in the stem of S.gordejevii and S.microstachya var.bordensis(P>0.05).(3)There appeared some correlation between the characteristics of vessel elements and habitats of the two species.The arid environment was more suitable for S.gordejevii to grow due to the higher water transmitting ability than S.microstachya var.bordensis.This study provided theoretical support for afforestation with S.gordejevii and S.microstachya var.bordensis,and provided reference for the correlational research of plant ecological adaptability.

Abstract:The micromorphological structure of bristle,wart and cutile ornamentation of cells of leaf apex and their neighbor cells of twelve mosses from the source area of Urumqi river were observed by LM and SEM.The results indicated that cells on the top of the leaf apex of most species of the species were transparent,longer and thinner than leaf cell,but with various shape;cell wall was sunken with irregular microgroove and fine particles when it was dry,but not always contracted.Margin of the leaf apex was involuted or twisted,and cell wall was thick with many small pores when it was dry.These characteristics are benefit to absorption of water and adaptive survival strategy for resisting hurt from long period cold and solar radiation.Types of leaf apex have little significance to the classification of family and genus of bryophytes,but the micromorphological structure of cells on the top of the leaf apex and shape,cell number and sunken degree of cell wall and micromorphological structure of wart,mastoid,cutile ornamentation and small pore of other cells are obviously different among different species in same genus,with certain meaning for classification of species under genus level.

Abstract:A pot experiment was conducted to investigate the allelopathic effect of decomposing leaf litter of camphor(Cinnamomum camphora) on the growth and photosynthetic characteristics of the two recipient crops [cabbage(Brassica chinensis) and lettuce(Lactuca sativa)].Four levels of leaf litter addition were applied to soil [namely 25,50 and 100 g·pot^-1) and CK(no leaf litter added)].The results showed that:(1)the decomposing camphor leaf litter showed inhibition effect on ground diameter,plant height,biomass,leaf number and leaf area of the two recipient crops.The inhibition effect to the recipient crops was enhanced with the increment of leaf litter,but with the extension of decomposition time the inhibition effect tended to weaken and even showed the promotion effect on recipient crops;(2)Leaf litter decomposition showed significant inhibition effect on photosynthetic pigment content of both crops,and the inhibition effect enhanced with the increment of leaf litter;(3)Application of leaf litter reduced the net photosynthetic rate(P_n),stomatal conductance(G_s),transpiration rate(T_r) and water use efficiency(WUE) and the intercellular CO₂ concentration(C_i) in all treatments;(4)With the increasing amount of leaf litter in soil,the maximum net photosynthetic rate(P_{n max}),apparent quantum efficiency(AQY),RuBP carboxylation efficiency(CE),light respiration rate(R_p) and dark respiration rate(R_d) of two crops were declined under the saturation condition of light and CO₂,but the light compensation point(LCP),light saturation point(LSP),CO₂ saturation point(CSP),CO₂ compensation point(CCP) showed different trends due to different recipient crops.Overall,this study suggested that,decomposing camphor leaf litter may release the allelochemicals which could reduce the chloroplast pigment synthesis and weaken the photosynthetic capacity of recipient crops,limit the vegetative growth of crops,and ultimately affect the biomass accumulation.Compared with lettuce,cabbage has the stronger tolerance to the inhibition effect of decomposing camphor leaf litter.It may be more suitable for intercropping with camphor.

Abstract:To investigate the differences in photosynthesis,protective ability and repair capability between the invasive weed Eupatorium adenophorum L.and the native weed Artemisia argyi Levl under the condition of enhanced UV-B radiation,we designed a seven-week experiment under the condition of UV-B radiation up to 0.46 mW·cm^-2·h^-1 and an extra experiment after stopping radiation to observe the changes in both species’ growth conditions.Moreover,the effects on photosynthetic capacity,the contents of oxides and antioxidants as well as the activity of antioxidant enzymes were measured and analyzed.And the results showed as follows:(1)the maximum photosynthetic assimilation rate (P_{n max}),photochemical efficiency in the light and maximal quantum yield of PSⅡ were restrained,but the former was showed more repressive significantly in E.adenophorum L.as the durations of UV-B radiation increased.(2)The contents of malonaldehyde (MDA) and super-oxygen ion (O^-·₂) in both species were accumulated as the durations of UV-B radiation increased,but the increased proportion of them was more significant in A.argyi Levl.(3)The contents of antioxidants concluding ascorbate (ASA) and glutathione (GSH) turned out different tendencies that the contents tended to firstly increased and then decreased in E.adenophorum L.while to increased and maintained a high level in A.argyi Levl.Besides,the enzymatic activities of peroxidase (POD) and superoxide dismutase (SOD) were improved remarkably after radiation in both species.And the enzymatic activity of ascorbate peroxidase (APX) in both species firstly increased and then decreased.As for the enzymatic activity of catalase (CAT),it was gradually inhibited in E.adenophorum L.but firstly enhanced and then inhibited in A.argyi Levl.As a consequence,we found the physiological mechanism of photosynthesis and antioxidation of E.adenophorum L.and A.argyi Levl responded to enhanced UV-B radiation were similar with some differences.

Abstract:In order to make certain the effects of inoculations in the seedlings of Taxus chinensis var.mairei at the micro-ecological level,we studied the number of culturable microorganisms,the enzyme activity and the soil microbial functional diversity of rhizosphere soil,after inoculated with Sinorhizobium meliloti CHW10B (phosphate solubilizing bacteria,PSB) and/or Glomus constrictum (arbuscular mycorrhizal fungi,AMF).The results showed that:(1)inoculation had significant growth-promoting effects in Taxus chinensis var.mairei.The height,ground diameter and biomass of the inoculated groups had significantly increased when compared with the control group.(2)The number of culturable bacteria,fungi and actinomycetes contents in the rhizosphere soil of Taxus chinensis var.mairei were higher obviously compared with those of the control with the extension of time.Inoculation can improved the soil microbial carbon utilization,changed the species richness of soil and increased the soil biodiversity.(3)Inoculation increased the activities of enzymes in the soil,included acid phosphatase,dehydrogease and invertase.All these benefits are especially for co-inoculation treatment.These results indicated there were synergistic benefits between PSB (Sinorhizobium meliloti CHW10B) and AMF (Glomus constrictum).Moreover,the growth-promoting effect of co-inoculation depend on the increase of the number of culturable microorganisms in rhizosphere soil of Taxus chinensis var.mairei,soil enzyme activity and soil biodiversity which lead to soil enhancement of microbial carbon utilization and soil fertility.

Abstract:Ground cover plants are one of the essential landscape plant species among the current urban greening,and understanding the physiological mechanism of these plants resistance to sulfur dioxide (SO₂) can help us choose the suitable species.In this study,three ground cover plant species (Petasites japonica,Stachys lanata and Trigonotis omeiensis) growing under the greenhouse condition were selected and screened for tolerance to acute SO₂ injury.Four SO₂ treatments including 0,5.71,11.43,and 17.14 mg·m^-3 were used in this study,and release of SO₂ were achieved using the artificial simulated fumigation method.Differential response to SO₂ injury among these three species was manifested through the phenotypic injuries and the various physiological indexes.Our results showed that:(1)the phenotypic injury of three species is ordered in sequence from severe to light as S.lanata>T.omeiensis>P.japonica.The content of chlorophyll and the value of leaf pH decreased gradually with the increase of SO₂ concentration,while the levels of MDA content,the electrolyte leakage rate,and the contents of soluble sugar and the proline rose in the varying degree among the three species.Furthermore,the activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT) were activated dramatically.(2)Through the subordination function and principal component analysis,we concluded that the resistance to SO₂ among these three species is ordered in sequence from high to low as P.japonica>T.omeiensis>S.lanata.(3)The purification ability to SO₂ is ranked in order from high to low as P.japonica>S.lanata>T.omeiensis by analogizing sulfur accumulation within leaf under SO₂ stress.The results shows that P.japonica has the strongest capacity of resistance and purification of SO₂ and it can also has no obvious phenotypic injury through its own stress protection system to improve resistance to SO₂.This conclusion can guide us in respect of large-scale use of P.japonica in heavily SO₂-polluted urban areas.

Abstract:The soil cultivation experiment was used to investigate the effects of uranium on the photosynthetic characteristics of spinach(Spinacia oleracea L.) leaves.Spinach seedlings of the six-leaf stage were treated with different concentrations of uranium [UO₂(CH₃CO₂)₂·2H₂O](0,20,50,100,150 mg·kg^-1),and photosynthetic pigment content,photosynthetic gas exchange parameters,chlorophyll fluorescence parameters of leaves,growth indexes were investigated after 7,14,21 and 28 days of uranium treatment,respectively.The results showed that:(1)compared with the control,the chlorophyll content,net photosynthesis (P_n),stomatal conductance (G_s),transpiration rate (T_r) were significantly improved by low uranium concentration (20,50 mg·kg^-1),after that with the increase of uranium concentration all of the parameters significantly decreased,and along with elevated levels of uranium as well as the duration of treatment,all the parameters then decreased significantly compared with the control while intercellular CO₂ concentration (C_i) was getting rise.It showed that the decline of P_n was caused by nonstomatal factors.(2)High uranium concentration obviously influenced on the chlorophyll fluorescence parameters of plant leaves.PhotosystemⅡ (PSⅡ) maximum fluorescence (F_m),PSⅡ maximum photochemical efficiency (F_v/F_m),PSⅡ potential activity (F_v/F₀),declined obviously,while minimum fluorescence (F₀) were obviously rise.(3)Root length,plant height and biomass showed a obvious rise under low concentrations of uranium treatments,and a decline under high concentration(100,150 mg·kg^-1) uranium treatments.Thus,low uranium concentration could improve photosynthetic function of spinach seedlings and increase photosynthetic efficiency,but a high concentration can harm the photosynthetic apparatus and inhibit photosynthetic efficiency.

Abstract:To explore the role of exogenous BR on the induced resistance of cucumber seedlings to Ca(NO₃)₂ stress,we determined the effects of different treatments of exogenous BR (0.01 mg·L^-1 BR soaking seeds,0.1 mg·L^-1 BR spraying leaves and combination of both) on growth,physiological indexes,and photosynthetic characteristics of cucumber seedlings under 60 mmol·L^-1 Ca(NO₃)₂ stress in this paper.The result indicated that:(1)the exogenous BR significantly increased the height,stem diameter,number of expand leaves,leaf area,contents of proline and soluble sugar of cucumber seedlings and decreased the content of MDA,activity of POD increased,promoted the photosynthesis rate,transpiration rate and stomatal conductance of cucumber seedlings and inhibited the increase of intercellular CO₂ concentration.(2)BR soaking seeds and spraying leaves with suitable concentration of exogenous BR could effectively enhance the cucumber seedlings osmotic adjustment capacity,reduce membrane peroxidation damage,improve antioxidant enzyme activity and photosynthetic efficiency,thus showing Ca(NO₃)₂ stress resistance,and the treatment of 0.01 mg·L^-1 BR soaking seeds showed the best results.

Abstract:Under the conditions of 16 h light/8 h dark,13 h light/11 h dark and 10 h light/14 h dark,the authors studied the effects of photoperiod on agronomic traits and photosynthetic characteristics of ensilage corn ‘Huanong 1’,at different nitrogen levels of N₁ (75 kg/hm²),N₂ (225 kg/hm²),N₃ (375 kg/hm²).The capacity of tolerating high nitrogen stress was analyzed.The results showed that:(1)the root length,root surface area and root volume were increased by 113.19%,45.73% and 97.71%,respectively,under 16 h light,compared with 10 h light.The contents of chlorophyll and net photosynthesis rate of leaves were higher by 97.90% and 60.24% under 16 h light.The leaf number under 16 h light was twelve more than that under 10 h light,with extremely significant difference.While photoperiod did not influence plant tiller number significantly.(2)Root diameter was decreased gradually with the extension of photoperiod.‘Huanong 1’ ensilage corn displayed the biological characteristics of resisting high nitrogen stress under 16 h light,and the indexes of root morphology and some agronomic traits were improved with increasing of nitrogen level,but the traits indexes declined gradually with the increasing of nitrogen level under 10 h light.(3)As the photoperiod extended gradually,aboveground biomass also increased significantly.Therefore,the authors believed that long photoperiod promoted the growth and development of photoperiod sensitive corn ‘Huanong 1’,and also enhanced the adaptation ability of it to high nitrogen.

Abstract:In order to know the different capacity of water cycle in the forest ecosystem,we monitored the trunk sap flow in different diameter at breast height (DBH) of Pinus sibirica which in sunny side and shady side using TDP (thermal dissipation method) constantly in the Kanas National Nature Reserve,northwest of Xinjiang.The aims were to explain the relationship between water cycle of tree and environment,and provide basis on forest ecosystem water cycle responding to the climate change in the regional scale.The results showed that:(1)the diurnal variation of sap flow in sunny day,rainy day,and cloudy day were all multi-peak type.There were significant changes on frequency and range among these three weather conditions.The sequence of daily maximum sap flow value was sunny day>cloudy day>rainy day.(2)There was the hysteresis effect between sap flow and photosynthetically active radiation,hysteresis time of the maximum sap flow was about 30-207 min,respectively.(3)From June to September,the sap flow of P.sibirica in the sunny side were greater than those in the shady side,and the sequence of monthly mean sap flow was July>August>September>June.(4)The maximum transpiring water-consumption of P.sibirica was in July,and the value of it was 61.8% of the total value of whole growing season.Total transpiring water-consumption of P.sibirica with big diameter was 6 716.79 g in sunny side,while 4 649.08 g in the shady side.It was the 2.00 times and 2.45 times small diameter of P.sibirica,respectively.(5)Air temperature,air relative humidity,and photosynthetically active radiation were significant factors that affected the sap flow.Otherwise,the soil temperature in the layer of 0-5 cm and 20-30 cm were highly impacted on the sap flow too.This research showed that both sap flow and transpiring water-consumption of P.sibirica with big diameter were higher than that of P.sibirica with small diameter in the process of growth;these changes mainly happened in the sunny side of the trunk,especially in July.

Abstract:Based on identification of collections of 1 500 bryophyte samples and literature survey,we analyzed bryological composition and floristic characteristics in Qingliangfeng National Nature Reserve,Zhejiang Province.The species richness comparison and similarity coefficients of the area with the other eight regions of mosses were discussed.The ecological habitats of the bryophytes were also introduced.The results showed:(1)62 families,143 genera and 337 species(including three variants) from Qingliangfeng National Reserve are reported.Among them,49 species and 29 genera belonging to 20 families are liverworts,288 species and 114 genera belonging to 42 families are mosses.(2)There are nine dominant families and 16 dominant genera all belonging to mosses in the area deleted.(3)The floristic types of bryophytes in the reserve showed that East Asia element is dominant,up to 41.84% of the total species and followed by temperate element with 28.57% of the total species.Tropical is the third with 20.74% of all.(4)The bryoflora of Qingliangfeng National Reserve is more closely related to Tianmu Mountain;Dapan Mountain;Jinhua Mountain and Fengyang Mountain which are in Zhejiang Province.(5)The ecological distribution types of bryophytes are complicated and the most common type is on rock(47.09% of the total number of samples),soil on rock(27.68% of the total number of samples) and soil type(12.85% of the total number of samples) is the second.Therefore,establishing nature reserve plays an important role in researching and for conservation of bryophytes in Zhejiang Province.

Abstract:Reproduction isolation is the basis of species preservation and divergence,but little is known about the breeding system of Rehmannia.We studied the floral syndroma and reproductive characteristics of the five Rehmannia species (R.chingii,R.piasezkii,R.henryi,R.glutinosa,R.solanifolia) through investigating the following indices in field:flowering dynamics of natural populations,floral morphologies of flower organs,nectar volume and sugar concentration,out-crossing index,pollen-ovule ratio,pollination and bagging experiment.Our results indicate that:(1)Rehmannia species flowers are hermaphroditic.The flowering duration of a single florescence was 5-7 days,and the whole population flowering duration was 40-60 days.There are distinct difference among the five Rehmannia species in inflorescence types,floral characteristics,flower color,pollen amounts and P/O values.We found that R.solanifolia were pollen abortion.(2)The evidence of the out-crossing index,pollen-ovule ratio and hybridization experiment supported that the breeding system of Rehmannia was belonged to cross pollination system,partially self-compatible,with no apomictic ability,and pollinators required.We also found there was vegetative reproduction in Rehmannia,especially in R.glutinosa and R.solanifolia.(3)There are nectaries on the base of Rehmannia corolla and they can produce nectar with higher concentration of sugar,and this also supports the existence of pollinators.However,we did not observe any effective pollinators in Rehmannia species except in R.glutinosa with bees,which might be due to the scattered individual,isolated habitats and the bad weather conditions during pollination observation.Longer flowering duration could compensate for the insufficiency of pollinator visits.According to our results,we suppose that the different flowers display of five Rehmannia species possibly attracting distinct pollinators,together with genetic,geographic and ecological isolation,results in the differentiation of the breeding system in Rehmannia species.

Abstract:With sterile leaves of Ardisia crenata Sims by tissue culture as explants,we performed hairy root induction by using four kinds of Agrobacterium rhizogenes strains,named A4,ATCC15834,LBA9402,R1601,respectively.The investigation selected optimal media types,pre-culture time,infection ways,co-culture time,and the ability of A.rhizogenes on hairy root induction.The study showed that 1/2 MS was the better medium for sterile leaves on hairy root induction,and hairy root induction rate was the highest (31.87%) under pre-cultured 2 d and co-cultured 2 d.It was the best way for infection that put sterile leaves and bacteria which was supplied with AS (100 mg/L) co-shake under dark,28 ℃ and 180 r/min for 8 to 15 min.All of the four strains could induce hairy root on A.crenata Sims,but ATCC15834 was the most effective strain,and A4 followed it.For ATCC15834,A4,LBA9402 and R1601,the ability of hairy root induction on A.crenata Sims was declining in turn.It demonstrated that T-DNA on Ri plasmid of A.rhizogenes had been integrated into the genome of the host cell successfully through molecular identification by PCR.

Abstract:The ectomycorrhizal fungus from Ziwuling forest region on the Loess Plateau was isolated by tissue isolation technique,identified based on ITS sequence,and the cultivation condition in vitro was further investigated to establish the basis of inoculum production.Result showed the isolated fungus from Ziwuling forest region was Handkea utriformis,which could form ectomycorrhiza with Pinus tabulaeformis.Using MMN medium,the optimum pH was 6.0 and temperature was 25 ℃.Growth rate of H.utriformis on MMN medium with sucrose was the fastest,followed by maltose and glucose,and the slowest growth rate was for lactose.This fungus did not grow on medium using chitin and sodium bicarbonate as carbon source.For organic nitrogen source,H.utriformis grow fastest on MMN medium with proline,followed by casein,and slowest with urea.For inorganic nitrogen source,H.utriformis grow fastest with diammonium hydrogen phosphate,followed by calcium nitrate,and slowest with ammonium molybdate.For the first time,this study reported the ectomycorrhizal fungus H.utriformis in the Ziwuling region on the Loess Plateau,and its optimum growth condition in vitro was preliminary confirmed.

Abstract:Salix staintoniana A.K.Skvortsov and S.pseudocalyculata Kimura,two newly recorded species of Salicaceae from China,are reported.The taxonomic feature pictures of the two species are provided.The female morphology of S.staintoniana is described.The diagnoses are given between the two newly recorded species and their respective relatives.