Abstract:In this study, the IiEMF gene was first cloned based on the Isatis indigotica transcriptomic analysis. (1) Sequence analysis showed that the IiEMF gene contains an open reading frame of 1 896 bp encoding 631 amino acids. The phylogenetic analysis suggests that the IiEMF protein was relatively close to the EMF protein of Brassica oleracea. (2) Realtime quantity PCR (QPCR) resulted that IiEMF existed in all organs in I. indigotica. The highest expression level was observed in leaves and the lowest was in fruits. IiEMF expression level in the leaves increased first and then decreased and the highest peak emerged at first flower appearing stage. The IiEMF expression level in flower/fruit stage was significantly lower than that in flower bud stage. (3) The overexpression vector pCAMBIA1300EMF was constructed and then was introduced into A. thaliana by Agrobacterium. There are 7 strains of A. thaliana plants of transgenic EMF gene detected by PCR. (4) The results of phenotype observation indicated that the flowering time of the two transgenic EMF arabidopsis strains was significantly earlier than that of the wild type (6~10 d) under longday and shortday conditions. The rosette leave number of transgenic IiEMF gene lines was at least ten more than that of the wild type, and the leaves were also larger and thicker than that of wild type. (5) QPCR resulted that overexpression of IiEMF significantly inhibited the expression of AtAP1, AtCO and AtLFY and promoted the expression of AtFLC in the vegetative growth process of A. thaliana. The expression levels of AtAP1 and AtFLC in transgenic IiEMF gene lines were higher than that of wild type, and the expression levels of AtCO and AtLFY were significantly lower than that of wild type in reproductive growth period of A. thaliana. This study showed that overexpression of IiEMF promoted A. thaliana flowering and IiEMF may regulate A. thaliana flowering time by influencing multiple flowering pathways.

Abstract:In order to study the effect of ice recrystallization inhibition protein gene (TaIRI5) on wheat growth and development, we cloned the TaIRI5 gene from wheat cultivar‘Beijing841’by RTPCR technique. The gene was studied by bioinformatics analysis, tissuespecificity analysis, promoter activity analysis, subcellular localization analysis. The results showed that: (1) the TaIRI5 gene was successfully cloned, and the full length of TaIRI5 gene is 1 203 bp. The open reading frame was 858 bp, encoding 285 amino acids. The size of TaIRI5 protein is about 70.7 kD and the isoelectric point is 5.07. TaIRI5 is a hydrophobic protein. (2) Quantitative real time PCR analysis showed that TaIRI5 gene was expressed in roots, stems, leaves, stamens, pistils, glumes, seeds and the relative expression level of roots was the highest and stamens was the lowest. It is speculated that TaIRI5 gene plays an important role in the growth and development of wheat. (3) The promoter of TaIRI5 analysis showed that in addition to the core elements of CAATbox and TATAbox, the sequence also contains 9 light response elements and 6 hormone response elements as well as other elements. We have successfully constructed pCAMBIA1301 fusion expression vector containing GUS gene by three candidate promoters of TaIRI5 gene with different length of 498 bp, 999 bp and 1 500 bp. Tobacco transformation experiments showed that the three promoter candidates had strong activity with different expression patterns. (4) We have successfully constructed pCAMBIA1300TaIRI5GFP fusion expression vector containing GFP gene, subcellular localization analysis showed that TaIRI5 was located on the cell membrane. The results laid a foundation for the further study of TaIRI5 gene function in wheat.

Abstract:The ZFHD (zinc finger homeodomain) protein family is one kind of plant specific transcription factor family which plays important roles during stress response, flower development and seeds longevity of plant, but their function in strawberry is unknown. This study isolated and obtained 10 genes of ZFHD family from woodland strawberry (Fragaria vesca). The phylogenetic tree indicated that this gene family can be divided into 6 subfamilies according to the evolutionary relationship. The analysis of the ciselement of the promoter indicated that there are a large number of ciselements which related to the adversity stress and hormone response. The qRTPCR analysis indicted that FvZFHD7 expressed more abundant compared with other genes. The tissue organ specific expression analysis indicted that FvZFHD7 expressed the highest in the flowers, but also expressed in leaves and stem and it is highly expressed in the earlier stage, but decreased rapidly in the later stage during fruit development. The FvZFHD7 gene was successfully cloned by using the cDNA of woodland strawberry ‘Yellow Wonder 5AF7’ (YW). The bioinformatics analysis suggested that the full length of FvZFHD7 is 1 083 bp, encoding 360 amino acid. The sequences alignment indicated that the encoded protein possesses both ZF and HD conserved domains. The molecular weight of the protein is expected to be 39 153.89 Da with abundant αhelix and random coil. The expression vector pGWB5FvZFHD7 was successfully constructed and the GFP signal was detected in the nucleus of the transgenic tobacco by transfer the target gene into the tobacco and observed under laser Confocal microscope which indicated that FvZFHD7 protein localizes in the nucleus. The study indicated that FvZFHD7 may widely take part in the regulation of flower development and stress response.

Abstract:The dormancy associated MADSbox (DAM) gene plays an important role in the induction of plant bud dormancy. In this study, we used the different stages of Cerasus humilis ‘Nongda 4’ as materials to obtain the ChDAM gene using PCR technology. The gene has a total length of 705 bp and encodes 234 amino acids. Multisequence comparison and domain analysis found that the gene encoded protein has a typical MADSbox domain and Kbox domain, and its amino acid sequence is more homologous to peach DAM5 protein. The promoter analysis found that the expression of the ChDAM5 gene may be regulated by low temperature and abscisic acid. Realtime quantitative PCR results found that the expression of the ChDAM5 gene gradually increased with the process of dormancy induction. So it was speculated that the gene played a key role in inducing C. humilis dormancy, laying the foundation for further indepth metabolic pathway research.

Abstract:The EPSPS gene which encodes 5enolpyruvylshikimate3phosphate synthase, the key enzyme of aromatic amino acid synthesis has been cloned and widely studied in bacteria, fungi, algae, and plants. EPSPS is the target enzyme of glyphosate herbicide and its overexpression can improve glyphosate resistance of crops. In this study, primers were designed according to the genomic database of sweet potato, RNA was extracted from the sweet potato variety, ‘Guangshu 87’, and the gene amplified by RTPCR. After sequencing, bioinformatic analysis and expression analysis were carried out. The results showed that: (1) the total CDs of the IbEPSPS gene was 1 569 bp, encoding 522 amino acids, among these, there were two conserved domains of IbEPSPS gene in amino acid sequence 98-113 and 173-183 positions. (2) Phylogenetic tree analysis showed that the EPSPS of sweet potato was closely related to Ipomoea triloba, Calystegia hederacea, Convolvulus arvensis, and Ipomoea nil. (3) The results of realtime quantitative PCR showed that the IbEPSPS gene was highly expressed in the stem, leaf and shoot tip of sweet potato, and the expression of the IbEPSPS gene increased after the stress of glyphosate. The results provide a reference for further study on the function of the IbEPSPS gene and the mechanism of resistance of sweet potato to glyphosate.

Abstract:Our works focused on the anatomical structure of roots generated from different parts of Dendrocalamus brandisii. New theoretical information was supplemented for the root anatomy of bamboos by exploring the anatomical structure of these roots. Resin slicing and freehand crosssections were cut from the root hair zone, and were stained by Toluidine blue O and Sudan red 7B. The results showed: (1) the ratio of cortical width to root diameter, the width and number of cell layers of sclerenchyma, and the thickness of endodermis cell walls increased with time. (2) Significant suberization occurred in the exodermis and endodermis of all the roots, but with significant difference in the suberization degree of periendodermis. (3) After measuring the number and diameter of the xylem vessels of all the roots, we noticed that the number and diameter of xylem vessels were higher in July as compared to those in other months. (4) The tips of roots generated at the base of branches were more blunt and flat, with smaller area of root caps, as compared with those generated in other parts. The tips of those roots generated in the culm underpart were so hard that their anatomical characteristics were unsuccessfully observed. The conclusion is that the roots of four originations had the same basic structure, but with significant differences in their specific structures. The structural differences may be closely related to their living environment and development status.

Abstract:In the research of the gemma in bryophyte, the bryologists mainly focus on the morphological traits and the uses in the classification. On the contrary, they virtually ignored the formation and liberation process of gemmae in the past. The present paper documented these process based on new observations on cultured materials, Gymnostomiella vernicosa var. acuminata. The aim of the study is to understand the formation pattern of gemma in this taxon and its related groups; to add classification characteristics for this variety; to understand the ecological and evolutionary significance of gemma in bryophytes. The results show that three stages can be divided roughly for occurrence process of the gemma: (1) the part of outer tangental wall in epidermis cell on the stem extrudes. These bulging epidermis cells have aboundant chloroplasts, reflects considerable photosynthetic autonomy. (2) The bulging cell divides transversely into one basal cell and one apical cell. The basal cell continues to divide transversely, and matures into a stalk structure with a trumpetshaped distal cell. The apical cell subsequently divides for several times, and forms one ellipsoidal to sphere gemma. The thick walled cells of gemma have aboundant chloroplasts originally, and then number of chloroplasts drops lower gradually. The color of the gemma becomes generally into the thick brown to red brown after the gemma is mature. (3) The thin walled stalk cells break randomly that lead the gemma to liberation from the parent plant. In contrast to sexual reproduction, genetic, energetic and ecological cost of asexual reproduction is generally shown to be lower. In the inhabiting unpredictably varying environments, production of gemma for G. vernicosa var. acuminata can be interpreted as a risk spreading strategy, which effectively use of resources and enhances survival, and an effective way to maintain and enlarge populations.

Abstract:We analyzed the anthocyanin profiles in 8 cultivars of Rieger begonia, including red, redwhite, pink, rose red, yellow, yellowred, pinkwhite, white. The petal phenotype was observed according to Visual inspection, Royal Horticultural Society Color Card (RHSCC) and Colorimeter (CR400). The microstructure and distribution of pigment cell was observed by the tissue section method. Dualbeam UVvisible spectrophotometer and HPLCESIMS were used to measure and analyze the anthocyanin composition in petals. Its hoped to provide references for further studying of the colouration mechanism and color breeding of Rieger begonia. The results showed that: (1) the L^* value of Rieger begonia petals decreased as the color became darker, while the a^* value showed the opposite trend. The a^* and C^* value were significantly negatively correlated with L^* value, and were the main factors affecting L^*. (2) The petal pigments of red varieties were mainly distributed in the upper epidermal cells and sponge tissue. The petal pigments of redwhite varieties were mainly distributed in the upper and lower epidermis, and the accumulation of the lower epidermis was greater. The petal pigments of pink and rosered varieties were mainly distributed in the upper and lower epidermal cells. A small amount of pigment was contained in the epidermis of yellowpink petals, while the yellow and white varieties had almost no pigment accumulation in the petals. The upper epidermal cells of Rieger begonia petals were all conical, the red and redwhite varieties had the highest conization. The lower epidermal cells of the petals were flat rectangles. (3) A total of 15 anthocyanins were detected in the petals of 8 cultivars of Rieger begonia, of which 10 were peonidin, 3 were cyanidin, 1 was malvidin, and 1 was delphinidin, with the majority of acylated anthocyanins. The total anthocyanins in petals of red varieties was the highest, followed by rosered varieties, while no anthocyanins in yellow and white petals. Except for pink flowers, other anthocyaninscontaining varieties had the highest content of peonidin, accounting for more than 50% of total anthocyanin. Its the main coloring substances in the petals. (4) Total anthocyanins in petals of Rieger begonia was positively correlated with a^* and C^* values, and negatively correlated with its L^* value. The study shows, anthocyanins accumulation is beneficial to the redness of Rieger begonia petals, and affects the C^* and L^*. The number of pigmentdistributed cells and the upper epidermal cell conization significantly affect the petal coloration and the main coloring substance of the petal is peonidin and acylation which may affect the brightness of the petal.

Abstract:Mengnong sainfoin was not only a good forage crop, but also can be used as a garden ornamental and honey plant. In this study, the mutant petals from light color flower and the petals with pink color and amaranth color were used as the test materials. Based on the comprehensive analysis of petals parameters, pigment species and content to confirm the main substances affecting floral color. The result shows that: (1) the light color flower by EMS treated and the control (pink and amaranth) were three different color systems, and the light color flower was defined as yellowwhite flower according to the b^* and the h°. (2) 10 kinds of flavonoids and 5 kinds of anthocyanins were detected in 3 colors of sainfoin, but 6 varieties of kaempferol derivatives, 2 types of petunia derivatives, 2 varieties of delphinidin derivatives and 1 types of mallowin derivative were firstly reported in Mengnong sainfoin. We also found the Kaempferol3Orutinoside, Kaempferol3Oglucoside and Delphinidin3rutinoside contents were the most in 3 different color of flowers. The color change of Mengnong sainfoin was influenced by the rutin, Kaempferol3Orhamnosylrutinoside and Kaempferol3Oglucosidepcourmaric ester.

Abstract:Light quality and photoperiod can regulate the formation of underground storage organs such as fleshy roots during plant growth. In this test, ‘Superior Queen No.2’ cherry radish was used as the test material, and white light (W) was used as a control to study the redblue light ratio of 8R2B, 5R5B, and 2R8B (the ratio of red and blue light was 8∶2, 5∶5, 2∶8, respectively) and 8L/16D, 12L/12D, 16L/8D photoperiod (light/dark was 8 h/16 h, 12 h/12 h, 16 h/8 h, respectively) on the effects of the growth and quality of cherry radish, which is screening combinations of light and quality photoperiod suitable for cherry radish growth. The test results showed that: long light (16L/8D) W, 8R2B treatment significantly promoted cherry radish leaf growth, fleshy root size and rootshoot ratio, and long light W was beneficial to cherry radish to form enlarged fleshy roots faster; The content of polyphenols and antioxidant capacity of cherry radish roots under long light W and 8R2B treatments were not significantly different; long light W was beneficial to the accumulation of soluble sugar and soluble protein in fleshy roots of cherry radish, and long light 8R2B was beneficial to the accumulation of soluble proteins in fleshy roots. The study found that the appropriate combination of light quality and photoperiod can significantly promote cherry radish leaf growth, fleshy root enlargement, and accumulation of nutrients in the root, thereby obtaining good growth and nutritional quality. The combination of long light (16L/8D) and white light was the best.

Abstract:The test material was the seeds of Allium mongolicum, which were unaged and artificially aged. Seeds soaking with Ce³⁺ and La³⁺ were used to determine seed germination and physiological indicators, and to explore whether the seed soaking with Ce³⁺ and La³⁺ could promote seed germination and the effect on seed vigor and physiological characteristics of aged A. mongolicum.The results showed that: (1) at 0 ~ 5 h of aging, Ce³⁺ and La³⁺ treatment could significantly promote seed germination and improve seed vitality of A. mongolicum; After 5 h of aging, Ce³⁺ and La³⁺ treatment had no significant effect on seed germination. (2) During 0-15 h of aging, antioxidant enzyme activity and AsA content in Ce³⁺ and La³⁺ treated seeds of A. mongolicum were increased, and the accumulation of O₂^-· generation rate, H₂O₂ content and MDA content were significantly decreased. After aging for 15 h, antioxidant enzyme activity of Ce³⁺ and La³⁺ treated seeds increased, AsA content decreased, O₂^-· generation rate and MDA content increased. (3) At 5 h of aging, the seed respiration rate of A. mongolicum reached the maximum, and Ce³⁺ and La³⁺ treatment significantly reduced the seed respiration rate. (4) Ce³⁺ and La³⁺ treatment increased ultraweak luminescence (UWL) intensity of A. mongolicum seeds when aging for 0-5 h, but decreased UWL intensity of A. mongolicum seeds after aging for 5 h. According to the research, in the early stage of artificial aging, Ce³⁺ and La³⁺ seed soaking can induce and enhance antioxidant enzyme activity and AsA content of seeds, effectively remove excessive ROS accumulated due to aging, reduce peroxide damage and improve seed vitality. In the middle and late stage of seed aging, the internal ROS production and clearance system was disordered, which aggravated the damage of ROS to the seed structure, and the alleviating effect of Ce³⁺ and La³⁺ infusion was lost.

Abstract:In this study, the 2yearold seedlings of Calamus tetradactylus were selected as the research object. Through the control experiment, we set four light intensity gradients—S0 (control, full light), S1 (75% to 80% full light), S2 (45% to 50% full light), and S3 (20% to 25% full light), and three water gradientsW0 (control, RSWC 85%), W1 (moderate drought, RSWC 55%), W2 (severe drought, RSWC 25%), on a regular basis to determine seedling growth characteristics (plant height, ground diameter, leaf number), photosynthetic capacity ［net photosynthetic rate (P_n), transpiration rate (T_r), intercellular CO₂ concentration (C_i), stomatal conductance (G_s)］ and absorptive capacity (root, stem and leaf biomass), and path analysis using structural equation model, to explore the pathway of light and water on the growth characteristics of C. tetradactylus seedlings, and to provide theoretical support for seedling cultivation and resource restoration. The results show that: (1) with the decrease of light intensities, the growth characteristics, absorption capacity and photosynthetic capacity of seedlings showed a consistent change trend, increased firstly and then decreased. (2) With the decrease of soil water content, the growth characteristics, stem and leaf biomass of seedlings decreased gradually, while the ratio of root and root crown increased firstly and then decreased. In terms of photosynthetic capacity, P_n, C_i and T_r were significantly reduced by 23.65%, 20.61% and 25.40% compared to the control group (P < 0.05). G_s and WUE were increased but not significantly different from the control group (P > 0.05), and L_s was significantly increased by 170.00% compared to the control group (P < 0.05). (3) Structural equation model analysis showed that light could affect the photosynthetic capacity of seedling leaves and water could affect the growth characteristics of seedlings by affecting the root biomass. This study shows that SEM model can effectively analyze the environmental factors that affect the growth of C. tetradactylus seedlings, and quantitatively explain the path process affected by environmental factors. Light and water transfer influence on growth characteristics through photosynthetic capacity and absorption capacity, and the influence of light factor is greater than that of water factor, with path coefficients of 0.89 and 0.56, respectively. During the cultivation of C. tetradactylus seedlings, the standard factor load of ground diameter was 0.85, which could effectively reflect the growth characteristics of C. tetradactylus seedlings. The seedlings grew best under moderate shade (45%-50%) plus normal water supply (RSWC 85%).

Abstract:Under the climatic and ecological conditions of Hexi Corridor of Gansu Province, using nectarine variety ‘Zhongnong Jinhui’ as experimental material, we designed the differences of root restriction volume 135 L, 225 L, 360 L, 576 L and control 1 440 L(RV₁₃₅, RV₂₂₅, RV₃₆₀, RV₅₇₆ and RV₁₄₄₀) and investigated the growth, chlorophyll content, photosynthetic gas exchange parameters and fluorescence parameters of nectarine tree grown in Gobi greenhouse. The effects of root restriction on vegetative growth, photosynthetic and fluorescence characteristics of nectarine were studied. The results shown that: (1) compared with the control RV₁₄₄₀, the stem diameter and shoots length of RV₁₃₅ and RV₂₂₅ treatments were significantly reduced; the stem diameter of RV₃₆₀ treatment was decreased significantly, while the shoot length had no significant effects; both parameters of RV₅₇₆ treatment did not shown significant difference. (2) Compared with RV₁₄₄₀, the chlorophyll content and net photosynthetic rate, transpiration rate and stomatal conductance of RV₁₃₅ and RV₂₂₅ were significantly reduced, and the intercellular CO₂ concentration was significantly increased at 14:00, however, RV₃₆₀ and RV₅₇₆ did not show differences. (3) Compared with RV₁₄₄₀, the JI phase fluorescence value of OJIP curve of nectarine leaves in root restriction treatments decreased significantly; at 14:00, the relative variable fluorescence difference (ΔV_t) was less than 0 in K phase, and the relative variable fluorescence difference (ΔV_t) of RV₁₃₅ and RV₂₂₅ was decreased significantly. The fluorescence chlorophyll specific activity parameters of RV₁₃₅ and RV₂₂₅ were higher in the absorption flux per reaction center (ABS/RC) and the dissipated flux per reaction center (DI₀/RC), and were lower in the maximum photochemical efficiency (F_v/F_m) and the quantum yield (φE₀) for electron transport (φE₀) of PSⅡ. Compared with RV₁₄₄₀, comprehensive performance index PI_total of RV₁₃₅ and RV₂₂₅ were decreased by 34.9% and 27.1%, respectively, while the difference between RV₁₃₅ and RV₂₂₅ were not significant. It was found that proper root restriction could not only control the vegetative growth of nectarine trees, but also keep their photosynthetic characteristics and economic yield, and the optimal root restriction volume is 360 L, which provided a theoretical basis for root restriction cultivation of nectarine trees in greenhouse in gobi area.

Abstract:In order to investigate the relationship between leaves carbon (C), nitrogen (N) and phosphorus (P) contents and environmental factors in different vegetation types on the eastern slop of Helan Mountains, we selected five typical vegetations including alpine meadow (Ⅰ), pure forest of Picea crassifolia (Ⅱ), pure forest of Populus davidiana(Ⅲ), shallow shrub (Ⅳ) and desert grassland (Ⅴ) along the elevation gradient. The contents of C, N and P in the leaves of 63 plant species and soil nutrient characteristics in sample plots were determined. The relationship between the C, N, and P contents and their stoichiometric characteristics of plant leaves and the environmental factors were investigated. The result showed that: (1) Based on the 63 plant species on the eastern slop of Helan Mountains, the average leaf C, N and P contents were 520.46±62.08 mg·g^-1, 24.03±3.37 mg·g^-1 and 1.69±0.51 mg·g^-1, respectively. Leaf N, P, C/N, C/P and N/P had a normal distribution (P>0.05), while leaf C did not conform to positive distribution (P<0.05). Leaf C/N and N/P were more variable than C/N. (2) Leaf stoichiometric characteristics in different life forms had significant difference. Trees had the highest leaf C and P contents, while the herbs had the highest leaf N content. The trees had the highest C/N and lowest N/P, while the shrubs had the highest C/P. (3) The leaf N, N/P, and C/P were increased with the altitude rising, only decreasing at 2 073 m (pure forest of P. davidiana). Leaf P and C/N reached peak at 2 073 m, then decreased with altitude rising. (4) Our results suggested that desert grassland, shallow shrub were subjected to P, while the pure forest of P. crassifolia was limited by N. The alpine meadow was limited by N and P, although N/P of pure forest of P. davidiana was under 14, the high absorptivity of N and P rejected the N limitation.

Abstract:To explore the seasonal variation rule of C, N and P stoichiometric characteristics of different shrub plant leaves, and reveal the adaptation strategies of desert plants to environment, with four main shrub plants in Minqin arid desert area (Haloxylon ammodendron, Calligonum arborescens, Nitraria tangutorum, Caragana korshinskii Kom.) as the research object, and in the growing season, we analyzed C, N and P contents and their measurement ratios. The results showed that: (1) The content of C in the leaves of C. arborescens and C. korshinskii Kom. were significantly higher than that of N. tangutorum and H. ammodendron (P< 0.05); N. tangutorum were significantly higher than H. ammodendron (P < 0.05); the difference between C. arborescens and C. korshinskii Kom. was not significant. The N content in the leaves of N. tangutorum was significantly higher than that of the other three plants (P< 0.05); the P content of N. tangutorum was the highest, and was significantly higher than that of C. korshinskii Kom., but both of them were not significantly different from H. ammodendron and Calligonum mongolicum. (2) Based on the total variation (resulting from two factors: season and species) for each parameter in these four shrubs, the rank of CV for each parameter was P (28.34%) > C∶P (24.70%) > N∶P (19.07%) > N (17.49%) > C∶N (16.89%) > C (2.91%). (3) C content was positively correlated with N and P contents but not significantly (P >0.05); except for C. mongolicum, the N content in leaves was significantly positively correlated with the P content (P < 0.05), the N∶P of four desert plants in Minqin was mainly determined by the change of P content. (4) Leaf C and N contents and leaf C∶N, C∶P and N∶P mass ratios were mainly determined by plant species, and leaf P content was mainly affected by growing season. It was thus clear that the contents of C, N, P and C∶N, C∶P and N∶P ratios in the leaves of desert plants in Minqin varied from species to species in the growing season, and their coefficient of variation in the growing season were also different among plant species.

Abstract:In order to reveal the changes of undergrowth shrubs and herbs community structure and diversity after fire of mixed Pinus thunbergiiQuercus acutissima forests understory plant community and explore the relationship between community species distribution and diversity index and soil factors in Jiaodong Hilly Area, we took medium fire, low fire and unburned forest in Weihai burned area as research object. Quantitative soil analysis and plant species diversity surveys were conducted on different firesoiled forests, and the canonical correspondence analysis (CCA) and redundant analysis (RDA) were used to sort and compare the diversity of shrub plants under different fireburning areas. The main soil factors affecting the species diversity of understory shrub communities in different fire areas were also explored. The results show that: (1) the richness, diversity and evenness index of all forestlands presented as herb layer > shrub layer in the vertical direction of the community. The richness, diversity and evenness index of shrub layer rose firstly and then decreased with the increase of fire intensity, reaching the maximum value in the low fire. It is the key transitional period of shrub community characteristic change. The herb layer Patrick, ShannonWiener and Simpson index gradually decreased, and the Margalef index firstly decreased and then slightly increased, reaching the maximum value in the unburned forest, and the evenness index showed no significant difference among the woodlands (P> 0.05). (2) The MoristaHorn index between unburned and medium fire was the smallest in shrub layer, herbaceous layer and shrub layer, with the highest βdiversity, and different composition of undergrowth species. Low and medium fire had higher heterogeneity at shrub level, while unburned and low fire had higher heterogeneity at herb level. (3) Medium fire and low fire understory shrubs and herbs communities can be roughly divided into three groups. The shrub layer and herbaceous layer plants under unburned forest scattered without forming a community. The main positive factors of moderate burning on plant diversity were carbon nitrogen ratio (C/N), and the main negative factors were total phosphorus (TP) and total potassium (TK). The forward factor is phosphorus nitrogen ratio (N/P) and the reverse factor is pH. The species diversity of unburned forest land is affected by a variety of soil factors. (4) Fire increased the rate of species replacement in undergrowth shrub community, increased the species diversity in shrub layer, and decreased the species diversity in herb layer. There are similarities and differences in the factors that affect the species diversity of the community in the fire area. TK and TP are the common influencing factors of plant diversity in the burned area, and P is the common limiting element of plant diversity in the burned area.

Abstract:We conducted an experiment on 9 years of continuous nitrogen application to explore the effect of nitrogen addition on plant community structure in Stipa baicalensis steppe, with different nitrogen addition levels of 0(N0), 15(N15), 30(N30), 50(N50), 100(N100), 150(N150), 200(N200) and 300(N300) kg·hm^-2·a^-1. The responses of community structure and important value, diversity as well as biomass to different nitrogen addition in 9 years of continuous nitrogen application were explored. The results showed that: (1) community structure was significantly responded to longterm nitrogen addition with the lowest species number in high nitrogen application rate, while the highest important value in dominant species under high nitrogen application rate was observed. (2) Plant diversity index in S. baicalensis steppe was reduced with varying degrees in longterm nitrogen addition. The dominance index was increased with longterm nitrogen addition with the most prominent value in N300 level addition (P<0.05). (3) The productivity of grassland vegetation (aboveground and belowground biomass) increased firstly and then decreased after longterm nitrogen addition. The peak value of aboveground biomass was observed under N100 level addition, while the maximum value of belowground biomass was appeared at N50 level (P<0.05). Root was characterized at 0-10 cm distribution. (4) RDA analysis showed that aboveground biomass of Carex duriuscula and Bupleurum scorzonerifolium were significantly positively correlated with soil pH (P<0.05), and Thalictrum sguarrosum and Potentilla bifurca were significantly positively correlated with soil organic matter (P<0.05). The community structure in S. baicalensis steppe was greatly responded to longterm nitrogen addition composition with diversity decreased and changes in community composition.

Abstract:Different artificial forest lands under typical slopes in southern Ningxia mountainous region were selected as research objects. We collected soil samplings from 0-600 cm different profiles to analyze vertical profile characteristics of soil moisture in apricot, poplar, elm, locust, pine, and with farmland as control group. Soil desiccation index, compared soil water deficit index, dry layer initial depth, thicknesses of desiccated soil layer and average water content in the dry layer were used to evaluate soil desiccation intensity and distribution characteristics, and used redundant analysis to determine the effects of relevant environmental factors on soil desiccation and dry layers. The results showed that: (1) the soil moisture of apricot, poplar, elm, locust and pine trees were moderately variable, and the average soil water content of 0-600 cm was 31.17%, 24.15%, 23.19%, 29.67% and 18.35%, respectively, which were lower than that of farmland. (2) The initial depth of soil dry layer, the thickness of soil dry layer and the distribution of soil moisture in vertical profile were obviously different in different lands. The initial depths of apricot, poplar, elm, locust, pine and farmland trunk layers were 90, 160, 140, 140, 160 and 600 cm, respectively. The thickness of dry layer was 510 cm, 460 cm, 480 cm, 480 cm, 460 cm and 0 cm, respectively. (3) The soil drying index of 0-600 cm profile of apricot, poplar, elm, locust and pine were 63.48%, 91.88%, 95.17%, 73.97% and 111.91%, respectively. The relative deficit index of soil moisture was 0.68, 0.59, 0.52, 0.63 and 0.41, respectively. The order of soil moisture desiccation intensity and deficit degree from high to low was apricot > locust > poplar > elm > pine. (4) RDA analysis showed that the arbor types， clay content and topographic conditions were important factors affecting soil dry layer.

Abstract:The widespread use of antibiotics abuse lead to bacterial resistance increased, thus to explore the new method of antibacterial, search for new antimicrobial agents has very important significance. In this paper, solvents of different polarity were used to extract extracts from jujube fruits with different polarity ranges from low polarity to high polarity. By detecting the antimicrobial we screened the effect of the extracts and the synergistic antimicrobial effect of the extracts and antibiotics, the active extracts with antimicrobial and antibiotic sensitization effects. The active extracts were further isolated and purified by column chromatography with activity tracking. (1) Among all the extracts of jujube fruits, only chloroform extract of wild jujube fruits has broadspectrum antibacterial effect and can significantly enhance the sensitivity of Pseudomonas aeruginosa to ampicillin, while other extracts have no corresponding biological activity. (2) Fr.2a component obtained by further refining the chloroform extract of wild jujube fruits, GCMS analysis showed that it contained 49.59% of 1, 3dichloropropanol, 5.49% of 1, 1dichloromethyl ether, 0.96% of hexachloroethane, 7.81% of 1, 1, 2, 3tetrachloro2propylene, 1.33% of lauric acid, 1.34% of myristic acid, 0.87% of palmitoleic acid, 7.37% of palmitic acid, 9.75% of dibutyl phthalate, 2.02% of trans13octadecentenoic acid, 1.88% of oleamide, 3.06% of βamyrin, 0.93% of αacorenol alcohol, 6.20% of lupeol, 1.42% of ursolic aldehyde. (3) The combination of Fr.2a with a variety of antibiotics showed extensive synergistic antimicrobial effects, while Fr.2a in a dosedependent manner promoted the formation of microbial biofilms, reduced microbial motility and significantly inhibited the growth of microorganisms in milk. These studies have laid a foundation for the development of wild jujube medicinal products and natural preservatives.

Abstract:In the observation of diatom samples from Dianshan Lake, Shanghai, China, two species are new records of China. They are Cyclotella costei Druart & Straub and Sellaphora pseudoventralis (Hustedt) Chudaev & Gololobova. For the two newly reported species, morphological characters, habitat and distribution were described in detail. It enriched the biodiversity of diatoms in China.

Abstract:By the fourth survey of Chinese medicinal resources in Jiali County and Mangkang County of Tibet Autonomous Region, a Rhodiola plant was discovered on the limestone of bushes at an altitude 4 000-5 000 m, which is morphologically similar to Rhodiola humilis (HK. f. et Thoms.) S. H. Fu, but it is unique characteristics in inflorescence aterminal cymose, flowering stems closed to 7-13 branches, caudex leaves apex acute, sepals long triangular, apex organs of leaves and sepals dark pink finely mammilla, et. al, which is not same as R. humilis. Molecular biology evidence indicates that phylogeny is associated with R. humilis and Rhodiola smithii (Hamet) S. H. Fu. Based on morphological and molecular biological evidence, we described it as a new variety, named Rhodiola humilis (HK. f. et Thoms.) S. H. Fu var. jialiensis H. Wang, X. Z. Lan & H. P. Deng.

Abstract:This paper reports a new record of Orchidaceae from the Qinling Mountains, Neottia papilligera Schltr. This species was previously known from the northeast China, the east Siberia and the Far East Russia, the Korean Peninsula and Japan. The occurrence of N. papilligera in the Qinling Mountains extends its distribution in China for about 8 degrees of latitude to the south, from the cold and moderate temperate zones to the south edge of the warm temperate zone in China. A key to the 8 species of Neottia in the Qinling Mountains is provided.