Abstract:The WRKY transcription factors family gene NtWRKYY2（GenBank: KX056496）were cloned by PCR technology from Narcissus tazetta var. ‘Yunxiang’. The Open Reading Frame (ORF) of NtWRKYY2 contained 867 bp, encoding a protein of 289 amino acid residues. Multiple alignments and phylogenetic analysis showed that NtWRKYY2 proteins containing one WRKY consecutive structural domain and C₂H₂ type zinc finger（Csx4Cx23HxH）belong to Ⅱd subgroup of WRKY transcription factor together. Quantitative realtime PCR (qRTPCR) analysis demonstrated that the NtWRKYY2 gene was obviously induced by salt stress in ‘Yunxiang’. We constructed overexpressing vector pMDC140NtWRKYY2 using InFusion cloning technique, and transformed into tobacco by the method of Agrobacterium though leaf disc transformation. The carrier of PCR results indicated that the resistant plantlets were positive and the converting rate of 72%. Salt stress and chlorophyll fluorescence parameter analysis showed that after the salt stress treatment, overexpression of NtWRKYY2 transgenic tobacco showed less wilt and chlorosis than the wild type plants, and the decrease of F_v/F_m value was less than the wild type plants. Studies have shown that overexpression of the NtWRKYY2 gene remarkably increased the salt tolerance in transgenic tobacco. This study offers an alternative gene for salt tolerant transgenic breeding of Narcissus.

Abstract:GND coded glucose 6phosphate dehydrogenase (G6PDH) is a key enzyme in the pentose phosphate pathway. In order to understand molecular information of GND and mechanism in response to drought stress, we cloned GND by designed specific primers based on sequences of homologous cyanobacteria species. The sequence was analysed by bioinformatics methods, and the differential expression of GND and G6PDH activities of N. flagelliforme under drought stress were also discussed. The results indicated that: (1) the full length of GND is 1 431 bp（GenBank access number: KX553955）. Nucleotide sequence and deduced amino acid sequences of GND from N. flagelliforme were similar to that of N. punctiforme PCC 73102 with similarities above 96% and 98%, respectively. Ile is the most hydrophobic in site 26 and 27, but Arg is the most hydrophilic in site 302. Thr, Ser and Tys have 19, 18 and 5 phosphorylation sites, respectively. Secondary and tertiary predicted structures of G6PDH were made up of α helix, β sheet, β turn and random coil. (2) GND was expressed in E. coil then a 47.23 kD heterologous protein was observed and tested by MALDITOFTOF/MS. (3) GND expression at the transcription level and G6PDH activity were all gradually increased under drought stress. The results provided a foundation for further research in GND expression and regulation of N. flagelliforme in response to drought stress.

Abstract:SUN gene is the major gene controlling fruit shape in tomato. In this study, we searched the grape sequence in NCBI, found the highest similar sequence of SUN gene in grape as compared with tomato and designed the specific primer. The cDNA of SUN gene, which is named VvSUN, is cloned by RTPCR technique. Sequence analysis showed that the VvSUN gene contains a 1 278 bp open reading frame (ORF), which encodes a polypeptide of 425 amino acids with a calculated molecular weight of 48.11 kD and an isoelectric point of 10.63. Moreover, the data also indicated that VvSUN is a nontransmembrane and hydrophilic protein and most likely located in the nucleus and mitochondrial membrane, without signal peptide. Secondary structure analysis indicated that αhelix and random coil are the main structural elements in VvSUN protein. The amino acid sequence encoded by VvSUN gene has an IQ conserved domain, and the sequence similarity to other seven plants IQD family members in NCBI is 43%-53%. The phylogenetic tree showed that grape has the closest relationship with Arabidopsis thaliana IQD12 gene. According to these observations, we predicted that VvSUN protein in grape has similar functions with SUN protein in tomato. In addition, we performed quantitative realtime PCR (qRTPCR) to determine the expression pattern of VvSUN in grape at different developmental stages and under gibberellin (GA₃) treatments and used the vertical and horizontal diameters to evaluate the effects of GA₃. Realtime PCR analysis revealed that the expression level of VvSUN gene showed the highest level at anthesis in two varieties, while maintained relatively low levels after anthesis. GA₃ treatments markedly increased the fruit shape index, and pronouncedly enhanced the expression level of VvSUN gene in young fruit. Thus, our results suggested that the VvSUN gene in grape may be involved in the regulation of fruit elongation.

Abstract:In this study, we analyzed genetic diversity and population genetic structure of 8 natural distribution populations (total 105 individuals) based on ITS1ITS4 sequence of endangered plant Amygdalus pedunculata, to darify the geographical distribution and genetic diversity of A. pedunculata. The results showed that: (1) the length of ITS1ITS4 fragments is 583 bp; 13 variation sites and 8 haplotypes were obtained. Total genetic diversity was 0.727, average genetic diversity within populations was 0.564, haplotype diversity and nucleotide diversity ranged from 0.182 to 0.636 and 0.000 6 to 0.006 3, respectively; (2) Genetic differentiation among these populations was not very significant. AMOVA analysis show that 33.65％ of total variation occurred among populations and 66.35% occurred within population. Mean gene flow among the populations was 0.986. A significant phylogeography structure was observed (G_ST=0.225, N_ST=0.362, P＜0.05). Results of neutrality tests and mismatch distribution curves show that A. pedunculata did not experience recent population expansion. (3) Haplotypes of the MJ network and ML tree show that populations of Inner Mongolia and Shaanxi clustered into two genetic lineages.

Abstract:In order to explore the molecular characteristics and evolution of the miR159 family members, we studied the miR159 family members registered in the miRBase database by distribution statistics, constructing the phylogenetic trees, comparing different families, and predicting their secondary structures and target genes. The results showed that the miR159 family was widely distributed in the plant community, and the ferns may be the evolutionary ancestors of the miR159 family. Phylogenetic tree analysis showed that there were multiple evolutionary directions among the members of the plant miR159 family, but the miR159 family members of the same type of plants tended to be clustered, and the members from the same evolutionary direction were highly homologous. Mfold predicts that premiR159 spontaneously forms a typical, stable stemloop secondary structure, and contains functional fragments ranged from 19~21 bases, which may be miR159 mature body. Target gene analysis showed that miR159 family members mainly regulate MYB transcription factor, transposable factor and hypothetical protein, but the types and numbers of target genes were differences among different species and among different members of the same species, especially between miR1593p and miR1595p.

Abstract:We studied the root and stem anatomical characteristics of Malus toringoides, Malus transitoria, Malus baccata and Malus hupehensis in Western Sichuan Plateau, to analyze the relationships between the anatomical characteristics and drought resistance, and to reveal their drought adaptation strategies. The results were showed as follows: (1) the anatomical structures of root and stem were basically similar: The secondary structure of root was consisted of periderm and vascular. The stem structure was composed of periderm, cortex, vascular and pith. (2) Some special structures occurred in the four plants: The xylem ray in root system widened to 6-8 rows that the axial transport of water was benefited evidently. The sclerenchyma cells in phelloderm and perimedullary zone, the ‘pseudoparenchymatous cells’ around vessels were special architectural feature in increment of water conduction and mechanical support. (3) The drought adaptation strategies of four Malus plants were different: M. toringoides had welldeveloped conductive organization in root and stem; M. transitoria had strong phloem in root and advanced pith in stem; M. baccatas phloem in stem was stronger and diameter of vessels in root was wider; M. hupehensis had advanced phelloderm and phloem structures in root and broader piths in stem.

Abstract:In order to evaluate the responses of physiological indexes of Sonchus oleraceus to shortterm salt stress and provide theoretical instructions to the further research of salt tolerance and tolerance mechanism for wild plants, we irrigated S. oleraceus seedings with Hoagland’s nutrient solution containing NaCl at various concentrations［0 (control), 66, 133, 200, 250, 300 mmol·L^-1］. After 1, 2 and 3 day of salt treatments, the leaves of plants were harvested, Na⁺, K⁺, malondialdehyde (MDA), soluble sugar, soluble protein, free proline contents and superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities were measured. The results showed that: (1) after 1, 2 day of 66~200 mmol·L^-1 NaCl，the changes of Na⁺ content were not obvious. K⁺ content and K⁺/ Na⁺ ratio significantly increased with salinity compared with CK and reached to the maximun at 200 mmol·L^-1 NaCl. After 3 day of salt treatment, the changes of K⁺ content had the similar tendency with 1 day and 2 day treatments. Na⁺ content significantly increased with salinity. K⁺/ Na⁺ ratio significantly decreased with salinity except at 66 mmol·L^-1 NaCl. (2) Soluble sugar, soluble protein and proline contents increased, then decreased with salinity after 1-3 day of salt stress. At 200 mmol·L^-1 NaCl, soluble protein content reached to the maximun after 1 day and 2 day salt stress and soluble sugar content reached to the maximun after 2 day and 3 day salt stress. Free proline had the similar tendency after 1 day and 2 day salt stress and significantly increased compared with CK with salinity after 3 day salt stress. (3) The activities of SOD, POD and CAT increased then decreased with salinity after 1~3 day salt stress. All of them reached to the maximun at 250 mmol·L^-1 NaCl and were much higher than CK at all levels of salinity after 1 day and 2 day salt stress. The activities of SOD and POD reached to the maximun at 200 mmol·L^-1 NaCl after 3 day salt stress, during which CAT activity reached to the maximun at 250 mmol·L^-1 NaCl and were much higher than CK except at 250 and 300 mmol·L^-1 NaCl. It was demonstrated that S. oleraceus was very salt tolerant and could tolerance 66-300 mmol·L^-1 NaCl, as judged from the higher ability to absorb K⁺ and reject Na⁺ as well as the higher osmoregulation and antioxidant capacity, almost relieving the toxicity of Na⁺ and osmotic stress. But, the osmoregulation and antioxidant capacity decrease when NaCl concentration exceed 200 mmol·L^-1.

Abstract:We selected the two shrubs Hippophae rhamnoides and Salix cupularis as the donator vegetation, which was pioneer species in the restoration process of desertification alpine meadow, meanwhile selected Festuca sinensis, Avena sativa, Elymus nutans, and E. sibiricus as the receptor vegetation. In order to find the suitable associated herb species which can cooccur with them, we compared the different effects of root aqueous extracts of the two shrubs on four different alpine forage species, including seed germination rate, seedling growth and antioxidant enzyme activities. The results showed that two kinds of root aqueous extracts of the pioneer species produced significant allelopathy effect on the four herbs and most of them indicated a tendency of inhibition under high concentration, but stimulation under low concentration. (1) Root aqueous extracts from the two shrubs facilitated significantly seed germination rate of each herb species under the 10 to 20 g·L^-1concentration(P<0.05), but subsequently it turned to inhibition with the concentration increasing. Except that seed germination of E. nutans was inhibited only under the concentration of 80 g·L^-1, and the other herb species germination decreased significantly(P<0.05). (2) The roots of F. sinensis and A. sativa seedling were absolutely inhibited by two kind of root aqueous extracts, but E. nutans only was inhibited when concentration reached 80 g·L^-1; the root aqueous extract of H. rhamnoides when concentration was 20 g·L^-1could significantly promoted the growth of A. sativa and E. nutans’ leaf and fresh weight (P<0.05), while S. cupularis only promoted F. sinensis. (3) When the concentrationof root aqueous extract of H. rhamnoides was 20 g·L^-1, the activities of CAT and SOD in every kind of receptor vegetation were stimulated significantly(P<0.05); when the concentration of root aqueous extract of S. cupularis was 20 g·L^-1and 40 g·L^-1, the activities of CAT in A. sativa and E. sibiricus and SOD in F. sinensis were improved significantly(P<0.05), but it inhibited the activity of SOD in A. sativa and E. nutans when concentration was 40 g·L^-1(P<0.05). Corresponding to changes in the activities of enzymes, the content of MDA reduced first and then increased. (4) According to the synthetical allelopathic index, E. nutans has best adaptation on root aqueous extracts of two shrub species, only inhibited under the concentration of 80 g·L^-1. All in all, S. cupularis facilitated the germination rate, seedling growth and the activities of antioxidant enzymes of F. sinensis and A. sativa better than that of H.rhamnoides, and moreover H.rhamnoides was more suitable with E. nutans and E. sibiricus.

Abstract:The seeds of quinoa variety “Yilong No.1” were used as experimental material in pot in 2016. We studied the effects of inoculating two kinds of arbuscular mycorrhizal fungi (AM) including Glomus mosseae (Gm) and Glomus tortuosum (Gt) on the quinoa growth, root growth indicators and root physiological indicators under the different nitrogen application rates of 0, 0.2, 0.4 and 0.6 g/kg, to provide the theoretical basis for increasing the utilization rate of nitrogen fertilizer and improve the growth of quinoa. The main results showed that: (1) inoculation of Glomus mosseae had the highest infection rate and mycorrhizal dependency of quinoa under 0.4 g/kg nitrogen application rate. (2) Under the same inoculated treatment, plant height, stem diameter, leaf area, aboveground weight, total root length and other root growth indicators, antioxidant enzyme activities of root system of quinoa seeds were initially increased and then decreased with the increasing nitrogen application rate; compared with the uninoculated treatment, the above indicators were significantly improved after AM fungi was inoculated. The values reached the maximum in the 0.4 g/kg nitrogen application rate, and the increase of Gm was greater than that of Gt. (3) Under the same inoculated treatment, MDA content, soluble sugar content and proline content were initially decreased and then increased with the increasing nitrogen application rate; compared with the uninoculated treatment, the MDA content was significantly reduced after AM fungi was inoculated, soluble sugar content and proline content were significantly increased after AM fungi was inoculated. Meanwhile, after inoculating Gm the decrease of MDA content, the increase of soluble sugar content and proline content were greater than that of incoculating Gt. These results showed that the infection rate and mycorrhizal dependency in root of quinoa with the proper nitrogen application rate increasing, the growth of aboveground and root of quinoa were promoted, meanwhile, increased the accumulation of antioxidant enzymes and osmotic adjustment substances, decreased the accumulation of harmful substances, especially 0.4 g/kg nitrogen application rate and Glomus mosseae were favorable for quinoa seeds to increase growth.

Abstract:In order to reveal the physiological response mechanism of Fagopyrum tataricum to low nitrogen(N) stress, were conducted the pot experiment to study the effects of low N stress on the seedling growth, root physiological traits and nitrogen uptaking. The experimental materials included 2 lowN tolerant cultivars (‘Diqing kuqiao’, ‘Guangku 1’) and 2 lowN sensitive cultivars (‘Xiqiao 1’, ‘Heifeng 1’). Three results were drawn from the this experiment. (1) Compared to the normal N treatment (15 mmol/L), the plant height, stem diameter, leaf area, shoot dry weight, root diameter, root volume and root area were declined, root/shoot ratio and main root length were increased under lowN stress (0.5 mmol/L) and very lowN stress (0.05 mmol/L). Besides, the root dry weight increased to a certain stress extent under lowN stress, and the amplification of lowN tolerant cultivars was more bigger (13.69% and 19.26%); (2) LowN stress could make leaf chlorophyll content, F_m, F_v/F_m, root activity, nitrate reductase (NR) activity and soluble protein content significantly decreased, but make F_o, root superoxide dismutase (SOD) activity, peroxidase (POD) activity, malonaldehyde (MDA) content, soluble sugar content and free proline content increased; (3) Plant N content and plant N uptake significantly decreased under lowN stress, while plant N uptake efficiency increased. The study has shown that the different F. tararicum cultivars to lowN stress were significantly different. Under low N environment, lowN tolerant cultivars had the obvious advantages of growth not only because the less influence of low N pressure to agronomic character, photosynthesis and root activity, but also because the higher root protective enzyme activity, osmotic adjustment substances contents, plant N contents and plant N uptake.

Abstract:In order to investigate the effect of Streptomyces JD211 on physiological mechanism of hypersensitive response in rice after inoculation with Magnaporthe grisea, with the rice variety “Luliangyou 996” as materials, we conducted pot experiments by applying powdered Streptomyces JD211 cultivation of rice and inoculated with rice blast fungus spore suspension, and then sprayed with water as control, hydrogen peroxide (H₂O₂), catalase (CAT), lipoxygenase (LOX), malondialdehyde (MDA) and cell membrane permeability in rice leaves were determined. The results showed that: (1) when the rice seedling age was 30 days, the treatment group with adding Streptomyces JD211, (CAT), (LOX) and (H₂O₂) increased by 50.30%, 40.85% and 45.31%, respectively compared with the control group and (MDA) decreased by 25.75%. (2) After inoculate with Magnaporthe grisea, plus JD211 treatment group, (CAT), (LOX) and (H₂O₂) were increased by 33.50%, 4.07% and 47.76% than that of the group without JD211, MDA decreased by 38.68%. (3) After inoculation of Magnaporthe grisea, the JD211 treatment group compared to the group without JD211, cell membrane permeability increased by 38.94%, 39.03% and 8.08% at the age of 32 days, 34 days, 36 days, respectively. It is considered that Streptomyces JD211 enhanced the content of H₂O₂, and the activities of CAT and LOX, while inhibited the accumulation of MDA. The cell membrane permeability also increased with the inoculation of Magnaporthe grisea in the later stages, which can effectively regulate the hypersensitive response in the cell, induced cell necrosis, further prevented pathogens infection, and effectively improved rice resistance to rice blast.

Abstract:This study was conducted to investigate changes of seed germination, seedling morphological and physiological indexes of endophyteinfected (E⁺) and endophytefree (E^-) perennial ryegrass (Lolium perenne) in latosols extracts solution with different pH（4.47-6.12）by using the laboratory germination experiment, to analyze the effect of the endophytic fungi on seedling growth and physiological characteristics of ryegrass in an acidic environment. The result showed that: (1) in the same endophyte infection［endophyteinfected (E⁺) or endophytefree (E^-)］ of case, the germination rate, germination energy, germination index, vigor index of seeds, shoot length, root length, fresh weight and dry weight of seedling showed a decreasing trend with the decrease of latosols extracts solution pH value (the acidity of the extracts is enhanced), and the treatments of five latosols extracts solution were significantly lower than that of CK (pH, 6.12) (P <0.05); proline content, superoxide dismutase activity (SOD), peroxidase activity(POD), and malondialdehyde content (MDA) of ryegrass had minimum value under pH 6.12, and were significantly lower (P <0.05) than that of other five treatments of latosols extracts solution. (2) In addition to the control (CK), endophyteinfection significantly (P<0.05) improved germination rate, germination energy, germination index, vigor index, shoot length, fresh weight, dry weight, proline content and SOD activity, and decreased the POD activity and MDA content under pH 4.47-5.01. In the acid latosols extracts solution, the root length of perennial ryegrass that endophyteinfected (E⁺) had no significant difference (P>0.05) with endophytefree (E^-) when the acid latosols extracts solution pH 4.47-6.12.The results showed that the effects of latosols extracts solution with different pH on seed germination, growth and physiology of endophyteinfected (E⁺) and endophytefree (E^-), and endophytic fungi improved the growth and adaptive capacity of host in wider pH of latosol extraction. The symbiont of perennial ryegrassendophytic fungi can be used for improving acid soil.

Abstract:The ultradry preservation of the rare and endangered species Populus euphratica seeds was carried out to determine the optimal moisture content and rewetting method in this paper. The feasibility of ultradry preservation of P. euphratica seeds was determined by measurements of contents of various enzymes, soluble sugar and malondialdehyde(MDA). The P. euphratica seeds with different water contents were prepared by the method of dehydration of silica gel. The seeds were rewetted with different solutions, and the optimal wetting method was selected. After treated by aging, the activities of enzymes, soluble sugar, and malondialdehyde in the optimum moisture content of seeds were determined after rewetting to determine the effect of ultradry preservation. The results showed that: (1) the seed germination rate decreased with the water content decreased to 3.4%. The seed germination rate and germination potential of P. euphratica seeds could be restored to the samples without ultradry treatment after rewetting. The optimum moisture content was determined as 3.4%. (2) After comparison of four different methods, the results showed that rewetting with saturated NH₄Cl for 12 h after rewetting with saturated CaCl₂ was a better method of rewetting. (3) The aging results showed that the suitable ultradry treatment could increase the activities of peroxidase, catalase, dehydrogenase and the content of soluble sugar, and decrease the content of MDA in the seeds with 3.4% moisture at 50 ℃. Therefore, ultradry preservation of P.euphratica seeds has a certain feasibility for enhancing the antiaging ability of the seeds.

Abstract:In this study, with melon variety ‘Hamilü’ as material, we studied the seed vigor indexes, physiological and biochemical changes, and controlling bacterial fruit blotch of different dryheat treatments (temperature: 70 ℃, 75 ℃, 80 ℃; time: 24 h, 48 h, 72 h). The results as followed: (1) the seed germination indexes and seedling rate of melon significantly decreased with the increase treatment of temperature and time. However, the treatments of 70 ℃ for 24 h and 48 h had no significant effect on seed germination index (except vigor index) and seedling rate. (2) Compared with the control, SOD activity, soluble sugar and proline contents of melon germ increased. At the same temperature, SOD activity and soluble sugar content showed a increasing trend, while proline content decreased with the increase of time treatments; on the other hand, the POD, APX activities and soluble protein content decreased with the increase of temperature and time treatments. Compared with the control, CAT activity decreased of 70 ℃ treatment and increased of 75 ℃ and 80 ℃ treatments, but they were decreased with the increase of time treatments. Compared with the control, changes of O-·2 production rate of 70 ℃ and 75 ℃ treatments had no significant difference, but it increased with the increase of time treatment under 80 ℃ treatment. (3) Compared with the control, seed inoculated Acidovorax citrulli of melon seedlings significantly decreased with the increase of temperature and time treatments. Comprehensive analysis showed that the proper dryheat treatments and times caused enhances in antioxidant enzyme activities and osmotic adjustment substance contents, decreases in O-·2 production rate, as well as increased seed germination indexes and seedling rate. Meanwhile, the results showed that 70 ℃ for 48 h was the effective and safe treatment for melon seeds.

Abstract:To understand the growth adaptability and salt tolerance mechanism of Juniperus chinensis seedlings under NaCl stress, we investigated the cationic absorption and distribution in different organs (such as roots, stems and needles) of the raw J. chinensis seedlings and its biomass accumulation under different levels of NaCl (0, 100, 200, and 300 mmol·L^-1) stress through potted soil culturing in greenhouse. The results showed that: (1) with the increase of NaCl concentration, the growth including plant height, ground diameter, relative height growth and biomass accumulation were declined, while the root/shoot ratio was increased, indicating that the growth was inhibited; (2) under the NaCl stress, the Na⁺ concentrations in the roots, stems and needles of the J. chinensis seedlings were significantly increased compared with those of the contrast seedlings, and the Na⁺ concentration in the needles was significantly higher than that in stems and roots, the Na⁺ concentration in the needles was 5fold higher in the roots; (3) with the increase of NaCl concentration, the K⁺, Ca²⁺ and Mg²⁺ contents, K⁺/Na⁺, Ca²⁺/Na⁺ and Mg²⁺/Na⁺ ratios in different organs of the seedlings were decreased; (4) under the NaCl stress, the K⁺Na⁺ selective transportation coefficients (S_{K, Na}), Ca²⁺Na⁺ selective transportation coefficients (S_{Ca, Na}) and Mg²⁺Na⁺ selective transportation coefficients (S_{Mg, Na}) of the roots were significantly decreased, but the S_Ca,Na and S_Mg,Na of the stems and needles were generally decreased, while S_K,Na of the needles were significantly declined with the increase of NaCl concentration. And large amount of Na⁺ was retained in shoots, which was advantageous for reducing the damage of salt stress to roots. In conclusion, our findings suggested that the saltadaptation mechanisma of J. chinensis seedlings were primarily implemented by root growth stimulation, stems and needles Na⁺ accumulation, and are also correlated with a remarkably increased ability of K⁺, Ca²⁺ and Mg²⁺ selective transportation in roots and steadyability of K⁺, Ca²⁺ and Mg²⁺ selective transportation in stems and needles.

Abstract:To understand the response and adaptation of carbon（C）, nitrogen（N）and phosphorus（P）stoichimetry to environmental changes, we conducted a provenance experiment on C.liouana,the dominant shrub species in the Mu Us Sandland of Northern China. We collected seeds from nine provenances and seedlings were cultivated under uniform condition, measuring the concentrations of C, N and P of different organs of C.liouana originated from nine provenances. The results showed that: (1) there were significant differences in C, N and P concentrations among provenances for different organs, with C concentrations of roots, stems and leaves ranging from 361.12 to 426.30 mg·g^-1, from 412.32 to 463.13 mg·g^-1, from 419.21 to 478.94 mg·g^-1, respectively, with N concentrations ranging from 20.52 to 33.67 mg·g^-1, from 15.77 to 23.92 mg·g^-1, from 27.60 to 36.44 mg·g^-1 and with P concentrations from 1.52 to 3.73 mg·g^-1, from 1.24 to 2.14 mg·g^-1, from 1.44 to 2.38 mg·g^-1, respectively.The C/N, C/P and N/P were also significantly differed among provenances for different organs. (2) GLM analysis revealed that relative to the strong effect of organs on C, N and C/N, the provenances appeared to have greater effects on P, C/P and N/P. (3) There were also significant correlations between N and C/N, P and C/P. The N/P was significantly correlated with both N and P. Overall, these results suggest that adaptation of C.liouana to different environments has led to its genetic differentiation in stoichiometric traits, and differences in C, N and P stoichiometry among different organs probably suggest that C.liouana has evolved a series of strategies in nutrient utilization.

Abstract:To study the spatial heterogeneity of soil organic matter (SOM) and soil enzyme of Caragana korshinskii shrub nebkhas, we evaluated the content of SOM and enzyme activities (urease, saccharase, phosphatase, catalase) of different size C.korshinskii shrub nebkhas in three positions (the top, the middle and the bottom of nebkhas). The results indicated that: (1) the different sizes of nebkhas had no significantly effect on content of soil water moisture and pH value and it had little different among top, middle and bottom positions. The content of SOM decreased with the nebkhas development. The SOM content of top is higher than that of others obviously. (2) The activity of urease and saccharase decreased with the nebkhas development, while phosphatase and catalase first increased and then decreased. The soil enzyme activities decreased from top to bottom of nebkhas. The soil enzyme activities decreased with soil depth. The soil pH value, nebkhas size and soil water moisture were shown significant negative relation to soil saccharase enzyme activities（P ＜0.05), while had very significant negative to phosphatase. The SOM content had no correlation with catalase, while had very significant positive to others. These results suggested that C.korshinskii could increase soil nutrient and enhance soil enzyme activities. Caragana could play a vital role in soil recovery in a graded area of a desert zone and gradually reduced with the development of the nebkhas.

Abstract:In order to investigate the response of growth and PSⅡ of Dunaliella salina to different nitrogen sources, we performed experiments by using NaNO₃, CO(NH₂)₂, NaNO₂, and NH₄Cl as nitrogen sources and N control was set in this study. Our results showed that: (1) D. salina grew faster under CO(NH₂)₂ with a maximum growth rate［μ_max, (0.482±0.032)/d］ per day than under other nitrogen sources. (2) Results of chlorophyll fluorescence indicated no significantly different in the initial slope of the RLC before the onset of saturation (α), the maximum potential ETR (rETRmax), the maximum photochemistry efficiency (F_v/F_m), the maximum quantum yield of primary photochemistry (φ_P0), quantum yield for electron transport (φ_E0), probability(t=0) that a trapped exit on moves an electron into the electron transport chain beyond Q_A^- (ψ₀), absorption flux per RC (ABS/RC) and trapped energy flux per RC(t=0) (TR₀/RC) among NaNO₃, CO(NH₂)₂, and NaNO₂ groups (P＞0.05), while there is significantly different in these parameters when compared with NH₄Cl and N controls (P＜0.05). (3) Compared with the NaNO₂, NaNO₃, and CO(NH₂)₂ groups, the relative variable fluorescence (V_j) of D. salina increased significantly under nitrogen free treatment (P＜0.05), which suggesting restriction of photosynthetic electron transport of D. salina from Q_A^- to Q_B and accumulation of Q_A^-. However, we can infer destroy of the oxygen evolving complex (OEC) of D. salina by the NH₄Cl from the appearance of K phase under NH₄Cl. As a whole, these results showed that D. salina grew much faster under CO(NH₂)₂ than that under NaNO₃ and NaNO₂, whereas the growth of D. salina was inhibited significantly by nitrogen deficiency, and the number of reactive centers in PS II was decreased, and the electron transport was blocked. However, toxicity effect of NH₄Cl on D. salina caused its death in a short time and the OEC of D. salina was damaged.

Abstract:Primula florindae is a typical distylous speices of Primula and an endemic species in the QinghaiTibet Plateau. In this research, we set 5 plots of natural population from 3 100 m to the treeline (4 350 m) along the Sygera Mountains without anthropogenic interference and select flowering phenology, floral display traits, pollinators, sex allocation, and natural seed set as characters. By comparing these characters among five populations along altitudinal gradients, we make certainly the adaptive strategies of reproductive characters to altitudinal variation, and discuss the possible influences of future climate change on distribution pattern of P. florindae. We highlight three conclusions: (1) initial blooming time of P. florindae did not show a correlation with elevation: the middle elevation population bloomed the earliest and the highest population bloomed last. Nevertheless, with the increase of elevation, flower longevity and floral display area of both morphs of P. florindae increased significantly, but varieties of pollinators decreased, and both morphs tend to allocate more resources to assure female sexual function. The adaption of the traits studied to heterogeneity habitats among different elevations may lead to the variation of reproductive strategies. (2) With the increase of elevation, flower number of P. florindae significantly diminished, but both herbivory number and rate also reduced, so effective fruit number of all populations showed no distinct disparity, and there were also no significant differences in seed number, showing that by shaping corresponding reproductive strategies to different environment, P. florindae guaranteed breeding success, then stabilized population in all elevations. (3) Climate change will have profound and lasting impacts on the distribution of P. florindae, the lower altitudinal limit may shift up, but sandy soils at higher elevations are unfavorable to its growth, while the temporalspatial distribution of pollinators under climate change are still unknown. We predict the lower altitudinal limit of P. florindae will move up to middle elevation and result in a decrease in its distribution over the next 100 years.

Abstract:Keteleeria davidiana is tertiary period relict gymnosperm, which is listed as Chinas endangered tree species, and also is one of the most important tree species compositions of the natural vegetation along the Nanpan River. In this study, a standard permanent plot with 100 m × 80 m sizes was set up in Guangxi Yachang Orchid National Nature Reserve of Nanpan River basin by the typical sample method. The bivariate distribution of forest stand spatial structural parameters (BDFSSSP) was used to analyze the spatial structural characteristics of the whole population and its big trees (DBH≥15.79 cm) and small trees (5 cm≤DHB＜15.79 cm) to reveal structural diversity of the K. davidiana population in natural secondary community in Nanpan River basin. The results showed that: (1) K. davidiana population was randomly distributed (W^-= 0.468) and moderately mixed by other species (M^-= 0.480), with obvious diameter differentiation among individuals (U^-= 0.472). (2) Most big trees of the population were in a status of dominance (U^-= 0.204) and moderate mixture (M^-= 0.436), and their distribution pattern had a state of random distribution (W^-= 0.483). (3) Small trees had a similar distribution pattern and mixture with the whole population. The most of the small trees belonged to the inferior individuals (U = 0.75-1.00). The study suggested that the spatial structural diversities existed between K. davidiana and its adjacent populations, and it also could be found in K. davidiana population. It may imply that K. davidiana was in a stage of stable development.

Abstract:Chishui Alsophila National Nature Reserve regards Alsophila spinulosa as the protective object. According to the field investigation of A. spinulosa community in the reserve, methods including niche breadth, niche overlap, variance ratio, chisquare test and association coefficient（AC）based on 2×2 contingency table were used for analyzing the interaction between the species population. The results show that：（1）Phyllostachys heterocycla has the largest niche breadth, followed by A. spinulosa and Mallotus barbatus.（2）The niche overlap of Pinus massoniana and Vernicia fordii, Cunninghamia lanceolata, Musa basjoo and Melliodendron xylocarpum are larger than that of other populations.（3）The overall correlations of 14 dominant species in tree layers showed nonsignificant negative correlation. The chisquare test showed that the association between A. spinulosa and other populations was not significant. Only a few species pairs of the community had a significant association，90.10% of species pairs did not reach a significant level. Most of the AC, OI, JI values are not high, the correlations between species pairs are weak, and species are relatively strong independence. The negative association of the community was more than positive association, and the community is in the unstable stage of dynamic succession.（4）The analysis of the relationship between the association of species and the corresponding niche overlap showed that there was a positive correlation between them. The stronger the interspecific association, the greater the niche overlap. The stronger the negative association, the smaller the niche overlap.

Abstract:Soil fungi community play a significant role in many key ecosystem processes, such as litter decomposition and nutrient cycling. The biodiversity and activities of soil fungi are also very important for evaluating the ecosystem health. It is significant to study metabolic characteristics of fungi community and underlying environmental correlates in rhizosphere soils of Populus euphratica for the protection of arid ecosystem, considering the important status of the species in that harsh environment areas. In our study, we collected 89 soil samples from typical P. euphratica forest to explore the metabolic characteristics of fungi community and underlying environmental factors. The results showed that (1) Carbon sources used by fungi could be grouped into 3 clusters based on OD value. About 53.8% of amino acids could be included into clusterⅠ(OD:0.106 1-0.316 4), 83.3% amines and 70% miscellaneous into cluster Ⅱ(OD:0.016 6-0.224 2), 47.1% of carboxylic acids into cluster Ⅲ(OD:0.232 1-1.115 5). (2) Redundancy analysis (RDA) indicated that the total variances explained by soil factors was 30.02%, and RDA1 which was markedly correlated with electric conductivity and available potassium could explain 84.6% of its variances. (3) Samples at RDA2 axis were gradually dispersed with the decrease of salt, which may suggest soil fertility and soil texture may be the secondary important factor in determining the metabolic characteristics of fungi community. In conclusion, the dominant carbon sources used by fungi community in P. euphratica rhizosphere were amino acids, carboxylic acids, and some of carbohydrates, while weaker utilization intensities of amines and miscellaneous. Soil soluble salt, especially for the available potassium, was the most significant soil factor influencing the metabolic characteristics of fungi community. Soil fertility and soil texture were the secondary factors, only significantly correlated with metabolic characteristics of soil fungi community when the soil soluble salt content was low.

Abstract:Based on the documents collection and the field investigation, this study concentrates on the floristic characteristic of seed plant and the distribution of rare and protected seed plants in Dabie Mountain of Anhui Province, and we also compared Dabie Mountain of Anhui Province with the around districts. The results showed that: (1) The resources of seed plants are rich in Dabie Mountain of Anhui Province. This area contains 1 648 species (excluding subspecies) of seed plant species, which belong to 145 families and 731 genera. (2) By using statistical and the principal component analysis, the flora is geographically a transitional area from subtropical to the temperate types. (3) The coefficient similarity of species between Dabie Mountain in Anhui Province and Gujingyuan in Yuxi(64.52%) has a close relationship, and Qingliangfeng(40.22%) has a weekly relationship, and Wanfoshan in Shucheng(24.65%) has a distant relationship; (4) There are 21 rare and protected seed plants, including 5 kinds of rare and endangered plants, 2 kinds of firstclass state protected plants and 14 kinds of secondclass state protected plants.

Abstract:The species Lancea hirsuta is reported as a new record of Tibet and Qinghai, which distributed in Baxiu County（30°12′3.8″N,97°16′48″E），Linzhou County（30°4′58.8″N,91°16′48″E），Dangxiong County（30°32′24″N,91°20′24″E） and Zaduo County（33°4′48″N,95°9′36″E）, thereby the original distribution area of Lancea hirsuta can be enlarged to Tibet and Qinghai, and the altitude raised up to 4 300 m. The voucher specimens are kept in QinghaiTibetan Plateau Museum of Biology (HNWP).

Abstract:Casparian strips are a cellular feature found in the roots of all higher plants, which are ringlike, hydrophobic cell wall impregnations that tightly attach with the endodermal cell membrane. Casparian strip acts as a barrier to the free diffusion of solutes from the soil, and forces ions through endodermal cell into the stele. Casparian strip was found in 1865, but many botany textbooks cannot give completely correct information on it. The mechanism of its formation was gradually aware until Casparian strip membrane domain proteins (CASPs) were characterized and the substance of Casparian strip were revealed. The scaffold, which consists of CASPs and receptorlike kinases, was needed for Casparian strip formation. Casparian strip diffusion barrier in Arabidopsis is made of a lignin, and NADPH oxidaseRBOHF, PeroxidasePer64 and ESB1 dirigent protein were used to catalyze the polymerization with monolignol, which was transported from cell into Casparian strip membrane domain by ABCG transporter. Here, we reviewed the major findings and models related to Casparian strip and its function in light of recent molecular data. This article can provide a framework and inspiration for further molecular dissection.

Abstract:Adventitious rooting is a complicated organogenesis process involving perception of external signals and cascade coupling of internal and external signals. It has been one of the hot spots in the botany field. This review introduced the events of induction phase, initiation phase and expression phase during the development of adventitious root, and summarized signaling pathways, gene expression, cellular and metabolic characteristics in each developmental phase. This paper will provide theoretical foundation for further researches on adventitious rooting.