Abstract:The gene of lightharvesting cholorophyll a/bbinding proteins was cloned by homologous sequences from Agropyron mongolicum Keng, named MwLhcb1. The fulllength of cDNA sequence was 1 138 bp，bioinformatics analysis showed that MwLhcb1 had an open reading frame of 801 bp, encoding 267 amino acids. The calculated molecular weight of MwLhcb1 was 28.21 kD and isoelectric point was 4.92. The MwLhcb1 protein had a conserved domain of Lhcb gene family in the secondary structure. Phylogenetic analysis revealed that MwLhcb1 amino acids sequences was highly similar with the homologous proteins of other species, it was more than 87%, and the similarity degree of protein with wheat was the highest, it is 99%. Realtime quantitative PCR analysis showed that MwLhcb1 gene was mainly expressed in stem and leaf, and the expression in the root was minimal. The expression of MwLhcb1 gene was affected by drought stress, and the expression of MwLhcb1 gene was different under the different levels of drought stress. The results could be a foundation for further study on the function of MwLhcb1 gene in photosynthesis and drought resistance of A. mongolicum. Meanwhile, it confirmed was wild relatives of wheat based on gene genetic and evolution, so we supported that was ideal donor for improving to wheat resistance.

Abstract:A complete CDS sequence of a glycogen synthase kinase family gene, JcGSK, was cloned from Jatropha curcas. JcGSK contained an opening reading frame (ORF) of 1 230 bp, and encoded 409 amino acids. The predicted molecular mass was 46.33 kD with theoretical isoelectric point(PI) of 8.58. Conserved domain analysis indicated that JcGSK had a typical domain of the GSK family. Multiple alignment and phylogenetic analysis showed that JcGSK had the highest identity(96%) and closest relationship with Hevea brasiliensis. Tissue expression results showed that JcGSK expressed significantly in different organisms and had the highest expression in root, NaCl, Abscisic acid (ABA), PEG, cold and mechanical damage upregulated JcGSK gene expression, indicated JcGSK involved in response abiotic stress and signal transduction process of J.curcas. JcGSK also highly expressed in seed. The expression level change of JcGSK in seed had the same trends with seed growth, indicated that JcGSK involved in regulation seed growth of J.curcas.

Abstract:In this paper, two NAC genes were cloned from the shoots of Bambusa emeiensis, based on the transcriptome database of B. emeiensis. They were named BeNAC3 and BeNAC4. Their registration number were KU821587 and KU821588 in GenBank, respectively. The tissue expression and transcriptional activity of BeNAC3 and BeNAC4 were studied on the basis of bioinformatics analysis. The results shown that both genes have an obvious transmembrane domain, which could be a kind of membrane binding protein, based on the analysis of TMHMM and phylogenetic. Also, they are highly homologous to the NAC2 subfamily and the ANAC011 subfamily, respectively. Moreover, there is a speculation that BeNAC3 might be related to the regulation of hormone synthesis and flowering according to its relative expression in bamboo shoots, unexpanded leaves, expanded leaves and stems, and its relationship with the NAC2 subfamily in evolutionary trees. As for BeNAC4, it might be involved in the secondary metabolism, for its expression in mature tissues was significantly higher than that in young shoots and unexpanded leaves. The experiments of single hybrid transcription activity in yeast indicated that both BeNAC3 and BeNAC4 could activate the expression of the βGAL gene (lacZ), which indicated that both of them have a particular transcriptional activity. The research results lay a foundation for the future functional verification of transgenic plants from B. emeiensis.

Abstract:Using the homologybased cloning, we obtained a Fbox/LRR repeat protein 14 gene (TaFBL14) from wheat in the present study. TaFBL14 encoded a 486 aa polypeptide with predicted molecular weight of 53.48 kD and theoretical isoelectric point 5.93. The deduced protein included a Fbox domain in the Nterminal and 7 LRR domains in the Cterminal. No signal peptide and nuclear localization sequence were detected. Subcellular localization showed TaFBL14 mainly expressed in the cytoplasm. αhelix was the most important secondary structure, which made TaFBL14 the globular protein. Neighbourjoining tree showed that the deduced TaFBL14 protein shared high similarity with FBL14 from Aegilops tauschii and Triticum urartu. Quantitative reverse transcription PCR showed that TaFBL14 mainly expressed in wheat young leaves and flag leaves, and were upregulated expression from 6 hpi to 96 hpi. These results implied that TaFBL14 may be involved in wheat resistant to leaf rust pathogen infection.

Abstract:In this study, we performed the genomewide identification of the KUP/HAK/KT family genes in soybean based on soybean genome sequence information. We also analyzed the gene character, protein structure, chromosome location, gene duplication and expression pattern of the family members. Our results showed that: (1) 30 KUP/HAK/KT transporter genes (GmHAK01-GmHAK30) had been identified in soybean genome, which were distributed on 15 chromosomes of soybean; The segmental duplication and tandem duplication were the contributors to the expansion of GmHAKs genes in soybean genome. (2) The sequence identity of GmHAKs was very high, and all of them had 12-14 transmembrane regions, and were located on the plasma membrane. (3) Phylogenetic analysis indicated that the GmHAKs in soybean can be classified into 4 clusters: ClusterⅠ-Ⅳ, and the number of ClusterⅡmembers was the most (16), and the number of Cluster Ⅳmembers was the least (1). (4) Gene structure analysis revealed that all GmHAKs genes had intron and exon. The intron number was between 7-9, and GmHAKs genes in the same subfamily exhibited similar exonintron pattern. (5) Expression pattern analysis showed that the expression of GmHAKs can be roughly divided into two categories: one is the expression of some tissuespecific genes, including all members of ClusterⅠand Cluster Ⅳ, part members of ClusterⅡ. These genes expressed highly in root (GmHAK30 and GmHAK04), or flower (GmHAK03 and GmHAK15), or pod (GmHAK10), or seed (GmHAK25); The other is the expression of some nontissue specific genes, including all members of Cluster Ⅲ, part members of ClusterⅡ, these genes (GmHAK05, GmHAK17 and GmHAK28) were highly expressed in all the examined tissues. The differential gene expression patterns of KUP/HAK/KT gene family in different evolutionary clusters suggested that it may be affected by selection in the process of evolution. The above results not only provide the important gene information for studying the KUP/HAK/KT gene function and the characteristics of potassium absorption in soybean, but also provides theoretical basis for the breeding of soybean varieties with high potassium efficiency.

Abstract:Aimed to study the characteristics and functions of ACS gene, in the present study, we cloned a 1aminocyclopropane1carboxylate synthetase gene named NtACS1 (GeneBank KX082936) based on the RNASeq database from the flower of Narcissus tazetta var.‘Yunxiang’ using RTPCR method. The length of the open reading frame (ORF) of ACS is 552 bp, encoding 183 amino acids coupled with a molecular weight of 20.6 kDa and theoretical isoelectric point of 6.30. qRTPCR analysis showed that the relative expression level of NtACS1 both in petals and coronas are decreased gradually along with the aging of flower. Moreover，the expression data of NtACS1 gene were consistent with those obtained by RNASeq，implied that the NtACS1 protein as an ACC synthetase might play a role in the catalytic system 1 of ethylene biosynthesis. Furthermore, sense plant expression vectors of NtACS1 were successfully constructed with agrobacterium mediated transformation, and 6 positive transgenic tobacco plants were ultimately obtained. Our current study will lay an experimental foundation for the future application of the genetic transformation to prolong florescence of ‘Yunxiang’.

Abstract:Seven precursors (premiRNAs) and seven mature sequence of the miR171 family were obtained for analyzing the evolutionary characterization and its expression from Dimocarpus longan Lour. (longan) mRNA and miRNA databases. The prediction results using mfold showed that the sequence of premiR171 family members could form a typical secondary structure，and the minimum folding free energy (dG) in the range of -39.37 to -55.13 kal/mol. Other members of the mature sequence matched exactly with vvimiR171a， ptcmiR171f and ctrmiR171 except premiR171scaffold112 and premiR171fscaffold38. NJ phylogenetic tree analysis showed higher sequence homology with that from Citrus reticulata and Populus trichocarpa. Target prediction showed that the main target of longan miR171 family were Scarecrowlike6，which was the same as miR171 target of other plants. qPCR results indicated that premiR171 family were strong expressed in the male flower and low in the fruit. It was suggested that the miR171 family was highly conserved during the evolution and might play important roles in the development of male flowers in longan.

Abstract:The genetic diversity of Magnolia sieboldii was assessed with simple sequence repeat (SSR, also known as microsatellite) DNA marker technique among 9 populations in seven provinces of China. The results indicated that: (1) A lower genetic diversity of 0.098 5 for the average Nei gene diversity (H), 0.146 8 for the average Shannon information index (I), and 0.597 9 for gene flow（＜1, again relatively low）among the 9 populations. (2) Certain genetic differentiation has occurred over longterm evolution, with genetic distance ranging from 0.068 8 to 0.214 2 and genetic similarity from 0.82 to 0.93. (3) The clustering analysis suggested that the 9 populations have evolved into two main branches, one with the Majiang population in Guizhou Province and the other with the rest of the populations. Comparatively, the Majiang population was in poor conditions. (4) The genetic diversity of M. sieboldii was positively related to population longitude. Our results suggest that the low genetic diversity and gene flow among M. sieboldii populations are probably the main genetic mechanisms of the species becoming endangered.

Abstract:Effects of the various colchicine treatments on 2n pollen induction in Dendrobium officinale were carried out in the current work. Cytological mechanism of 2n pollen formation were also studied. The results showed that the optimum method for 2n pollen induction was injecting 0.1% colchicines into the flower buds at about 5.53 mm long and 2.3 mm wide for 3 times, once a day，with the highest induction rate up to 6.22%. the diameter of 2n pollen was 49% larger than n pollen. The abnormal phenomena like parallel spindles and tripolar spindles at meiotic metaphase Ⅱ,triads and dyads at the tetrad period were observed, so the abnormalities in spindle positioning may be one of the cytological mechanism of 2n pollen formation in Den. officinale, and its 2n pollens were genetically equivalent to FDR (first division restitution)type.

Abstract:The microstructure studies on Astragalus membranaceus var. mongolicus’vegetative organs were done with the method of plant anatomy and the officinal ingredients’ specific stored parts were ensured using the method of histochemistry. The results showed that: (1) the root of A. membranaceus var. mongolicus is composed of periderm and secondary vascular tissue. The secondary phloem is the main part of root, accounts for about 70% root transverse area, in which the secondary phloem parenchyma cells are the main ingredient. The stem of A. membranaceus var. mongolicus consists of three parts: epidermis, cortex and vascular column. Epidermis is composed of a layer of cells. Cortex is composed of dozens of layer of cells. Vascular column is ectophloic type, the arrangement is tight and pith ray is narrow. The leaves of A. membranaceus var. mongolicus are bifacial and include three parts: epidermis, mesophyll and vein. Vegetative organs of A. membranaceus var. mongolicus show droughtresistant characteristics. (2) Histochemical studies showed that saponins are stored in parenchymal cell of root, such as phelloderm, secondary phloem, dimensional root ray tube, forming layers, and its also stored in parenchyma cell of stem, such as cortex, forming layers and leafs mesophyll tissue and vein. Polysaccharides are mainly stored in parenchyma cell of root, such as phelloderm, phloem and dimensional root ray tube, as well as the leaf mesophyll tissue. Flavonoids are stored in the epidermis, cortex, collenchyma and pith ray cells of stem. (3) The quantitative analysis of ultraviolet spectrophotometer showed that the contents of saponins,flavonoid and polysaccharides in root, stem and leaf are consistent with the results of histochemistry. The results revealed that active constituent contents in root, stem and leaf of A. membranaceus var. mongolicus are higher, the stem and leaf of A. membranaceus var. mongolicus also have medicinal value and should be reasonable harvested and utilized.

Abstract:High temperature in summer often leads plants to lose water and even to die, which is a serious problem in application of solid soilless substrate in vertical greening. In order to solve this, the water retention of the traditional substrate, the imported solid soilless substrate ‘Pafcal’, and the domestic solid soilless substrate ‘Tan Mian’ were compared, and a comprehensive evaluation on the drought adaptability of 7 landscape plants, including Hedera nepalensis, Trachelospermum asiaticum‘Ougonnishiki’, Ligustrum quihoui Carr., Ligustrum japonicum ‘Howardii’, Serissa japonica ‘Variegata’, Gardenia jasminoides cv. prostrata and Ligustrum japonicum ‘Jack Frost’, were carried out by factor analysis, using drought stress response time, recovery after rewater, endogenous substances content and protective enzyme activity as indexes. The results showed that: (1) the traditional substrate had the strongest water retention, and ‘Tan Mian’ had stronger, while ‘Pafcal’ had the worst; (2) all of the plants in the traditional substrate had the longest drought stress response time, and which in ‘Tan Mian’ had longer, while which in ‘Pafcal’ had the shortest; (3) after rewatering, most plants in traditional substrate recovered much better than that in solid soilless substrates, but H. nepalensis and G. jasminoides cv. prostrata recovered well in solid soilless substrates; (4) MDA content and POD activity of most pants in all substrates increased firstly and then decreased; SOD activity of H. nepalensis and L. japonicum ‘Jack Frost’ in ‘Tan Mian’ at 20 d increased markedly, yet which of the other plants showed no significant changes in all substrates; soluble protein content showed the same variation trend in all substrates, which was that H. nepalensis and S. japonica ‘Variegata’ continuously decreased, while the others increased firstly and then decreased; (5) H. nepalensis, L. japonicum ‘Jack Frost’ and Serissa japonica ‘Variegata’ had extremely strong drought adaptability in the traditional substrate, yet H. nepalensis, S. japonica ‘Variegata’ and L. japonicum ‘Howardii’ had strong drought adaptability in both two solid soilless substrates.

Abstract:To figure out the protective effect of exogenous salicylic acid (SA) on inducing clubroot resistance of pakchoi and the reactions of physiological indicators on susceptible pakchoi plants, with ‘Xinaiqing’ pakchoi as the tested material, after inoculated clubroot disease(Plasmodiophora brassicae Wor) by the method of the soil bacteria inoculation, we investigated the effects of 0.2~0.8 mmol·L^-1 exogenous salicylic acid （SA） on pakchoi plants growth, inducing resistance, reactive oxygen and defense enzyme activities of leaf and root infected clubroot，with the possible action mechanism of SA discussed. The results showed that: (1) the clubroot disease significantly affected the growth and increased the damage of membrane lipid peroxidation. (2) The best effect on the alleviation of clubroot disease stress damage was observed in the treatment of 0.6 mmol·L^-1 SA. At this concentration, the plants growth, resistance of clubroot disease. (3) The activities of superoxide dismutase（SOD）, peroxidase（POD）, ascorbate peroxidase（APX）, polyphenol oxidase (PPO), phenylalanine ammonialyase (PAL), glutathione reductase (GR) were were increased significantly in leaves and roots, while malondialdehyde (MDA), hydrogen peroxide (H₂O₂) contents and the production rate of superoxide anion(O^-·₂) were significantly decreased. The above results indicated that dosage effect of SA existed on the alleviation of clubroot disease stress in pakchoi plants, and the best alleviating effect on clubroot disease stress damage was 0.6 mmol·L^-1 SA by irrigating at the plant roots, which was favorable for the plant to grow, and improve the ability of resistance of clubroot disease.

Abstract:The pot experiment was conducted to compare and analyze the changes of the physiological and photosynthetic characteristics of 2 year old Malus hupehensis (Pamp.) Rehd. seedlings of different pretreatments by three consecutive days spraying fulvic acid(FA), glyeine betaine(GB) and combination of fulvic acid and glyeine betaine (FA+GB) and with water as control (CK) pretreatment before drought treatment to explore the physiological drought mechanism of FA and GB for M. hupehensis. The results showed that: (1) compared with the control, FA, GB and FA+GB pretreatment can significantly improve the relative water content in leaves of M. hupehensis, and the water retaining effect of FA was the best. (2) Under drought stress, the three pretreatments could significantly increase the contents of soluble protein, soluble sugar and proline; and the soluble sugar and proline accumulation of the FA+GB were significantly higher than that of the single application of fulvic acid and betaine treatment. (3) Under drought stress, all the three pretreatments could significantly increase the SOD, POD and CAT activities of seedlings and significantly reduce the accumulation rate and content of MDA. While the pretreatment of FA+GB had the lowest MDA content and the highest antioxidant enzyme activity. (4) The net photosynthetic rate and instantaneous water use efficiency of M. hupehensis treated with GB and FA+GB pretreatments were significantly higher than those of CK and FA. And the photosynthetic characteristics of FA+GB were the best, followed by GB. The results showed that under the drought stress, spraying fulvic acid, glyeine betaine and combination of fulvic acid and glyeine betaine on M. hupehensis leaves could increase the osmotic adjustment substance, the waterholding capacity and the relative water content, regulate the activities of antioxidant enzymes, reduce malondialdehyde content, increase cell membrane stability, and could also improve the photosynthetic performance; thereby enhance the drought resistance of M. hupehensis, and effect of pretreatment with compound spraying (FA+GB). Was the best Pamp.

Abstract:To explore the influence of the wheat seedling growth under nickel stress with exogenous betaine was studied the effects of rootapplying glycinebetaine (GB) with 1.0, 2.0, 3.0, 4.0, 5.0, 10.0, 15.0, 20.0 mmol·L^-1 treatments with 100 μmol·L^-1NiSO₄. And the physiological and biochemical indexes of stress resistance under the stress of 100 μmol·L^-1NiSO₄ by solution culture method. The results indicated that: (1) under the stress of 100 μmol·L^-1 of NiSO₄ , the root length,seedling height, fresh weight and dry weight decreased significantly by 14.7%, 11.7%, 15.0% and 16.7%, respecticely, as compared with the control. (2) With the increasing concentration of applied glycinebetaine, the root length, seedling height, fresh weight and dry weight increased at first and then descended, compared with the 100 μmol·L^-1 of NiSO₄. And the effect of exogenous GB with 4.0 mmol·L^-1 treatment was better. (3) Under the concentration of 4.0 mmol·L^-1 of GB, the activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) and ascorbate perxoidase (APX) in roots increased by 284.7%, 40.3%, 82.9% and 20.4%, respectively; Superoxide anion (O^-·₂) , hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) contents decreased by 50.6%, 38.4% and 40.6%, respectively; soluble sugar and free proline contents decreased by 19.2%, 45.4%, respectively; Root activity significantly increased by 358.0%, compared with the 100 μmol·L^-1 of NiSO₄. Therefore, the appropriate concentration of rootapplying GB could significantly enhance the antioxidant capacity in root of wheat seedlings, and restore the root activity, so as to effectively reduce the harm of nickel stress on the growth of wheat seedlings.

Abstract:The physiological and biochemical characteristics of Humulus scandens seedlings under NaCl stress (0, 100, 200, 300 and 400 mmol/L NaCl) was studied. The study results indicated that: (1) the growth of H. scandens seedlings has severely inhibited with the increase of NaCl concentration, and the root, stem and leaf dry weight, single leaf area, specific leaf area(SLA) and root/shoot ratio(R/S) also reduced. (2) The P_n, G_s, C_i, T_r and Ψ_w in leaves of _{H. scandens} seedlings were all decreased, but the values of L_s and WUE_i obviously increased , and the effects strengthened with the increasing of salinity concentration. (3) The NaCl stress obviously had a lower Chl a and Chl b contents CAT activity, and a higher superoxide dismutase (SOD), peroxidase (POD) activities and malondialdehyde (MDA) content. It shows that the antioxidant enzyme system of H. scandens seedlings has a positive response strategy to NaCl stress. (4) The minimum fluorescence (F_o), variable fluorescence (F_v), maximum fluorescence (F_m), electron transport rate (E_TR) and photochemical quenching coefficient (qP) of H. scandens seedlings were also significantly increased in different NaCl concentrations, but the effective photochemical quantum yield (F_m′/F_o′) and nonphotochemical quenching coefficient of PSⅡ(qN) effectively decreased. In summary, there was no apparent effect of H. scandens seedlings under low NaCl stress（100 mmol/L）. However, gas exchange parameters, chlorophyll contents, chlorophyll fluorescence parameters, antioxidant enzyme activities were inhibited with the increase of NaCl concentration. Especially, high concentration of NaCl stress seriously affected the growth of H. scandens seedlings, their physiological and biochemical indexes showed a gradually decreasing trend.

Abstract:Tobacco (Nicotiana tabacum L.) plants were cultivated in phytotron set at relatively low temperature (daily average 16.5 ℃), normal temperature (daily average 23.5 ℃) and relatively high temperature (daily average 30.5 ℃), and the effects of different temperature on growth, development and photosynthesis of tobacco plants were investigated. The results showed that：(1) Compared with the plants under normal temperature, the plants grown under the relatively higher and lower temperatures decreased the plant height, leaf length, width and showed an inhibiting effects on tobacco plants to some extent. (2) Plants under relative higher and lower temperature reduced the net photosynthetic rate (P_n), intercellular CO₂ concentration (C_i), stomatal conductance (G_s), transpiration rate (T_r), maximum quantum yield of PSⅡ photochemistry (F_v/F_m), quantum efficient of PSⅡ (Φ_PSⅡ), photochemical quenching (q_p), Rubisco activity, but increased the minimal fluorescence of darkadapted state (F₀) of tobacco leaves. Tobacco plants grown under longterm relative higher and lower temperatures both inhibited the growth by partly damaging or inactiving the photosynthetic apparatus, and reduced the photosynthesis efficiency of tobacco plants to some extent. Longterm daily average temperature at 23.5 ℃ could be the optimal temperature for growth and photosynthesis of tobacco plants.

Abstract:Cutting seedlings of amur grape (V. amurensis Rupr. ) cultivars ‘Shuangyou’ (weak resistance) and ‘Zuoshanyi’ (strong resistance) were grown in plastic pots in shelter greenhouse. The effects of different salinealkali stress levels (light stress, moderate stress and severe stress) on photosynthetic characteristics and activities of photosystem Ⅱ (PS Ⅱ) in amur grape were studied using gas exchange and chlorophyll fluorescence induction dynamics analysis technology, and we surveyed their growth development. The results showed: (1) the net photosynthetic rate (P_n) and stomatal conductance (G_s) decreased significantly in lightly, moderately and severely stressed for ‘Shuangyou’ seedlings compared to control plants, but the transpiration rate (T_r) decreased significantly only under severe stress treatment. For ‘Zuoshanyi’ seedlings, P_n and T_r decreased significantly only under severe stress treatment, G_s decreased significantly under moderate and severe stress treatments, and intercellular CO₂ concentration (C_i) decreased significantly under different stress treatments. The reduction of P_n was mainly caused by stomatal limitation and nonstomatal limitation. (2) The specific energy fluxes for absorption (ABS/RS), the density of QA^- reducing PSⅡ reaction centers per cross section (RS/CS) and performance index (PI_ABS) decreased significantly in lightly and moderately stressed for ‘Shuangyou’ seedlings compared to control plants. For ‘Zuoshanyi’ seedlings, ABS/RS, RS/CS and the specific energy fluxes for electron transport (ET_o/_CS) decreased significantly only under severe stress treatment, other parameters under different stress treatments were similar to control plants. (3) Sap flow rate, plant height, leaf number and root biomass had significant decrease under different treatments, and decrease rate of ‘Shuangyou’ was higher. In conclusion, for ‘Zuoshanyi’ seedlings, salinealkali stress has relatively little effect on P_n, light energy absorption, electron transport efficacy and growth compared to ‘Zuoshanyi’, so ‘Zuoshanyi’ cultivar was more resistant to salinealkali than ‘Shuangyou’. For evaluation and detection of salinealkali tolerance in amur grape, we not only need to evaluate some physiological parameters such as photosynthetic function, but also to evaluate comprehensive growth indexes.

Abstract:In order to explore the impact of planting density on the locust growth, understory vegetation and soil moisture on the Hillygullied Loess Plateau in northern Shaanxi, we observed and analyzed the locust woodland planted around 2 000 with five different planting densities. The results show that: (1) in sunny aspect, the average DBH, tree height and crown between different densities were significantly different(P<0.05). In shady aspect the average DBH and tree height in the density of 2 500 plants/hm² were significantly different from the another two lower densities. The average crown was significantly different from 1 670 plants/hm² while insignificantly from 2 000 plants/hm²(P>0.05).(2) Woodland soil moisture, cover of understory vegetation and species diversity were relatively higher under the density of 1 670 plants/hm². (3) Soil moisture in 0~500 cm depth of locust woodland with each density was lower than that of stable soil moisture (12%) in the study area. （4） In sunny aspect, soil moisture in 0~500 cm depth with density of 3 330 plants/hm² was only 4.5%, while the density of 830 plants/hm² reached 7.8%, and the soil moisture with density of 1 670 plants/hm² and 2 000 plants/hm² was relatively higher in shady aspect, which was 7.5%~8.2%. The study suggests that the initial planting density of locust should not be more than 1 670 plants/hm² (spacing of 2 m×3 m) in the hillygullied loess area and thinning management should be taken to adjust the stand density after entering the peak growth period in order to maintain the stability and sustainability of locust plantation.

Abstract:In order to reveal the phenotypic diversity and variation pattern of Alpine Rhododendron species, we measured 12 phenotypic traits of Rhododendron rubiginosum natural populations at five different altitudes in Jiaozi Mountain National Natural Reserve of Yunnan Province and studied the levels of phenotypic diversity by using ANOVA analysis, correlation analysis and cluster analysis. The results indicated that: (1) there were significant differences in phenotypic variations among and within populations. Coefficient of variation (CV) of these traits ranged from 8.51% to 34.32%, and RHL (R′) ranged from 38.04% to 100%. High phenotypic variations were occurred in the relative low elevation populations (P1 and P2), while low degree of variations occurred in the moderate and high elevation populations (P3、P4 and P5). (2) Based on the ShannonWeaver diversity index (H′) analysis, the mean phenotypic diversities index of 5 sample elevation populations was 2.453 4, and the mean phenotypic diversity index of 12 phenotypic traits was 4.076 3. It indicated that there were richness phenotypic diversity in R. rubiginosum populations. (3) The correlation analysis showed that there were significant correlations among these traits. There were significant negative correlations between elevation and FSL and IW. However, there was no significant correlation between elevation and other traits. (4)The 5 sampled populations of R. rubiginosum could be divided into two groups according to the UPGMA cluster analysis. Therefore, the trait variations of natural populations at different altitudes were affected mainly by microenvironmental heterogeneity of different R. rubiginosum populations.

Abstract:Chloroform fumigationextraction were employed to study the content of soil microbial biomass. We choose three typical communities which in Yanchi County of Ningxia desert grassland as the research object, to determine the changing characteristics of soil basic physical and chemical properties and soil microbial biomass carbon and nitrogen, in different soil layers (0-5,5-10,10-15 cm) of two soil habitat in different communities (Caragana korshinskii, Artemisia ordosica, Stipa breviflora), The results show that: (1) the study area of C. korshinskii community, A. ordosica community and S. breviflora community of soil microbial biomass carbon (MBC) concentration range were 77.00-393.18, 17.27-221.71 and 81.05-173.37 mg/kg, soil microbial biomass nitrogen (MBN) concentration range were 7.59-64.81, 1.43-13.95 and 4.25-22.13 mg/kg, At the same time, the soil MBC and MBN have the same rule the content is continuously reduced with the depth increase which performed “fertile island” and the canopy content is higher than that in plexus in the same depth. (2) Community types had significant effects on the changes of soil microbial biomass carbon and nitrogen contents. Under the 3 typical communities,the content of the soil microbial biomass (qMB), carbon nitrogen ratio (SOC/TN) and microbial biomass carbon and nitrogen ratio (MBC/MBN) range were 0.76-4.10, 15.02-52.50 and 5.34-23.07, respectively. Analysis showed that the ratio in different habitats and different depth of soil layers has obvious difference, besides, the correlation of MBC, MBN, SOC, C/N and qMB in the soil of the 3 typical communities reached significant or extremely significant level. (3) Considering the soil MBC,MBN and soil nutrient indexes have the same change trend, the soil MBC, MBN can evaluate the quality of the soil as a biological indicator on a degree.

Abstract:Based on several field investigations and numerous data references, we analyzed the floristic composition, geographical element, floristic affinity, floristic characteristics and floristic origination of pteridophytes in Naban River Watershed National Nature Reserve in the present paper. The main results are as follows: (1) there are totally 239 fern species, belonging to 90 genera and 43 families in the area. The dominant families are Thelypteridaceae, Pteridaceae, Athyriaceae and Aspidiaceae, and the dominant genera are Pteris, Microlepia, Cyclosorus and Pyrrosia. (2) Floristic analysis reveals that the pteridoflora is of tropical nature, but characterized with conspicuous transition to southern subtropics. It is confirmed that the pteridoflora of Naban River Watershed National Nature Reserve is a part of Tropical Asian pteridoflora, but affected by SinoHimalaya pteridoflora in some extent. (3) On the aspect of geographical connection, the pteridoflora of Naban River Watershed National Nature Reserve has the strongest affinity with Dawei Mountain, followed by Hainan Island and Ailaoshan Mountain Nature Reserve, and has a distant relation with Cangshan Mountain, Jiaozixueshan Mountain and Diaolin Mountain Nature Reserve.

Abstract:To establish a stable and highefficiency plant regeneration system for Pterocephalus hookeri (C.B.Clarke) Heck via plant tissue culture, we studied the optimum seed disinfection method, and the main factors which affected callus induction, proliferation and plant regeneration of explants from aseptic seedling. The results indicated that: (1) the optimum disinfection method for seeds removed exopleura of P. hookeri was 75% ethanol 1 min＋0.1% HgCl₂ 7 min＋derosal (50%wp, diluted 500 times)30 min, the seeds were thoroughly bioclean, and the germination rate was 60.67%. (2) Leaf piecesand stem segments excised from the seedlings were suitable to induce calluses with the percentage of 84.00% and 97.33% respectively on medium MS＋5.0 mg·L^-1 6BA＋2.0 mg·L^-1 2,4D after 10 d. (3) The optimal medium for callus proliferation was MS＋3.0 mg·L^-1 6BA＋2.0 mg·L^-1 IAA, growth rate of calluses reached 74.37% and 70.52% with leaf pieces and stem segments, respectively. (4) The optimal medium for clustered shoots induction was MS＋3.0 mg·L^-1 6BA＋2.0 mg·L^-1 IAA＋250 mg·L^-1 Lproline＋150 mg·L^-1 casein hydrolysate, the differentiation rate were 100% and 94.44% with leaf and stem, respectively. (5) The optimal rooting medium was 1/2 MS＋0.5 mg·L^-1 NAA, the rooting rate was 100% after 30 d. As a result, an efficient plant regeneration system was established in order to provide an effective solution for protecting the wild resources and industrial seedling of P. hookeri.

Abstract:In this test, the experimental materials are root tips of Solanum nigrum var. suaveolens and Solanum nigrum. In order to determine pretreatment methods of the most suitable for karyotype analysis, we optimized processing the root tips by different pretreatment, fixed and different dissociation. Root tips of Solanum nigrum L. are pretreated with 0.05% colchicine for 2.5 h at 15℃. Then root tips were hydrolyzed or 6 min in 1 mol/L HCl at 60 ℃. The results showed the chromosome clearer. S. nigrum var. suaveolens and S. nigrum are both belong to small chromosomes, S. nigrum var. suaveolens is tetraploid, the karyotype formula is K (4n) =48=4sm+44m, karyotype asymmetry belongs to 2B. The karyotype asymmetry coefficient was 56.22%. S. nigrum L. is hexaploid, the karyotype formula is K (6n) =72=72m, karyotype asymmetry belongs to 1B and the karyotype asymmetry index was 55.89%.

Abstract:In type specimens deposited at China National Herbarium (PE), Institute of Botany, Chinese Academy of Sciences, the types of some taxon names in Sympetalae from China are found to be syntypes under Article 9.5 of International Code of Nomenclature for algae, fungi, and plants (Melbourne Code), including Androsace gmelini (Lam.) Grtn. var. geophila Hand.Mazz., Pomatosace filicula Maxim. and Primula stenocalyx Maxim. in Primulaceae, Gentiana fukienensis Ling, G. przewalskii Maxim., G. purpurata Maxim. ex Kusnez., G. siphonantha Maxim. ex Kusnez., G. wutaiensis Marq. and Swertia tetraptera Maxim. in Gentianaceae, Caryopteris terniflora Maxim. in Verbenaceae, Ajuga lupulina Maxim., Dracocephalum tanguticum Maxim., Salvia cavaleriei Lévl. var. simplicifolia Stib. and S. omeiana Stib. var. grandibracteata Stib. in Lamiaceae. According to Article 8.1, 9.11 and 9.12, and Recommendation 9A.3, lectotypes for these fourteen names are here designated.

Abstract:The genus Synstemon Botsch., which is endemic to Mongolia Plateau, also is a monotypic genera. After examining a large number of specimens and type mterials, as well as field observations, We reduced Synstemon lulianlianus AlShenhbaz et al. to the synonym of Synstemon petrovii Botsch.

Abstract:Hydrogen is widely studied as a new active gas. In plant growth and development, hydrogen has the role of promoting seed germination, seedling growth and adventitious root growth; In the process of plant stress, the body produces a large number of reactive oxygen species. Through the regulation of antioxidant enzyme activities, antioxidant generation and its corresponding transcripts, hydrogen improves plant resistance to drought, salt stress, heavy metal stress, herbicides, ultraviolet radiation and other stresses. At the same time, hydrogen can also regulate the expression of stressrelated genes such as resistance to pests and diseases.This paper reviews the role of hydrogen in promoting plant growth and improving plant resistance, and the mechanism of hydrogen as a signal molecule to enhance the stress resistance of plants by regulating antioxidant defense systems under adversity stress, with a view to a better understanding and promotion of hydrogen in agricultural science research and application.

Abstract:As one of the key parameters of seed quality, seed longevity is directly related to seed germination, the growth and development of young seedlings, and finally the crop yield. Seed longevity is a complex biological process which regulated by numerous exogenous and endogenous factors, such as structure, nutrient composition and related key genes. Investigating the changes of physiological and biochemical indices, biological function of the related genes during seed storage process to reduce the energy consumption of seed, is great significant to further extend the longevity of seed. In this review paper, we summarized the physiological and molecular mechanisms, related key genes which have dominant roles on the changing of seed longevity. Furthermore, the regulation mechanisms of various external indices on seed longevity are discussed. Finally, we discussed probable research directions in the future.