Abstract:NHX2 belongs to the CPA1 gene family and encodes a Na⁺/H⁺ reverse transporter which controls the uptake of active K⁺ in vacuolar membrane and regulates the closure of stomatal. In this study, the NHX2 gene was cloned by PCR from the salttolerant plant Spartina alterniflora and transferred into Arabidopsis thaliana for function identification. The results showed that: (1) the fulllength sequence of NHX2 (1 602 bp), encodes 533 amino acids, which was named SaNHX2 gene. The molecular weight of SaNHX2 protein was about 58.65 kD and located in the nucleus and cell membrane. These results indicate that SaNHX2 gene may play a role in transcriptional regulation. (2) The qRTPCR analysis results indicated that the expression of SaNHX2 gene was upregulated in leaves and roots of S. alterniflora under ABA, NaCl and drought stresses. (3) In order to identify its function, plant expression vector was constructed and SaNHX2 gene was transformed into A. thaliana. After high salt stress treatment, the length of root, the total chlorophyll content and the expression of related stress response genes of transgenic A. thaliana with SaNHX2 gene were all higher than those of transgenic A. thaliana without SaNHX2 gene. The results indicated that SaNHX2 gene may play a regulatory role in salt stress regulation and may be an important candidate gene for improving crop salt tolerance.

Abstract:The VAL2 gene was cloned by using Lilium oriental hybrid ‘Sorbonne’as a material (hereinafter referred to as LoVAL2). Sequence analysis showed that the coding sequence of LoVAL2 was 2 793 bp long and LoVAL2 encoded 930 amino acids containing five domains: PHDL, B3, CW, ZnFlike and EAR motif. Phylogenetic analysis showed that LoVAL2 was closely related to Asparagus officinalis, the following were Zea mays and Dendrobium catenatum, Arabidopsis thaliana and other plants were far away. Realtime RTPCR expression analysis showed that LoVAL2 expressed in stem root, tender stem, upper leaf, lower leaf and floral organ; LoVAL2 expressed in four kinds of floral organs. The relatively high expression levels in the pistils and stamens occurred in 5 mm buds; afterwards, the expression levels were downregulated with the development of flower buds; then, the expression levels were significantly upregulated in the pistil of 20 mm buds and the stamen of the 25 mm buds, indicating that LoVAL2 may play an important role in the early and the subsequent development of the pistil and stamen. LoVAL2 was localized in the nucleus of tobacco epidermal cells, which was consistent with the nuclear localization characteristic of transcription factors.

Abstract:Based on the analysis of miRNAs omics in longan ECs, we selected the differentially expressed miR396a3p_2 and miR396b5p for further analysis and verification, which play a key role in the regulatory pathway about effect of blue light on longan. We analyzed the phylogenetic tree of precursor and mature sequences, the secondary structure and cisacting element of precursor, the prediction of target genes, as well as expression patterns responding to blue light of miR396 in this study. These results showed that: (1) the miR396 mature sequences from 5p arm were highly conserved and from 3p arm were quite specific. The stem sequence was more conserved than loop sequence, and the miRNA from 5p arm sequence was more conserved than that from the 3p arm. (2) They both contain many lightresponsive elements, hormoneresponsive elements, and biotic and abiotic stress responsive elements, which might play a regulatory role in response to blue light through these ciselements. Their targets responding to blue light both contain growthregulating factor 2 (GRF2), LRR receptorlike serine/threonineprotein kinase (FLS2), ethyleneinsensitive protein 3 (EIN3) and DNAdirected RNA polymerase subunit alpha (ropA) etc. Realtime quantitative PCR showed that there were differences in the expression patterns of miR396a3p_2 and miR396b5p under different light qualities. The expression trends of miR396b5p and its targets presented negative correlation under the blue light conditions with different light intensities, while miR396a3p_2 was not negatively correlated with rpoA. This might be the reason that other miR396 family members or miRNAs were also involved in this process to achieve regulation of target gene transcription levels.

Abstract:CBLinteracting protein kinase (CIPK) is a family of specific serine/threonine (Ser/Thr) protein kinases in plants, which participates in response to various biotic and abiotic stresses. In this study, the fulllength cDNA of Jatropha curcas JcCIPK2 gene was cloned by RTPCR, and the expression patterns of JcCIPK2 in different tissues and treatments (low temperature at 12 ℃ and 1 ℃, high temperature at 42 ℃, 30% PEG, 250 mmol/L NaCl, 150 μmol/L ABA) were analyzed by fluorescence quantitative qRTPCR. The results showed that: (1) The open reading frame of JcCIPK2 gene was 1 398 bp, encoding 465 amino acids, the relative molecular weight was 52.95 kD, and the isoelectric point was 8.89. (2) Protein structure analysis indicated that the Nterminus of JcCIPK2 contains serine/threonine kinase_sucrose nonfermenting1 related protein kinase 3 catalytic domain STKc_SnRK3, which located between the 11th and 265th amino acids, and with an activation loop in the kinase domain; Cterminal contains the CIPK protein kinaseregulated domain CIPK_C, between the 316th and 430th amino acids, and its regulatory domain also contains a NAF domain which is specifically associated with CBL, and is typical of the CIPK family, between the 314th and 369th amino acids. (3) Phylogenetic analysis showed that the JcCIPK2 protein has the highest homology with Manihot esculenta belonging to the Euphorbiaceae, and the sequence identity is up to 87%. (4) JcCIPK2 gene was expressed in roots, stems and leaves of J. curcas. After treatment at 12 ℃ and 1 ℃ the expression of JcCIPK2 gene in leaves was upregulated and then downregulated. The highest expression level was observed at 24 h under the low temperature treatment, and was increased by 6.0 and 16.72 folds, respectively, compared with the control. In addition, JcCIPK2 gene was induced to different levels by treatments with NaCl (250 mmol/L), high temperature (42 ℃), ABA (150 μmol/L), and drought stress (30% PEG). These results indicated that JcCIPK2 gene plays important roles in the response and adaptation of J. curcas to various stresses.

Abstract:Plant Rboh gene family encodes NADPH oxidases. The information and expression characteristics related to SaRboh genes in sandalwood (Santalum album Linn.) will contribute to study the roles of Rboh in sandalwood growth and development. Based on the fulllength transcriptome data, the cDNA sequence of SaRbohA (respiratory burst oxidase homolog) gene was obtained from roots of sandalwood. The full length of SaRbohA is 2 790 bp, encoding 929 amino acids with molecular weight 105.37 kD and isoelectric point 9.13. Subcellular localization analysis showed that SaRbohA localized on the cell membrane. Sequence alignment indicated SaRbohA has six transmembrane domains; The protein includes a typical NADPH binding domain and a FAD binding domain in Cterminal, and two EF hand structures in Nterminal. Phylogenetic tree analysis showed that the amino acid sequence similarity between SaRbohA and MdRboh of apple was the highest, reaching 63.65%. Tissuespecific expression analysis showed that the SaRbohA gene was low expression in stems, high expression in young leaves and apical buds, especially in roots of sandalwood. 2, 6dimethoxyρbenzoquinoe (an important haustoriuminducing factor) can strongly induce the expression of SaRbohA. SaRbohA may play important roles in the development of ROSmediated haustorium development and be induced by the chemical factor.

Abstract:In order to understand the function of the sweet potato brassinolide (BR) response gene BES1 and its expression characteristics in different tissues, we used the sweet potato (Ipomoea batatas L.) genomic library to screen the wellpreserved BES1 gene sequence primers, and the genomic DNA of sweet potato variety ‘Guangshu 87’ was used as a template for PCR amplification. The sweet potato BES1 gene (GenBank accession number MH448304) was successfully cloned, and gene length is 2 256 bp, encoding 322 amino acids. Phylogenetic tree analysis showed that BES1 is closely related to that of tomato and sesame, and the amino acid sequence has a highly conserved Nterminal domain and PEST domain. qRTPCR analysis showed that the expression of BES1 gene was the highest in the growth stage of sweet potato, and it was induced by phytohormone brassinolide. The expression was the highest when the concentration of BR was 10 μmol/L. The results laid a foundation for further study of the function of sweet potato BES1 gene, and had certain reference value for genetic improvement of sweet potato and breeding of resistant varieties.

Abstract:We investigated the function of SWEET family genes in the flowering process of tree peony. Based on the ‘Luoyang red’ tree peony petal transcriptome database, the SWEET family genes were identified and analyzed by bioinformatics. The results showed that: (1) a total of 10 SWEET genes with complete open reading frame were obtained. (2) There were little difference in isoelectric point and extinction coefficient of peony SWEET family proteins, among which 5 peony SWEET genes encoded proteins were unstable proteins. Subcellular localization predicted that the 10 SWEET genes of tree peony were located in the cell membrane. Evolutionary tree analysis showed that the SWEET genes of tree peony was more closely related to Arabidopsis thaliana. Structural analysis showed that the structures of tree peony SWEET proteins were very conserved in the evolutionary process. The 10 peony SWEET proteins had 5 identical motiations and all contained two MtN3 saliva domains. (3) The results of soluble sugar content showed that the content of sucrose in tree peony petals decreased continuously, while the contents of fructose and glucose increased continuously, and both reached the peak in the blooming period. (4) Through the analysis of RTqPCR, we found that the expression level of PsSWEET4 at flowering stage was 34 times than that in small bell, and the expression level of PsSWEET8 at flowering stage was 60 times than that in small bells. Combined with the relationship between the expression and evolution of these two genes and the change value of soluble sugar, we presumed that PsSWEET4 and PsSWEET8 might regulate the flowering process indirectly by regulating the transport of fructose and glucose, which layed a foundation for further study of the function of peony SWEET genes in the plant growth and development.

Abstract:Perilla is the medicinal and food homogeneous cash crop with the highest αlinolenic acid content. The seed oil contains more than 60% of αlinolenic acid. However， the molecular regulation mechanism of efficient synthesis and accumulation of αlinolenic acid is still unclear. Based on the sequencing results of perilla transcriptome， this study cloned Leafy Cotyledon 1 (Pf LEC1)， a key gene in the process of plant embryogenesis， from Perilla seed， and performed relevant bioinformatics analysis， realtime PCR and different determination of fatty acid content of seeds at different stages. (1) Sequence analysis results show that the gene coding region is 621 bp in length and can encode 206 amino acids. It belongs to the NFYB subunit family and contains the conserved functional domain B region of the HAP3 subunit. The protein was predicted online as an unstable，hydrophilic protein with no signal peptide or transmembrane region and localized to the cytoplasm. Evolutionary analysis showed that the protein sequence is closely related to Arabidopsis， Brassica napus， rice and corn. (2) Realtime quantitative PCR analysis showed that PfLEC1 gene was expressed in roots, stems, leaves, flowers and seeds, with the highest expression in seeds and the lowest expression in roots； PfLEC1 expression was higher in the early stages of seed development， and with seed development, the expression level decreased significantly. (3) Analysis of fatty acid content of perilla seeds at different stages showed that the contents of oleic acid and αlinolenic acid gradually increased with the development of the seeds， while the content of palmitic acid，stearic acid，and linoleic acid changed in reverse. It increased from 33.16% in 5 days to 65.16% in 20 days，indicating that the content of αlinolenic acid in perilla seeds accumulated rapidly with the development of seeds. It is speculated that PfLEC1 may be closely related to the highlevel synthesis and accumulation of αlinolenic acid in perilla seeds. This study lays the molecular foundation for further exploration of the function of PfLEC1 gene in the future.

Abstract:To reveal the function and expression patterns of CmCAD genes in ‘Sanhongmiyou’ pummelo fruit during its fruit development stages, we cloned three CmCAD genes named CmCAD1, CmCAD3 and CmCAD4 by reverse transcription PCR. The proteins encoded by these genes were analyzed by series of bioinformatic methods, the expression patterns of CmCAD genes in ‘Sanhongmiyou’ pummelo and its bud mutation varieties at different development stages were analyzed either. The results showed that the cDNA length of the three CmCAD genes were 1 032 bp, 1 080 bp and 1 071 bp respectively, encoding 344, 360 and 357 amino acids. Bioinformatic analysis showed that proteins encoded by threse CmCAD genes contained same conserved domains. All of them had transmembrane spiral structure and phosphorylation sites. Phylogenetic analysis revealed that CmCAD1, CmCAD3 and CmCAD4 were closely related to Citrus sinensis CsCAD1, Arabidopsis thaliana AtCAD9 and Citrus sinensis CsCAD4, respectively. The results of realtime quantitative PCR showed that the expression levels of CmCAD gene members in different pummelo varieties had significant differences at fruit development stages. Meanwhile, during ‘Sanhongmiyou’ fruit development stages, the expression patterns of CmCAD gene members were different either. We speculated that CmCAD4 gene has some potential functions and might involved the regulation of lignin synthesis in ‘Sanhongmiyou’ fruit, but the specific function and regulatory mechanism of the gene need to be further explored.

Abstract:In order to intensify QTL fine mapping, mapbased gene cloning, functional analysis and molecular marker assisted breeding of the low hydrocyanic acid content trait of sorghumsudangrass, we used 500 isolated individual clone plants and their parents of diploid hybrid sorghumsudangrass F₂ generation population as materials, which was constructed in the early stage of the research group. The QTL mapping of hydrocyanic acid content trait of the highdensity molecular linkage map of sorghumsudangrass was determined by interval mapping method. The results showed that: (1) the generalized heritability of the hydrocyanic acid traits in the four different environments was 61.70%, 72.05%, 40.16% and 69.25%, respectively, indicating that the hydrocyanic acid content is both environmentally affected and controlled by microeffects. The frequency of population measurements showed a characteristic of singlepeak normal distribution, which met the QTL mapping requirements. (2) Under the condition of LOD>2.5, 16 QTLs related to hydrocyanic acid traits were detected, which were distributed on LG1, LG2, LG4, LG6, LG7, LG8 and LG10 linkage groups. (3) There are 9 stable QTLs that can be repeatedly detected in 16 QTLs, and the genetic contribution rate ranges from 1.17% to 39.9%. Among them, the main QTLs with contribution rate >20% are Qcn22, Qcn41, Qcn6 and Qcn61, a total of four. The experiment identified the genetic effects and molecular marker sites of each QTL.

Abstract:The mature leaves of dioecious plant Podocarpus macrophyllus were studied. The differences of leaf morphology, microstructure and ultra microstructure between male and female plants were observed by light microscope, scanning electron microscope and transmission electron microscope, so as to make clear the adaptability of female and male leaves to environmental function in the process of evolution. The results showed that: (1) the leaves of female plants were larger than that of male plants, and there were significant differences in leaf length, leaf width and petiole length between them, but there were no significant differences in petiole thickness, leaf area, leaf volume, leaf mass, specific leaf weight (SLW) and ratio of area to volume (A/V). (2) The stomata of female plants were relatively large and dense, and the stomatal width of female plants was significantly larger than that of male plants. The width of long cells in upper epidermis and short cells in lower epidermis of female leaves were significantly larger than that of male leaves, but the length of long cells and short cells in upper epidermis of female leaves were significantly smaller than that of male leaves. (3) The thickness of palisade and sponge tissue, length and width of transport tissue, thickness of upper and lower cuticle, thickness of vascular bundle, cell tense ratio (CTR) and spongy ratio (SR) of female leaves were significantly larger than that of male leaves, while the thickness of lower epidermis of female leaves was significantly smaller than that of male leaves. However, there was no significant difference in the thickness of upper epidermis cells and the ratio of palisade to spongy tissue between male and female leaves. The palisade cells, chloroplasts and mitochondria of female plants were longer and thinner than that of male plants, and the width of mitochondria of female plants was significantly smaller than that of male plants. (4) There were remarkable differences between male and female plants in the four micro morphological characteristics, such as waxy ornamentation on the upper epidermis, cuticle ornamentation of lower epidermis, and ornamentation and inner margin of outer stomata ledge. (5) The analysis of waxy layer energy spectrum of leaf epidermis showed that there were 9 elements in female leaves, but only 8 elements in male leaves (lack of K element). The content of Si element in female leaves was higher than that in male leaves, while the contents of C, O, Na, Mg, Al, Ca and Au element in male leaves were higher than that in female ones. The results suggest that there were obvious secondary sexual characteristics between male and female plants of P. macrophyllus, and the leaf structure of female plants was helpful to improve the photosynthesis to meet reproductive needs. The difference of leaf morphological structure between male and female plants was the adaptive strategy for species reproduction in the longterm evolution of P. macrophyllus.

Abstract:The study used seeds of Paeonia rockii treated with different concentrations of gibberellic acid (GA₃) to investigate the effects of rooting. Meanwhile, the seed coat surface decoration of P. rockii was observed by scanning electron microscopy (SEM) and endosperm structure by fluorescence inversion microscopy and transmission electron microscopy (TEM). Our purpose is to investigate the effect of GA₃ on the hypoderm of P. rockii seeds, the changes of seed coat and endosperm structure and effect of rooting during axle dormancy release. (1) GA₃ treatment could effectively promote the rooting of P. rockii seeds. 300 mg/L GA₃ treatment was the best to promote rooting with the highest rooting rates of 62.33% and made the first seed rooting time shorter 14.66 days than that of control treatment. (2) Scanning electron microscopy (SEM) showed that the seed coat of P. rockii contained wax. During seed maturation, the wax content increased obviously, the mesh on the seed coat surface disappeared gradually, and the seed coat shrank obviously. (3) The results of optical microscopy showed that the endosperm cells of P. rockii seeds with GA₃ treatment contained more amyloid and proteasome, which accumulated gradually during seed germination and provided enough nutrients for seed germination. (4) Transmission electron microscopy (TEM) showed that seeds with GA₃ treatment macromolecule nutrients in the endosperm gradually decomposed, mitochondria, endoplasmic reticulum, golgi apparatus appeared, and its hypocotyl dormancy was broken and cell wall was thinner and ablated later, which was conducive to nutrient transport. It can be seen that GA₃ treatment can effectively accelerate the change of seed coat structure and endosperm cell metabolism, and promote seed germination. 300 mg/L GA₃ treatment for 24 hours can perform the best rooting efficiency.

Abstract:Autotoxicity is one of the key reasons for serious continuous cropping obstacles in melon cultivation. In this experiment, the aqueous extract of melon plant was used to simulate the autotoxicity stress of melon. The mechanism of melon autotoxicity was investigated by measuring the changes of seed germination, protective enzyme activity and MDA content in root of melon seedlings and transcriptome analyses under autotoxicity stress. The results showed that: (1) the autotoxicity inhibited the germination and subsequent growth of melon seeds, and 0.03 g/mL plant aqueous extract was the threshold value of autotoxicity stress. (2) The activities of protective enzymes and MDA content changed dramatically in root of melon seedlings after treated by melon plant aqueous extracts. SOD activity decreased first, then increased and then decreased. POD activity decreased first and then increased, CAT activity increased first and then decreased and MDA content continued to increase. (3) Transcriptome analysis identified 2 599 differentially expressed genes (DEG) related to melon autotoxicity. There were 2 251 DEGs on 2 d after stress, significantly more than 329 on 4 d. 923 DEGs were upregulated and 1 328 were down regulated in 2 d compared with 0 d. (4) The results showed that melon seedlings had a positive response to autotoxicity at the gene level. Relevant bioinformatics analysis showed that the DEGs caused by autotoxicity were mainly related to phenylpropanoid metabolism, reactive oxygen species (ROS) metabolism, photosynthesis and plant hormone signal transduction, as well as gene differential expression in osmotic regulation, membrane and protein protection. Moreover, these DEGs were mainly enriched in 2 d and 0 d, indicating that photosynthesis of seedlings changed under autotoxicity stress, and this change mainly occurred in the early stage of stress. (5) Six DEGs closely related to melon autotoxicity, AP22, bZIP1, bZIP2, AP21, bHLH and HIS, were analyzed by qRTPCR. The results showed that the expression of AP21, bHLH and HIS reached the peak at 2 d, and AP22 peaked at 2 d in the control group, which were consistent with the results of transcriptome analysis results. The results showed that autotoxicity of melon caused the abnormality of plant cells, and then deteriorated the growth and the formation of organ structure. At the same time, a large number of DEGs related to stimulation or stress were induced. The number of shortterm response genes or transcription factors was significantly higher than that of longterm response under autotoxicity stress, suggesting that melon seedlings can respond quickly to autotoxicity stress.

Abstract:The objective of this experiment was to investigate the reduced glutathione (GSH) participated in the effects of photosynthesis and fluorescence regulation pathway of exogenous nitric oxide (NO) in cucumber seedling leaves under low temperature (10 ℃/6 ℃) stress. The substratecultured ‘Jinyan No.4’ cucumber seedlings were used as the test materials. Fourleaf onehearted plants were set at a photoperiod of 14 h/10 h, day and night temperature of 25 ℃/20 ℃ in a light incubator, and leaf surface pretreatment with GSH synthase inhibitors (BSO, butanamine sulfoxide amine), NADPH synthetase inhibitor (6AN, 6amino nicotinamide), and nitric oxide NO donor (SNP, sodium nitroferrocyanide) after 8 hours The daynight temperature dropped to 10 ℃/6 ℃ 24 h after the first spraying, and cucumber leaves cell membrane permeability, gas exchange and chlorophyll fluorescence parameters and other changes were measured after 24 h of cold stress. The results showed that： (1) compared with the control, the SNP treatment significantly increased the relative water content, chlorophyll content, net photosynthetic rate (P_n), transpiration rate (T_r) and stomatal conductance (G_s), Maximum photochemical efficiency (F_v/F_m) of photosystem Ⅱ (Φ_PSⅡ), the quantum yield of PSⅡ regulated energy dissipation (NPQ), photochemical quenching coefficient (qP), apparent photosynthetic electron transport rate (ETR), the relative fluorescence of the nitric oxide, the OJIP phase of rapid chlorophyll fluorescence induction curve of cucumber seedlings and maintain high fluorescence yield after 24 h of low temperature stress, significantly decreased intercellular CO₂ concentration (C_i), alleviated continual enhancement of MDA content and the quantum yield of nonregulatory energy dissipation Y_NO. (2) Compared with SNP treatments, BSO+SNP and 6AN+SNP treatments significantly reduced the effect of SNP; SNP treatment of cucumber seedling leaves the maximal photochemical efficiency of primary photochemistry (φ_Po), the quantum yield of light energy absorption by PSⅡ reaction center for electron transfer (φ_Eo) and the probability of capturing excitons for transporting electrons to other electron acceptors downstream of the electron transport chain Q_A (ψ_o), fluorescence parameters related to the acceptorside properties of the PSⅡ reaction center include the oxygen release complex (F_OK), the reduction capacity of Q_A (F_KJ), the reduction capacity of Q_B (F_IP) and the density of active reaction centers per excited crosssection (RC/CS) were significantly higher than that of CK. (3) Compared with SNP treatment, the values of φ_Po, φ_Eo, ψ_o, RC/CS, F_KJ, F_JI and F_IP were significantly decreased in BSO+SNP and 6AN+SNP treatment, while M_o and V_J increased significantly. Under low temperature stress, GSH plays an important role in exogenous NO increasing the relative water content, reducing lipid peroxidation, stabilizing photosystem Ⅱ and promoting electron transfer capability of donor side and recipient side of electron transfer chain in PSⅡ reaction center and improved the cold resistance of cucumber seedlings.

Abstract:In order to reveal the effects of single and combined treatment with different concentrations (0, 2, 4, 8, 16 mg·L^-1) of hydroxylated multi walled carbon nanotubes and 10 μmol·L^-1 Cd, we studied root growth physiological indexes and Cd content of Vicia faba seedlings by hydroponic method. The results showed that: (1) with the treatment of single MWCNTsOH, with the increase of MWCNTsOH concentration (2-8 mg·L^-1), the length of V. faba root increased, and the production rate of OO₂^-· increased along with the increase of SOD and POD activities. (2) The MDA content and O₂^-· production rate of seedlings treated with single Cd were both higher than that of the control group, and the O₂^-· production rate was 1.98 times higher than that of the control group. (3) The MWCNTsOH combined treatment induced the production of O₂^-· and the increase of MDA content in the root of V. faba seedlings. The 16 mg·L^-1 MWCNTsOH combined with Cd caused the greatest damage to the root of V. faba seedlings, and some root tip cells were damaged and shed, and Cd content was significantly decreased. It was found that low concentration of MWCNTsOH could promote root length and reduce the toxicity of Cd, while high concentration (16 mg·L^-1) of MWCNTsOH combined with Cd had a synergistic effect on root toxicity of V. faba seedlings.

Abstract:In order to explore the effect of exogenous MT on the growth and physiological mechanism of Toona sinensis seedlings under salt stress, we studied the effects of different concentrations of melatonin (0, 50, 100, 200 and 400 μmol/L) on the growth indicators, mineral ion (Na⁺, K⁺, Ca²⁺ and Mg²⁺) contents and net photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s) and intercellular CO₂ concentration (C_i) of T. sinensis seedlings under 150 mmol/L NaCl. The results showed that: (1) compared with the control (CK), the growth of T. sinensis seedlings was significantly inhibited by salt stress and had a lower P_n. 150 mmol/L NaCl significantly increased Na⁺ contents in leaves and roots and reduced the contents of K⁺, Mg²⁺ and Ca²⁺ with the decreased values of K⁺/Na⁺, Mg²⁺/Na⁺ and Ca²⁺/Na⁺. (2) Exogenously suitable concentration of MT increased the plant growth indexes of seedlings under salt stress, decreased Na⁺ contents, increased the levels of K⁺, Ca²⁺ and Mg²⁺ and values of K⁺/Na⁺, Mg²⁺/Na⁺ and Ca²⁺/Na⁺. At the same time, P_n, T_r, water use efficiency (WUE), G_s, C_i and decreased stomatal limitation value (L_s). (3) The chlorophyll contents increased and MDA content decreased significantly with MT treatment. The results showed that appropriate concentration (100 μmol/L) of MT can reduce the concentration of Na⁺ by increasing the concentration of K⁺, Mg²⁺ and Ca²⁺ in the leaves and roots of T. sinensis seedlings, regulate the ion balance in plants, enhance the absorption of nutrients, and improve the photosynthesis efficiency in order to improve the resistance of T. sinensis seedlings to salt stress.

Abstract:To explore the effects of different biogas slurry concentrations and application methods on growth, physiological characteristic indexes and component content of Astragalus membranaceus var. mongholicus (Bge.) Hsiao, we potted 1yearold A.membranaceus var. mongholicus (Bge.) Hsiao seedlings, set four biogas slurry concentrations (0%, 50%, 80% and 100%), one chemical fertilizer concentration (the concentration is same as 50% biogas slurry concentration). The experimental results showed: (1) using base fertilizer and base fertilizer+spray as the 2 kinds of application methods, the growth index of A. membranaceus var. mongholicus (Bge.) Hsiao increased firstly and then decreased with the increase of biogas slurry concentrations, the growth of single plant was based on base fertilizer+spraying, which showed a trend of decreasing firstly and then increasing, the above indicators were higher with chemical fertilizer. (2) The contents of chlorophyll, proline and soluble sugar firstly increased and then decreased with the increase of biogas slurry concentrations, the indicators of chlorophyll, osmotic adjustment substance were higher with 80% biogas slurry fertilizer (P<0.05). (3) Using base fertilizer as the application method, the activity of SOD decreased firstly, then increased and decreased finally. The activities of POD and CAT increased firstly, then decreased and increased eventually. Using base fertilizer and spray as the application method, all indicators of antioxidase activities showed a same trend of increasing firstly and then decreasing with the increase of the biogas slurry concentration, and the SOD value of 80% biogas slurry fertilizer treatment and the POD and CAT values of chemical fertilizer treatment were significantly higher than other treatments (P<0.05); the content of malondialdehyde (MDA) decreased firstly, then increased and decreased finally with the application of base fertilizer method, the application of base fertilizer + spraying increased firstly and then decreased, and the indicator was higher with 80% biogas slurry fertilizer (P<0.05). (4) The contents of astragaloside and calycosin7OβDglycosides increased firstly and then decreased with the increase of biogas slurry concentration compared with the two irrigation methods. As a whole, the contents of astragaloside and calycosin7OβDglycosides increased by 57.44% and 24.06% compared with the control, respectively. Compared with the same concentration of chemical fertilizer, the content of astragaloside in the biogas slurry treatment increased by 74.47%, while the content of calycosin7OβDglycosides decreased by 42.16%. These results indicated appropriate biogas slurry concentration and irrigation method can improve the growth and index component content of A. membranaceus var. mongholicus (Bge.) Hsiao seedling. The A.membranaceus var. mongholicus (Bge.) Hsiao seedling which treated with 80% biogas slurry fertilizer had better growth and higher quality.

Abstract:By using the seeds of Codonopsis pilosula as the experimental material and by cultivating C. pilosula with different concentrations (0, 0.01, 0.05, 0.2, 0.5, 1.0, 2.0, 3.0, 5.0 and 10.0 mmol·L^-1) of ferulic acid (FA) and the growth medium with different volume ratios of attapulgite clay (attapulgite)/vermiculite (0/1, 1/120, 1/80, 1/50 and 1/20) under indoor condition, we analyzed the effects of FA in the growth medium on the seed germination, growth, and chlorophyll fluorescence of C. pilosula, and studied whether the negative effects of FA on C. pilosula could be alleviated by different concentrations of attapulgite presented in the growth medium. The results showed that when the concentration of FA was higher than 1.0 mmol·L-1, the activity of C. pilosula seeds were inhibited and the germination of seeds was delayed. If FA was applied to the growth medium before cultivation, the biomass accumulation and photochemistry reaction of the C. pilosula seedlings were increased by lower concentrations of FA but were decreased by higher concentrations of FA. During the growth period of the seedlings, shortterm treatment with different concentrations of FA also significantly decreased the photochemistry reaction of the seedings. The attapulgite presented with different volume ratios in the growth medium can effectively alleviate the negative effects of higher concentration of FA on C. pilosula during the germination and growth. And, the volume ratio of attapulgite/medium at 1/50 seemed to be the most optimized content in alleviating these negative effects. These results indicate that high concentration of FA in environment can significantly inhibit the seed germination, growth, and photochemical reaction of C. pilosula seedling, while the addition of attapulgite into the medium with appropriate ratio can alleviate the damage of FA that would emerge at different stages during C. pilosula growth.

Abstract:This study explored the C, N, P stoichiometry characteristics in fine roots of Phyllostachys praecox with different mulching years, to understand the response of fine root nutrient dynamics to mulching management, and to provide a theoretical basis about reasonable development of coverage management to achieve efficient and sustainable economic benefits. Investigation was carried out in the P. praecox plantation with different mulching years，include longterm mulching (LM， continuous coverage for 4 years)， shortterm mulching (SM， continuous coverage for 2 years) and not cover (CK), located in Caoba Town, Yucheng District, Yaan City. The mulching materials are rice husk (insulation layer) and rice straw (warming layer). In midlate of July, October 2017 and January, April 2018, sshaped points were selected in each sample plot. Fine root samples were collected at 0-30 cm depth and the C,N,P stoichiometry characteristics of fine roots were determined. This results showed that: (1) the effects of different mulching years on fine root C content, N content, P content, C/N ratio, C/P ratio and N/P ratio of P. praecox were greater that of different seasons. Compared with seasons, mulching years were more important factors for C content, N content, P content and their stoichiometric ratios. (2) Shortterm mulching could increase the nutrient contents of fine roots, while longterm mulching could reduce the nutrient contents of fine roots, and mulching could affect the seasonal variation of C and N nutrient contents in fine roots, but not P. (3) C/N, C/P and N/P ratios of the three treatments had the same seasonal variation law. Shortterm mulching reduced the average annual and each season C/N ratios in fine roots, while longterm mulching increased the average annual and each season C/N ratios in fine roots. Mulching could reduce the average annual and each season C/P ratio in fine roots, but the longterm mulchings C/P ratio was higher than that with shortterm mulching. Mulching could reduce the average annual and each season N/P ratios in fine roots. There was no significant difference between longterm mulching and shortterm mulching in each season N/P ratios of fine roots (P > 0.05). (4) The correlation analysis showed that the increase of mulching years would lead to a more complex significant correlation between C, N, P and their stoichiometric ratios. This results indicate that longterm continuous mulching can reduce the C, N and P contents in fine roots of P. praecox, and cause the imbalance of nutrients of fine roots. The mulching management of P. praecox plantations needs to reduce the continuous mulching time, adopt shortterm mulching management measures, and give the time for fine roots to recover, so as to achieve the goal of sustainable management of P. praecox plantations.

Abstract:The study on the biomass allocation and stoichiometric ratio of desert plants in different growth periods can help todeeply understand nutrient cycling and limiting conditions of Guerbantongut Desert plants in extreme environment. In this study, four ephemeral plants, Hyalea pulchella (Ledeb.) C. Koch, Nonea caspica (Willd.) G. Don., Erodium oxyrrhynchum M.B. and Lactuca undulata Ledeb. were selected. The results showed that: (1) the biomass distribution of the four desert plants showed a consistent growth law during the whole growth cycle, while rootshoot ratio (R/S) showed a decreasing trend. However, the biomass accumulation rate was not the same in each growing period, but the final distribution ratio of the four plants converged with the completion of life cycle. (2) The C elements of the four plants remained high throughout the growth cycle, and the N and P elements in the plants showed an overall downward trend. As for the metrology ratio analysis, there is a positive correlation between C∶N and C∶P, but both are negatively correlated with N∶P, while the results of N∶P study are lower than the average of all xerophytes. (3) Comprehensive ranking of biomass and stoichiometric ratio showed that the degree of explanation of the first and second axes was 58.89% and 19.43% respectively, and 78.32% of the total information could be explained cumulatively, indicating a high credibility, but with weak correlation between overall index. The results illustrates that the four desert ephemeral plants grow in the process of stoichiometric ratio did not decide on the biomass allocation. Plants may be due to the drought environment caused by the different survival strategy results or biomass allocation of the main factors of plants could be decided by their own genetics.

Abstract:Fermentation processes using cordycepinproducing fungi other than O. sinensis may be an alternative way to produce cordycepin, which is a nucleoside analogue compound possessing many pharmacological functions. In order to screen cordycepinproducing fungi from traditional Chinese medicine Ophiocordyceps sinensis, we isolated a total of 42 fungal strains from the fruiting bodies of O. sinensis. In the present study, a cordycepinproducing fungal strain OS17 was isolated from O. sinensis. The strain produced cordycepin when grown in potato dextrose broth (PDB) medium, and the amount of cordycepin produced by this fungus was quantified to be 40.16 mg/L by HPLC. The fungal cordycepin which was analyzed by HPLC was shown to be identical to authentic cordycepin. The strain OS17 was identified as Bionectria ochroleuca based on its morphology and ITS sequence analysis. To the best of our knowledge, this is the first report concerning the isolation and identification of cordycepinproducing Bionectria spp. from its host, which showed that endophytic fungi have the potential to produce many bioactive compounds.

Abstract:Firmiana kerrii (Craib) Kosterm. (Malvaceae) was previously known from Thailand and Myanmar. It was newly found growing in rocky crannies of limestone hilltops in Mengla County, Xishuangbanna, Yunnan Province, China. Vouchers were deposited at the Herbarium of Xishuangbanna Tropical Botanical Garden (HITBC). A key to the nine species of Firmiana currently known from China is provided.

Abstract:The genus Ypsilandra Franch. and its species Ypsilandra thibetica Franch. are reported for the first time as new records from Shaanxi Province, China. A brief description and photos are provided. The voucher specimens were deposited in Herbarium of Shaanxi University of Technology (HZTC).