Abstract:Based on the transcriptome data of longan embryogenic callus, we cloned the Dimocarpus longan DRM1 gene. The functions of DlDRM1 was analyzed by means of bioinformatics and realtime quantitative PCR. Expression of DlDRM1 was analyzed in the stages of somatic embryogenesis, exogenous hormone (2,4D, IAA, KT) treatment and different tissues in D. longan. The purpose is to reveal the D. longan DRM1 gene function in the process of longan somatic embryos. The results showed that: (1) the fulllength sequence of longans _{Domains Rearranged Methyltransferase} 1 gene (DlDRM1) was successfully cloned from embryogenic callus of ‘Honghezi’ longan by using RTPCR (GenBank accession number is KY990493) based on the transcriptome data of longan embryogenic callus unigene sequences. The cDNA fulllength is 2 574 bp, including 494 bp 5′UTR and 184 bp 3′UTR, and it could encodes protein with 631 amino acids. (2) Bioinformatics analysis showed that DlDRM1 (molecular formula: C₃₁₀₄H₄₈₃₉N₈₅₁O₉₈₄S₂₈) was an unstable hydrophile protein, without signal peptide and transmembrane domain. Sequence alignment result showed DlDRM1 was highly similar to DRM in navel orange (up to 76.85%), and the closest genetic relationship was also found between the two proteins according to phylogenetic analysis. (3) Quantitative realtime PCR showed that DlDRM1 expresses in all of the tissues and organs in longan and the highest expression was found in flesh, followed by flower buds, and the lowest expression was found in leaves. Notably, the expression of DlDRM1 in nonembryonic callus was found to be significantly higher than that in embryonic callus, and its expression decreases during the process of the non embryonic callus changes to be embryonic. These indicated that DlDRM1 was negatively correlated with the embryonic of somatic embryo and it might contribute to the longan somatic embryogenesis. Moreover, we also studied the effects of hormones on the expression of DIDRM1. And it was found that certain concentrations of IAA and 2,4D could promote its expression, while KT inhibit its expression. (4) Subcellular localization result showed that DlDRM1 was located in nucleus and cell membrane.

Abstract:In this study, we identified a lowluminescence mutant referred to as rll4 (reduced LUC luminescence 4) by screening a M₂ population derived from an ethyl methane sulfonate (EMS)mutagenized transgenic parental line ColLUC, which harbors a firefly luciferase reporter (LUC) gene under the control of 2×35S promoter. Genetic analysis demonstrated that the rll4 locus contains a single nuclearencoded recessive mutation. By using mapbased cloning strategy, we narrowed down the rll4 locus between the molecular markers CL417B10M1 and CL418B2M2, which are located at BAC (Bacterial Artificial Chromosome) clones F20D10 and F20M13 on chromosome 4, respectively. Methylationsensitive restriction enzyme PCR (ChopPCR) results showed the DNA methylation levels of a few genomic loci were increased in rll4 mutant. Reverse transcriptionPCR (RTPCR) results revealed that the expression levels of several endogenous targets of RNAdirected DNA methylation (RdDM) pathway were decreased in rll4 mutant while the expression of ROS1 (REPRESSOR OF SILENCING 1) remained unchanged. Taken together, these results suggest that RLL4 locus is probably involved in DNA demethylation process in A. thaliana.

Abstract:In this research, we use GUS histochemical staining method to analyze the expression pattern of GUS gene of ProUPLs∶GUS transgenic plant, which initiate the GUS report gene by the promoter of HECT E3s genes (UPLs). The results of these six HECT E3s genes at different development stages and tissues show different expression patterns, but all of them have high activity at the early stage and senescence stage of leaf development. Interestingly, we find that the leaf shape of upl3 mutant show significant difference and both upl3 and upl4 mutant delay senescence and have different expression levels of senescence-associated genes compared to wild type. Thus, we speculate that both UPL3 and UPL4 are likely to regulate the leaf development and the progress of plant senescence.

Abstract:In the present work, we obtained the full length sequence of DlDCL gene through longan transcriptome data and analyzed them by means of bioinformatics and realtime quantitative PCR. The purpose is to clarify the expression pattern of DlDCLs in longan somatic embryos and different tissues, as well as their expression profiles responses to hormones and light treatment. The study is help to lay the foundation for the further research on the regulation of DlDCLs genes during longan somatic embryos. The results showed that: (1) there are four members of DCL family genes, i.e. DlDCL1, DlDCL2, DlDCL3 and DlDCL4, and different DlDCLs genes were differentially expressed at somatic embryogenesis stage based on the FPKM value of Unigene. (2) Bioinformatics analysis showed that the physical and chemical properties of the DlDCLs are mostly similar, all of them are hydrophilic and unstable proteins with transmembrane structure and without signal peptide. Meanwhile, there are also some differences: DlDCL2 is basic protein while DlDCL1, DlDCL2 and DlDCL4 are acidic proteins. Subcellular localization prediction showed that DlDCL2 was located in nucleus and chloroplast, while the other three members were located in the nucleus. Protein domain prediction showed that DCLs were highly conserved proteins. (3) Phylogenetic tree analysis showed that the genetic relationship of DlDCLs family in longan were close to those from Citrus sinensis. (4) QPCR analysis showed that the expression patterns of different DlDCLs in nonembryogenic callus (NEC) and somatic embryogenesis (SE) varied a lot, but DlDCLs are relatively high in the stage of embryogenic callus (EC), which may indicated that DlDCLs have distinct but cooperative functions in the process of the NEC and during SE. The expression patterns of DlDCLs in different tissues were also investigated. The results revealed that DlDCL1 and DlDCL2 had the highest expression in the leaf and followed by floral organ tissues, which suggested that DlDCL1 and DlDCL2 may participate in photosynthesis and floral organs development. Moreover, DlDCLs expression was induced by light quality and the concentrations of 2,4D, MeJA, SA, indicating that the DlDCLs signaling pathway might be regulated by several kinds of hormones and light.

Abstract:In this study, the antistress At1g67520 gene from Arabidopsis thaliana was used as a probe, a RLCK gene of GbRLCK10 was cloned through the in silico cloning and RTPCR. To reveal the expression, regulation and mechanism of RLCK family genes in Gossypium barbadense, we has analyzed the genomic structure and the expression pattern of GbRLCK10 by combining with qRTPCR technology under mRNA organization and different stress inducements. Results show that: (1) the ORF of GbRLCK10 was 1 179 bp, encoding 392 amino acids. GbRLCK10 contained only the Serine/Threonine kinase domain, and belonged to receptorlike cytoplasmic kinase gene family. Phylogenetic analysis showed that GbRLCK10 closed to GaRLCK10 and named as GbRLCK10 (Genebank: 2022184 ). The gene was made up of 5 exons and 4 introns. (2) The GbRLCK10 expression were detected by qRTPCR, the results showed that GbRLCK10 gene is expressed in root, stem and leaf of resistant cultivar ‘Xinhai 21’ and susceptible cultivar ‘Xinhai 14’. With the duration of the treatment of Verticillium dahliae, while the relative expression of GbRLCK10 was significantly lower and the response was later in the susceptible cultivar than that in resistant cultivar. Both NaCl and PEG6000 could induce the expression of GbRLCK10, the expression of GbRLCK10 increased firstly and decreased. After resistant cultivar ‘Xinhai 21’ was treated by NaCl, response time of GbRLCK10 is earlier than PEG6000, but the response to PEG6000 was more intense. Salicylic acid, ethylene, methyl jasmonate and gibberellic acid could also induce the expression of GbRLCK10. After the treatment of salicylic acid, the level of GbRLCK10 expression increased and decreased, then increased again. The expression of GbRLCK10 increased and maintained at a high level when induced by ethylene. However, the expression of GbRLCK10 firstly increased and then decreased when induced by methyl jasmonate. Compared with salicylic acid, ethylene, methyl jasmonate, the gibberellic acid induced expression levels of GbRLCK10 were significantly lower. We suggested that GbRLCK10 may be response to pathogens, NaCl, PEG6000 and hormones stress in Gossypium barbadense L., but its function still need further study.

Abstract:IiMYB34 was cloned (GenBank accession No. MF373610) from tenderleaves of Isatis indigotica with RTPCR method, and its bioinformatics and expression pattern analysis were performed in this study. The results indicated that: (1) the full length gDNA of IiMYB34 was 1 854 bp, including 3 exons and 2 introns; Its ORF was 951 bp in length, encoding 316 amino acid residues; The alpha helix structures and coiled coils were in higher proportions than those of the extension chain structures in the secondary structure of IiMYB34 protein, and the results were consistent with its tertiary structure; The functional structure domain analysis results showed that IiMYB34 protein was a typical R2R3MYB protein with two conserved MYB DNAbinding domains; The characteristic of the amino acid sequences of IiMYB34 was highly homologous with Brassica napus and Brassica oleracea. (2) The qRTPCR analysis results indicated that IiMYB34 exhibited a tissuesspecific expression and was highly expressed in leaf. Moreover, IiMYB34 could be induced significantly by MeJA, SA and Glu, but repressed by low temperature (4 ℃) and mechanical wounding. The obtained results laid the foundations for the further functional research on IiMYB34.

Abstract:The present study obtained a PKS Ⅲ gene from the transcriptome of the lichenizedfungi Nephrmopsis pallescens. We first cloned fulllength cDNA of a PKS Ⅲ gene through the method of RTPCR, and named it NpPKS3, then we had a trial of NpPKS3 gene expression in the different media, to acquire the optimal media culturing the lichenforming fungi N. pallescens, apply some basis to further explore the function of NpPKS3 gene, and simultaneously offer some necessary material to the heterologous expression of polyketide compounds in the lichenizedfungi N. pallescens. The results showed: (1) the full length of NpPKS3 gene(GenBank ID: MF351559) has 1 335 bp, codes 444 amino acid, its transcriptional product could be polyketide synthase of N. pallescens (NpPKS3), and indwells cytoplasmic matrix. (2) The phylogenetic analysis revealed that the NpPKS3 amino acids sequence and the csyB of polyketide synthase Ⅲ clustered into one clade, therefore we could speculate it might be csyB. (3) We detected that the conditions of the NpPKS3 gene expression in the different media by OSMAC(one strain, many compounds) strategy. The result showed it is the best expression ability of NpPKS3 gene in BMG medium, and the weakest in BD medium.

Abstract:Arceuthobium sichuanense belongs to semiparasitic seed plants. To explore the genetic diversity of A. sichuanense and its relationship with the host selection and geographic distribution, we collected 100 samples on 5 species of Picea from 3 sites which distributed in Sichuan, Gansu and Qinghai provinces, and molecular marker of A. sichuanense was conducted by ISSR technology. The results demonstrated that 130 bands were amplified by 10 primers, among which 129 bands were polymorphic, accounting for 99.23%. Genetic diversity analysis showed Neis genetic diversity (H_e) was 0.313 9 and Shannons genetic information index (I) was 0.476 5, indicating that the genetic diversity among 100 samples was abundant. Gene flow among A. sichuanense populations was relatively weak (N_m=0.528 7), which might limited the genetic differentiation among the populations (G_st= 0.486). The unweighted pairgroup method with arithmetic average (UPGMA) dendrogram classified the 100 strains into two major groups. The two groups could be further divided into 3 and 2 subgroups, respectively. Based on the different hosts, A. sichuanense grown on P. asperata and P. likiangensis var. balfouriana clustered into the first group, and the others clustered into the second group. The result indicated that geographical isolation and host selection played an important part in the genetic diversity of A. sichuanense.

Abstract:In the study, 47 SSR polymorphic sites which have steady and specificity amplification were selected. PCR using 159 Eucalyptus germplasms accessions including 42 species of eucalyptus were applied to the genetic diversity analysis and clustering analysis, through the method of constructing a two dimensional database composed of the numbers of bands. （1） A total of 137 alleles obtained from the analysis of PCR results among all 159 accessions by 47 pairs of SSR primers with an average of 2.915 alleles per pairs of primers ranging from 2 to 7. （2）The results of genetic diversity showed that the average Shannons information index (I) was 0.181. The average observed heterozygosity(H_o) was 0.068, and the average value of polymorphism information content (PIC) was 0.182. The highest genetic diversity level was found in the three loci eSSRGR018, eSSRGR083 and eSSRGR109 by comprehensive comparison. These three SSR loci would play an important role in genetic diversity and germplasm identification among Eucalyptus germplasm resources. （3）The results of UPGMA analysis and principal coordinate analysis (PCoA method) were consistently indicated that 159 accessions were divided into two groups, and this classification agreed with the taxonomy of Hill & Johnson (1995) that based on morphology. Two cluster results showed that the relationship between Eucalyptus cloeziana and E. pauciflora was relatively higher genetic similarity and they were more likely to produce hybrids. The results in present research revealed high level of genetic diversity among the 159 Eucalyptus germplasms accessions including 42 species of Eucalyptus introduction in China. The 110 pairs of SSR primers could be applied to analyze Eucalyptus germplasm identification, effectively.

Abstract:In order to reveal flower formation mechanism of Cymbidium kanran Makino, we documented the floral ontogeny and development of this endangered orchid species by paraffin section and anatomy, with focus on the primitive and middle develop stages of labellum and gynostemium (before the elongation of the column part). Results show that: the differentiation process of inflorescence is acropetal and follows the sequence: inflorescence primordium differentiation, floral primordium differentiation, perianth differentiation, and gynostemium formation. Differentiation of the labellum follows the sequence: lamella, sidelobes, and purplish red patches on the midlobe and stripes on the sidelobes. Because of the late initiation of the sidelobes and lamella of the labellum, they may not be related to the staminodes. During the formation of gynostemium, anther initiates first, then the median carpel apex and lateral carpel apices emerge, stigmatic channel forms, and finally the rostellum and viscidium differentiate.

Abstract:Using classical taxonomic method, 130 specimens, which were deposited in HBNU and other native herbariums, belonging to Pohlia Hedw. section Cacodon Lindb. ex Broth. and its related groups were studied. The propagules of the eight propaguliferous species of Pohlia Hedw. section Cacodon in China were compared with the size, shape, quantity and length of leaf primordia. Results showed that: (1) the checklist of Pohlia Hedw. section Cacodon in China was updated, which including eight species: Pohlia annotina (Hedw.) Lindb., P. camptotrachela (Ren. & Card.) Broth., P. drummondii (Müll. Hal.) Andr., P. flexuosa Harv., P. hisae T. J. Kop. et J. X. Luo, P. leucostoma (Bosch & Sande Lac.) M. Fleisch., P. lutescens (Limpr.) H. Lindb., and P. proligera (Kindb. ex Breidl.) Lindb. ex Arnell. (2) As the features of propagules growing in rhizoid or axillae play important roles in identification, the shape of propagules and the quantity and shape of leaf primordial in Pohlia Hedw. section Cacodon Lindb. ex Broth. were significantly different, such as P. lutescens (Limpr.) H. Lindb. has toruloid propagules growing on the rhizoids, P. flexuosa has two different types of propagules. (3) The taxonomic features, habitat and characteristic comparison of related species are described in detail. Meanwhile, ink drawing of eight species of Pohlia section Cacodon were made. This study provided taxonomic evidence of the identification of Pohlia Hedw. section Cacodon Lindb. ex Broth. in China.

Abstract:This paper used oriental lily varieties ‘Sorboon’ as experimental material and set lasting 4, 8, 12, 16, 20, 24 days water stress and rewater 4 days after 24 days water stress.Chlorophyll content, photosynthetic characteristics, protective enzyme, MDA were tested and root system development situation was observed. Pollen fertility was also researched during water stress, rewater and flowering periods. The effects of root, leaf physiology function and pollen fertility under water stress situation were also discussed. The results show that: (1) compare with normal conditions, after 4 days water stress, lily begin to be effected. 4-8 days, stomatal limitation is the major factor to effect lily. 8-12 days, fluorescent chlorophyll index of leaf decreased dramatically. The limitation of photosynthetic had transferred from stomatal factor to non stomatal factor. After 12 days water stress, membrane began to be oxidized and MDA content increased. After 16 days, protective enzyme system was effected and antioxidant enzyme activity decreased gradually. At the end of water stress, index of fluorescent chlorophyll recovered slightly. (2) After 4 days rewater treatment, all index of photosynthesis recovered, but lower than the level of normal. The results show that chloroplast was destroyed under the 24 days water stress treatment. (3) Compare with the control, root system became short and thick firstly, then less, dry and shrink at last with water stress aggravate. Pollen fertility was no significant change during water stress, rewater and flowering periods. This research discovered: leaf photosynthetic function, protective enzyme and root system suffered damage after lasting 24 days water stress, but pollen fertility was normal under this situation. This study will provide important reference for water saving production and partly reveal the relationship between photosynthetic physiology and water stress of cut flower lily.

Abstract:In this study, we used three cotton accessions‘Xinluzao No.33’, ‘Xinluzao No.36’ and ‘Xinluzao No.50’which were locally approved and widely used to explore protein changes resulted from seed deterioration in cotton. By accelerating aging at high tempreture and humidity（40 ℃，RH 100%），we obtained cotton seeds with different vigor levels.Proteomic of vigor deteriorated seed of ‘Xinluzao No.50’ analysised by two dimensional gel electrophoresis technology, and differential protein spots were identified by MALDITOFMS/MS mass spectrometry technology，to explicit change of proteome expression in the process of cotton seed vigor deterioration. The results showed: (1) among the three accessions, ‘Xinluzao 50’ displayed a linear decrease in seed vitality as the aging treatment extended. (2) Approximately 350 protein spots were observed in the 2DE gels within the area of pH47 and molecular weight from 14.4 kD to 97.4 kD. Among them, 30 were identified as differential protein spots with at least two fold change of expression levels and statistically significant difference at 99% level. (3) Using the method of MALDITOF/TOF, twentynine protein spots were successfully identified.Bioinfomatic analysis results indicated that we obtained 13 storage related proteins, two immunity related proteins, one lipid metabolism related protein, one energy metabolism related protein, two actins, two regulatory related protein, one secondary metabolites, one cell defense related protein, one secreted protein, and five proteins with unknown functions. The study identified 29 differentially expressed proteins probably are associated with cotton seed vigor deterioration.

Abstract:Effects of moderate (200 mmol/L NaCl) and severe (400 mmol/L NaCl) salt stress on the growth characteristics of Sophora alopecuroides were studied by measuring gas exchange, chlorophyll fluorescence parameters and growth indexes. The results showed: (1) one day after moderate salt stress, significant decreases were measured in photosynthetic rate (P_n), stomatal conductance (G_s), transpiration rate (T_r) and intercellular carbon dioxide concentration (C_i) of S. alopecuroides seedlings. Five days after moderate salt stress, slight decrease occurred in P_n while slight increase was measured in C_i. However, one day after severe stress, significant decreases were measured in gas exchange of S. alopecuroides, with it getting worse along with longer time stress. The reason for the decrease of photosynthetic rate of S. alopecuroides was due to the combined effect of stomatal factors and nonstomatal factors. The decrease of P_n was mainly caused by nonstomatal factors under severe salt stress. (2) The maximum photochemical efficiency (F_v/F_m), photochemical quenching coefficient (qP), actual photochemical efficiency (Φ_PSⅡ) decreased in different levels. The decrease was more significant in severe salt stress than in moderate salt stress treatment. The change of fluorescence parameters was not obvious under moderate salt stress, while it was significant under severe salt stress along with the prolongation of stress time. (3) With the aggravation of salt stress, water content and growth indicators (plant height, root length, dry weight) were markedly decreased, leading to a serious inhibition in plant growth. The results showed that the tolerability of halophytes to salt stress was also limited. The growth of S. alopecuroides was slightly inhibited under 200 mmol/L NaCl stress while it was seriously damaged under 400 mmol/L NaCl stress.

Abstract:To analyze the changes of carbohydrate content and the activities of related enzymes in bearing branches and their effects on fruit setting before and after period of dormancy, and to provide theoretical basis for the transformation of almond low yield garden, we selected the same age and the same species in 2012-2014 under three consecutive years of sustained low yield and sustained high yield orchards as the research object, taking the main cultivated varieties ‘Zhipi’ as test material, analyze the contents of carbohydrate components and activities of related enzymes in the phloem and flower bud of bearing branches before and after the period of dormancy. Meanwhile, we also carried on the statistical analysis to the percentage of fruit set and the yield per tree, the results show that: (1) soluble sugar accumulation of bearing branches is basically about sucrose and sorbitol during dormancy. (2) The trend of carbohydrate content changes in the phloem and flower bud of bearing branches before and after period of dormancy is identical to the changes of activities of related enzymes（acid invertase, neutral invertase, sucrose synthase, sucrose phosphate synthase, ect.） in the highyield orchard and lowyield orchard. (3) The carbohydrate contents and related enzyme activities of bearing branches in highyield orchard are higher than those in lowyield orchard. It is thus clear that the level of carbohydrate accumulation of bearing branches during dormant period is one of the key factors that can influence the percentage of fruit set and the yield in the following year.

Abstract:Wettingdrying alternation irrigation, which has a higher grain yield than traditional flooded rice because the water regime is more favorable to yield formation, is considered as an important watersaving cultivation technology in rice plants. In addition, the two different irrigation regimes have significant effects on ratios of ammonia nitrogen and nitrate nitrogen in the root zone, and then could alter the growth and development of rice plants. Therefore, soil water and nitrogen forms could be critical regulatory factors affecting yield formation of rice plants in wettingdrying alternation irrigation. To investigate the interaction effect, we conducted pot experiments in 2016 with cultivar Ningjeng 8 in different water regimes and N forms. In this study, water regimes included traditional flooding irrigation (W₁) and wettingdrying alternation irrigation (W₂), and N forms treatments set three categories：ammonia and nitrate nitrogen ratio=0∶100 (N₁), ammonia and nitrate nitrogen ratio=50∶50 (N₂), ammonia and nitrate nitrogen ratio=100∶0 (N₃). The results showed that: (1) the grain yield, yield components, photosynthetic production, harvest index, N harvest index, and nitrogen grain production efficiency in the W₂ treatment are significantly higher than that in the W₁ treatment (_P<0.05). But slightly lower N content in the W₂ treatment was observed when compared with the W₁ treatment. From the perspective of N forms, grain yield in the N₂ treatment was the greatest, and yield in the N₁ treatment was the minimum among N treatments, which were mainly from a higher matter translocation from sheath to kernel and photosynthetic produce ability during grain filling stage in the N₂ treatment than that in the N₃ and N₁ treatments. The greater N content and N concentration could be an important physiological basis for high photosynthetic ability in the N₂ treatment than the others. The N₁ treatment had the highest N use efficiency, and then followed by the N₂ and N₃ treatments. Moreover, there were significant interaction effects between water regimes and N forms for grain yield, yield components, and harvest index (P<0.05). The W₂ treatment coupled N₂ treatment was the optimal combination for yield formation of rice plants.

Abstract:We conducted a study to investigate morphological indicators, chlorophyll, soluble sugar, ergine and ergonovine contents under different photoperiods (8, 12, 14 and 16 h·d^-1) and illumination intensities (1 500, 2 500 and 3 500 lux), to explore the optimum conditions for the growth of the symbiotic Achnatherum inebrians seedling and the accumulation of alkaloids. it was found that: (1) the plant height, chlorophyll and soluble sugar content of symbiotic A. inebrians seeding were increased with the prolonging of photoperiod, which were significantly （P<0.05） lower than that of other three treatments under 16 h·d^-1, but the root length, tiller amount per plant and biomass per plant were increased first and then decreaseds, which had a peak value under 14 h·d^-1. （2） The plant four morphological indicators, chlorophyll and soluble sugar content of symbiotic A. inebrians seedling were increased with the illumination intensity increased that had a peak value under 3 500 lux. (3) With the prolonging of treatment time, the content of ergine and ergonovine were increased in different photoperiods. The contents of ergine and ergonovine were significantly （P<0.05） higher than that of other treatments under 12 h·d^-1 and 2 500 lux, which had a peak value at 15 days. It can be seen that the appropriate light environment can significantly promote the growth of symbiont of Epichlo gansuensisAchnatherum inebrians seedling and the accumulation of alkaloids, and the most suitable condition for the accumulation of ergine and ergonovine were 12 h·d^-1 and 2 500 lux.

Abstract:Populus simonii, which is one of the dominant and fastgrowing species in the Liudaogou watershed of China, plays a crucial role in the ecological restoration and construction of the area. However, there are few studies on the changes in photosynthetic parameters, water potential, δ¹³C, the total nitrogen and total phosphorus variations along the tree height in this area. Consequently, we measured these indicators of the leaves at different months and canopy leaves, and analyzed the water use efficiency and photosynthetic characteristics of P. simoniis leaves at different canopy heights. The results showed that: (1) the photosynthetic rate (P_n), stomatal conductance (G_s), intercellular CO₂ concentration (C_i) and transpiration rate (T_r) decreased with the increasing canopy height, indicating that the leaves were subjected to water stress caused by the tree height; (2) The values of δ¹³C and instantaneous water use efficiency (WUEi) increased with the increasing canopy height, and the δ¹³C values ranged from -29.81‰ to -27.43‰ along the canopy height; (3) The δ¹³C values of the leaves were positively correlated with the water use efficiency of the plant, and they could reflect the longterm water use status. The variation range of δ¹³C value was 2.22‰ and 2.12‰ along the tree height in different months, which suggested that genetic characteristics and environmental factors have common effects on leaf δ¹³C. This research provides a theoretical basis for elucidating the area of P. simonii mechanism of the tree height of water stress, and for the construction and management of arid and semi arid region of P. simonii plantation.

Abstract:We conducted a 6year field manipulative experiment in Kobresia humilis meadow of QinghaiTibet Plateau to study the effects of clipping (stubbled 1 cm, 3 cm and unclipped) and fertilizing (12.75 g·m^-2 urea + 3.06 g·m^-2 diammonium phosphate, unfertilized) on the N, P ecostoichiometric characters of soil and plants in alpine meadow. We look forward to exploring the type of plant nutrient limitation, and providing information for the management, protection and restoration of the natural grassland. The results showed that: (1) clipping and fertilizing had no significant effects on total N, P contents and N∶P ratio in soil. No significant change was found in soil available N content, while the soil available P content was raised significantly after clipping. Neither the total N, P content nor the available N, P content in soil changed significantly under fertilizing treatment as a result of those available nutrients added into the soil was quickly absorbed by plants rather than stored in soil nutrient pool. (2) Both clipping and fertilizing increased the N, P content of leaf layer in community, and fertilizing decreased the N∶P ratio. (3) Experimental treatments did not changed the N, P content and N∶P ratio of legumes, but clipping increased the P content of grasses and the N content of sedges, decreased the N∶P ratio of grasses independently. Fertilizing increased the P content of grasses and the N, P content of sedges independently. Thus legumes had the highest levels of N content, while lowest P content was found in sedges as well as N∶P ratio in grasses. (4) Whether the leaf layer of community, grasses or sedges, N content was positively related to P content, N∶P ratio had no significant correlation with N content and was negatively related to P contents. For legumes, there was a negative correlation between N and P content, and N∶P ratio positively related to N content and negatively related to P contents. This suggested that the nutritional status of community and plant species were more restricted by P content. (5) The relative growth rate of community aboveground biomass was significantly positive correlated with the content of N, P in community, significantly negatively correlated with community N∶P ratio. This result was consistent with the growth rate hypothesis and suggested that the hypothesis applies not only to species level, but also to community level.

Abstract:Based on 5 afforestation densities (1 m×1 m, 1.5 m×1.5 m, 2 m×1 m, 2 m×2 m and 2 m×3 m respectively), we determined the effect of stand density on the spatial distribution fine root biomass and provided theoretical supports for plantation management and operation in a 14yearold plantation of Pinus kesiya var. langbianensis in Puer City, Yunnan Province. The result showed that: (1) tree height and the diameter at breast height (DBH) increased with the decrease of stand density, while stand biomass increased with the increase of stand density. (2) The fine root biomass decreased with the development of stand density in the 14yearold P. kesiya var. langbianensis plantations, while the fine root biomass per single tree increased with the reduction of stand density. Meanwhile, the coarse and dead root biomass had no significant difference in five stand densities. (3) The fine root biomass mainly distributed in the soil surface, and 40.21 %-54.73 % of fine root biomass focused on 0-10 cm of soil depth. The fine root biomass indicated the trend with decreased accompanied by the increase of soil depth in the different stand densities. (4) With the increase of stand density, the proportion of fine root biomass showed firstly increase, then decrease in the soil upper layer, stand density and soil depth had significant effect on the fine root biomass. Tree individual size inequality had a negative influence on the fine root biomass, while fine root biomass per singe tree had significant negative influences on the stand density, individual size inequality, belowground biomass and basal area at the DBH, with the positive influences on the DBH and height.

Abstract:The study site is located in Siziwang Banner of Inner Mongolia. Taking the Stipa breviflora desert steppe grassland as the research object, based on the individual scale of the plant, we analyzed the relationship between plant species diversity, plant diversity and productivity by field experiment of wild plants in 2016, The responses of the gradient ［0 (CK), 0.91 (LG), 1.82 (MG), 2.71 (HG) sheep / (hm²·a^-1)］ were studied. The results showed that: (1) there were 30 species of 13 families and 13 species in the control area, only one species of Allium ramosum in the light grazing area. Compared with the control area, the vegetation species in moderate and heavy grazing areas were reduced by 30% and 40%, respectively, among them, most of the reduced species belonged to perennial miscellaneous grasses and perennial rhizome grasses.(2) The functional group structure had different responses to the stocking rate, and the perennial clover had always dominated the desert steppe and increased with the increase of the stocking rate. The results showed that the other four functional groups showed a decreasing trend with the increase of the stocking rate. (3) In the two diversity indices, the other diversity indices were in addition to the Margalef index of the functional group diversity and the size of the control > light> moderate> heavy grazing area. (4) The results showed that there was a significant positive correlation between the three α diversity index and the grassland productivity (P<0.05), and the functional diversity index had no correlation with the productivity (P> 0.05). In summary, the study shows that longterm grazing makes the desert grassland community structure tends to be simplified, so that perennial grassland formation advantages of a single species. In addition, the increase in stocking rate makes the diversity and productivity of S. breviflora desert steppe grassland plants significantly decrease, and high levels of diversity lead to high levels of grassland productivity. Comparing the two diversity index indicators, the species diversity index contributes more to the productivity of the desert grassland.

Abstract:Based on the population life table and survival analysis theory, I used the method that space instead of time and piecewise sliding technology to create the timespecific life table of Populus euphratica population in the lower reaches of Tarim River. Then, I drew the survival curve and mortality curve of P. euphratica population, and analyzed the dynamic variation process. The results are as follows: （1）the survivorship curve of P. euphratica population was a concave; the death rate, which were all below 20% in Ⅰ-Ⅲ, increased rapidly from Ⅲ to Ⅷ and reached the peak at Ⅷ ageclass, and maintain above 50% after Ⅷ ageclass. （2）Cumulative mortality rate of P. euphratica population increased 75.79% from Ⅰ to Ⅷ ageclass; However, the cumulative mortality rate form Ⅸ to Ⅻ only increased 5.07%, that indicated there was a high death rate of seedling and sapling of P. euphratica population ; Hazard index, which was 0.142 3 at Ⅶ age, was reached 0.217 4 at Ⅻ age, which indicated that hazard index was increased along with the increase of age of P. euphratica ; The mortality density decreased 0.018 7 that was remarkable between Ⅶ age and Ⅸ age, explained that there was amount of P. euphratica died from Ⅶ to Ⅸ .（3）Spectral analysis of the population showed that the natural regeneration of P. euphratica population was a minor periodic change in Ⅵ age class, that perhaps be connected with the physiological property of P. euphratica and human disturbance.

Abstract:In order to provide basis for assessing the plant protection of Maoer Mountain National Forest Park, we investigated plant species of Maoer Mountain National Forest Park twice on the spot in 1983 and 2013 by the method of sampling and sample survey, and analyzed the floristic characteristics. The results showed that: (1) compared with 1983, the number and composition of families were the same. However, 20 genera and 60 species decreased in 2013. The difference in the number of families at different levels is small, but the difference in the number of genera at different levels is large. (2) The difference in the composition of the dominant families was smaller, but in 2013, Orchidaceae became a nondominant family from the dominant family, while the Chenopodiaceae and Pinaceae became the dominant family from the nondominant family. The number and composition of the dominant genera was different, decreased eight. (3) The two surveys showed a large change in the number and composition of typical families, but the difference in the number and composition of the typical genera was smaller, in 2013 compared to 1983, only 2 typical genera decreased. (4) In 1983 and 2013, the geographical composition of the families, genera and species were all dominated by temperate distribution. The geographical composition of the families was the same, and the geographical composition of the genera was less than that of the MediterraneanWest Asia to Central Asia in 2003. In the geographical composition of genera, there was a lack of MediterraneanWest Asia to Central Asia in 2013, but in the geographical composition of species, there were more AsiaNorth AmericaArctic distribution than in 1983. According to the research, flora composition of Maoer Mountain National Forest Park in 30 years is basically stable, indicating that the plant protection in this area is effective. But the number of genera and species decreased significantly, and the species diversity was significantly reduced in 30 years, indicating that the status of plant protection was still not optimistic, especially in some important families, such as the reduction of Orchidaceae plants sounded the alarm for plant protection in this area.

Abstract:Fbox proteins are a protein family containing Fbox motif and in charge of recognizing the substrate to be degraded during ubiquitinproteasome pathway. In order to promote the functional study of Fbox family in Arabidopsis thaliana and other important crops, and draw a complete metabolic network of the family in plants as soon as possible, the present paper focuses on the research progress of Fbox family in A. thaliana reported in recent years, including the amount, type of member of Fbox family and their roles during growth and development, cell signal transduction, biotic and abiotic stress resistance and other physiological processes.