Abstract:Plantspecific transcription factors NAM family belongs to NAC transcription factor superfamily that play an important role in plant growth and development, physiological metabolism and response to various stresses. This study used bioinformatics methods to identify NAM genes in rice genome, analyzed their spatiotemporal expression patterns, subcellular localization and protein interaction, and used realtime quantitative qRTPCR to analyze the expression characteristics of NAM genes under different exogenous hormones (such as SA, ABA and MeJA) and abiotic stresses (including drought, salt and cold), and laid the foundation for further exploring the function and stress mechanism of NAM genes in abiotic stress and hormone regulation pathways. The results showed: (1) 48 NAM genes were identified from rice genome, clustered into five subfamilies through evolutionary analysis. There were nine pairs segmentally duplications of NAM genes in the rice genome. (2) Tissue expression analysis showed that NAM genes specifically expressed in different tissues and developmental stages of rice, especially high expression in the leaf sheath, stems and nodes; most of them are nuclear localization; there are many protein interactions. (3) Realtime quantitative qRTPCR expression analysis showed that 10 NAM genes were specifically expressed in different tissues; most of NAM genes were upregulated under salt and drought stresses, while the expression was low under cold stress.; the transcript levels of NAM genes were highly altered under SA, ABA, and MeJA application. The results showed that NAM genes play an important role in rice growth and development, hormones response and abiotic stresses response.

Abstract:CalciumDependent Protein Kinase is a key enzyme and plays an important role in the signal transduction pathways of plant stress resistance. In this study, using reverse transcriptionPCR and rapid amplification of cDNA ends (RACE) techniques, we cloned EkCDPK gene from Epimedium koreanum Nakai, its fulllength about 2 036 bp. The results showed that: (1) EkCDPK gene cDNA is 1 410 bp, 5′UTR is 387 bp and 3′UTR is 239 bp，and the ORF encodes for 469 amino acid. Conserved domain of EkCDPK protein consists of S_TKc domain in N end and EFhand domain in C end. EkCDPK was predicted to be a stable hydrophilic protein, possessing a typical and conserved serine/threonine protein kinase domain and a transmembrane structure domain, also an ATP site, 4 Ca²⁺ binding sites, and without signal peptide. The secondary structure of EkCDPK is abundant in αhelices (43.71%) and random coils (37.10%). (2) The phylogenetic relationship analysis showed that EkCDPK is closely related to Isatis tinctoria (95%). (3) The qRTPCR results showed that EkCDPK gene expressed in root, stem, leaf and flower tissues, with the highest expression in root, followed by stem. After drought stress, EkCDPK expression was significantly higher than that in the control group in 15 h, then began to decrease, and its life index decreased too. After salt stress 5, 15 and 25 h, its expression was significantly higher than that of control group. (4) pET28aEkCDPK prokaryotic expression vector was constructed and induced the expected size protein, which is about 50 kD, indicating recombinant protein EkCDPK was expressed successfully. These results provided a basis for the further study on improving the plant stress resistance of E. koreanum Nakai using genetic engineering.

Abstract:In order to explore the function of wheat (Triticum aestivum L.) WRKY gene, we cloned two WRKY genes named TaWRKYⅢA37 and TaWRKYⅡcD2 from wheat variety ‘Kenong 199’ by homologous cloning, and their bioinformatics and expression under different stresses were analyzed. Bioinformatic analysis showed that TaWRKYⅢA37 and TaWRKYⅡcD2 genes contain two introns and three exons, encoding 206 and 138 amino acids, respectively. The encoded proteins are all hydrophilic unstable non secretory nucleoproteins. Phylogenetic analysis showed that TaWRKYⅢA37 protein was the closest to its two homologous copies, while TaWRKYⅡcD2 protein was the closest to that of Aegilops tauschii. The results of qRTPCR showed that TaWRKYⅢA37 and TaWRKYⅡcD2 genes were expressed in the roots, stems and leaves of wheat. The former had the highest expression level in the roots, while the latter had the highest expression level in the leaves, all of which were low expression in the stems. The expression of TaWRKYⅢ_A37 gene in seedling stage was upregulated by PEG, H₂O₂ and ABA stress, and down regulated within 4~8 hours after NaCl treatment, which was lower than that of the control; While the expression was up regulated by PEG, NaCl, H₂O₂ and ABA in the filling stage. At seedling stage, TaWRKYⅡcD2 gene was down regulated by NaCl, H₂O₂ and ABA stress, and up regulated by PEG treatment for 2 hours, which was higher than that of control; While the expression was down regulated by PEG and NaCl stress at the filling stage, and up regulated by H₂O₂ and ABA stress. The results of this study lay a theoretical foundation for further exploring the antistress function of TaWRKYⅢA37 and TaWRKYⅡcD2 genes.

Abstract:The proline transporter protein (ProTs) family plays an important role in proline distribution and protective stress responses in plants. To understand the profile of ProTs in tea plant, we used the bioinformatics methods to identify the members of CsProTs from genome of tea plant, and analyzed their phylogenetic relationship, protein structure and gene expression patterns in the present study. The results showed that： (1) there were six CsProT genes in tea plant: CsProT1, CsProT2, CsProT3, CsProT4, CsProT5 and CsProT6; We found that the number of amino acids encoded by CsProTs genes in tea plant is ranged from 441 to 574, the IP is covered from 8.51 to 9.41 and the molecular weight is distributed from 48.5 to 63.0 kDa; Most of them are basic proteins, which containing a large number of αhelix, free curls, a small number of elongation chains and βcorner structures. (2) The subcellular localization analysis showed that CsProT1, CsProT2, CsProT4, CsProT5 and CsProT6 were located in cell membrane, but CsProT3 located in Golgi. (3) The prediction results from amino acid sequences showed that each of CsProTs contained 9-11 transmembrane domains. The conservative motif analysis showed that the ProTs had high conservation in tea plant and Arabidopsis, and the consistency of amino acid sequence among different members was as high as 40.14%. (4) CsProT1, CsProT2 and CsProT3 genes were highly expressed in all tissues of tea plant, but CsProT4, CsProT5 and CsProT6 genes were low; And except CsProT5 gene, CsProTs genes were all induced by NaCl, drought and cold stress in the leaves of tea plant. (5) The proteinprotein interaction analysis showed that CsProTs could interact with proline oxidase ERD5, proline biosynthesis rate limiting enzymes P5CS1, P5CS2, δpyrroline5carboxylic acid dehydrogenase ALDH12A1 and other proteins related to proline synthesis, transport, degradation and jointly regulate proline content in tea plant. In conclusion, there were six CsProTs in tea plant, which are widely involved in the regulation of proline homeostasis and responding to different abiotic stress.

Abstract:Phenylalanine ammonialyase was ratelimiting enzyme of phenylpropanoids components formation of Jasminum sambac. To understand the floral scent formation mechanism, we cloned the fulllength cDNA sequence of phenylalanine ammonialyase gene from J. sambac by RTPCR (reverse transcriptasepolymerase chain reaction) and RACE (rapid amplification of cDNA ends) methods (GenBank: KM406501.1). A 2 220 bp fulllength cDNA sequence was obtained and named JsPAL. The ORF (open reading frame) of JsPAL was 2 140 bp and encodes 712 amino acids, containing the conserved domain of lyase_I_like superfamily, active sites and tetramer interface (polypeptide binding site). The promoter of JsPAL was isolated by Genome Walking Method. A 1 201 bp sequence was found to be the promoter，which contains many important cisacting elements involved in flowering and floral scent formation, such as CCAATBOX1 (regulating flowering), elements of BOXLCOREDCPAL, PALBOXPPC, PALBOXLPC and TATABOXOSPAL (related to PAL gene), and MYBPLANT (involved in flowerspecific phenylpropanoid biosynthetic). The gene expression patterns in different stages of flower opening and different tissues were detected by the realtime PCR. The realtime PCR analysis revealed that the expression of JsPAL gene was high in flower buds and petals. Its expression was high before 22:00 and downregulated with the development of flower.

Abstract:In order to understand the mechanism of neckpanicle elongation in protein level, we used ‘Changxuan 3S’ and ‘Peiai 64S’ as experimental materials. The proteins in the uppermost internodes were separated on the 2 day before heading by using solidphase pH gradient twodimensional gel electrophoresis and mass spectrometry. A twodimensional gel electrophoresis map (2DE) with good resolution and reproducibility was obtained. And the different proteins were studied. The results showed that: (1) two dimensional gel electrophoresis maps with good resolution and reproducibility were obtained. (2) 40 differential protein spots were selected from the 2DE map and analyzed by MALDITOF/TOFMS peptide mass fingerprinting, and 27 of them were identified successfully. Compared with ‘Peiai 64S’, there are 17 upregulated and 10 downregulated proteins in ‘Changxuan 3S’. (3) According to their functions, these differential proteins can be divided into six categories, mainly including cell metabolism relative proteins and cell wall reconstruction proteins. In addition, these discrepant proteins may be interrelated to the vigorous elongation of the internodes at heading stage of ‘Changxuan 3S’, especially the proteins related to cell wall reconstruction and cell elongation. (4) The protein spot 2, 7, 8, 24, 35 and 36 were tested by qPCR. The expression levels of 2 (Os10g08550), 7 (Os12g42876) and 8 (Os01g55830) in ‘Changxuan 3S’ were significantly lower than that in ‘Peiai 64S’, while the expression levels of 24 (Os06g48760), 35 (Os05g25850) and 36 (Os07g42300) were significantly higher than those of ‘Peiai 64S’. The qPCR results were consistent with the results of protein gel analysis. According to the study, the eui may promote cell division and elongation by regulating the expression of these proteins at heading stage.

Abstract:Cypripedium tibeticum is a unique orchid species with high ornamental and medicinal value. As one endangered species, it is currently listed as a national protected plant. In this study, genetic structure and genetic diversity of 7 C. tibeticum populations collected in western China was analyzed using ISSR molecular markers. This study can provide a reference for species conservation in natural habitats of C. tibeticum. The results showed: (1) 12 polymorphic ISSR markers with strong repeatability were chosen from 100 ISSR primers. A total of 136 bands were identified, and the percentage of polymorphic bands (PPB) was 100%. Neis gene diversity (H_e) and Shannons information index (I) were 0.318 6 and 0.484 3, respectively. The Neis genetic distance ranged from 0.033 3 to 0.170 1 and genetic similarity ranged from 0.843 5 to 0.967 3 among populations. The overall gene differentiation coefficient (G_st) was 0.222 9 and the estimated value of gene flow was 1.743 0. (2) The UPGMA and NeighborJoining clustering analysis both indicated clear differentiation between populations from Sichuan and Shaanxi. The overall correlation between genetic distance and geographical distance was not significant. This study indicated high genetic diversity in C. tibeticum populations and great divergence between Sichuan and Shaanxi populations on molecular level. ISSR markers could be used for investigating the genetic structure, diversity and genetic differentiation of C. tibeticum populations.

Abstract:With Amomum villosum (genus Amomum, family Zingiberaceae) as material, we obtained the complete chloroplast genome sequence using Illumina Hiseq 4000 sequencing platform, and then assembled, annotated, and characterized by bioinformatic methods. This study clarified the genetic relationship among species of Zingiberaceae, and provided scientific basis for the study of phylogeny and species identification of genus Amomum. The results showed that: (1) the total length of chloroplast genome was 164 069 bp and the GC content was 36.1%, including a pair of 29 959 bp reverse repeat region (IR), a large single copy region (LSC; 88 798 bp) and a small single copy region (SSC; 15 353 bp). A total of 133 genes were annotated, including 8 rRNA genes, 38 tRNA genes and 87 protein coding genes. (2) 157 SSR loci were detected in the A. villosum genome, and most of the SSR was composed of A and T. The cp genome size and IR boundary of genus Amomum were highly conserved, while nucleotide variability mainly occurred in LSC and SSC regions. (3) The maximum likelihood method (ML) cluster analysis showed that A. villosum had the closest genetic relationship with A. compactum and A. krervanh, and had a close relationship with genus Alpinia.

Abstract:Morphological and anatomical characteristics were observed during the formation of adventitious roots of Platycladus orientalis with paraffin method, external morphological changes, origin and formation process of adventitious roots were analyzed. We also discussed the occurrence pattern and histological origin of adventitious. The results showed that, adventitious roots protruded from callus and skin, including callus rooting type, cortex rooting type, both callus and cortex rooting type. We also found few latent root primordia in stem cutting, but most of the roots were formed on primordial induced from callus, xylem, vascular cambium and secondary phloem. Through our research, we consider the formation of adventitious root primordial of P. orientalis belong to multilocus models, and the histological origin adventitious is callus, pith ray, ray primitive cells and undifferentiated xylem cells. Simultaneous activation of these root origin sites through artificial induction can significantly improve rooting rate and rooting quality.

Abstract:Species delimitation of the Chinese endemic genus Clematoclethra (Actinidiaceae) has been greatly controversial due to overlapping variations of morphological features and distribution. It was classified into 20 species or treated as a monotypic genus containing 1 species with 4 subspecies. In this study, leaf epidermal morphology of 184 specimens from 29 populations covering its distribution were investigated using light microscope and scanning electron microscope (SEM) in order to provide some clues to its taxonomy. The results indicated that: (1) the leaf trichomes morphology of genus Clematoclethra varied greatly which were grouped into three types (the glabrous type with few short pillar hairs, the setose type with long pillar/stab hairs, the woolly type with the uniserate hairs). And due to the obvious variation of leaf trichomes among the populations, members of Clematoclethra should be classified into three groups (the glabrous group, the setose group, and the wooly group) with a disjunctive geographically distribution. (2) Additionally, the three groups of Clematoclethra also appeared to be distributed partially with a sympatric pattern in several populations and with a vertical geographically one in 3 populations at different altitudes in Emei Mountain. (3) The other characters of leaf epidermis of Clematoclethra, such as the irregular epidermal cells, 6 types of stomata, reticulum waxy sculptures with 2-4 types of secondary waxy sculptures, commonly and randomly observed in all populations, might have no taxonomic significance. (4) Based on the shared features of leaf epidermis and overlapping distribution, it was suggested that C. scandens subsp. hemsleyi might be grouped into C. scandens subsp. tomentella. Therefore, it was supported that Clematoclethra should be treated as a monotypic genus of ongoing speciation, containing 1 species with 3 subspecies.

Abstract:We conducted a pot experiment in growth chamber with two CO₂ concentrations (400 μL·L^-1 and 800 μL·L^-1) in this study by using seedlings of superior clone of Cunninghamia lanceolata ‘Yang 061’ to investigate the effects of CO₂ enrichment on seedlings growth, roots morphology, photosynthetic physiology, and nutrient concentration of C. lanceolata seedlings, and to explore the response characteristics of superior clone of C. lanceolata to elevated CO₂ concentration, and ultimately providing theoretical basis for highquality and efficient cultivation of C. lanceolata seedlings. The results showed that: (1) CO₂ enrichment significantly promoted the biomass accumulation and the height growth of C. lanceolata seedlings, and significantly promoted the roots growth as well. The root length, root surface area, root volume and root diameter under CO₂ enrichment treatment were 14.60%, 28.26%, 41.98% and 14.70% higher than that of control, respectively. (2) CO₂ enrichment significantly increased the carotenoid content in leaves of C. lanceolata seedlings, and this was also true for net photosynthetic rate (P_n), intercellular CO₂ concentration (C_i) and water use efficiency (WUE), which were 51.03%, 14.13% and 151.20% higher in CO₂ enrichment treatment as compared with control, respectively, while stomatal conductance (G_s) and transpiration rate (T_r) were decreased by 58.72% and 44.00%, respectively, when compared with control. (3) CO₂ enrichment significantly increased the maximal fluorescence (F_m), variable fluorescence (F_v), PSⅡpotential efficiency (F_v/F_o), PSⅡ actual photochemical efficiency (Φ_PSⅡ) and photochemical quenching coefficient (qP), which were 11.48%, 11.25%, 6.33%, 20.38% and 30.34% higher than that in control, respectively, while nonphotochemical quenching coefficient (NPQ) were significantly decreased by 21.90%, and no significant difference was observed in initial fluorescence (F_o) and PSⅡ maximal photochemical efficiency (F_v/F_m) between treatments. (4)CO₂ enrichment significantly increased plant calcium concentration, while significantly decreased plant phosphorus concentration. Taken all these results together, our results showed that shortterm CO₂ enrichment can promote the growth of C. lanceolata seedlings by increasing photosynthetic pigment contents and net photosynthetic rate and light use efficiency in leaves, which resulted in a higher photosynthetic capacity, and by promoting the growth of roots, which inturn enhanced plant nutrient uptake capacity.

Abstract:The 8yearold ‘Junzao’ plants were selected in the irrigation area along the Yellow River. With no potassium fertilizer as the control, 300 g potassium sulfate was applied in the flowering stage, young fruit stage, fruit expansion stage and color transformation stage of fruit trees. The changes of fruit quality, yield, leaf photosynthesis and fluorescence parameters of each treatment were measured, and the best potassium application period of ‘Junzao’ in the irrigation area along the Yellow River was determined, which provided a theoretical basis for the formulation of reasonable fertilization measures for jujube trees. The results showed that: (1) compared with the control, the application of potassium fertilizer promoted the photosynthesis and improved the fruit quality of ‘Junzao’ jujube, and the effects were different in different growth stages. And the application of potassium fertilizer in the fruit expansion stage had the most significant effect on improving fruit quality, yield and leaf photosynthesis of Junzao jujube. (2) After applying potassium fertilizer during fruit expansion stage, the vertical diameter, transverse diameter, fruit shape index, weight per fruit and yield per plant of ‘Junzao’ significantly increased by 22.64%, 39.33%, 13.62%, 19.52% and 19.58%, respectively compared with the control. The content of Vitamin (Vc), soluble sugar and fructose contents, the ratio of sugar and acid significantly increased by 37.98%, 22.82%, 31.37% and 29.95% compared with the control, respectively. The leaf chlorophyll content, net photosynthetic rate (P_n), stomatal conductance (G_s), transpiration rate (T_r) significantly increased by 28.91%, 38.44%, 36.75% and 27.25% compared with the control, respectively. The leaf initial fluorescence (F₀), maximum fluorescence (F_m) and electron transfer rate (ETR) significantly increased by 28.18%, 29.15% and 37.75% respectively compared with the control. However, the intercellular CO₂ concentration (C_i) and fruit cracking rate reached the lowest value during the fruit expansion stage, which significantly decreased by 28.34% and 35.50% respectively compared with the control. It was found that the application of 300 g potassium fertilizer to the plant during the fruit expansion period of Junzao could significantly increase the chlorophyll content, photosynthesis efficiency, light energy absorption and electron transfer efficiency of the plant leaves, improve the photosynthetic capacity of the tree, significantly reduce the fruit cracking rate, effectively improve the external and internal quality of the fruit, and significantly increase the yield per plant.

Abstract:Using the leaves of Populus euphratica forest age groups (young trees and mature trees) from eight different habitats in Xinjiang as material, we measured natural stable carbon and nitrogen isotope composition (δ13C and δ15N) value, carbon content, nitrogen content of leaves and specific leaf area, analyzed its δ13C and δ15N values with altitude, latitude and longitude, leaf carbon and nitrogen contents, specific leaf area as well as the relationship between water use efficiency. The result showed that: (1) the average δ13C value of sapling and mature leaves was -27.863‰(-28.776‰ - -26.695‰) and -28.230‰(-29.717‰ - -26.033‰), respectively. δ¹³C values of P. euphratica leaves in different habitats were significantly different (P<0.05), and δ¹³C values of sapling leaves were all greater than those of mature trees. The average δ¹⁵N values of saplings and mature forest leaves were 3.259‰(-1.842‰-9.082‰) and 3.651‰(0.798‰ - 5.779‰), respectively. (2) The variation ranges of carbon content in leaves of saplings and mature forests were 44.573‰ - 49.056‰ and 43.226‰ - 47.349‰, respectively, with an average values of 46.225‰ and 45.720‰. The variation ranges of nitrogen content in young trees and mature forest leaves were 1.327‰ - 2.116‰ and 1.164 - 2.450‰, respectively, with the average values of 1.708‰ and 1.823‰. The content of carbon in mature forest leaves was negatively correlated with its δ¹³C value (P<0.01), while the content of nitrogen was positively correlated with δ¹³C value (P>0.05). There was a significant positive correlation between carbon content and δ¹⁵N value in mature forest leaves (P<0.01), while there was a significant positive correlation between nitrogen content and δ15N value (P<0.05). (3) The average specific leaf area value of saplings (91.565 cm²/g) was lower than that of mature trees (103.141 cm²/g). (4) δ¹³C and δ¹⁵N values in leaves of young and mature trees were significantly positively correlated with latitude (P<0.01), δ¹³C and δ¹⁵N values in leaves of young trees were also significantly positively correlated with altitude (P<0.01), and δ¹⁵N value in leaves of young trees was also significantly positively correlated with longitude (P<0.05). (5) The average water use efficiencies of young and mature trees were 77.618 μmol/mol (68.070 - 91.069 μmol/mol), 72.463 μmol/mol (62.809 - 97.111 μmol/mol), respectively. The water use efficiencies of young and mature trees were significantly positively correlated with their leaves δ¹³C (P<0.001), their δ13C values (-26.695‰ and -26.033‰) and water use efficiencies (91.069 and 97.111 μmol/mol) were the highest in Yutian County.

Abstract:We studied leaf and twig functional traits, namely, leaf thickness(LTS), leaf area(LA), specific leaf area(SLA), leaf dry weight of every leaf (LM), leaf dry matter content(LDMC), leaf tissue density(LTD) and twig length(TSL), twig diameter(TSD), leaf area ratio(LAR), leaf/stem mass ratio(LSMR), Twig stem wood density (TSWD) and Huber value(HV) of Populus euphratica Oliv. in Tarim extremely arid area. We analyzed the variation characteristics of these functional traits along the groundwater depth gradient (GWD), and the tradeoff between leaftwig traits and functional traits combination by Oneway ANOVA, Pearson correlation and principal component analysis(PCA), in order to reveal the ecological strategy of P. euphratica to adapt the extremely arid desert environment. The results showed that： (1) the variation coefficient was from 8.61% to 59.31%, the HV was the largest (59.31%), LDMC and LAR were the smallest (8.61%, 9.75%) and the most conservative traits. (2) Variance analysis showed that thirteen traits of P. euphratica had significant difference between GWD 1.5 m and 4.8 m, and there were significant difference of LTS, LTD, TSL and HV between GWD≤2.4 m and GWD≥3.5 m. (3) Correlation and principal component analysis (PCA) showed that LA, SLA, LDMC, LTS, LTD, LAR, TSWD and HV could be used as important indicators to reflect the characteristics of P. euphratica twigleaf traits. There were significant correlation between 28 pairs of leaftwig traits(P<0.05), especially HV was significantly negative correlation with TSL and positive correlation with TSD(P<0.05), and TSL was negative correlation with TSD, as well. HV was significantly negative correlation with LAR, LSMR, LA, LM(P<0.05). Also, leaf display efficiency(LAR and LSMR) were significantly negative correlation with LDMC(P<0.05), and TSWD was negative correlation with LA and SLA. It indicated that there was a potential tradeoff mechanism between machinewater safety and carbon availability of P. euphratica in arid areas. P. euphratica adopted the ecological strategy, such as reducing LA, SLA and leaf display efficiency (LAR and LSMR), increasing LTS, LDMC, TSWD and HV, which were beneficial to reduce water loss, storing resources (nutrients and water) and enhancing resilience, to adapt the aridbarren desert environment. Plant economic spectrum also existed in desert ecosystems. With global warming and regional water shortage, it generally shifted towards the conservative strategy of slow investmentreturn.

Abstract:Age structure and dynamics of plant population are important for revealing its life history characteristics and development trend. However, there are few reports on the analysis of hermaphroditic populations of dioecious plants. Salix gordejevii, a common dioecious plant, is an important sandfixing pioneer plant in Hunshandake Sandy Land. In this paper, the present situation and future development trend of male and female population were studied by using age structure map, static life table, survival curve, survival analysis and time series analysis based on the field investigation of the natural S. gordejevii population. The results showed that: (1) the age structure and development trend between male and female S. gordejevii population were significantly different in the study area. Among them, the age structure of female population was stable type, and that of male population was declining type. (2) The number of females accounted for about 70%, and that of males only accounted for about 30%, which indicated sex ratio of S. gordejevii population was femalebiased seriously in Hunshandake Sandy Land. (3) Dynamic index showed that the dynamic characteristics of female population were “lack in early stage, and stability in middle and late stage”, and those of male population were “deficient in early stage, fluctuation in middle and late stage”. (4) The survival curves of male and female S. gordejevii population tended to DeeveyⅡ type. At the same time, the survival curves and survival function curves showed that female population entered the recession earlier than male population. (5) Time series analysis showed that the number of old individuals increased with time in the study area. Lack of young individuals was an important reason for the decline of male and female population. It is suggested that male and female young individuals should be supplemented by artificial cuttings, and the middleoldage individuals should be rejuvenated in order to ensure the future reproduction of the natural S. gordejevii population in this area.

Abstract:Based on the 6 hm² monitoring plot abundance data of Qizimei mountains Nature Reserve, we used the cumulative experience distribution curve (ECDF) to characterize the speciesabundance distribution pattern of different lifeform functional groups in the plot, and six models were used for each function. The species rankabundance curves of different sampling scales were fitted and the fitting effect was tested. The differences between the abundance pattern and model fitting at different scales were analyzed, and the ecological processes andmechanisms behind them. Research indicates: (1) the number of deciduous species is larger than that of evergreen species at various scales, and the species diversity index is greater, but the number of individuals is relatively small. The ranking of rare species in different functional groups is: deciduous species

Abstract:Pohlia tundrae was formerly described from North America, and subsequently was found also in Central Europe, Russian Far East and northern West Siberia. Recently, we discovered this species in Tibet, China. In this paper, morphological characteristics of P. tundrae are described; the photographs, habit, global distributions are provided; and morphological comparison of it with the similar species are discussed. The voucher specimen is deposited in the herbarium of China Agricultural University (BAU).

Abstract:The habitat conditions in the karst area are complex and the ecosystem is fragile and rocky desertification has become an important factor in restricting the development of karst areas. In this paper, we reviewed the stress resistance of biological soil crust in ecosystem and its key role in accelerating soil formation rate, improving surface erosion resistance, improving soil environmental state, regulating precipitation infiltration, changing soil water redistribution pattern, promoting soil microbial derivation and vegetation succession, and improving ecosystem biodiversity. The feedback mechanism of biological soil crusts and karst ecosystems and the application potential of the technology of artificial cultivation crust vegetation for rocky desertification control were demonstrated. In addition, the interaction mechanism between biological soil crusts and ecosystems is the key to studying ecological management in karst areas. The relationship between biological soil crusts and ecosystems is a dynamic process and requires longterm uninterrupted multidimensional monitoring. The researches on mechanism between biological soil crust and karst habitat and their interaction in karst processes, the stress tolerance of biological soil crust in karst areas and artificial cultivation technology and mechanism in karst habitat are recommended to strengthen.