Abstract:LAS/LS subfamily plays an important role in the regulation of plant branching and development. The 35s∷SpsLAS overexpression vector was constructed and transformed into wild type A.thaliana. These transgenic A.thaliana were screened by phenotype. The expressions of genes related to branching, auxin and cytokinin were analyzed by fluorescence quantitative PCR. The results showed that: (1) 35S∷SpsLAS overexpression vector was successfully transformed and nine homozygous transgenic lines of A.thaliana were obtained. The germination speed of transgenic lines were faster and life cycle was longer than that of wild type. Seven transgenic lines of them showed rapid growth, increased plant height, enlarged rosette leaves and more branches. Two lines showed a series of changes as dwarfing, more branches and lower fertility. (2) Fluorescent quantitative PCR showed that there were no significant changes for auxin and cytokinin pathway related genes at 24 h of seedling, while upregulated at 4 d. Gene expressions of RAX1 and RAX3 related branching were upregulated while MAX1, MAX3, REV and AXR1 had no obvious changes at 30 d. The research showed that the overexpression of SpsLAS gene has significant effects on plant architecture and rosette leaves of A.thaliana and laid the foundation for further research on the regulation of branching mechanism.

Abstract:A CBF1like gene was isolated from Crocus alatavicus Regel et Sem, a perennial ephemeral plant distributed in high mountain of Xinjiang, China, by RTPCR method using a cDNA template. The gene is named as CrCBF1. Sequence analysis indicates that the open reading frame of CrCBF1(GenBank accession MF681 787) gene has 642 bp length, which encoding 213 amino acids with the molecular mass of 23.8 kD and the pI value of 4.99, the CrCBF1 protein encompasses conserved motif of AP2; The result of subcellular localization indicated that CrCBF1 protein was located in the nuclear, the transcriptional activation activity analysis in yeast indicated that CrCBF1 protein harbors the transcriptional activation domain and possess selfactivation ability; The result of function identification in yeast indicated that overexpression of CrCBF1 gene enhance the ability of coldresistance of recombinant yeast.

Abstract:In this study, utilizing the salt tolerant gene E3 ubiquitin ligase HERC2 sequence in sunflower which acquired previously, we constructed the transient expression vector Cam35SHERC2GFP. Subcellular localization was carried out by transforming onion epidermal cells with particle bombardment. The expression analysis, that of root, hypocotyl and leaf between the salttolerant hybrid P50 and the saltsensitive hybrid P29 under 120 mmol·L^-1 NaCl stress, was done by RTqPCR. Plant expression vector pPZP221HERC2 was constructed. HERC2 was transferred into tobacco to verify salttolerant functionality by Agrobacteriummediated. The results showed that: (1) subcellular localization showed that HERC2 protein expressed in cell membrane, cytoplasm and nucleus; (2) the expression of HERC2 gene was upregulated between the salttolerant hybrid P50 and saltsensitive hybrid P29 under NaCl stress, but the expression quantity of the former is higher than that of the latter; (3) the salt tolerance of transgenic HERC2 tobacco was stronger than that of the wild type tobacco. The study laid a foundation for analyzing of salt tolerance mechanism in sunflower and breeding salttolerant cultivar.

Abstract:The recombinant strain Escherichia coli BL21∷pET30aHcUKPP was obtained by the method of prokaryotic vector construction after cloning of unknown functional peptide HcUKPP gene, and then tested its tolerance under different abiotic stresses. The results revealed that open reading frame(ORF) of the gene was 243 bp, the molecular weight of the recombinant HcUKPP was approximately 15 kD. In addition, the expression of HisHcUKPP fusion protein could be induced with different concentrations of isopropyl βD1thiogalactopyranoside (IPTG) for 4 h at 37 ℃. Furthermore, the growth of recombinant strain E.coli BL21∷pET30aHcUKPP have shown obvious advantages under treatment of different concentrations of NaCl (100-900 mmol/L), polyethylene glycol (2.5%-20%, PEG 6000) and methyl viologen (25-200 μmol/L). Especially under the condition of 500 mmol/L NaCl, 10% PEG 6000 and 75 μmol/L methyl viologen for 12 h, interestingly，recombinant E.coli BL21 showed significant advantages, their growth reached 1.81, 1.47 and 3.48 fold of control bacteria respectively. Overall, the HcUKPP gene of Halostachys caspica can significantly improve tolerance of recombinant E.coli BL21 under different abiotic stresses, which proved that the HcUKPP is a kind of newly discovered polypeptide in response to abiotic stress.

Abstract:Picea mongolica, P. meyeri and P. koraiensis as research objects, the genomic DNA of P. meyeri and P. koraiensis were used respectively as the probes to hybridize with the midchromosomes of P. mongolica by the Genomic In Situ Hybridization (GISH) to study the genetic relationship among the three Picea species, and demonstrate the origin of the P. mongolica. In this study, our results show that: (1) the chromosome numbers of all three Picea species were 2n=24 and the karyotype type was 1A, and most of the chromosomes were subcentral centromere. The As.K% of P. meyeri and P. koraiensis were 57.78% and 57.64% respectively, which were lower than that of P. mongolica (58.75%). (2) The 14 chromosomes of P. mongolica showed obvious hybridization signals using P. meyeri genomic DNA as a probe, the stronger signal sites were mainly concentrated in the kinetochore domain, secondary constriction and short arms of the chromosomes. The obvious hybridization signal appeared on 12 chromosomes of P. mongolica using the P. koraiensis genomic DNA as the probe, the stronger signal was mainly located on the kinetochore domain, secondary constriction and long arms of the chromosomes, and the hybridization signal distribution range and intensity were weaker than that of P. meyeri. Therefore, our study shows that the genetic relationship of P. mongolica and P. meyeri were closed than that of P. koraiensis. Then, it was the first to prove that P. mongolica can not be produced by the hybridization between P. meyeri and P. koraiensis.

Abstract:In order to understand the biological function of soybean SUS family genes, and provides basic information for breeding of high yield varieties and functional utilization of GmSUS genes in soybean, in this study, we performed the genomewide identification and expression analysis of sucrose synthase (SUS) gene family based on published soybean genome sequence. Our results showed that: (1) a total of 12 putative SUS genes (GmSUS1-GmSUS12) were identified in soybean genome. (2) The sequence identity of GmSUS proteins was very high, and all of them had the sucrose synthase domain and glycosyl transferase domain. In addition to GmSUS5, other GmSUS proteins had a conserved serine phosphorylation site at their N terminal. (3) A phylogenetic analysis showed that GmSUS proteins in soybean could be classified into three groups (SUSI-SUSⅢ), and GmSUS genes in the same group exhibited similar intron/exon pattern. (4) 12 GmSUS genes were unevenly located on 10 chromosomes of soybean, and tandem duplication was the contributor to the expansion of GmSUS genes in soybean genome. (5) Expression pattern analysis indicated that GmSUS genes exhibited differential tissue expression patterns. GmSUS8 was highly expressed in seed; GmSUS1, GmSUS7 and GmSUS5 were highly expressed in nodule; GmSUS3, GmSUS11 and GmSUS12 were highly expressed in all examined tissues.

Abstract:In order to make a rough drawing of H3K9ac and identify genes which regulated by H3K9ac modification, provide information for regulation of gene expression in Hippophae rhamnoides, western blot and ChIPseq were carried out. The results showed that the binding capacity of H3K9ac antibody with histone of H. rhamnoides is tightness. Highthroughput sequencing of enrichmental DNA fragments obtained 2.2×10⁷ and 3.6×10⁷ raw reads. Unique mapped reads were widely distributed in the genome of H. rhamnoides and obviously enriched in both ends of the structural genes. There are 1 011 peaks were identified by predicting the functions of gene enrichment areas, these results showed that H3K9ac played important roles in gene expression of H. rhamnoides. The enrichment and highthroughput sequencing of DNA fragments of H. rhamnoides proves that antibodies can be used to study the types of histone modification. The first H3K9ac modification sketches of genetic and the genes regulated by H3K9ac were identified. It is important for investigating genes expression of H. rhamnoides regulated by histone modification.

Abstract:Pigmented potato contains massive antioxidants such as anthocyanin and flavonoid, thus they can be used as nutrient and healthy foods. To investigate the genetic background of pigmented potato and provide effective information on parental combination for potato breeding, we used 22 SSR markers for genetic diversity analysis and fingerprint profile of 33 pigmented potato varieties (lines). The results indicated that 95 alleles were amplified from 22 SSR markers, and 82 alleles showed polymorphism. Polymorphism information contents (PIC) of 22 SSR markers ranged from 0.168 7 (STM1053) to 0.991 9 (STI033) with an average of 0.841 1. UPGMA method was used for clustering analysis. With the similarity coefficient of 0.71, all the pigmented potatoes were classified into four cluster groups. A significant diversity was found among four cluster groups. Five SSR markers (STM0031， STM0030, STI014, STM1029, STI001) were used to select construct the molecular fingerprint profile of 33 pigmented potato varieties (lines). The research results were useful to the parental combination during breeding for pigmented potato and rapid identification of pigmented potato germplasm resources.

Abstract:Two kinds of Viola cornuta and four kinds of Viola wittrockiana were used as experiment materials to analyze chromosome karyotype including the chromosome number, relative length and average arm ratio by traditional squash method. The studies on chromosome karyotype of pansy will provide a better understanding of their cytology characteristics and classification, which will lay the foundation for the pansy breeding. The results showed that: (1) chromosome number and the basic chromosome number in the V. cornuta were 2n=2x=26 and x=13, respectively, and the karyotype formula of these two kinds of plants were 2n=2x=26=8m+12sm+6st and 2n=2n=26=4m+16sm+6st. The index of karyotypic asymmetry was 67.20%-70.10% and their karyotype were classed into 3B type. (2) All kinds of V. wittrockiana belong to tetraploid, two of which had 44 chromosomes and their karyotype formula were 2n=4x=44=4m+16sm+6st and 2n=4x=44=16m+24sm+4st, respectively, and their karyotype were classed into 2B type. The other two of V. wittrockiana had 48 and their karyotype formula were 2n=4x=48=8m+20sm+20st and 2n=4x=48=4m+36sm+8st, and their karyotype were classed into 3B type. The index of karyotypic asymmetry of all V. wittrockiana was 66.74%-71.77%.

Abstract:The epidermal morphology of 24 species of Dryopteridaceae was observed under light microscope. The results indicated that: （1） the shapes of upper epidermal cells of 24 species are strip or irregular, with sinuate or sinuolate anticlinal walls. The shapes of lower epidermal cells of 24 species are irregular, with sinuate anticlinal walls. The length to width radio of the upper epidermal cells is between 1.5-5.7, and the length and width radio of the lower epidermal cells is between 2.2-3.9. （2） Among these 24 species, 8 types of stomatal apparatus are observed, including aisocytictype, anomotetracytictype, polocytictype, axillocytictype, diacytictype, dnomocytictype, coaxillocytictype and copolocytictype. Each species has two to eight types of stomatal apparatus, all the stomatal apparatuses occur in the lower epidermis, and most of them are elliptical. Stomatal length to width ratio is between 1.2-1.8; the stomatal density is 17.4-86.0/mm², and the stomatal index is 8.60%-37.4%. （3）The shapes of the epidermal cells, the shapes of the anticlinal walls, the ratio of the length to width of the upper epidermal cells, the type of stomatal apparatus, the main types and the derived types can be served as the evidences for morphological classification of leaf epidermis. （4） On the basis of the leaf epidermis morphology, 24 species of Dryopteridaceae can be divided into two categories, Polystichum, Dryopteris. According to the results of leaf epidermal morphology, the classification system of Ching RenChang was supported to a certain extent. This study provided basic data for the evolution and classification of the species of Dryopteridaceae.

Abstract:To explore the degeneration problem of cutting seedling caused by age effect in white poplar we chose hardwood cuttings of different ages of triploid hybrids white poplar ‘Beilinxiongzhu 2’ as experimental material and observed growth morphology of seedling, photosynthetic characteristics, root development characteristics, anatomatical structure of bark, total soluble sugar (TSS), total soluble protein (TSP), chlorophyll (Chl), proline (Pro), gibberellin (GA), auxin (IAA), abscisic acid (ABA) and IAA/ABA. The results showed as follows: (1) height growth, leaf area, petiole length, internode length, base diameter, main root number, main root length, rooting percentage, root effect index and net photosynthetic rate (P_n) decreased with the increasing of cuttings age. While lateral root number, lateral root length, intercellular CO₂ concentration (C_i), transpiration rate (T_r), stomatal conductance (G_s) were not affected by cuttings age. (2) Anatomical structure of stem bark showed that periderm and xylem thickened with the increasing of cuttings age. However, the thickness of phloem was basically similar among different ages of cuttings. (3) With the increasing of cuttings age, contents of soluble sugar, soluble protein, chlorophyll, gibberellin, auxin, IAA/ABA in seedling leaves gradually decreased, in opposition to the change in contents of proline and ABA. Comprehensive analysis showed that accumulated age effects led to the general senescent growing status in seedling of cuttings.

Abstract:In this study, the new growth layers (the new formed secondary xylem) were demarcated from Sonneratia caseolaris branches collected in 10 different continuous time spans within one year under a microscope since S. caseolaris was characterized by growth ring in the secondary xylem. The quantitative vessel anatomical features in new growth layers was observed and measured by means of microscopy, and variations in soil physicochemical factors corresponding to formation periods of new growth layers were determined as well, the relationship between the quantitative vessel anatomical features in new growth layers and corresponding soil physicochemical factors was analyzed by stepwise multiple regression to explore variations in quantitative vessel anatomical features of S. caseolaris branches with dynamic changes of soil physicochemical factors within one year and their adaptive significance. The results showed: (1) 8 quantitative vessel anatomical feature indexes including radial vessel diameter, tangential vessel diameter, intervessel wall thickness, vessel element length, vessel density, solitary vessel index, vessel grouping index and intervessel wall length in new growth layers showed significant difference (P<0.05), with exception of intervessel contact fraction, which showed no significant difference (P>0.05). 8 quantitative vessel anatomical feature indexes which show significant difference (P<0.05) varied to some extend. (2) Soil physicochemical factors including soil organic matter content, soil total nitrogen content, soil total phosphorus content, soil pH value and total soil salt content corresponding to the formation period of new growth layers show significant difference (P<0.05), and 5 soil physicochemical factor indexes varied to some extend. (3) The stepwise multiple regression analysis between the quantitative vessel anatomical features in new growth layers and corresponding soil physicochemical factors indicated the trends that the tangential vessel diameter is larger and vessel grouping index is higher with the increasing total soil salt content which show significant difference at 0.05 level. In conclusions, in 10 different continuous time spans within one year, the osmotic potential increased in the soil with the increase of soil salt content, which led to reduction of the safety of water transport in the secondary xylem vessels of S. caseolaris, and the safety of water transport might decrease further if the larger tangential vessel diameter developed under conditions of higher soil salt content. However, the higher vessel grouping index with the increasing soil salt content would ensure safety of water transport in xylem vessel of S. caseolaris based on the viewpoints of ecological wood anatomy, which might be an adaptive strategy for S. caseolaris to adjust its xylem vessel anatomy to the variable soil salt content.

Abstract:The 2yearold Vitis vinifera grape seedlings were cultured in nutrient solution and pretreated with 0, 0.05, 0.10 and 0.20 mg/L of exogenous 24Epibrassinolide (EBR), respectively, and then stressed with 50 mmol/L NaCl. The content of superoxide anion (O^-·₂), malondialdehyde (MDA), antioxidants and the activities of related enzymes in the seedling leaves were measured at 6 and 12 days after salt stress, respectively. This study was conducted to determine the influence of EBR pretreatment on antioxidant substances and enzyme activities of grapevine seedling leaves under salt stress. The results showed that compared with the salt stress alone, the EBR pretreatment at different concentrations decreased the contents of O^-·₂ and MDA significantly in the grape leaves, as well as, the contents of ascorbate (AsA), dehydroascorbic acid (DHA), reduced glutathione (GSH) and oxidized glutathione (GSSG). In addition, the EBR pretreatment significantly increased the activities of ascorbate peroxidase (APX), glutathione reductase (GR) and superoxide dismutase (SOD). Among these treatments 0.10 mg/L EBR pretreatment showed the best performance. Compared with the salt stress alone, after salt treated for 12 days, the 0.10 mg/L EBR pretreatment decreased the contents of O^-·₂ and MDA by 30.5% and 22.0%, significantly increased the contents of AsA and GSH by 82.8% and 27.9%, improved the activities of GR, APX and SOD by 7.2%, 8.5% and 24.0%, respectively. The results showed that exogenous BRs pretreatment reduced the content of reactive oxygen and increased the contents of antioxidant substances and activities of enzymes through promoting the ascorbateglutathione (AsAGSH) cycle. Meanwhile, BRs pretreatment reduced the oxidative damage and mitigated the effects of grape seedling leaves in salt stress, enhancing the tolerance of grape seedling to salt stress.

Abstract:This study is based on the 10 year old Cabernet ‘Gernischet’, which was treated with 300 kg·hm^-2 urea at the germination stage (S1), new shoot vigorous growth stage (S2), flowering stage (S3), the first expansion stage of fruit (S4), secondary shoot vigorous growth stage (S5) and the second expansion stage of fruit (S6). No nitrogen fertilizer was used as the control (CK). The indicators in leaves were analyzed at 5 days before flowering (DBF5), 25 days after flowering (DAF25), 55 days after flowering (DAF55), and 85 days after flowering (DAF85), for clarifying the regulation and influence of nitrogen application period on nitrogen metabolism in grape leaves. The results showed that: (1) S1 and S2 treatments significantly increased the total nitrogen and soluble protein contents in leaves at DAF 25. (2) The activities of NR and GS in S3 and S4 treatments were significantly higher than those in other treatments at DAF 85. At DAF 25, the GOGAT activities of S1 and S2 were 0.29 and 0.33 μmol·g^-1·min^-1, respectively. The GDH activities of S3 and S4 significantly higher than those of control and other fertilization treatments, which were 225.0 and 227.3 U·g^-1, respectively. (3) Quantitative analysis showed that the expression level of VvNR was higher than that of control at different stages, and was 3.4 times and 2.7 times higher than that of control in S3 at DAF25 and DAF85, respectively. The expression levels of VvGS in S3 and S4 were the highest at DAF55 and DAF85, respectively. The expression level of VvGOGAT in S3 and VvGDH in S4 were significantly higher than that of other treatments at DAF55 and DAF85. In addition, the expression level of VvGDH in S3 at DAF55 and DAF85 was second only to S4. Correlation analysis showed that there was a linear relationship among nitrogen content, nitrogen metabolism enzyme activities and the expression levels of regulatory genes. Therefore, nitrogen could induce the response of leaf nitrogen metabolism genes, thereby regulating nitrogen metabolism in leaves. S3 and S4 treatments were higher in the activities of nitrogen metabolizing enzymes and the corresponding gene relative expression levels in different periods, and were more conducive to the transformation and metabolism of nitrogen in the leaves. This study could provide some support for the scientific application of nitrogen fertilizer.

Abstract:The effects of arbuscular mycorrhizal fungi (AMF) on the photosynthetic characteristics of melon under low light and salt stress were investigated by pot experiment in greenhouse. It follows that AMF significantly increased chlorophyll content, net photosynthetic rate (Pn), photosynthetic electron transport rate (ETR), water use efficiency (WUE) and stomatal limitation factor (L_s) in melon seedlings under low light and salt stress. Stomatal conductance (G_s), transpiration rate (T_r) and intercellular CO₂ concentration (C_i) also increased with the prolongation of stress time. The changes of photochemical quenching coefficient (qP) and actual photochemical efficiency (Φ_PSⅡ) were significantly higher than those of inoculation (A_max), light saturation point (LSP) and apparent quantum efficiency (AQE) significantly increased (P <0.05), and the maximum photochemical efficiency (F_v/F_m) was significantly enhanced by inoculation with AMF, but the difference was not significant, while light compensation point (LCP) and dark respiration rate (R_d) reduced. We propose that AM symbiosis can protect melon plants from low light and salt stress by improving their chlorophyll fluorescence, gas exchange parameters and light response parameters.

Abstract:Using ANOVA, correlation analysis and cluster analysis, we investigated six active components in leaves of 105 Eucommia ulmoides germplasm resources, discussed the genetic variation to provide theoretical basis for breeding and utilization of leafused E. ulmoides. The results showed that: (1) the variation of six active component contents in leaves were different among different E. ulmoides germplasm resources. The largest coefficient of variation appeared in isoquercitrin (34.42%) and the content ranged from 1.16 to 6.92 mg·g^-1, while the lowest coefficient of variation appeared in total flavonoids(19.35%) and the content ranged from 6.70 to 22.53 mg·g^-1. The diversity index of six active components were all above 2.0. The contents of six active components showed extremely significant difference (P＜0.01) among different germplasm resources. (2) There were significant differences in the contents of chlorogenic acid, geniposidic acid, asperuloside, isoquercitrin and total flavonoids among different origins. (3) Correlation analysis showed that the contents of aucubin, geniposidic acid and asperuloside were extremely significantly related to each other. The content of chlorogenic acid was extremely significant and positive correlated with aucubin, asperuloside, isoquercitrin and total flavonoids. No significant correlation was found between total flavonoids and other components except for isoquercitrin and chlorogenic acid. (4) E. ulmoides germplasm resources were divided into four groups according to the content difference of the six components, in which the group Ⅳ including 13 materials had higher contents of active components than that of other groups, which could provide basic material for breeding of E. ulmoides resources. Great variation and rich diversity of six active component contents were found in different E. ulmoides germplasm resources.

Abstract:In this study, we selected the four typical halophyte plant communities of beachwetland of semiarid area in the Dangjiacha Wetland Nature Reserve of Xiji, Ningxia to explore diversity patterns of four halophyte plant communities, including Tamarix sp., Salicornia europaea, Suaeda glauca and Phragmites australis(dwarf type) and also studied the characteristics of total salt and pH in soil of four halophytes communities and bare beach. The main conclusions are as follows：(1) a total of 26 plant species were found among four halophyte communities. Among them, Chenopodiaceae, Gramineae and Compositae respectively accounted for 23.08%,19.23% and 19.23% of the total plants. Tamarix sp. community species diversity and the community composition of S. europaea, S. glauca and P. australis are monotonous, mostly monotonous community patches. The important values of the dominant species in the three halophyte communities were significantly higher than those in the saline shrub (P<0.05). The important value of Tamarix sp. community was between 0.13 and 0.54, which was significantly different from that of the three salted meadows (P<0.05). (2) Margalef index,Shannonwiener index and Simpson index were the largest of Tamarix sp. community, which were 1.105,1.706 and 0.552, respectively. Pielou index is S. europaea > P. australis> S. glauca > Tamarix sp., namely 1.166,1.021, 0.997 and 0.813. (3) The effects of total salt content on the surface layer of the four kinds of halophyte communities and the bare beach were significant (P<0.05). In the surface layer the soil total salt was bare beach＞ S. europaea community> S. glauca community> Tamarix sp. community> P. australis community, respectively between 0.44％-0.58%,0.49％-0.53%,0.15％-0.54%, 0.27％-0.45% and 0.18％-0.39%. The soil pH of Tamarix spp community was decreased with the soil depth. The soil pH of the salted meadow is quickly increased with the soil to deepen, after the basic unchanged. The pH of the bare beach is quickly declined with the soil to deepen, after the basic unchanged.

Abstract:Using chlorophyll fluorescence induction kinetics and analysis technique (JIPtest)，the study analyzed the damage status of plants and the photosynthetic response of plants to stress. The result is very important to vegetation restoration and reconstruction in mining area. Taken Caragana korshinskii as the target plant, which live in Shendong Mining subsidence area of different slope positions (upslope, mesoslope and downslope). The study compared the differences in chlorophyll fluorescence parameters from 1 to 2 years after coal ming subsidence. In this paper, it has explored that the degree of damage and adaptability mechanism of different slope positions in coal mining subsidence. The results show that: (1) on upslope and downslope, V_j and M_o of C. korshinskii leaves increased significantly; at the same time, ABS/RC, TR_o/RC and DI_o/CS_o increased, while F_v/F_m and PI_ABS decreased greatly; after 1 years of subsidence, the maximum increase of W_k value reached 74.54%, and it was close to the control value after 2 years of subsidence. (2) On mesoslope, V_j and M_o of C. korshinskii increased first and then decreased, while ABS/RC and TR_o/RC decreased significantly, F_v/F_m, PI_ABS and W_k changed little. (3) The first two axes of redundancy analysis effectively explained 52% of Fluorescenceenvironmental variation. The correlation coefficients of soil water and available phosphorus with the first axis were 0.57 and 0.5, respectively. It suggest that the photosynthetic system Ⅱ (PSⅡ) of Caragana was severely damaged in the upper and lower slopes, and the reaction center reduced damage by dissipating excess excitation energy; the PSⅡ of Caragana in middle slope was less affected by coal mining, and the reaction center protected itself by reversible inactivation; soil water, available phosphorus and available potassium are the key environmental factors that affecting the PSⅡ of Caragana in the coal mining subsidence area.

Abstract:Geostatistics method in combination with GIS was employed in this research to study the spatial distribution characteristics of soil nutrients for Osmanthus serrulatus community and to figure out the coordinated relation between O. serrulatus community and soil nutrients with Dongla Mountain in Baoxing County of Sichuan Province as the study area, aiming at protecting the O. serrulatus population which is declining due to habitat fragmentation. The results show that: (1) only a small number of species with barren tolerance such as O. serrulatus can finish the life circle in the active limestone mountain region of Dongla Mountain, which is characterized by low maintaining capacity of soil moisture and fertilizer. (2) The distribution of O. serrulatus community in Dongla Mountain is significantly correlated with the content of organic matter, nitrogen, phosphorus and potassium in community soil and the nitrogen, phosphorus and potassium determine the reproductive pattern of O. serrulatus community. (3) As part of the whole O. serrulatus ecosystem, soil achieves the balance of matter and energy in the ecosystem, leading to the formation of “isolated island” of small ecosystem by O. serrulatus among the geographical isolation suitable for their growth.

Abstract:The diversity of wild medicinal plants on Shegyla Mountains was investigated based on sample plots, field collections and literatures, which provides scientific basis for the protection, utilization and systematic research of wild medicinal plant resources in the area. The results showed that: (1) there were 647 wild medicinal plants, belong to 350 genera and 104 families, 22 of which from 15 genera and 13 families were ferns, and 9 of which from 3 genera and 2 families were gymnosperms, 616 plants species from 332 genera and 89 families belonged to angiosperms. From the life history of the wild medicinal plants, 478 of them were herbs and 169 of them were woody plants, accounting for 73.88% and 26.12%, respectively. The proportion of total herb used for traditional medicine was 46.21%, and that of roots and rhizomes was 30.14%. (2) At familys level, families including less than 5 wild medicinal plants accounted for 72.11%, which was far more than the proportions of families including more than 5 wild medicinal plants, but the total number of these plant species was only 22.57% of the total number of wild medicinal plants on Shegyla Mountains. In contrast, families including more than 7 plant species accounted for 6.73% of the total number of families, but 255 the wild medicinal plants were included in these families and accounted for 39.41%, which played an important role in the components of wild medicinal plants on Shegyla Mountains. (3) On genus level, those including 1 species accounted for the 64.00% of the total number of genus, which suggested a high diversity of medicinal on genus level since no genus including most of the medicinal plant species was found. (4) On functional diversity, clearing heat was found in the 260 medicinal plant species, accounting for the 40.19% of the total number of wild medicinal plants. (5) About 360 plants, belonging to 249 genera and 83 families, were found to be ethnobotanical uses. Among these plant species, 235 accounting for 65.28%, were used by Tibetan. Collectively, this research suggested a high level of diversity of medicinal plant species on Shegyla Mountains, which was demonstrated by the diversified life histories, medical parts, medical function, and ethnobotanical uses. Some of the rare and endangered resources of individual small quantity, such as Rhodiola yunnanensis, Gastrodia elata and Dysosma tsayuensis, etc. recommended the establishment of special protection areas, strengthen the protection of wild medicinal plant resources and its original habitat, and strengthen the artificial breeding research, making reasonable plucking and utilization in view of resource reserves, as to achieve sustainable development of wild medicinal plant resources.

Abstract:The flora of wild seed plants in Baotou area was investigated, counted and arranged, and the geography distribution，life styles，water ecotypes of seed plants here from taxonomic grade of families, genera and species were analyzed. The results showed that: (1) there are 595 species of seed plants in Baotou area，which belong to 274 genera and 71 families. Among them there are 2 families, 3 genera, 5 species in gymnosperm; 69 families, 271 genera, 590 species in angiosperm, which accounted for 62.28%, 43.81% and 27.78% of all families, genera and species of angiosperms in Inner Mongolia. (2) From the point view of the composition of family and genus, the singlegenus family and fewgenera family were evident in the number of species of wild seed plants in Baotou area; (3) From the point view of the geographical component, temperate components are dominant. Herbage is dominant in life style. In water ecotype，the mesophyte is most primary，the xerophile is primary either. That means the water condition is worse and here is semidrought area.

Abstract:Two chloroplast DNA intergenic spacers, trnLtrnF and rpl16, were employed to study phylogeography of Saxifraga tangutica, which aimed to explore genetic structure and phylogeographical history of this species. The result showed that: (1) based on rangewide sampling (18 populations and 209 individuals), we detected 74 haplotypes. Only one haplotype (H5) was widespread, while 71.62% were private haplotypes, i.e., observed in single populations. (2) Analysis of molecular variance showed that withinpopulation variation was described as 91.85% of the total variation, while amongpopulation variation was not distinct (F_ST = 0.081). An estimation of nonsignificantly larger N_ST (0.109) than G_ST (0.097, P > 0.05) value across all populations suggested an absence of phylogeographical structure across the whole distribution range. (3) Neutrality tests of Tajimas D (-2.045 07, P < 0.05) and Fu & Li D^* (-3.629 27, P < 0.05) showed significantly negative values, in combination with unimodal of mismatch distribution analysis, suggested a recent demographic expansion of S. tangutica. Based on results given above, we speculated that there might be multi microrefugia for S. tangutica on the QinghaiTibetan Plateau platform during Quaternary glaciations. Climatic oscillations during Quaternary glaciations fragmented the distribution range of S. tangutica into isolated populations, subsequent allopatric divergence resulted in the formation of numerous private haplotypes across its distribution range. Populations of S. tangutica possibly experienced in situ altitudinal migrations to respond glacial and interglacial intervals, instead of extensively horizontal migration.

Abstract:We used unfertilized ovaries of ‘Guiyang xiaoqinggua’ (pumpkin) as the explants to study the heat shock time and TDZ concentration on embryo induction via in vitro culture. Furthermore, we optimized the test steps and researched the method of obtaining regenerated plants directly. The results showed that the best obtained pumpkin plants were inducted regenerated plants directly under dark at 35 ℃ for 5 d, and then moved to light condition at 25 ℃ for 90 d; The unfertilized ovaries can induct regenerated plants in the TDZ concentration at 0.04-0.06 mg/L, the best TDZ concentration was 0.06 mg/L, and the ratio of inducted embryo and regenerated plants were 22.57% and 14.30%, respectively.

Abstract:circular RNA (circRNA) is a group of endogenous noncoding RNA with closed loop structure, which widely and very stably exists in all eukaryotes. It has the features of construct stability, sequence conservative and tissuespecific expression. Prior studies have discovered that circRNAs could act as microRNA (miRNA) sponge to regulate the expression of them. Besides, some circRNAs could regulate gene expression by interacting with proteins. Some studies have shown that circRNAs are not only participated in physiological processes, such as plant hormone signal transduction, but also play an important role in the process which response to biological stress in plants. In this paper, we reviewed the classes and biogenesis of circRNAs, as well as the function of circRNAs. In addition, we discussed the undiscovered issues and the meanings of existence about circRNAs. As research continues, we believe that it can provide theoretical reference for the formation mechanism and gene regulatory networks of circRNAs in plants.