Abstract:DELLA protein is a core component of GA signaling pathway, and belongs to the GRAS nuclear transcription regulator family. In the present study, we used the grapevine cv. ‘Wink’ as the test material to identify the precise sequences and predict the potential functions of VvRGL1 and VvRGL2 through gene cloning, promoter analysis, chromosomal location, gene protein structure and phylogenetic analysis. And the qRTPCR method was used to detect the temporal and spatial expression of VvRGL genes in the grape berry peel, berry flesh and seed (or seed area) induced by exogenous GA. Result showed that: (1) the chromosomal localization of VvRGL1/RGL2 were Chr14 and Chr7, the open reading frame (ORF) were 2 007 bp and 1 815 bp, and the number of amino acid were 668 and 604, respectively. Both of VvRGL1 and VvRGL2 contained a GRAS conserved domain, but did not have a DELLA domain, and were members of the GRAS transcription factor gene family, but not the DELLA subfamily. Gene structure analysis result showed that their gene structures were highly conserved with the DNA sequence of VvRGL1 was only one intron and two exons, while the DNA sequence of VvRGL2 had no intron and only one exon. Phylogenetic analysis showed that VvRGL1 was closely related to Arabidopsis and citrus, while VvRGL2 was closely related to strawberry and poplar. (2) The promoters of two genes both contained elements that were responsible for GA and endosperm development, suggesting that they might be involved in response to GA signaling and endosperm development. (3) The results of qRTPCR showed that exogenous GA treatment reduced the expression of two genes in grape peel and seed area, but upregulated their expression in the flesh of young fruit, suggesting that in the peel and seed areas, GA might participate in the regulation of grape seedless fruit development by inhibiting the expression of VvRGL1/RGL2. This study provides an important basis for further explore the function of VvRGL in GA signaling pathway and in seedless fruit development of grapevine.

Abstract:Phenylalanine ammonialyase (PAL) is encoded by a multigene family and is the starting enzyme for the synthesis of polyphenolic substances such as anthocyanins, and PAL has a regulatory effect on anthocyanins synthesis. The Gateway technology system was used to construct the tea plant CsPAL3 overexpression vector pGWB502: CsPAL3 and pGWB505: CsPAL3: GFP from purple leaf tea cultivar Wuyi qizhong C18 (Camellia sinensis), and successfully transferred into Agrobacterium tumefaciens GV3101. By transient expression of the injected tobacco, GFP green fluorescence was observed by laser confocal scanning microscopy, indicating successful transient expression, and the results showed that the CsPAL3 is mainly concentrated in the nucleus and cell membrane. Through invading Arabidopsis thaliana, the homozygotes were screened to obtain stably expressed transgenic CsPAL3 A. thaliana. The expression of CsPAL3 in the transgenic CsPAL3 gene A. thaliana was significantly higher than that in the leaves by realtime quantitative PCR (qPCR), and the CsPAL3 gene was regulated by light. This study provides a scientific basis for further study of the function of CsPAL3 gene in tea tree and the molecular regulation mechanism of tea anthocyanin synthesis and accumulation.

Abstract:MYB is the most important transcription factor in plant anthocyanin biosynthesis pathway. In this study, the anthocyanin StAN1 gene of purple potato was cloned by homologous cloning technique. The results showed that: （1） the full length of the StAN1 gene was 774 bp, encoded 258 amino acids; Phylogenetic tree analysis showed that StAN1 had the closest relationship with pepper, eggplant and asparagus, and had the furthest relationship with Petunia and apple. （2）Fluorescence quantitative PCR analysis showed that StAN1 gene was expressed in different tissues of potato. (3) The expression vector pJAM1502AN1 was successfully constructed by Agrobacterium (Gv3101) transformation to obtain the root, stem, leaf and vein are purplered transgenic tobacco, the expression vector StAN1 gene was transformed from small to large as the root < leaf < stolon < tuber skin < tuber. （3） Transgenic tobacco with StAN1 gene was constructed successfully through Agrobacterium (Gv3101) transformation. PCR identification showed that the target gene StAN1 had been successfully transferred into tobacco. （4） The anthocyanin content of wild type tobacco leaves was 2 mg/g, and the color of leaves was green. However, the anthocyanin content of the transgenic tobacco leaves reached 20 mg/g, and the color of the leaves changed to purplish red.

Abstract:In this study, Loropetalum chinense var. rubrum was used as tested material. A flavonol synthase (FLS) homology gene named LcFLS1 was cloned by PCR based on the transcriptome sequencing results. The bioinformatic analysis shows that the open reading frame of LcFLS1 gene contains 996 base pairs encoding 331 amino acids. Amino acid alignment results indicate that LcFLS1 may encodes a typical 2oxoglutarate and Fe(II)dependent oxygenase. Protein structure prediction indicates there are ten loci at the core domain of globular protein interacting with 2oxoglutarate ligand in LcFLS1. The phylogenetic tree analysis illustrates that LcFLS1 is closely related to Camellia sinensis and other woody plants but is far related to herbaceous plants like Arabidopsis thaliana. The express pattern of different tissues by qPCR shows that LcFLS1 expressed highest in L. chinense var. rubrum flower while lowest in stem. The pLcFLS1SUPER1300 overexpression vector was successfully constructed and transferred into Arabidopsis thaliana by Agrobacterium infection inflorescence method to obtain transgenic plants. PCR identification shows that positive transgenic plants of LcFLS1 were obtained. This research laid important foundations for studying the mechanism of flavonol biosynthesis as well as development and utilization of medicine value in L. chinense var. rubrum.

Abstract:Growth regulating factor (GRF) is a plantspecific transcription factor family that plays an important regulatory role in plant growth and development. In this study, 11 CsGRF transcription factors were identified in tea plant genome with complete characteristic domains QLQ and WRC. The CsGRF family members contained 3 to 6 exons and were divided into 6 groups based on phylogenetic relationships, which are closer to the grape and kiwi. The transcriptome data analysis of different tissues indicated that the GRF family was highly expressed in the tender shoots. Upstream promoter region analysis revealed a large number of cisacting elements closely related to plant development, hormone and stress response. Fluorescence quantitative detection showed that 10 and 2 CsGRF members were upregulated under low temperature and drought stress, respectively, and CsGRF8 and CsGRF11 responded to both abiotic stresses. Furthermore, the expression levels of 9, 3 and 6 CsGRF genes were significantly different by ABA, MeJA and GA hormone treatments, respectively. This work indicates that the CsGRF family genes are involved in the growth and development and stress response in tea plants, speculating that CsGRF genes may play a role in the stress response relying on the hormone signal transduction pathways.

Abstract:In this paper, a MYB gene named BnMYB3 was isolated from ramie (Boehmeria nivea L.) by amplification of cDNA ends (RACE), whose GenBank accession number is MF741320.1. The sequence analysis showed that the fulllength cDNA of BnMYB3 contained 1 216 base pairs, with a coding region of 900 base pairs. This sequence encoded a protein of 299 amino acids in length with a molecular weight of 33.63 kD and a theoretical isoelectric point of 9.16. The protein contains two typical MYB domains which belong to R2R3MYB gene family. The 1 681 base pairs promoter sequence of BnMYB3 was cloned from the genome of ramie. By bioinformatics analysis, the promoter sequence contained several stressrelated cisacting elements, such as ABRE, GAREmotif, CGTCAmotif and TGACGmotif. Realtime quantitative PCR analysis showed that BnMYB3 was a constitutive gene, but the expression levels of BnMYB3 in stems and leaves were significantly higher than that in roots. Furthermore, BnMYB3 gene was apparently induced by cadmium, and the relative expression level of BnMYB3 increased dramatically with the prolongation of treatment time and the increasement of Cd²⁺ concentration.

Abstract:In this study, the wildtype Panax notoginseng was used as the experimental material. The transcription factor gene PnWRKY1 was isolated from the P. notoginseng by homologous cloning, and the overexpression vector pCAMBIA2300sPnWRKY1 was transferred into P. notoginseng cells by Agrobacterium tumefaciensmediated transformation system. The contents of total saponins and four important monomer saponins were detected, and the expression levels of enzyme genes in the biosynthetic pathway were analyzed by qRTPCR. It provides a theoretical basis for the establishment of a highly efficient regulation strategy for the biosynthesis of P. notoginseng saponins. The results showed that: (1) the transcription factor PnWRKY1 is 810 bp in length encoding 269 amino acids. (2) PnWRKY1 overexpression vector pCAMBIA2300sPnWRKY1 was successfully constructed. Six transgenic cell lines (T₁-T₆) with resistance to kanamycin were obtained by Agrobacterium transformation. PCR analysis of the kanamycin gene nptⅡ showed that all cell lines had a 450 bp specific band consistent with the expected length, indicating that six PnWRKY1 transgenic cell lines were obtained, which overexpressed PnWRKY1 successfully. (3) The expression levels of PnWRKY1 in six transgenic cell lines were very significantly higher than that in wildtype cell lines, and the T₃ cell line with the highest expression was 5.36 times higher than the wildtype cell line. (4) The total saponins biosynthesis in PnWRKY1overexpressed cell lines was significantly promoted, the contents of total saponins in T₁-T₆ were 2.46, 1.98, 2.67, 1.74, 2.54 and 1.98 times of the wildtype cell line, respectively. In six PnWRKY1overexpressed cell lines, the content of four monomer saponins (R1, Rg1, Re and Rb1) were increased to some content compared with wildtype cell line, especially the T₃ cell line, the content of monomer saponin Re was the highest (37.81 mg/g). (5) Compared with the wildtype cell line, the highest expression levels of key enzyme genes PnDS, PnSS and PnSE in the synthesis pathway of P. notoginseng saponins in the overexpressed PnWRKY1 cell line were increased by 3.1, 4.0 and 4.5 times, respectively. This study showed that the transcription factor PnWRKY1 may affect the synthesis of P. notoginseng saponins indirectly by regulating the expression of key enzyme genes in the biosynthetic pathway of P. notoginseng saponins. The results provide references for the establishment of a highly efficient regulation strategy about the biosynthesis of P. notoginseng saponins.

Abstract:In this study, a glycerol 3 phosphate acyltransferase gene, named HaGPAT1, was isolated from oil sunflower seeds. The length of HaGPAT1 is 1 656 bp, encoding 551 amino acids with calculated molecular mass of 62.132 kD and isoelectric point (PI) 8.84. The expression profile of HaGPAT1 was detected by quantitative realtime PCR (qRTPCR) in different tissues through different developmental stages of seeds and under abiotic stress treatments. Multiple sequences alignment showed that HaGPAT1 was closely related to GPAT1 protein of higher plants. The expression of HaGPAT1 reached its highest level in buds and upregulated under drought and salt stresses. The results suggested that HaGAT1 might play an important role in floral organ development and may be involved in abiotic stress regulation of sunflower.

Abstract:In this study, we compared and measured the main physiological characteristics, chloroplast ultrastructure and stem microstructure between dwarf mutant C1056 and wild type CCMC, so as to explore the plant height regulation mechanism of cucumber, excavate new dwarf germplasm, and provide basis for dwarf breeding of cucumber. The results showed that: (1) the mutant C1056 had significantly shorter plant height, darker leaf color, thickened veins, curled leaf tips, wrinkled and shrunk leaves. There was no significant difference in stem diameter, internode number between mutant and wild type, but the internode length of mutant was extremely obviously shorter than wildtype. (2) The stem transverse microstructure showed that the number of mutant vascular bundle was not significantly different from the wild type, while the vessel diameter was reduced. The stem longitudinal section showed that the internode cell became significantly shorter and smaller than that of wild type, while the number of cell was slightly compensated. (3) Compared with wild type, the content of chlorophyll and carotenoid of the mutant both decreased and the ratio of chlorophyll to carotenoid and chlorophyll a/b significantly increased. (4) The chlorophyll fluorescence parameters of mutant did not significantly change. The net photosynthetic rate of the mutant was 8% lower than that of wild type, and stomatal conductance and transpiration rate were 15% and 10% higher than that of wild type, respectively, but the differences were not significant.In mutant, the intercellular CO₂ concentration was significantly higher than that of wild type. (5) The results of transmission electron microscope showed that the mesophyll cell of mutant was smaller than that of wild type, the cell area occupied by chloroplast was significantly larger, and the shape of chloroplast was semicircle and spindle. Most of the stromal and grana layer of abnormal chloroplasts were not obvious, and the stacking was not neat. The results of this study showed that the dwarfing of cucumber mutant C1056 was mainly caused by significantly shortened internode length and smaller cells, and the chloroplast structure of mutant was affected to some extent, but its photosynthetic capacity was not significantly affected.

Abstract:According to the existing Agrobacterium rhizogenes infection method, we used the leaves of Ginkgo biloba L. sterile seedlings as explants to optimize the experimental operation of Agrobacteriuminduced ginkgo hairy roots, and observe the growth of ginkgo hairy roots. The polyphenol content, relative expression of enzyme gene which related to polyphenol synthesis and POD gene in hairy root tissues on different days of subculture were determined to explore the physiological mechanism of browning of ginkgo hairy roots. The results show: (1) the optimal preincubation time of Agrobacterium rhizogenes infection was 3 d, the strain was R1601, the coculture medium was White, and the infection time was 30 min. The induction rate of Ginkgo biloba hairy root after optimization of infection operation reached 72.36%; the optimal IBA concentration for ginkgo hairy root growth was 0.5 mg/L. (2) The hairy roots of ginkgo have a milky white color when initial rooting and they are mostly clustered at the wound. These hairy roots are nondirectional when growing and can be induced at the wound both on the front and back of the leaves. The root length can reach 0.4-0.8 cm at 20 days after sterilization. After 25 days of subculture, the hairy roots are white. However, at 35 days of subculture, part of the hairy roots which from bottom to middle turned yellow. At the 45 days of subculture, most of the hairy roots turned from white to yellow, and browning began to appeared from the root to the middle. (3) The relative expression levels of PAL, C4H, 4CL and POD of hairy roots in 35 d after subculture were respectively account for 68%, 44%, 51% and 52% of 25 days, and the relative expression of PAL, C4H, 4CL and POD gene at 45 d after subculture were respectively account for 19%, 75%, 86%, and 105% of 35 days. (4) The total phenolic contents of ginkgo hairy roots at 35 and 45 d after subculture were 17.14 and 13.78 mg/g, respectively. The change of PAL gene expression was inconsistent with the expression of other two key enzyme genes (C4H, 4CL) at downstream, and the significant decrease of PAL gene expression did not affect the expression of C4H and 4CL gene, which indicate the change of PAL gene expression has little effect on the downstream synthesis rate, and it may not be the ratelimiting enzyme of the phenylalanine metabolic pathway of ginkgo hairy root; while the trend of C4H and 4CL gene expression is highly consistent, indicating that C4H should be one of the ratelimiting enzymes in this pathway; it is speculated that PPO may be involved in the early stage of browning reaction of hairy roots, which leads to the inhibition of hairy root growth and the increase of POD gene expression level, then bring POD participates in browning reaction.

Abstract:In order to study the ecological adaptability of Corylus heterophylla×Corylus avellana in the arid regions of Xinjiang, we collected 38 varieties (lines) of C. heterophylla×C. avellana from the planting resources collection in Chabuchaer County, Xinjiang, and applied the paraffin wax method. The optical microscopy technique was used to determine the epidermal thickness, epidermis thickness, leaf thickness, main vein thickness, palisade tissue thickness, sponge tissue thickness, palisade tissue thickness/sponge tissue thickness (gatetosea ratio), palisade tissue tightness and sponge, looseness of tissue structure. These nine droughtrelated anatomical structural parameters were used with statistical analysis and comprehensive evaluation of drought resistance. The results showed that: (1) the differences in main vein thickness, upper and lower epidermis thickness, leaf thickness, palisade tissue thickness and sponge tissue thickness of different varieties (lines) showed extremely significant levels, and there was a significant correlation and significant correlation between epidermal thickness, epidermis thickness, leaf thickness, palisade tissue thickness and sponge tissue thickness. (2) Principal component analysis showed that the eigenvalues of the first, second and third principal components were 3.109, 2.614 and 1.884, respectively. The cumulative contribution rate of the first three principal components was 84.52%, which basically summarized the main information of all indicators. (3) The cluster analysis method was used to divide 38 varieties (lines) into five categories. The comprehensive evaluation of drought resistance by the membership function method showed that 8448, 8121, 84310, F03, B11, and 85162 had strong drought resistance, 85127, 8588, B21, and 804 drought resistance is poor.

Abstract:Cytoplasmic malesterile (CMS) lines, especially K (Aegilops kotchyi), V (Aegilops ventricosa), and T (Triticum timopheevii) types of cytoplasm, are of high value in heterosis utilization in wheat (Triticum aestivum L.). The aim of this study was to discuss the relationship between CMS and chloroplast and to reveal the mechanism of CMS by investigating chloroplast DNA and RuBP carboxylase (rubisco) activity in CMS malesterile lines. The experiment was conducted with cultivars of the K, V, Ttype CMS lines, the common maintainer ‘Tai 911289’ and ‘Ji 5418’, the F₁ hybrids and the cytoplasmic donors under field conditions. The major results are as follows: (1) the polymorphism between male sterile lines and maintainer lines in cpDNA, and specific fragment in the different cytoplasm type male sterile lines provides evidence of three types of cytoplasm male sterile lines from different sources, and found 5 specific primers and 7 specific primers respectively to identify V and T type sterile lines. (2) There is no difference in cpDNA between the male sterile lines and their cytoplasm donors, except K‘ji5418’, and because of its nature of maternal inheritance also showed no polymorphism in cpSSR amplified fragment between the male sterile lines and its fertility restoration in the F₁ generation. (3) RuBP carboxylase activity of two sets of male sterile lines was significantly higher than that of maintainer lines. In the F₁ generation, with the recovery of fertility restorer, its RuBP carboxylase activity is higher than that of maintainer lines, but lower than the respective male sterile lines in standing and flowering period. However, there is no difference between them in jointing stage.

Abstract:In order to reveal the relationship between Lilium male sterile and fertile lines in changes of hormones, some endogenous substances contents and energy metabolism enzyme activities, this study used chromatographytandemmass spectrometry and high performance liquid chromatography to test hormones. Endogenous substances and energy metabolism enzyme activities were measured by colorimetry. The effects of hormone content, hormone ratio, endogenous substance content and energy metabolism enzyme activity on male sterility of Lilium were analyzed. The results show that: （1） during the development period which is from sporogenous cell stage to tetrad stage, changes of endogenous hormone, endogenous substance content and energy metabolic enzyme activity in male sterile line and fertile line were different. The content of IAA in male sterile line was higher than that in fertile line at all stages. The contents of ZR and GA₄ in male sterile and fertile line were similar at pollen mother cell stage, but two contents in male sterile line were lower than those in fertile line at tetrad stage. ABA content in male sterile line accumulated at tetrad stage. JA content in male sterile line was lower than it in the fertile line at the pollen mother cell stage. However, the trend is opposite at the tetrad stage. （2）The contents of soluble sugar, soluble protein and proline in fertile line were higher than those in male sterile line at all stages. However, the content of MDA in male sterile line was significantly higher than that in fertile line at tetrad stage. （3）The activities of COD and ATP in fertile line were higher than those in sterile line at all anther development stages. This study suggest that: from sporogenous cell stage to tetrad stage, high IAA, ABA and low GA₄, ZR contents may lead to the deficiency of soluble sugar, soluble protein, proline contents and lower energy metabolism enzyme activities. These are the possible reasons to cause male sterile phenomenon of Lilium.

Abstract:In this study, Riesling annual nutrition bag cuttings were used as experimental material. We conducted artificial climate chamber hydroponic experiments to investigate the effect of various concentrations EBR (0.05, 0.10 and 0.20 mg/L) pretreatments on active oxygen, antioxidants, antioxidant enzymes activities and osmotic adjustment substance contents in grape (Vitis vinifera L.) seedlings with PEG simulating drought stress, revealing the mechanism of drought resistance of EBR on grape seedlings under drought stress. The results showed that: (1) compared with the growth control in normal, simulating drought stress significantly increased the contents of anion radical (O₂^-·), hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) in the leaves of grape seedlings. Compared with the PEG treatment alone, different concentrations of EBR pretreatment could reduce the contents of O₂^-·, H₂O₂ and MDA in leaves. (2) Compared with the growth control in normal, the contents of ascorbic acid (AsA) and reduced glutathione (GSH) were significantly reduced in PEGtreated seedlings. Compared with PEG treatment, EBR pretreatment significantly increased AsA and GSH contents in grape leaves, and 0.10 mg/L EBR treatment was the best. (3) Superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) activities in grape seedling leaves showed a trend of rising first and then decreasing in PEG treatment alone and it remained basically unchanged under normal growth conditions. Moreover, the activities of SOD, CAT, POD and APX in EBR pretreatment were always higher than those in PEG treatment. (4) The contents of proline and soluble protein in PEG treatment alone was higher than that growth control in normal. Different concentrations of EBR pretreatment could significantly increase the contents of proline and soluble protein in grape leaves during middle and late stages of drought stress. It was showed that under drought stress, EBR pretreatments could effectively reduce the excessive accumulation of reactive oxygen species (ROS) and the increase of membrane lipid peroxide level induced by drought stress through improving antioxidant defense system activities and osmotic adjustment substance contents in the leaves of grape seedlings, resulting in improving the drought resistance of wine grape seedlings. Among these, 0.10 mg/L EBR pretreatment got the most remarkable effect.

Abstract:In order to investigate the changes of NO synthesis and sucrose metabolism in melon seedlings under chilling stress, cultivar ‘Hongyou’ (chillingtolerant) and ‘XL1’ (chillingsensitive) melon seedlings were treated with 6 ℃ for 0，1，3，6，12，24 h，3 d，5 d and 7 d in climate chambers. The results showed that： （1） chilling stress increased the activity of nitrate reductase (NR) and induced NO production. The response time and change of NO to chilling stress were earlier and more obvious in chillingtolerant cultivar ‘Hongyou’. （2） Compare with the control, the chilling stress condition increased sucrose, fructose and glucose contents, enhanced the activities of sucrose phosphate synthase (SPS), sucrose synthase (SS), acid invertase (AI), neutral invertase (NI), and decreased starch content. （3） The contents of soluble sugar, soluble protein and proline in the leaves of the two melon seedlings increased under chilling stress. These results indicated that melon seedlings could respond to chilling stress by inducing NO and carbohydrate generation. In addition, the accumulation of sugar substances induced by chilling stress was later than the production of NO.

Abstract:Pruning is an important measure for the aging of artificial Caragana intermedia in the desert steppe. It is a systematic understanding of the physiological and ecological response processes and their changes after the pruning of C. intermedia. The study sets a comparative observation plot to and using unpruned C. intermedia (WPC) as a control, and photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO₂ concentration, water use efficiency of C. intermedia were treated that continuously grown for 1 to 5 years (PC1-PC5). The photosynthetic physiological characteristics and the effects of soil water content and distribution were analyzed. The results showed that: (1) the effect of pruning treatment on the physiological characteristics of C. intermedia was different due to the increase in the number of pruning years. The photosynthetic rate and transpiration rate of PC1 and PC2 were slightly higher than that of WPC, and PC1 was in the active period of compensatory growth, and its water use efficiency was significantly higher than that in other pruning years of C. intermedia. The water use efficiency of C. intermedia in PC2 began to decrease. The transpiration rate, photosynthetic rate and stomatal conductance of PC3 and PC4 increased significantly, reached the maximum value in PC4 as well as the corresponding water use efficiency gradually recovered. Pruning measures had a greater impact on the intercellular CO₂ concentration of C. intermedia in PC1 and PC5. (2) The water status of C. intermedia in PC1 was lower than that of other pruning years because the soil water content was significantly reduced by canopy closure at 0-100 cm; the soil water of C. intermedia in PC2 was slightly improved and it of C. intermedia in PC3 and PC4 was significantly increased, and the soil water status of C. intermedia in PC5 was gradually closer to that of WPC C. intermedia. (3) With the increase in the number of pruning years, there is a dynamic relationship between photosynthetic characteristics and soil water content of C. intermedia. The soil moisture of PC1 is slightly decreased, and the growth slowed down. The soil profile water content of C. intermedia in PC2 gradually recovered, and the growth rate of soil water content of C. intermedia in PC3 began to decline and the physiological indexes increased. The physiological indicators and soil water content of C. intermedia in PC4 reached its highest value. The indicators of PC5 began to decline. In summary, PC4 treatment is the inflection point of photosynthetic physiology and soil water response of C. intermedia, which can be used as a time node for optimal management of pruning C. intermedia.

Abstract:We made a germination test to study the characteristics of soil seed banks in the different sand dunes (fixed dune, semifixed dune, mobile dune) of Yellow River diversion area waterlevelfluctuating zone (including the flooded, nonflooded and control areas of different sand dunes). This study was conducted to evaluate the seed density, species diversity and horizontal distribution pattern of soil seed banks in areas with different local conditions based on field sampling and an indoor bourgeoning experiment. In order to provide a theoretical basis for the restoration and reconstruction of the surface vegetation in the Yellow River diversion area, we discussed the soil seed bank in waterlevelfluctuating zone of the Yellow River diversion area to guarantee the formation of aboveground vegetation and the succession trend of plant community structure in the future. The results showed that: （1） there were significant differences in the soil seed bank of three waterlevelfluctuating zones, The density of waterlevelfluctuating zone soil seed bank is the following in order: nonflooded area (733 seed perm²)>control area (609 seed perm²)>flooded area (176 seed perm²).（2） The seed density decreased with soil depth. With the intensification and prolonging of flooding, the amount of seeds in top soil (0-5 cm) tended to decrease.（3） A total of 10 species belonging to 4 families and 10 genera were detected in the soil seed bank of flooded area. A total of 14 species belonging to 5 families and 14 genera were detected in the soil seed bank of nonflooded area. A total of 15 species belonging to 5 families and 15 genera were detected in the soil seed banks of control area. Most of them belong to Chenopodiaceae and Poaceae, which were annual and perennial herbage species. It indicated that soil seed banks have little contribution to regeneration and succession of shrub layers. （4） Compared with those in control area，all the species diversity indices, richness indices and evenness indices of the standing vegetation decreased significantly in flooded area， but increased in nonflooded area．And the similarity index between the flooded and nonflooded areas was the highest.

Abstract:In order to explore the key factors of maintaining the understory vegetation diversity in forest light condition and canopy structure in the alpine region of Qinghai, we observed five typical plantations in Datong County, Qinghai Province, including Picea crassifolia forest (Ⅰ), Populus cathayana forest (Ⅱ), Larix principisrupprechtiPicea crassifolia mixed forest (Ⅲ), Betula platyphyllaPopulus cathayana mixed forest (Ⅳ), and Betula platyphyllaPicea crassifolia mixed forest (Ⅴ), to study the characteristics of the canopy structure and light conditions and their effects on understory vegetation. Data were collected using a canopy analyzer and combined with field investigations. The results showed that: （1） the canopy openness of stands Ⅰ and Ⅲ was significantly lower than that of stands Ⅱ, Ⅳ and Ⅴ (P<0.05). The order of leaf area index of each forest was Ⅲ, Ⅰ, Ⅱ, Ⅴ and Ⅳ. The canopy openness of broadleaved forest was larger than that of coniferous forest, but its leaf area index was lower than that of coniferous forest. The understory direct PPFD, understory diffuse PPFD and total understory PPFD of stands Ⅱ and Ⅳ was significantly higher than that of those of forest stands Ⅰ, Ⅲ and Ⅴ (P<0.05), in which total understory PPFD and understory diffuse PPFD were Ⅱ>Ⅳ>Ⅴ>Ⅰ>Ⅲ, the understory direct PPFD was Ⅱ>Ⅳ>Ⅰ>Ⅲ>Ⅴ; K of the stands Ⅱ, Ⅳ and Ⅴ was significantly higher than Ⅰ and Ⅲ; broadly expressed as broadleaved forest > coniferous forest.（2）The canopy openness of each stand was very significantly positively correlated with the understory light indices (P<0.01), the leaf area index was significantly negatively correlated with the understory light indices (P<0.01); and it had the strongest control ability for understory diffuse PPFD. Canonical correlation analysis showed that canopy openness of pure forest had greater contribution and interpretation of canopy structure than leaf area index and mean leaf angle. The leaf area index of mixed forest had greater influence on the understory light than that of pure forest. （3） The understory species ShannonWiener index (H) and Patrick index (P) of mixed forest were higher than that of pure forest; The ShannonWiener index (H) and Patrick index (P) of the undergrowth herb layer were positively correlated with canopy openness and understory light radiation and negatively correlated with leaf area index (P<0.05); there was a very significantly negative correlation between Pielou index (J_sw) and mean leaf angle (P<0.01) and significantly positive correlation between Pielou index (J_sw) and understory diffuse PPFD (P<0.05). It is more conductive for the maintenance of understory vegetation diversity to replant associated tree species in the arbor layer, gradually adjust to multitree mixed forest and increase canopy structure and the understory heterogeneity.

Abstract:In this paper, a quantitative analysis of 14 large tree species (DBH ≥ 10 cm), 15 small tree species (5 cm ≤ DBH < 10 cm) and 19 saplings (1 cm ≤ DBH < 5 cm) in secondary forest of Pinus yunnanensis Franch. var. tenuifolia Cheng et Law, was carried out by methods of variance ratio test, χ² test, Pearsons correlation coefficient test and Spearmans rank correlation coefficient test. The results showed that: (1) there was nonsignificantly negative correlation of big trees or small trees, and nonsignificantly positive correlation of saplings or the whole community. The results of χ² test indicated that the proportion of positive correlation, negative correlation and noncorrelation for big trees, small trees, saplings and the whole community had different characteristics. For big trees and small trees, the negative correlated speciespairs were in the majority (48.35% and 46.67%, respectively). The positive and negative correlated speciespairs were basically the same for saplings (40.35% and 39.18%, respectively). For the whole community, the noncorrelated speciespairs had the largest proportion (41.13%). (2) Pearsons correlation coefficient test and Spearmans rank correlation coefficient test revealed that there was largest proportion of negative correlation for big trees, small trees, saplings and the whole community. (3) There was intense competition in resources and unstable structure between big trees and small trees. Besides, the saplings adapted to the shaded environment under the canopy, and had lower requirements for light, thus had a relatively lower stability and even individual species show independence. On the whole, there is a certain correlation among species in the secondary forest community of P. yunnanensis var. tenuifolia in Nanpan River basin, yet still without the formation of stable allocation relationship. The community is still in the early stage of succession and its structure is still unstable. The results of this article can provide scientific reference such as the management and protection, sustainable management and utilization for secondary forest of P. yunnanensis var. tenuifolia, as well as vegetation restoration and ecological restoration in dryhot valley areas.

Abstract:An investigation was conducted on the population structure and dynamics of Alsophila spinulosa in Mount Emei with the onthespot investigation method, adopting height class (H) to represent age class. By establishing a static life table, plotting a population survival curve, analyzing the survival function, we characterized the population structure and dynamics. In addition, by constructing a time series prediction model, was also examined and predicted the current survival status and future development trend of the population, respectively. Results showed: (1) the population structure of A. spinulosa in Mount Emei was irregular pyramidal. The middleaged individuals (0.6 m＜H≤2.1 m) shared 58.5% of the total population amount, while, the young (H≤0.6 m) and the elder ones (H＞4.8 m) only accounted for 12.7% and 1%, respectively. Young individuals were deficient, and the maintenance and development of the population structure mainly relied on the middleaged and adult (2.1 m＜H≤4.8 m) individuals. (2) The dynamic index of population age structure quantity with future external disturbances considered V′_pi=3.027＞0 showed an overall, but gradually declining growth of the population. (3) The population survival curves tended to be DeeveyⅡ type, as the mortality rate remained stable among the 1st-6th class, but increased acutely from the 7th class to the 8th class, which indicated the following dynamic features of the A. spinulosa population: early stage, declining; middle stage, stable; and last stage, recession. (4) Time series prediction revealed that after a short period of growth, the population of A. spinulosa would gradually decline, and the species might even become endangered if not protected. In conclusion, the research showed the loss of young individuals and failure of population replenishment is the main cause of A. spinulosa population’s endangerment in Mount Emei. Our suggestions including the establishment of local nature reserves, artificial breeding, and the advances of research into highefficient breeding techniques are proposed for the rejuvenation and renewal of A. spinulosa there.

Abstract:Urushiol is a unique biochemical component in Anacardiaceae, which has excellent biological activities in antioxidation, antitumor and antivirus, and then has great values in the development of pharmaceutical and industrial production. In this study, comprehensive statistic analyses on the diversity and distribution of urushiol in the family were carried out based on urushiol data of different groups of Anacardiaceae extracted from literatures. Meanwhile, the origin and evolution of urushiol in the family were inferred using the nuclear ETS and the chloroplast genes rps16 and trnLF sequences. The results show that： （1） the urushiol has a high diversity and has great variation in its phenol and R chain. （2） Urushiol is only found in the Anacardioideae and is an important feature of the subfamily. （3） Reconstruction analysis of ancestral traits based on the structure of urushiol phenol and R chain indicates that urushiol from the lacquer family evolved from catechol to resorcinol, while the pentadec(en)yl group of urushiolR chain evolved to the heptadec(en)yl group.

Abstract:Two species Pycnarrhena pleniflora Miers ex Hook. f. & Thomson (Menispermaceae) and Begonia gemmipara Hook. f. & Thomson (Begoniaceae), are newly recorded from China. They were found in Yunnan Tongbiguan provincial Nature Reserve, Dehong, Yunnan province, China and their vouchers are kept in the Herbarium of Xishuangbanna Tropical Botanical Garden (HITBC).

Abstract:Callicarpa japonica var. luxurians Rehd. (Verbenaceae) was reported as a newly recorded variety of Chinese Mainland from Dongfushan Island, Putuo District, Zhejiang Province. The morphological descriptions and photos were provided. Its values on economy and endangered degree were also briefly discussed. The species with a disjunct distribution between Zhoushan Islands, Taiwan and Japan were enumerated and discussed, which indicated that there was a close link between the three floristic regions. The voucher specimens were preserved in the herbarium of Zhejiang A & F University(ZJFC).