Abstract:This study was conducted on nine crosses, covering seven female parent and four male parent, to obtain flavorful seedless grapevine seedlings. The hybrid ovules after field hybridization were cultured in vitro to insure the further development of embryo. Then embryos converted into plant in medium, and the hybrid progenies were detected via molecular marker technology. All the seedlings were acclimatized in greenhouse, and then transplanted in field. The study showed: (1) 365 hybrid seedlings were obtained by means of embryo rescue technique, and 182 of them survived after transplanting into field. (2) Two kinds of genetic molecular markers GSLP1569, SCF272000 were selected for detecting the cross parents and some of hybrid progenies. Form 72 hybrid strains, we detected 8, 38 hybrid strains with seedless gene, respectively. (3) The three seedless cultivars (Ruby Seedless, Flame Seedless and Kunxiang Seedless) were suitable as female parent in embryo rescue, with higher seedling rate. Muscat was proved as the best male parent. (4) The optimal sampling times were 43 days and 51 days after pollination (DAP), with the highest developed embryo rate (6.96％-8.54％ and 16.92％-18.13％) and seedling rate (6.45％ and 8.75％-10％), for the crosses of Flame Seedless and Kunxiang Seedless as female parent. For these crosses, Ruby Seedless × Muscat, Melissa Seedless × Muscat, Perlette × Muscat, the suitable sampling times were gained at 59~60 days, 54 days and 52 days after pollination (DAP), respectively. (5) Embryo abortive time of Crimson Seedless × Muscat kyoho and Fantasy Seedless × Kunxiang Seedless were considered at 39 days and 48 days after pollination (DAP), respectively. Cotyledonshape embryo accounted for the highest seedling rate. Besides the percentage of abnormal embryo was found a significant increase with the extension of the culture time. So the research suggests that ovule culture time should be controlled in 8-10 weeks.

Abstract:The full length cDNA of the key ratelimiting enzyme gene CsNCED2 (9cisepoxycarotenoid dioxygenase, NCED) in the ABA synthesis pathway was cloned by RTPCR from the leaves of tea cultivar ‘Tieguanyin’ in this study. The full length cDNA was 1 931 bp with an ORF of 1 821 bp, encoding 606 amino acids with 78% homologous of the NCED2 from Vitis vinifera, named as CsNCED2. Amino acid sequence analysis showed that CsNCED2 contains three conserved domain FLNO2258, MIAHPKxDP and HDFAITE, being the characteristic feature of NCED gene families. It possessed four conserved histidine residues requiring Fe²⁺ binding site and Nterminal chloroplast targeting transit peptides. Quantitative PCR analysis showed that the expression of CsNCED2 was highly in leaf, stem and flower. White and Oolong tea processing procedure could significantly upregulate the expression of CsNCED2. The expression of CsNCED2 was significant upregulate under the treatment of ABA and cold, but repressed by drought. In conclusion, CsNCED2 might play an important role in the ABA synthesis metabolism and the responses to different stress in tea plant.

Abstract:In this study, ‘Baguazhou Shuiqin’ and the purplepetiole mutant ‘Nanxuan Baguazhou Zishuiqin’ were used as plant materials. A gene encoding cinnamyl alcohol dehydrogenase（CAD） was cloned from the cDNA of ‘Nanxuan Baguazhou Zishuiqin’ by RTPCR method and designated as OjCAD. The OjCAD gene contained a fulllength open reading frame of 1 074 bp, which encoded 357 amino acids. The relative molecular mass and theoretical isoelectric point of OjCAD protein was 39 143.10 and 6.91, respectively. The protein encoded by OjCAD is a member of MDR superfamily. The protein belonged to hydrophobic protein and its tertiary structure included 7 αhelix and 17 βturn. Alignments and phylogeneticanalysis indicated that OjCAD was highly conserved and had the closest phylogenetic relationships with the CAD protein from Daucus carota. Quantitative realtime PCR analysis demonstrated that the relative expression levels of OjCAD gene in leaf blades and petioles of purple and nonpurple Oenanthe javanica were different. The relative expression levels of OjCAD gene in leaf blades were higher than that in petioles. The relative expression levels of OjCAD gene in ‘Baguazhou Shuiqin’ were higher than that in ‘Nanxuan Baguazhou Zishuiqin’. Those results provided a basis for further research on the lignin biosynthesis in O. javanica.

Abstract:This study was based on the soybean genome database. According to the amino acid sequence of Arabidopsis thaliana ABI4 protein, we obtained two GmABI4 genes in soybean genome and named GmABI41 (GenBank accession number XM_014766551.1) and GmABI42 (GenBank accession number NM_001249003), respectively. The TMHMM software and phylogenetic analysis showed that the proteins encoded by these two genes had no signal peptides, and their secondary structures mainly consisted of extended strand and random coil. Phylogenetic analysis revealed that soybean GmABI4 was closely related to that of wild soybean. The results of real time quantitative PCR analysis showed that the expression levels of GmABI41 and GmABI42 in seeds and soybean meal were higher than those in roots, stems, leaves, flowers and other tissues, which suggest that GmABI4 is probably involved in seed biology.

Abstract:The study of gene function in Phalaenopsis aphrodite is hampered by the low efficiency of transformation systems and the long time span needed for the generation of transgenic plants. Therefore，the establishment of transient expression system of Phalaenopsis aphrodite petals will be an effective method for gene function analysis. An experiment was conducted to investigate the transient expression mediated by Agrobacterium tumefaciens using the sepals and petals of Phalaenopsis aphrodite （P. ‘Big chili’）. Effects of A. tumefaciens concentration，infection time，acetosyringone concentration，and coculture length on the transient expression of βglucuronidase（GUS）gene were analyzed to determine the optimal transformation condition. The chalcone synthetase gene RNAi interference vector was transiently transformed into the petals of Phalaenopsis aphrodite. After 3 days of cocultivation, changes in the phenotype and pigmentation of the flower color were observed，and RTPCR was used to detect the expression level of CHS gene transcription. （1）A higher transient expression level of GUS gene could be obtained as OD₆₀₀ value of A. tumefaciens 0.6，infiltrating for 60 seconds，adding 150 μmol/L acetosyringone to coculture medium，and coculture for 3 days in darkness. It reaches 85.01%. （2）The color of the petals of transgenic Phalaenopsis aphrodite was significantly lighter and pigment content decreased. （3）Semiquantitative PCR showed that the transcriptional activity of CHS gene was significantly lower than that of the control group. The experiment successfully established a rapid gene function verification method，providing technical support for the study of gene function and breeding work of the Phalaenopsis aphrodite.

Abstract:To advance barley research, we produced a TILLING (Targeting Induced Local Lesions IN Genomes) population of the sixrowed barley cultivar ‘Xiyin2’. Through ethyl methane sulfonate(EMS) mutagenesis treatment, we established a 3 750 mutagenised M₁ population and a 2 012 mutagenised M₂ population. Totally phenotypic variations in 17.35% of the M₂ population were observed. In which 115 lines showed chlorosis, 98 lines showed dwarfing, 101 lines showed very early/late flowering, and others 35 lines showed less tilling, small leaves, or produced no seeds. Likewise, genomic DNA was extracted from the M₂ lines for studying the mutation frequency. The estimated mutation frequency was one mutation per 661 kb by CELⅠbased screening, it is the same range as the previously studies. During our investigation, 3 different mutations in the EDR1 (AF305912) gene were identified, among which the Pro to Ser transition happened in extron region. The ‘Xiyin2’ TILLING population will be an important resource in the development of barley with specific characters.

Abstract:In this study, genetic diversity of Corydalis yanhusuo W.T.Wang was analyzed with SSR molecular markers, twelve pairs of primers with high polymorphism and good stability were screened for population genetic analysis for 360 individuals sampled from 19 populations. The results showed that: (1) a total of 227 polymorphic loci were amplified from 12 pairs of SSR primers, 4-9 alleles were detected and average of 5.25 per primer, which showed the primer pairs were of abundant polymorphism and could be used to analyze the genetic diversity of C. yanhusuo. The study revealed that the genetic diversity among the population groups was high (N_a = 5.25, I = 1.192 6, H = 0.387 9), the degree of genetic differentiation was high (F_st = 0.388 3), and the gene flow among species was limited (N_m = 0.393 8). (2) The results of cluster analysis used by both UPGMA and Bayes method showed that 19 populations obviously clustered into 4 branches. The result of Mantle test (r = 0.326, P = 0.01) indicated the population with shorter geographical distance performed tighter genetic relationship. The genetic structure of C. yanhusuo may be resulted from its predominantly selfing breeding system, clonal growth, geographic isolation and limited gene flow. In situ conservation should be accepted in its protection considering its genetic structure.

Abstract:Bougainvillea spectabilis Willd., whose bracts are colorful and petallike, has been widely used in landscape gardening. In order to further understand the evolutionary mechanism of petallike bracts, we used RNAseq technology to sequence transcritomes in bracts and leaves, respectively, and compared the bracts and leaves at the level of gene expression. In total, 55 782 Unigenes with an average length of 1 003.79 bp and an N50 of 1 402 bp were de novo assembled from 54.48 M bidirectional clean reads of 150 bp in length. There were 30 874 Unigenes successfully annotated to the public database, of which 12 631 Unigenes can be annotated to Gene Ontology. Differential expression analysis identified a total of 456 differentially expressed genes (DEGs) between bract and leaf. The GO enrichment analysis and KEGG enrichment analysis of differentially expressed genes in different tissues showed that: (1) the DEGS highly expressed in bracts contained flavonoidrelated genes, a key enzyme in flower color synthesis (DODA), and genes related to the development of petals; (2) The DEGs highly expressed in leaves were mainly involved in photosynthesis.

Abstract:The stomatal characters of dominant grassland species in the Tibetan Plateau and Inner Mongolia Plateau were investigated by using plant microtechniques. We aimed to disentangle the stomatal characters and their relationships with environmental factors and reveal the adaptation strategies in two types of stomatal apparatus, which are composed of kidneyshaped and dumbbellshaped guard cells. The results showed: (1) the coefficient of variation of stomatal characters of dumbbellshaped stomatal apparatus was smaller than that of kidneyshaped stomatal apparatus. (2) The relationships between stomatal characters of dumbbellshaped stomatal apparatus and environmental factors were weaker than that of kidneyshaped stomatal apparatus. (3) The environmental factors showed different effects on the adaxial and abaxial stomatal characters in dumbbellshaped stomatal apparatus, while in kidneyshaped stomatal apparatus there were no different effects on the adaxial and abaxial stomatal characters. (4) The stomatal characters were closely correlated to precipitation in dumbbellshaped stomatal apparatus, while in kidneyshaped stomatal apparatus they were closely correlated to temperature. (5) The stomatal characters of the same stomata had significant differences in the two regions (Tibetan and Inner Mongolia Plateau). We came to the conclusion that there were significant differences in stomatal characters and the relationships with environmental factors between kidneyshaped and dumbbellshaped stomatal apparatus. The results indicate that it is necessary to distinguish the types of stomata when analyzing stomatal characters, and will be helpful for further understanding the adaptation strategies of leaf stomatal characters of grassland plants in China under the background of global climate change.

Abstract:Cibotium barometz (L.) J. Sm., an important taxa of the rare ornamental ferns, is listed in the Category II of State Key Protected Wild Plants. In present study, spores were used as materials to investigate the effects of different environmental factors (cultivation density, exogenous gibberellin, light quality) on the sex differentiation of C. barometz gametophytes, which could provide technical support for artificial propagation of C. barometz and study on sex determination mechanism of fern gametophytes. The results showed that: (1) The low density of cultivation (1 individual /cm², 5 individuals /cm²) is beneficial for the formation of archegonia and female gametophytes. With cultivation density increasing, number of archegonia per gametophyte and rate of female gametophyte decreased, in the meantime, number of antheridia per gametophyte and rate of male and hermaphroditic gametophyte increased, but excessive cultivation density (80 individuals /cm²) resulted in a mass of asexual gametophytes. (2) With the cultivation time prolonging, the rate of hermaphroditic gametophyte increased in the different cultivation density. (3) Exogenous gibberellin A₄ (GA₄) significantly suppressed the formation of archegonia and female gametophytes, and promoted the formation of antheridia and male gametophytes. However, exogenous gibberellin A₃ (GA₃) had no significant effect on the sex differentiation of C. barometz gametophytes. (4) Light quality (white, red, blue) had no significant effect on the sex differentiation of C. barometz gametophytes, but had some effect on gametophyte development and morphogenesis.

Abstract:Pollen morphology has a certain conservation, so it is often used as a classification basis for plant resources. The observation of citrus pollen morphology can provide some references for citrus classification. The pollen of 28 citrus materials were observed by FEI Quanta 200 field emission scanning electron microscopy including Guoposhan wild Zhoupigan and Yuanju. The morphological characteristics of pollen equatorial view, polar view and exine ornamentation were analyzed by the SPSS and NTsys software. And then analyze their genetic relationship, and reveal their classification status and system evolution relationship. The results showed that the pollen of Zhoupigan and Yuanju is 4colpate type. (1) Both of their pollens are medium size and Zhoupigan is slightly bigger. The pollen of equatorial axis of Zhoupigan is (35.24±1.94)μm, the polar axis is (20.39±1.35)μm. The pollen of equatorial axis of Yuanju is (30.21±1.14)μm, the polar axis is (22.12±1.97)μm. (2) Their exine ornamentation is different, Zhoupigan has irregular circular or polygonal pollen mesh, but the pollen mesh of Yuanju is round or roughly round. The mesh size of Zhoupigan is (1.65±0.09) μm and the width of mesh ridge is (0.51±0.10)μm. The width of mesh ridge of wild citrus of Yuanju is (0.47±0.09)μm and the mesh size is (0.86±0.08)μm. (3) The results of cluster analysis showed that 28 tested materials were divided into 9 groups at genetic distance of 0.827, among which Guposhan wild Zhoupigan in group Ⅸ alone and clustered with group Ⅷ at genetic distance of 0.976 ［C. mangshanensis (pointed leaves) and C. mangshanensis (round leaves)］; Yuanju and 10 of them were clustered into group Ⅴ and Cenxisuanju at genetic distance of 0.07, and C. reshni at genetic distance of 0.10. It speculates that the pollen morphology of Zhoupigan is similar to that of the C. mangshanensis. While the pollen morphology of Yuanju is similar to that of C. reshni and Cenxisuanju. According to cluster analysis, it is speculated that there are certain phylogenetic relationships between the Zhoupigan and C. mangshanensis, and has primitiveness uniqueness. C. mangshanensis (Guoposhan wild Zhoupigan) is supposed to be an independent and true species within the genus citrus, or it is a separate genus other than Poncirus, Fortunella Swing and Citrus L.. The wild citrus of Yuanju and Cenxisuanju, C. reshni have a certain genetic relationship.From the original analysis of pollen morphology, it is inferred that Yuanju is more primitive than C. daoxianensis and C.tachibana.

Abstract:With three 3yearold cutting seedlings of Euonymus europaea（E. europaea ‘Pumilis’， E. europaea ‘Aldenhamensis’， E. europaea ‘Albus’）varieties as test materials, changes of leaf color parameters and various physiological indicators were measured during the colorchanging period in autumn and winter. The relationships between pigment and leaf color parameters, soluble sugar, and related enzymes during the color change were analyzed. The mechanism of leaf color development during the color transformation period of Euonymus europaea was discussed to provide a basis for the application of garden in the later period. The results showed: （1） during the color change, the value of L^* and b^* of ‘Aldenhamensis’ and ‘Albus’ presented a single peak curve that rose firstly and then fell. The value of L^* and b^* of ‘Pumilis’ presented a single peak curve that drops firstly and then rises. The value of a^* of three varieties rose continuously. （2） Chlorophyll showed a decreasing trend as a whole, mainly due to a decrease in chlorophyll a. Chlorophyll b and carotenoids decreased more steadily; Anthocyanin content and anthocyanin/chlorophyll ratio were on the rise. Carotenoid/chlorophyll ratio showed a decreasing trend as a whole. （3） Soluble sugar mass fraction showed a single peak curve that rose firstly and then fell; The activity of PAL in three varieties showed a rising trend; POD activity showed a downward trend; PPO activity is slowly rising. （4） The correlation analysis showed: The leaf color parameters a^* value and anthocyanin content of three varieties were both presented extremely significantly positive correlation. Anthocyanin was significantly negative correlation with chlorophyll and carotenoids in ‘Pumilis’. Anthocyanin was no significantly negative correlation with chlorophyll and carotenoids in ‘Aldenhamensis’ and ‘Albus’. All in all, the main factors that affect the changes of leaves during the colorchanging period in autumn and winter in Euonymus europaea were the contents of chlorophyll, anthocyanin, soluble sugar and the activities of PAL and PPO. The content of carotenoid had minor effects while the POD activity had no direct effects.

Abstract:Hydroponic experiments were carried out to study the effects of exogenous salicylic acid (SA, 0-2.0 mmol·L^-1) on the metabolic mechanism of proline in Jatropha curcas seedlings under salt stress (200 mmol·L^-1 NaCl). Seedlings of J. curcas under salt stress were treated with SA, and the content of proline, the activities of the key enzymes of proline metabolism as well as the expression of proline metabolismrelated genes in leaves of J. curcas seedlings were measured. The results showed that: (1) the exogenous SA (0.9 mmol·L^-1) treatment led to a significant accumulation of proline in J. curcas seedlings under salt stress. It also induced almost immediate and rapid increase of activities of the key enzymes Δ¹pyrroline5carboxylate synthetase (P5CS) and ornithine aminotransferase (OAT) of proline biosynthesis, and upregulated JcP5CS and JcOAT expression. (2) SA decreased the activity of proline dehydrogenase (ProDH), a key enzyme of proline degradation, and inhibited JcProDH expression. (3) The SA treatment also increased tissue vitality, decreased the content of the lipid peroxidation product malondialdehyde (MDA), and alleviated electrolyte leakage in J. curcas seedlings under salt stress. These results showed that the SAinduced proline accumulation in the J. curcas seedlings under salt stress might be a combined result of the activation of glutamate and ornithine pathways of proline biosynthesis and the simultaneous inhibition of the proline degradation pathway. In addition, exogenous SA treatment can enhance salt tolerance in J. curcas seedlings, and proline might be a key factor in this increased salt tolerance.

Abstract:We carried out a hydroponic experiment to study the effects of silicon (Si) on the growth, Cd content, nutrient absorption, photosynthetic characteristics and antioxidant enzymes activities of two cabbage (Brassica oleracea L.) cultivars with different Cdtolerancers (Cdtolerant ‘Niuxin’ and Cdsensitive ‘Lüfeng’) under Cd stress in order to reveal the alleviation mechanism of exogenous Si in cabbage under Cd stress. The results showed that: (1) Under the stress of Cd, the growth, contents of nutrients (Mg, Fe, Mn, Cu), the activities of antioxidant enzymes (SOD, CAT, APX) and photosynthesis efficiency of leaves in plants were decreased significantly, while the malondialdehyde (MDA) content in leaves and roots of cabbages were increased significantly compared with the control. (2) Supply of exogenous Si under Cd stress promoted the biomass of plants, raised the nutrition element contents in shoots and increased the photosynthetic parameters (P_n, G_s, T_r), fluorescence parameters (F_v/F_m, Φ_PSⅡ, qP) and photosynthetic pigment contents. At the same time, MDA contents in plants and the transportation of Cd from roots to shoots were reduced significantly. It is suggested that Si can alleviate toxic effects of Cd by reducing the accumulation of Cd in shoots, increasing the activities of antioxidant enzymes to reduce membrane lipid peroxidation, promoting nutrient absorption and transportation, and enhancing photosynthesis.

Abstract:Taking the seedlings of Stachys lanata as test materials, and the normal water supply as control, we studied the influence of different water stress(waterflooding, waterlogging, moderate drought and severe drought) on the morphological and physiological indexes. The results showed that: (1) under waterflooding treatment for three days, the leaves gradually necrosis and root died, but adventitious roots germinated at the base of stem. Under waterlogging treatment, there was no obvious change in the aboveground state, and there were some brownish root tips in the root system. Leaves wilted under drought treatment for seven days, and the degree of leaf wilting in severe drought treatment was higher than that in moderate drought treatment. After relief, except that waterflooding treatment resumed growth on the 13th day, the other treatments plants returned to normal growth on the second day. (2) The relative water content in leaf and root vitality both decreased under the waterflooding, but no significant changes were found in waterlogging, while the former decreased rapidly and the latter increased in drought treatment. (3) Under the conditions of water stress, the relative conductance and MDA content in leaf and root were both significantly higher than that of the control. The damage of the root was more serious than that of the leaf, and the damage of waterflooding stress was the most serious. (4) Under the waterflooding treatment, the contents of soluble protein decreased, soluble sugar and free proline accumulated continuously with the extension of stress time, the content of soluble sugar, soluble protein and free proline in leaf and root under waterlogging and drought treatment all increased. It can be seen that S. lanata had strong osmotic adjustment ability. After the release of waterlogging and drought stress, the damage of membrane peroxidation was alleviated rapidly and then return to normal growth. Although S. lanata could not lived under waterflooding for long time, but could normally growth under waterlogging, while had a good tolerance to drought stress. So, it could be used in the regions where the water content changes greatly in the waterfront drop zone and so on.

Abstract:The effects of shading on the chlorophyll content, dry weight, dry weight ratio anthocyanin content, soluble sugar content and CmUFGT expression level in flowers were studied with Chrysanthemum cultivars ‘Zichonglou’ at different flower developmental stages. The results showed that: (1) shading at visible flower bud stage and visible flower color stage, Chl a and Chl b contents increased gradually with the decrease of light intensity; Chl a and Chl b contents of L3 treatment were significantly higher than that of other treatments. While Chl a and Chl b contents were first rose and then dropped with the decrease of light intensity under shading at fullbloom stage; Chl a and Chl b contents of L1 treatment were significantly higher than that of other treatments. (2) With the decrease of light intensity, the dry weight of inflorescence decreased, and the dry weight ratio increased firstly and then decreased; The dry weight ratio of L1 treatment increased. (3) Shading at visible flower bud stage and visible flower color stage, the anthocyanin content was increased firstly and then decreased following flower inflorescence development, while the anthocyanin content was decreased under shading at fullbloom stage; In the third and fourth stages of inflorescence development, anthocyanin content increased when the light increased; In the seventh and eighth stages, anthocyanin content was increased when the light decreased. (4) Following flower inflorescence development, the content of soluble sugar under shading increased initially and then decreased; The content of soluble sugar increased in L1 treatment. (5) Shading significantly inhibited the expression of CmUFGT at the fifth stage of inflorescence development, and its expression decreased gradually with the decrease of light intensity; The expression of CmUFGT reduced in the third and fourth stages in L1 treatment at visible flower bud stage and visible flower color stage. It has been concluded that following the flower inflorescence development under the mild shading (L1) inhibits the expression of CmUFGT, promotes the increase of soluble sugar content and the synthesis of anthocyanin at middle stages (the third, fourth stage); the severe shading (L3) alleviates the degradation of anthocyanin at the late stages (the seventh, eighth stage).

Abstract:Peony (Paeonia lactiflora Pall.) seeds stored for one or two years and newly harvested seeds were used as experiment materials. The seeds were treated with low temperature (-20 ℃ or -40 ℃) and then stored in the sand for elucidating the methods for promoting rooting process. Physiological and biochemical indexes were analyzed during different rooting stages for investigating the internal mechanisms. The results showed: (1) Oneway analysis of variance showed storage years, treatment temperature and treatment time length performed obviously significant main effects together or independently on rooting index, rooting rate and firstseed rooting time of peony seeds, and storage years performed strongest influence. (2) For peony seeds stored in the same year, treatment of -40 ℃ treatment for 30 days before sand storage performed the best rooting efficiency with the highest rooting rates of 88.33%. When under the same treatments, the rooting efficiency of oneyearstorage peony seeds is better than those of other storage time length. (3) Physiological and biochemical analysis showed that during the seed rooting process, for the peony seeds stored for the same time length, the water content kept raising, the soluble sugar content increased first and then decreased, the starch content kept decreasing, the soluble protein content decreased first and then increased; peroxidase (POD) activity increased first and then decreased, catalase (CAT) activity decreased after an increase. Conclusion: the treatment of -40 ℃ for 30 days can effectively break the dormancy of Paeonia lactiflora Pall. seeds and promote the rooting process, and oneyearstorage seeds performed the best rooting efficiency.

Abstract:Leguminous and nonlegume tree mixed system, as a sustainable development model for artificial forest cultivation, which plays an important role in ensuring timber yield and maintaining nitrogen balance. A pot experiment in greenhouse was conducted to investigate effects of different N fertilizer and root barriers on the seedling growth, leaf physiological, root morphology and biomass of E. urophylla and D. odorifera intercropping system. The experimental designs included three nitrogen fertilization levels of 0, 3 and 6·g N per tree and three root barrier patterns including no barrier, nylon barrier and plastic barrier. The results showed as follows: (1) seedling height and ground diameter of E. urophylla and D. odorifera presented an increasing trend with the increase of nitrogen application. Under different root barrier patterns, the seedling height of E. urophylla and ground diameter were the best without barrier, while D. odorifera grew much better under the model of the plastic barrier. (2) When compared to the non N treatment, the content of leaf superoxide dismutase (SOD) activity, peroxidase (POD) activity and soluble protein content for each species relatively increased, but the content of malonaldehyde (MDA) declined. (3) The total root length, total root surface area, total root volume, mean diameter, root tip and specific root length of E. urophylla and D. odorifera increased by applying nitrogenous fertilizers, and differed from each other significantly. Under the same nitrogen level, the root growth of E. urophylla was no barrier > nylon barrier > plastic barrier, while root growth of D. odorifera exhibited plastic barrier > no barrier > nylon barrier, and under different root barrier patterns the growth between both species was significant different. (4) The level of nitrogen, was resposible to the biomass of various organs and total biomass of E. urophylla and D. odorifera. and reached its maximum when the nitrogen level was 6 g N per plant. Among the biomass allocation of various organs, the proportion of biomass of each organ for E. urophylla was stem (40.59%) > leaf (32.37%) > root (27.04%), for D. odorifera was root (47.67%) > stem (40.08%) > leaf (12.25%). These results showed that E. urophylla and D. odorifera mixed system expanded the root horizontal and longitudinal level of nutrient ecological niche, and enlarged the space for root absorption of soil nutrients. At the same time, the root interaction enhanced the nitrogen fixation ability of D. odorifera, and it had a great impact on the production of soil available nitrogen.

Abstract:In order to ascertain the mechanism of nitrogen levels on the photosynthetic system in different tea varieties, we investigated the growth vigor, chlorophyll content, photosynthetic rate and chlorophyll fluorescence parameters in three tea varieties（Fuding dabai tea, Baojing huangjin tea No.1 and Baihaozao) by the pot experiment under nitrogen stress ［(control: N₀(0 g), low nitrogen: N₁(11 g), suitable nitrogen:N₂(22), high nitrogen: N₃(33 g)］. Results showed that：（1） Nitrogen application significantly promoted tea growth, and the chlorophyll content, net photosynthetic rate (P_n), stomatal conductance (G_s), transpiration rate (T_r) increased after nitrogen application, while the intercellular CO₂ concentration (C_i) decreased, of which N₂ treatment had the greatest impact to them. The variation trends of water use efficiency (WUE) in 3 tea varieties were different with each other. （2）After treated with N₂, the primary maximum photochemical efficiency of PSⅡ(F_v/F_m), photochemical quenching coefficient (qP) and the relative electron transport rate of PSⅡ(rETR) also increased most in three varieties, while the nonphotochemical quenching coefficient (NPQ) decreased. (3) The results indicated that there was a correlation between the chlorophyll content and photosynthetic parameters in tea leaves, and it represented a variety specificity between them. In conclusion, nitrogen application could increase the chlorophyll content, G_s and qP, and enhance net photosynthetic rate. Compared with control, the photosynthetic characteristics, chlorophyll fluorescence parameters and WUE showed different characteristics in tea varieties under different nitrogen levels. It indicates that we can rapidly evaluate the needs of nitrogen nutrition in tea plants based on the chlorophyll content, photosynthetic characteristics and chlorophyll fluorescence parameters, and provide guidance for the management of tea plantation.

Abstract:The study aimed to explore the effect of deepfurrow planting pattern on photosynthetic efficiency of grape in the northwest arid region. The effects of deepfurrow planting pattern on the rhizosphere soil moisture and photosynthetic efficiency were studied with flatfurrow planting pattern as control using the table grape types of ‘Jingya’ and ‘Red globe’ as testing materials.The results showed: (1) under drought stress, the rhizosphere soil relative water content, net photosynthetic rate (P_n), stomatal conductance (G_s),Intercellular CO₂ concentratio (C_i), transpiration rate (T_r) and water utilization efficiency (WUE) of grapevine in both deepfurrow planting and flatfurrow planting continued to drop; However, the rhizosphere soil relative water content and WUE under deepfurrow planting dropped at a slower rate than those under flatfurrow planting. In addition, during severe drought (towards the later part of drought stress), the rhizosphere soil relative water content and WUE under deepfurrow planting were significantly higher than those under flatfurrow planting. (2) Based on a logistic model, curve fitting was performed for the correlation between the soil relative water content to P_n, Cond, C_i, and T_r, and the following was revealed: relative water contents of 30%-50% and 40%-60% were the two ranges that significantly affected the photosynthetic efficiency in grapevines under deepfurrow planting and flatfurrow planting, respectively. (3) The inflection point of the logistic equation was defined as the soil moisture threshold. The rhizosphere soil moisture threshold was the point of highest efficiency in water utilization and photosynthesis for grapevine. Test results showed that the threshold of rhizosphere soil moisture in deepfurrow planting and flatfurrow planting were 41.76% and 52.60%, respectively. The above results apparently showed that under drought stress when compared with flatfurrow planting, water loss in rhizosphere soil could be effectively reduced in grapevines planted in deep furrow so that the WUE was higher in photosynthesis taking place in grapevines and higher photosynthesis efficiency could be achieved even when soil moisture was lower. Thus, deepfurrow planting is an ideal droughtresistant planting pattern for cultivating grapes in arid areas. In deepfurrow planting, the test results suggested that the rhizosphere soil relative water content of 43.43% and 40.19% were the most effective soil moisture that generated the highest WUE during photosynthesis in the leaves of ‘Jingya’ and ‘Red Globe’, respectively; the appropriate soil moisture range for ‘Jingya’ and ‘Red Globe’ were 43.32%-50% and 40.19%-50%, respectively.

Abstract:In order to study the effect of Laccaria bicolor on the growth and root morphology of Pinus thunbergii seedlings, we inoculated the seedlings of P. thunbergii with liquid fungus of L. bicolor in nutrition cup. We compared the differences of biomass, root morphology and root fractal dimension between inoculated and uninoculated P. thunbergii seedlings. The results showed that the L. bicolor showed obvious promotion effect on growth and biomass accumulation of underground roots and aboveground plants of P. thunbergii seedlings. Inoculation of L. bicolor also significantly improved the total root length, forks, root surface area, root volume and root fractal dimension. Moreover, its promoting effect on the growth of underground roots was earlier than that of the aboveground part, and the effect was significantly higher than that of the aboveground part. 15-30 days after the inoculation, L. bicolor had no effect on the aboveground part, but it had obvious promotion effect on the root system. However, the aboveground part began to show significant growth response on the 60th day. In summary, the L. bicolor can colonize the root of P. thunbergii successfully, promote the growth of seedlings and the accumulation of biomass, increase the total length, forks, surface area and volume of root system, and increase the fractal dimension of root system. It showed obvious promoting effect on root development, and the promoting effect was earlier befor the aboveground part growth.

Abstract:The research investigated the main distribution areas of the population of Acer catalpifolium, a precious and endangering plant in Sichuan Province, and analyzed the relationship between the diameter structure and the intraspecific and interspecific competition of the population, and explored the relationship about competition intensity, diameter and distance. The results show: (1) there is a significant power function relationship between A. catalpifolium diameter and height. The diameter class structure of the population is normally distributed. There are many trees at middle and small diameters and fewer trees at higher and higher diameters. (2) The intraspecific and interspecific competition intensity of the A. catalpifolium accounting for 15.16% and 84.84% of the total competition intensity (222.87), respectively, indicating that the competition mainly comes from the interspecies. (3) The competition intensity between A. catalpifolium and its main associated species was in order of Cryptomeria fortunei > Phoebe zhennan > Quercus fabri > Kalopanax septemlobus > Bothrocaryum controversum > Betula platyphylla > Cunninghamia lanceolata > Magnolia officinalis > Betula luminifera. The target trees and competitors distance and competition index are well subject to the exponential function relationship; When the distance between the target trees and competitors is less than 1 m, the competition index can reach 5.5; with the gradual increase of the distance, its competition index decrease accordingly and eventually tends to be flat. (4) The competition intensity decreased with the increase of the diameter of the target. When the diameter of the target is less than 20 cm, the competition pressure is the greatest, and the competition index is the largest among the A. catalpifolium and the entire forest (234.98) and the A. catalpifolium and interspecific (184.01); When the target diameter is less than 10 cm, the competition index can reach 18; when the target diameter is larger than 20 cm, the competition intensity changes little and the competition index is lower; the competition intensity and the target trees diameter obey the power function relationship (CI=AD^-B). (5) The model prediction results show that with the increase of the A. catalpifolium diameter, the competition index is getting smaller and smaller, and the competition intensity is decreasing. When the A. catalpifolium diameter is 0 to 5 cm, the competition intensity between A. catalpifolium and the entire forest is the highest, and the competition index was 7.14, accounting for 50% of the total competition intensity. When the diameter is greater than 20 cm, the competition index has changed little. This model can predict perfectly the intraspecific and interspecific competition intensity of A. catalpifolium.

Abstract:Based on the southwest direction of 20 plots in the Dabashan National Nature Reserve, we used hierarchical cluster analysis, species importance values, species richness, intensity of flora differentiation and α, β diversity index to study the distribution of vascular plant species diversity in Reserve along the altitudinal gradient. The results showed that: (1) there were 335 species vascular plants in the 20 studied plots, which belonged to 97 families and 226 genera. The total number of plant families, genera, and species increased first and then decreased with altitude. (2) Plant communities differed significantly in vertical gradients. Comprehensive community growth and hierarchical clustering analysis results showed that the forest communities could be classified into four types, including those the vertical vegetation spectrum was evergreen broadleaved forest and warm coniferous and deciduous mixed forest (below 1 000 m a.s.l.), mixed deciduous and evergreen broadleaved forest (1 000-1 600 m a.s.l.), warm and humid coniferous and deciduous mixed forest (1 600-2 100 m a.s.l.), and subalpine coniferous forest (above 2 100 m a.s.l.). (3) The α diversity index changed vertically. Simpson and Pielou indexes varied less with altitude, The ShannonWiener index of tree layer changed more obviously with the altitude gradient, and decreased with elevation. Mixed forest types had relatively higher α diversity and more intensive flora differentiation than the other types. (4) The β diversity index fluctuated considerably in the low altitude section, the change in Cody index pattern showed a gradual trend of tree layerthe heterogeneity of species between adjacent communities gradually decreased, the species turnover rate decreased and eventually reach to a relatively stable state.