Abstract:In the present study,a vector of pAN580-PpCAD was constructed based on the cDNA sequence of PpCAD gene from elephant grass (Pennisetum purpureum cv.Huanan),and transformed to elephant grass protoplasts by PEG-mediated method,attempting to figure out the subcellular localization of PpCAD protein.At the same time,the sense vector pBA002-PpCAD was constucted and overexpressed in tobacco by Agrobacterium-mediated method,aiming to study the relationship between PpCAD and plant lignin biosynthesis.The results showed that:(1)PpCAD was located in the cytoplasm of elephant grass protoplasts.(2)27 transgenic tobacco plants were obtained after transformed with overexpression vector pBA002-PpCAD,of which,25 plants were identified positive by PCR.(3)The expression levels of 6 transgenic plants were different after analyzed by semiquantitative RT-PCR.The Southern blot indicated the expression level was related to the insert copy number of target gene.(4)There was no obvious phenotype difference between PpCAD overexpressed plants and wild type,but the lignin contents were increased in varying degrees among 6 transgenic plants except OEC6.Compared with wild type,the maxium amplification rate of lignin content was 56.50%.This study demonstated that PpCAD was a cytoplasmic protein.Overexpression of PpCAD in tobacco would lead to a increase of lignin content,which indicated that PpCAD was involve in plant lignin biosynthesis and it could be available for regulation of elephant grass lignin biosynthesis.

Abstract:The synthesis of pathogenesis-related proteins (PR) is one prominent feature of plant defense responses on abiotic or non-abiotic stress situations.According to the transcriptome data of Salvia miltiorrhiza,designing specific primers and using reverse transcription-polymerase chain reaction (RT-PCR),we isolated an open reading frame of pathogenesis-related protein 10 (PR10) from S.miltiorrhiza and named as SmPR10-1 (GenBank Accession No.KF877034).The results indicated that:(1)SmPR10-1 has an open reading frame (ORF) of 477 bp,which encoded a protein of 158 amino acid residues,with a predicted molecular mass of 17.38 kD.(2)Bioinformatic analysis indicated that SmPR10-1 protein showed the highest homology,69% identity,with PR10 protein from Vitis vinifera with the same conserved sequence (G-X-G-G-X-G) and (K-A-X-E-X-Y).(3)Escherichia coli BL21 cells were transformed with the expression vector pET32a-SmPR10-1 and used for prokaryotic expression.Meanwhile,the four factors,inducing IPTG concentrations,initial density of host bacterium (A₆₀₀),inducing temperature and inducing time,which influenced protein expression,were optimized.The optimum expression conditions of SmPR10-1 were final IPTG concentration of 0.4 mmol/L,A₆₀₀ of 0.8,and the inducing time of 8 h at 30 ℃.Finally,the recombinant SmPR10-1 protein was purified through Ni²⁺ affinity chromatography.The results of this study provided not only the first and fundamental information about SmPR10-1 gene,but also a candidate gene for future genetic engineering of Chinese medical herbs,S.miltiorrhiza,against pathogen attack.

Abstract:A Gossypium hirsutum phospholipase C (GhPLC,GenBank Accession Number:KR154219) gene was cloned using RT-PCR method from developing ovule and fiber tissues,and the function of lipid metabolism was analyzed through transforming GhPLC into Arabidopsis.Sequencing identification showed that the full open reading frame of GhPLC was 1 524 bp containing a protein of 508 amino acids with a theoretical molecular weight of 55 kD.Sequence alignment analysis displayed that GhPLC gene belongs to the classical alkaline phosphatase superfamily.The recombinant proteins of GhPLC was obtained with molecular weight of 55 kD by prokaryotic expression of pET32a-GhPLC.Enzyme activity determination showed that recombinant GhPLC proteins has high activity of catalyzing phosphatidylcholine (PC) to diacylglycerol (DAG).Semi-quantitative PCR analysis indicated that GhPLC gene participates in cotton seed and fiber development.Plant overexpression vector 35S∷GhPLC was constructed and transformed into Columbia wild-type Arabidopsis.Transgenic GhPLC Arabidopsis showed significant promotion both in transcription and enzyme levels,and the oil content of transgenic Arabidopsis seeds increased with 5.3% higher than wide-type.

Abstract:MADS-box transcription factor plays a crucial role in plant development,especially controlling the formation and development of floral organs.In order to investigate the role of MADS-box transcription factor in mango flower development,we cloned the flower-specific gene from mango inflorescence,named MSOC1 (GeneBank accession no.KP404094) with homology-based cloning and RACE method.The open reading frame of MSOC1 was 733 bps,encoding 223 amino acids with molecular weight 25.6 kD and isoelectric point 8.96.Sequence alignment and phylogenetic tree analysis indicated that the MSOC1 deduced protein contained a conservative MADS-box and semi-conservative K domain and belonged to the SOC1/TM3 subfamily of the MADS-box family.Tissue-specific analysis showed that MSOC1 was expressed in various tissues of mango,high expression in stems,leaves and inflorescences,low expression in roots and flowers.

Abstract:Cloning of Nitrate Reductase Gene of Lettuce and Effect of Exogenous γ-Aminobutyric Acid on Gene Expression and Nitrate Content in Leaves under High Nitrogen Level

Abstract:In this study,Bougainvillea glabra ‘Mrs Butt’ was used to analyze the regulation mechanism of ABA in promoting its flowering promotion.The results showed that:(1)50 mg·L^-1 ABA treatment promotes B.glabra flowering,and 10 μmol·L^-1 NDGA (Nordihydroguaiaretic acid,one kind of ABA biosynthesis inhibitor) treatment inhibited this effect.(2)Exogenous ABA treatment increased the content of endogenous ABA and the enzyme content and activity of nine-cis-epoxy carotenoid dioxygenase (NCED) in B.glabra leaves,and these inductions could be inhibited by NDGA treatment.(3)The full length of cloned NCED gene was 2 380 bp,and the putative encoding protein is 618 aa,which showed the highest homology with FvNCED1 in the strawberry,and was named as BgNCED1.(4)Real-time PCR results showed that the expression of BgNCED1 was significantly induced by ABA treatment,and 10 μmol·L^-1 NDGA could significantly inhibit the induction effect.This expression pattern was similar to the changes of endogenous ABA content and NCED enzyme activity.Therefore,exogenous ABA may enhance endogenous ABA biosynthesis through the induction of BgNCED1 expression,which promoted B.glabra from vegetative growth to reproductive growth,and ultimately make it flowering early.

Abstract:Despite abundant germplasm resources in Southwest China for poplar genetic improvement,the varied species exist tiny difference in morphology and have unknown systematic relationship.Using Populus davidiana as outgroup,the phylogenetic relationship of 36 specimens covering 17 species or hybrids collected from Southwest China and other areas was explored based on sequence data of chloroplast atpF-atpH,trnL-F,matK and nuclear ITS.The results showed that:(1)the ranges of length in atpF-atpH,trnL-F and matK were 605-634 bp,957-1 010 bp and 819 bp respectively,and the combination of 3 chloroplast fragments had 29 variable sites and 15 informative sites,while the aligned length of ITS fragment including 19 variable sites and 17 informative sites was 646 bp.(2)The average genetic distance among all samples of chloroplast combination was 0.001 3 and that of ITS fragment was 0.003 6.Based on chloroplast combination data,the result of MP tree was consistent with that of Bayesian algorithms and both suggested the Populus section Tacamahaca species were divided into 2 clades,of which,clade 1 was formed by P.cathayana,P.trinervis,P.ussuriensis,P.maximowiczii,and the species in clade 2,namely,P.simonii,P.pseudo-simonii,P.szechuanica,P.haoana,P.qamdoensis,P.xiangchengensis,P.kangdingensis,P.schneideri,P.yunnanensis,P.szechuanica var.tibetica,could not be clearly separated and had close relationship with P.ciliata.(3)Although a few differences in phylogenetic tree based on chloroplast combination data,ITS fragment provided that P.pseudo-simonii existed closer affinity with other species in clade 1 (e.g.P.simonii and P.szechuanica) but larger genetic distance with others in clade 2.The results of this study made a understand on the phylogeny of poplar in section Tacamahaca species from Southwest China,and provided a scientific bases for their systematic classification and evolutionary relationship.

Abstract:The genus Dipteronia Oliv.(Aceraceae) is endemic in China which consists of two species:D.sinensis Oliv.and D.dyerana Henry.Dipteronia is one of the woody relic genera in the floristic regions of the northern temperate zone.In this study,we carried out a comparative study of D.sinensis Oliv.and D.dyerana Henry.to explore their degree of differentiation between two species from the aspects of morphology,molecular genetics and gene sequence analysis.(1)Morphological studies indicated that the presence of two species in morphological characters have significant differences.(2)Molecular genetic studies based on the AFLP of genomic DNA markers were also used to analyze the two species.And whether they are in species level or group level,the results showed that there was extremely significant genetic differentiation between the two species(Φ_ST=0.390 4).The level of genetic variation and genetic diversity of the two species have distinct differences(D.sinensis Oliv.＞D.dyerana Henry).(3)We also downloaded several chloroplast genes (psbM-trnD,trnD-trnT,trnL,trnL-trnF,rpl16) and nuclear gene sequences of ITS (ITS1,5.8SRNA,ITS2) of two known species from GenBank to analyze and compare their differentiation.t-test showed a significant difference between the two species occurred in chloroplast gene sequences.Hence,the results of the present study showed that the D.sinensis Oliv.and D.dyerana Henry have a extremely significant differentiation.And we infer the main reasons of the significant differentiation between the two species attributed to the long-term geographic isolation between them.

Abstract:The types,distribution and numbers of glandular hairs on the leaves at the upper,middle and lower nodes of the branches at vegetative and productive stage of Elsholtzia ciliata (Thunb.) Hyland were investigated by means of optical microscopy and scanning electron microscope technology;The process of secreting flavonoids by the glandular hairs were studied based on histochemistry method and fluorescence microscopy.The results showed that:(1)leaf epidermis of E.ciliata possessed peltate and capitate glandular hairs.Mature capitate glandular hair included basal cell,stalk cells and head.The head was small and hemispherical,with a diameter of (20±2) μm. Head of nearly mature peltate glandular hair was large and shield-shaped,with a diameter of (60±5) μm.(2)Glandular hairs distributed in abaxial and adaxial leaf epidermis of E.ciliata.The number of glandular hairs of the adaxial epidermis was more than that of the abaxial epidermis.Peltate glandular hairs were mainly distributed in the abaxial epidermis and capitate hairs were distributed in both sides of the leaves;the density of glandular hairs decreased with the lower of node.At the same node,the density of glandular hairs on the leaf at vegetative growth stage (283.9 per mm²) was higher than that at reproductive growth stage (194.4 per mm²).(3)Flavonoids can be secreted by peltate and capitate glandular hairs.With glandular hair development and maturation,flavonoids accumulated gradually in the head.This study provides a reference for further study on the mechanism of secreting essential oils by the glandular hairs of E.ciliata,and also provides a theoretical basis for determining the best sampling time to extract the flavonoids from the leave of E.ciliata.

Abstract:The anatomical structure and relationship to accumulation with alkaloid in vegetable organs of Dictamnus dasycarpus were studied,with plant anatomy,histochemistry and phytochemistry.The results show that:(1)the structures of perennial root,stem and leaf are in agreement with anatomy of the common dicotyledons.The perennial root consists of periderm,secondary phloem,vascular cambium and secondary xylem,and plenty of starch grains,calcium oxalate cluster crystals,fibers and oil cells are also observed.The stem constitutes epidermis,cortex,vascular tissue and pith.The leaf consists of epidermis,palisade tissue,spongy tissue and vein.The phloem fibers are detected at the location of primary phloem.The capitate glandular hairs and non-glandular hairs are located on the epidermis of stem and leaf,and the secretory cavities distribute in the mesophyll tissue which are closed to the epidermis.(2)Histochemically,the alkaloids are located in the periderm,parenchyma cells of secondary phloem,vascular cambium and parenchyma cells in xylem of perennial root.In stem,the alkaloids are detected in the epidermis,cortex,phloem,parenchyma cells of xylem,parenchyma cells surrounding the pith in stem.In leaf,the alkaloids are in the epidermis,parenchyma cells of the vein and phloem.In addition,the alkaloids are also detected in the secretory cavities and glandular hairs.(3)The HLPC results suggest that the content of dictamnine in Dictamni Cortex,and the xylem,stem and leaf are 0.041%,0.012%,0.004% and 0.002%,and the xylem also shows high content of dictamnine as some other regions.The study suggests that the xylem,stem and leaf are also characterized by certain content of dictamnine,indicating a potential exploitation and utilization value.

Abstract:Transmission electron microscopy and light microscopy are used to view the development of microga-metophyte and sperm in Isoetes sinensis and I.yunguiensis.The results show that:(1)lifetime of microgametophyte in the two quillwort species are only 15-30 d,live in sporoderm all life;(2)male gametophyte are consistes of 1 prothallial cell,1 antheridium wall cell and 4 sperm cells.There are plentiful inclusion in prothallial cell and antheridium wall cell;(3)sperm consists of nucleus,flagellum,microtubular ribbon and cytoplasm;(4)the gemination rate of microspore in I.sinensis is 4.5%,producting average 0.46 sperm per microgametophyte,swimming speed of sperm is 53 μm/s and lifetime of sperm is 8 min.The gemination rate of microspore and production of sperm in I.yunguiensis are higher than that in I.sinensis,but swimming speed and lifetime are lower than that of I.sinensis.The primary reason of endangerment of quillwort in China attributes to the low production rate of spermatozoid limit of reproduction and ecology and water pollution.According to the characteristics of male individual,Isoetes are higher than other Lycophytes.The development pattern of Isoetes male gametophytes was summarized.

Abstract:Aster vestitus Franch.,A.poliothamnus Diels and A.sikuensis W.W.Smith et Farr.comprise Aster Series Vestiti Ling (Asteraceae) whose monophyly was not supported by a new molecular phylogenetic investigation.Karyotypes of four populations of the three species were analyzed by conventional root tip squash method.The results showed that all the three species had a karyotypic formula of 2n=2x=18=14m+4sm(2SAT),while the two populations of A.vestitus belonged to the Stebbins’ 1A karyotype and the other two species to the Stebbins’ 2A.The karyotypic data of A.vestitus and A.sikuensis were reported for the first time and that of A.poliothamnus was quite different from that reported by the only previous related study.The results did not suggest maintaining Ser.Vestiti but support the comment of Li et al.on subgeneric classification.Satellite size of the three species belonged to “Asterinae type”,which supported the opinion that there is no close relationship between Eurasian Aster and North American asters.

Abstract:The karyotypes of 5 types of Xinjiang European plum were studied using traditional squash method.The results showed that:(1)the ploidy levels of tested materials were all hexaploid (2n=6x=48).All tested materials contained different numbers of ‘m’ and ‘sm’ chromosomes.All tested materials contained L,M₂,M₁ and s in total 4 types of relative length index.(2)Arm ratio means of 5 types of European plum ranged from 1.46 to 1.69.Karyotype types of 5 European plum types were all ‘2B’.Asymmetrical karyotype coefficients of 5 types of European plum ranged from 59.13% to 62.34%.In summary,karyotype of European plum in Xinjiang had their common characteristics.There were some differences among different types of European plum in Xinjiang.The karyotype evolutionary trends of European plum in Xinjiang were changed from symmetric to asymmetric in general.On the karyotype characteristic,introduced European plum varieties and Tacheng Binzi had the nearly phylogenetic relationship.However,Tacheng Smoked plum and wild European plum had the nearly phylogenetic relationship.

Abstract:Variation patterns of main taxonomic characters of Berberis sublevis W.W.Smith were investigated by field population sampling in Tengchong County,Yunnan Province,Southwest China,in combination with laboratory observations,checking type specimens,and statistical analysis.The research results are shown as below.(1)The leaves were 1.95-12.91 cm long,mean±SD=5.54±2.15 cm,and 0.45-1.94 cm wide,mean±SD=0.97±0.32 cm.Number of flowers per flower fascicle was 2-14,mean±SD=5.1±2.2.Flowers yellow,with 13-20 tepals per flower,mean±SD=15.36±1.34.The tepals with 2 nectaries narrowly obovate to broadly obovate,apexes usually emarginate to notched,occasionally entire,3.18-5.94 mm long,mean±SD=4.82±0.52 mm,and 1.45-4.41 mm wide,mean±SD=2.65±0.54 mm.(2)All the ovaries and fruits contained only one ovule or just one seed.Berries ellipsoid to ovate ellipsoid,purplish black,3.37-8.36 mm long,mean±SD=6.91±0.82 mm,and 2.85-5.13 mm wide,mean±SD=4.02±0.46 mm.Length of the fruit stalks was 0.47-2.20 cm,mean±SD=1.10±0.32 cm.(3)Among the coefficients of variation,number of flowers per flower fascicle (0.37)＞length of leaves(0.21)＞width of leaves(0.18)＞length of fruit stalks(0.17)＞width of nectariferous tepals(0.14 )＞length of nectariferous tepals(0.08)=tepal number per flower(0.08)＞length of fruits(0.07)= width of fruits(0.07).(4)Several photos of leaves,flowers and fruits are provided to fill the gap of illustration absence of B.sublevis in Flora of China.Furthermore,the effects of habitat conditions on the morphological variations between populations of B.sublevis,and its relationships with a sympatric congener,B.replicata are also discussed.

Abstract:In this study,we investigated the functions of 2-alkenal reductase(AER)in improving drought tolerance.Transgenic tobacco plants overexpressing 2-alkenal reductase and wild-type tobacco plants(SR)were used to measure the biomass,photosynthetic rate,chlorophyll fluorescence parameters,contents of chlorophyll,MDA and H₂O₂ under drought stress and rehydration.Results showed that:(1)the biomass,content of chlorophyll,photosynthetic rate,chlorophyll fluorescence parameters and the capability for scavenging H₂O₂ of the transgenic tobacco plants were significantly higher than those of control plants under drought treatment.(2)After rehydration,the physiological indexes of tobacco recovered.The recovery capability of transgenic lines is better than that of wild-type.These results indicated that overexpression of AER gene lead to enhanced drought tolerance in transgenic tobacco plants.

Abstract:The study investigated the effect of gas transmitter H₂S (by adding H₂S donor NaHS) on the physiological and biochemical characteristics of hydroponic growth tomato seedlings under nitrate stress.The result showed that:(1)with the increasing nitrate stress treatment time,the shoot height,root length,fresh weight and dry weight,chlorophyll a and b contents,net photosynthetic rate,gas conductance and transpiration rate decreased significantly,while the intracellular CO₂ concentration,the MDA and H₂O₂ contents increased.The activities of superoxide dismutase,catalase,peroxidase,and ascorbate peroxidase and the antioxidant substances of ascorbate and GSH contents decreased after nitrate stress treatment.(2)When NaHS was added,the shoot height,root length,fresh weight and dry weight,chlorophyll a and b contents,net photosynthetic rate,gas conductance and transpiration rate increased significantly after NaHS added for 1,3,5 days,while the intracellular CO₂ concentration decreased,compared with the nitrate stress treatment alone.The MDA and H₂O₂ contents decreased,while the antioxidant enzyme activities of superoxide dismutase,catalase,peroxidase,and ascorbate peroxidase increased,besides,the antioxidant substances of ascorbate and GSH contents increased after NaHS was added.The activities of nitrate reductase,glutathione synthetase,and glutamate synthase increased after NaHS was added.NaHS treatment stimulated the increase of L-desulfhydrase activity,which in turn induced accumulation of H₂S content.These results indicate that the alleviation of the nitrate stress damage on tomato by H₂S might be fulfilled through increasing the antioxidant enzyme activities and the antioxidant substances contents.

Abstract:The effects of lead (Pb) stress on some physiological indicators of five fast-growing willow clones (Salix ‘Zhuliu’,Salix jiangsuensis CL J-172,Salix jiangsuensis CL J-795,Salix matsudana var.anshanenensis and Salix matsudana Koidz) were studied in a pot experiment.The results showed that:(1)the POD,SOD and CAT activities of five clones increased initially and then decreased with the increase of lead concentrations;The Salix ‘Zhuliu’ was better than other four clones;(2)with the increases of lead concentrations,soluble protein,proline and soluble sugar contents of five clones significantly increased at the lower lead concentrations,and reduced at the higher concentrations.Salix ‘Zhuliu’ and Salix jiangsuensis CL J-172 had higher resistance to lead stress compared to other three clones at 1 500 mg·kg^-1 of lead;(3)MDA content of five clones generally increased with the increase of lead concentrations,but the increase rate was different (The lowest and the highest were Salix ‘Zhuliu’ and S.matsudana Koidz);(4)with the increase of lead concentrations,chlorophyll content of five clones increased initially and then decreased;Salix ‘Zhuliu’ has seen its decrease rate less than those of other four clones at 1 500 mg·kg^-1 of lead;(5)the root activity of five clones increased initially and then decreased with the increase of lead concentrations;The root activity of Salix ‘Zhuliu’ clone was the strongest;(6)the accumulation to Pb²⁺ of five willows had different performance under the same lead concentration,and the Salix ‘Zhuliu’ was better than others;(7)comprehensive evaluation of each physiological parameters indicated that the lead ions tolerance order are:indicated that:Salix ‘Zhuliu’>Salix matsudana var.anshanenensis>Salix matsudana Koid>Salix jiangsuensis CL J-795>Salix jiangsuensis CL J-172.

Abstract:In order to explore the adaptation mechanism of Cyperus rotundus seedlings to the water level change in the hydro-fluctuation belt of the Three Gorges Reservoir area,we conducted a simulation experiment to study the physiology response to different submerged environments induced by the water level change.Four treatments were set,i.e.,no submergence(CK),root submergence(T₁),semi-plant-submergence(T₂),and whole plant submergence(T₃).The results indicated that:(1)After treated for 45 days,chlorophyll a,chlorophyll b,carotenoid and total chlorophyll in all submergence treatments tended to be decreased,while chlorophyll a/b still kept the CK level.(2)Submergence had no significant effects on the contents of soluble protein,proline and soluble sugar in T₁ and T₃,but it significantly increased the contents of proline and soluble sugar in T₂.(3)With the increase of submergence time,the content of MDA was gradually increased in all submergence treatments,and was significantly different compared with CK after 15-day submergence.(4)The activities of antioxidant enzyme(such as SOD,CAT and APX)in all submergence treatments had some increase during the submergence,however,the activities of SOD and CAT in T₃ were gradually reduced as the submergence continue to increase.(5)After treated for 45 days,the starch concentrations in leaves and roots in all submergence treatments were higher than that in CK.This study indicates that although submergence have some adverse effects,C. rotundus can increase the physical defense to the submergence by adjusting a variety of inner protective enzyme activities and the contents of osmotic adjustment substances.Meanwhile,the accumulation of large amount of starch in root can offer a stable energy supply for tolerance to submergence.

Abstract:In order to investigate the physiological regulation mechanism of exogenous chitosan on vegetable soybean photosynthesis,we studied the effects of exogenous chitosan on photosynthetic and chlorophyll fluorescence parameters in seedling leaves of two vegetable soybean ［Glycine max (L.) Merr.］ cultivars with different salt tolerance under NaCl stress by adopting vermiculite culture.The results showed:(1)exogenous chitosan alleviated the decline of net photosynthetic rate (P_n) of salt-sensitive cultivar LX markedly at the 6th,9th and 12th days of salinity by inducing non stomatal factors,but this effect disappeared after 15 days of salt stress.For salt-tolerant cultivar LL,chitosan reduced the decline of P_n significantly at the 3rd and 6th days of salinity by inducing stomatal factors and non stomatal factors simultaneously,and reduced that of the 9th,12th and 15th days of salt treatment mainly by inducing non stomatal factors,and its growth of P_n compare with NaCl treatment were higher than that of LX.(2)Exogenous chitosan prevented the decline of non photochemical quenching coefficient (NPQ) of LX after 12 days of salinity,and prevented the decline of NPQ and markedly alleviated the decline of photochemical quenching coefficient (q_P) and actual photochemical efficiency (Ф_PSⅡ) of LL after 15 days of salinity.(3)Under no NaCl condition,chitosan increased the P_n of two vegetable soybean cultivars significantly by inducing stomatal factors and non stomatal factors such as stomatal conductance (G_s),q_P and Ф_PSⅡ at the early stage of spraying chitosan,but these effects disappeared at middle and later stage.All the results suggest that:vegetable soybean has potential resistance.The effects of exogenous chitosan on vegetable soybean under NaCl stress differ from those of no NaCl condition.Chitosan can only induce potential salt resistance of vegetable soybean when it is injured by salt stress.However,the induction route,induction timeline and induction effect of chitosan on vegetable soybean were different because of different salt tolerance of vegetable soybean.The salt tolerant cultivar LL has strong,durable and multiple potential resistance ability,which may play an important role in maintaining relatively higher P_n induced by chitosan.

Abstract:In this study,leaves of thirteen common ornamental trees were collected form sampling sites with different pollution degrees in Yan’ an Municipality to determine the sulfur content in leaves using BaSO₄ turbidimetry and spectrophotometer.One-way ANOVA analysis,average contaminative Index analysis were used to examine the absorption capacity of SO₂ for Yan’an ornamental trees.The leaf anatomical structure of the thirteen species of ornamental trees from three sampling sites were observed with paraffin sectioning method and nail oil seal.The twelve anatomical indices were analyzed.Through the methods of principal components analysis and path coefficients analysis to evaluate how the leaf anatomical structure influence the SO₂-absorption capacity.The results showed that:(1)with different pollution conditions,the SO₂ absorption capacities of different species were significant difference,and the SO₂ absorption capacity of same species in different pollution conditions were significant difference either.The order of average sulfur absorption capability of thirteen ornamental tree species in Yan’an was:Salix matsudana(2.64)＞Salix babylonica(2.28)＞Amygdalus persica var.duplex (2.20)＞Amygdalus persica(2.15)＞Prunus cerasifera cv.pissardii(1.95)＞Sophora japonica(1.73)＞Sophora japonica cv.pendula(1.67)＞Buxus sinica(1.57)＞Syringa oblata(1.41).Berberis thunbergii cv.atropurpurea(1.41)＞Ailanthus altissima(1.30)＞Fraxinus chinensis(1.28)＞Ligustrum vicaryi(1.27).(2)The twelve anatomical indices(thickness of leaves,thickness of upper epidermis,thickness of lower epidermis,cuticle thickness of upper epidermis,cuticle thickness of lower epidermis,thickness of palisade tissue,thickness of spongy tissue,thickness ratio of palisade tissue to spongy tissue,compactness of leaf structure,stoma density of lower epidermis,stoma length of lower epidermis,stoma width of lower epidermis) had significant differences among thirteen species of ornamental trees,and had higher sensitivity.(3)Through the methods of principal components analysis,the accommodation of former four components has reached 87.875%,which picked six indices with larger contribution rate (compactness of leaf structure,cuticle thickness of upper epidermis,cuticle thickness of lower epidermis,stoma density of lower epidermis,stoma length of lower epidermis,stoma width of lower epidermis);Cuticle thickness of upper epidermis,compactness of leaf structure,stoma width of lower epidermis;through the path coefficients analysis,the three indices,thickness of upper epidermis,compactness of leaf structure and stoma width of lower epidermis have great direct impact on SO₂-absorption capacity(their direct path coefficient are 0.92,1.49 and 0.65,respectively) and weak impact on indirect impact on SO₂-absorption capacity.Instead,the other indices,thickness of lower epidermis and stoma density of lower epidermis,stoma length of lower epidermis,have large impact on SO₂- absorption capacity.Those six anatomical indices could be the indices to evaluate SO₂-absorption capacity comprehensively.

Abstract:Flaveria bidentis was an invasive plant and Setaria viridis was its associated native plant species.The arbuscular mycorrhizal fungi gathered in the rhizosphere soil of F.bidentis during its invasion was selected.And then the effect of AM fungi on the root colonization rate,relative competition intensity,rhotosynthetic nutrient use efficiency,malonaldehyde content and antioxidant enzyme activities of F.bidentis and S.viridis were carried out in greenhouse pot.In the experiment there were 3 treatments:monoculture and mixture treatment of the two species,and each treatment including two levels:AM fungal inoculated and no AM fungi inoculated.The results showed that:(1)there were 4 genera and 10 species AM fungi in the rhizosphere soil of F.bidentis.Among them Glomus constrictum,Glomus perpusillum,Glomus reticulatum were the dominant species.The root colonization rate of F.bidentis was significantly higher than that of S.viridis.The relative competition intensity of F.bidentis was significantly reduced 29.57% after it was inoculated with AM fungi,while competition had no significant effect on S.viridis.(2)The AM fungi increased the nitrogen,phosphorus,photosynthetic nutrient use efficiency of F.bidentis,and then promoted the competitive growth of F.bidentis,while it had no significant effect on the growth of S.viridis.(3)The AM fungi has no significant effect on POD,CAT activities and MDA content of F.bidentis.The AM fungi significantly increased the activities of SOD and APX and the content of MDA,while the activities of POD,CAT and APX of S.viridis were significantly decreased.The results showed that AM fungi had different selectivity between F.bidentis and S.viridis.The colonization of AM fungi promoted the competitive growth of F.bidentis,increased the absorption of nitrogen and phosphorus,photosynthetic nutrient use efficiency,enhanced the activities of antioxidant enzymes in leaves and reduced the content of malondialdehyde of F.bidentis.AM fungi reduced the absorption of phosphorus,photosynthetic nutrient use efficiency and antioxidant enzyme activities of S.viridis.Thus the AM fungi produced laterality feedback on F.bidentis than S.viridis,which promoted the invasion of F.bidentis.

Abstract:In this study,to explore the relationship of post-drought recovery capacity and physiological and biochemical response during drought and rewatering,we selected two maize varieties,‘Zhengdan 958’ and ‘P3’ with similar drought resistance but different resilience as experiment materials.The changes of growth,water status,photosynthetic parameters,chlorophyll fluorescence parameters and chlorophyll content were studied with potted experiment during drought and rewatering at seedling stage.The results indicated that:(1)the two maize varieties showed similar drought resistance,but significantly different growth recovery capacity.(2)The leaf water content of ‘Zhengdan 958’ and ‘P3’ demonstrated no significance during the drought period,but ‘P3’ maintained higher water potential,maximal efficiency of PSⅡ photochemistry and chlorophyll content under drought conditions.(3)The recovery rate of photosynthetic rate,maximal efficiency of PSⅡ photochemistry and stomatal conductance of ‘P3’ was quicker than that of ‘Zhengdan 958’ after drought and rehydration.Research showed that the photosynthetic loss recovery capacity of ‘P3’ was higher than that of ‘Zhengdan 958’.The reason why the recovery capability of ‘P3’ was stronger is because it can maintain higher F_v/F_m and chlorophyll content under drought,and the damage of photosynthetic systems was lighter,and also because the recovery was faster than ‘Zhengdan 958’ after rehydration.These results revealed that reducing damage of drought stress on plant photosynthetic systems is the basis of rapid recovery after rewatering,and the rapid of damaged photosynthetic systems to accelerate the recovery of plant after rewatering.

Abstract:For grasping fluctuation cycle of Juglans cathayensis populations and forecasting change of the population structure,we conducted a large sample survey on sunny and shady slopes in valley of conservation area in Xinjiang,Using the diameter class structure representing the age structure,we drew up static life table,life expectancy chart,age structure plot,survival curve,and death rate curve chart of J.cathayensis populations.Also,we compared the fluctuation cycle of J.cathayensis populations on different slope aspects by using spectrum analysis method.The results showed that:(1)life expectancies of J.cathayensis populations were fluctuant,both on different slopes of the same age and the same slope of different ages.Life expectancy before 10th age class was higher on sunny slope than that of shady,but after 10th age class it was lower than that of shady slope.(2)J.cathayensis populations on different slope aspects showed increasing age structure.(3)Survival curve of J.cathayensis populations on different slope aspects tended to be Deevey-Ⅱ type,and the survival rate of each age class on sunny slope was higher than that on shady slope.(4)The 1st age plant developed into saplings at the cost of high mortality.The populations in sunny slope had two death peaks in their life history,with the highest peak in 16th age class.However,the shady populations had four death peaks,with the highest peak in 9th age class.(5)Spectrum analysis showed that the quantitative dynamics of J.cathayensis populations were influenced by fundamental wave and also showed obvious small periodic fluctuation,and they had characteristics of multi harmonic superposition that small periodic fluctuation in big one.In the meantime,the small periodic fluctuation of 11th age class was related to high growth characteristic of J.cathayensis,but it might be related to physiological property in 17th age class.

Abstract:A systematic vegetation survey on the effects of forest gap size on vegetation diversity was conducted in a Cryptomeria fortunei plantation in Zhougong Mountain,Southwest China.Plots were explored in five different sizes of forest gaps,and closed canopy was selected as control.Dynamics of plant community composition and plant diversity in gap centre,gap edge,and closed canopy along the forest gap gradient were investigated.(1)A total of 141 vascular plant species belonging to 76 families and 113 genera were observed across 18 plots including 231 quadrats in this study area.Overall,species diversity shows an increase-decrease pattern with the increase of gap size.The species diversity in shrub layer hierarchically distributes as forest edge>closed canopy>gap centre,while herbaceous species as forest edge>gap centre>closed canopy.(2)The dominant species and important value varies among different sizes of forest gaps.C.fortune and Mallotus japonicus are the dominant species in small size forest gaps,with a sum of important value as high as 0.292 3.While Cunninghamia lanceolata and Betula luminifera are the dominant species in large forest gaps,with plenty of seedlings.(3)Species richness index (D),Shannon-Wienner index (H),and Pielou index (J_sw) reach relative high level in the large forest gaps with sizes of 400-450 m² for shrub communities,while these indexes reach high level in small forest gaps with sizes of 100-150 m² for herbaceous communities.Indexes of D and H among differing communities hierarchically show as forest edge>gap centre>closed canopy.These results suggested that forest gap can influences the composition of plant community and enhances plant diversity,and the large size of forest gap is more beneficial for species regeneration and plant diversity increase.

Abstract:We have done a field study to investigate the community of Quercus wutaishanica in Qiliyu of Taiyue Moutain Shanxi.Based on the field study results to calculate the importance values and frequency of species,which were used to measure interspecific associations and cluster analysis for dominant species of arbors and shrubs;and using χ² tests,together with association coefficient and percentage co-occurrence,to measure interspecific associations of the dominant species of two layers.According to interspecific associations and cluster analysis of the dominant species,to study plant varies among plant functional types(PFTs) with altitude gradients,which reflect the change of Q.wutaishanica community.The results of this study show that:(1)Pinus tabuliformis,Acer ginnala,Populus simonii,Populus davidiana,Betula platyphylla are the dominant tree species changed with altitude gradients;(2)according to the dominant species we can defined three PFTs in arbors:Ⅰ.Syringa pekinensis,Populus simonii,Acer elegantulum(1 200-1 700 m);Ⅱ.Pinus tabuliformis,Carpinus turczaninowii(1 700-1 840 m);Ⅲ.Populus davidiana,Betula platyphylla,Syringa reticulata var.amurensis(1 900-2 100 m);(3)the dominant species of shrubs were divided into seven PFTs.Therefore,our study suggested that each functional type has its unique spatial distribution and morphological characteristics.These PFTs appear to effectively reflect the dynamic relations between vegetation and environment,and provide a theoretical foundation for the conservation and research of Q.wutaishanica.

Abstract:With Magnolia denudata Desr.mature seeds as material,we analyzed the volatile components type and content of the sarcotesta by steam distillation and gas chromatography-mass spectrometry.To discussion the ecology and biology function,we has carried comparative study of sarcotesta effect on seed water absorption and loss and the influence on seed germination.The results show that:(1)the sarcotesta accounted for 48.25% of the whole complete seed weight.With/without sarcotesta of M.denudata on the seed water absorption and loss was observed show that the presence of sarcotesta has no significant impact on seed water absorption,but can decrease the water loss rate,indicating it has certain water conservation function.(2)The main types of volatile constituents are terpenes (12) and alcohols (11),but the highest relative content of the components is ketones (32.84%) and the second is esters (18.03%),which include methyl heptenone (31.95%),butyl acetate (17.69%),p-cymene (13.64%) and linalool (6.61%).(3)By investigating the influence of sarcotesta leaching solution on peas and cabbage seed germination,it can be confirmed that the sarcotesta of M.denudata has obvious inhibitory effect.With the increase of concentration of leaching solution,pea seed germination rate reduced from 86.7% to 6.0% and cabbage seed germination rate from 28.0% to zero.We speculate that the sarcotesta of M.denudata in function is a kind of similar structure to pulp of fleshy fruit,which has the rich chemical compositions and plays an important role in its seed dispersal.It not only can attract birds spread their seeds,also has certain allelopathy.

Abstract:In order to establish an efficient transient expression system based on grapevine protoplasts,we used the mesophyll and callus of grape ‘Heixiangjiao’ to analyze the key factors related to isolating effectively protoplasts,such as cellulose and macerozyme enzyme composition,concentration of mannitol in enzyme solution,duration of enzyme dissolve,and so on.The protoplast was used as a vehicle to explore the establishment of a stable,efficient grape protoplast isolation and transient transformation system,and lay the foundation for building a transient expression system.The results showed that:(1)the optimal enzyme solution for leaf protoplast isolation was 3.0% cellulase onozuka R-10+0.75% macerozyme R-10+0.6 mol/L mannitol.The digestion was conducted in the dark under 28 ℃ for 14 h,and the protoplasts yield was 4.09×10⁶ per gram,the vitality was 83.12%.(2)The optimal enzyme solution for callus protoplast isolation was 2.0% cellulase onozuka R-10+0.5% macerozyme R-10+0.5 mol/L mannitol.The digestion was conducted in the dark under 28 ℃ for 14 h,and the protoplasts yield was 6.05×10⁶ per gram,the vitality was 84.13%.(3)The transient expression vector pEZS-NL with reported gene coding green fluorescent protein (GFP) was transferred into protoplasts by 40% PEG-4000 method.The GFP protein expressed stably and clearly in all over the protoplast.We establish grape protoplast isolation and transformation system in this paper.The gene can be expressed efficiently in grape protoplasts with a small amount of plasmid DNA,which provides technical support for grape functional genomics studies.

Abstract:Seven species and two varieties belonging to eight genera in seven families are reported as new records of Hubei Province in this paper,including Rubia schumanniana,Rhododendron haofui,Allium condensatum,Clematis montana var.sterilis,Dichocarpum arisanense,Distylium myricoides,Neillia thibetica,Neillia sinensis var.caudata,Galinsoga quadriradiata.And we provide their geographical location,altitude and pictures.All the vouchers specimens were preserved in Herbarium of College of Life Sciences,South-Central University for Nationalities.

Abstract:Three genera and three species of Compositae were reported as new records in geographical distribution in the territory of Gansu Province.The three genera were Matricaria,Symphyotrichum and Blumea.The three species were Matricaria matricarioides (Lessing) Porter ex Britton,Symphyotrichum subulatum (Michaux) G.L.Nesom and Blumea axillaris (Lamarck) Candolle.

Abstract:Most of Araliaceae plants are important medicinal herbs.Agrobacterium rhizogenes have been used to induce plants of Araliaceae produced hair root,in which the important secondary metabolites are obtained.It is one of the effective ways to protect rare medicinal resources of Araliaceae plant and to achieve effective industrial production of secondary metabolites.In this paper,an overview of rhizogenes transformation history and transformation mechanism in medicinal plants is given as the basis.Meanwhile the present researches on species and induction rate,various factors and regeneration plants in Araliaceae plants induced by rhizogenes are analyzed.In addition,some suggestions on further research in several key fields are presented.All above will provide a reference for the exploiting and developing medicinal plant in Araliaceae.