Abstract:We observed the processes of fertilization and embryo development in crosses between ‘butterfly’ (2n=4x=60) and the simple breeding line ‘NH6’ (2n=2x=30) using paraffin section.The results showed that:(1)At 17 h after pollination,pollen tube entered into one synergid and released contents,sperm nucleus got into one of polar nuclei and fused with two polar nuclei to form primary endosperm nucleus.At 1 day after pollination,sperm nucleus moved towards egg nucleus and adhered to the nuclear membrane of the egg cell.Formation of zygote and endosperm free nuclei was observed 2 day after pollination.Development of embryo went through stages of proembryo,globular embryo,heart embryo and torpedo embryo.The hybrid barriers were detected in fertilization and different embryo development stages.Barriers included sperm did not fused with egg or sperm did not fused with polar nucleus,and zygote did not divided,or primary endosperm nucleus did not divided,and embryos aborted.Embryos aborted at different developmental stages (proembryo to cotyledon embryo),but mainly at globular embryo.

Abstract:Cytological observation on microsporogenesis of inter-subspecific semi-sterility hybrid F₁ and its parents was conducted by using technique of paraffin section and extrusion chromosomes on slides.The results indicated that the anther wall of hybrid F₁ and its parents was normal.However,the meiosis of some microspore mother cells in hybrid F₁ was abnormal,e.g.chromosome pairing unequally,aberrant dyad and tetrad formation.The hybrid F₁ forms univalent at metaphase Ⅰ,delayed chromosomes and chromosomal bridge could be found at anaphase Ⅰ,delayed chromosome also could be found at anaphase Ⅱ.In summary,the main causes of the pollen semi-sterility of hybrid F₁ might be caused by the aberrant chromosome behavior of some microspore mother cells in hybrid F₁ at meiosis metaphase and anaphase.

Abstract:The megasporogenesis,microsporogenesis and the development of female and male gametophyte of Nicotiana debneyi were studied by carbol fuchsin staining and paraffin sectioning.The results showed that:(1)N.debneyi is hermaphrodite flower and the microspore develops earlier than megaspore.(2)Microsporogenesis and development of male gametophyte of N.debneyi are normal but there are chromosome bridges,chromosome fragment,laggard chromosome in a few cells.The meiosis in microspore of N.debneyi is simultaneous cytokinesis and the tetards are decussate or tetrahedral types.The mature pollens belong to 2 cell type.(3)N.debneyi is ovary 2-locular,axile placenta,ovules numerous and polygonum type of mature embryo sac.Megasporogenesis and the development of female gametophyte of N.debneyi are normal.

Abstract:Several leaf blades of the cultured Isoetes sinensis from tender to mature are used as experimental materials in this paper.With the method of paraffin technology,the development of ligule and velum are observed by continuous dissection.The relationship between the development process and the sporangium and blade are analyzed.The results show that:(1)The primeval developing speed of the ligule was faster than that of the leaf blade,although the ligule and leaf blade come from the same primordia in the early ontogenesis of I.sinensis.(2)Sporangium first occured at the fifteenth blade stage of I.sinensis,when the velum was obvious in the bottom of ligule.(3)When the antiphyte of I.sinensis achieve more than 30 pieces of blades,the sporangium that produced in plant peripheral in early time has been matured.In this period,the megasporangium and the microsporangium can be divided clearly and the length of ligule that relative to sporangium has become short in mature macrosporophyll.The labium is atrophied and the velum has disappeared;Compared with the macrosporophyll,the ligule of mature microsporophyll is longer and upturned extent is obvious.The atrophied degree of the labium is unconspicuous and the velum has disappeared.The studies suggest that the velum was a common structure in the early phylogeny stage of Isoetale,but significant degradation or even disappear in later stage of evolution at some areas;the difference between ligule and leaf blade was less obvious than that of morden isoetale,when I.sinensis was in the early phylogeny.

Abstract:The morphological and anatomical features of fruit,seed and seedling development of Ottelia alismoides were observed in the paper,using the morphological observation and GMA sections and inquire into the structures adapted to the water environment in the ontogenetic development of O.alismoides.The results showed:(1)The O.alismoides fruit enveloped by spathe usually have six carpels and their edges do not connect each other completely in the center of fruit and laminal placentation.The young fruit developed above the water was pulled by the carpopodium into water to mature.The seed is with hairs and its shoot apex develops before root apex.The hypocotyl develops unicellular hairs before the radicle differentiates,and then the radicle develops into primary root and the adventitious root formed in the leaf node.The pericarp and mesophyll are vascular bundles composed of a few cells and well-developed air cananls.The epidermal cells of the leaf have no cuticle and their outer walls are bulging and mesophyll is with less cells.All these features of the species are adapted to the water environment.(2)The authors observed that some features of the species (i.e.,seed has no endosperm;the starch grains are rich in hypocotyl,which offer the nutrient for its development;both primary and adventitious roots have root hairs) could be also found in Sagittaria sagittifolia and Alisma plantago-aquatica of Alismataceae.The study showed the close relationship between two families Hydrocharitaceae and Alismataceae.

Abstract:A GhZIP4 gene fragment was obtained from cDNA and genomic DNA of upland cotton Sumian 18 by RT-PCR and PCR with the primers designed according to the assembled ESTs of Gossypium hirsutum.The result showed that:(1)The length of the GhZIP4 cDNA sequence was 1 487 bp,it contained an ORF comprising of 1 269 bp nucleotides which encodes 422 amino acids.The amino acids sequence had the characteristics of the ZIP protein,containing 8 trans-membrane domains and a variable region between the third and the forth trans-membrane domains that included two histidine-rich domains of ‘HRHSHPHG’ and ‘HSHGHGHD’.(2)Phylogenic tree analysis showed that the protein sequence of the GhZIP4 was highly similar to AtZIP4 of Arabidopsis ZIP family.(3)The full length of coding region of the GhZIP4 DNA sequence was 1 778 bp,containing three introns and four exons.All exon/intron junctions of the gene contained the gt/ag consensus splicing site.(4)Semi-quantitative analysis of the GhZIP4 expression showed that the gene highly expressed in stem,indicating that it may play an important role in dynamic homeostasis of some metal ion between root and shoot.

Abstract:The EST-3 related to the powdery mildew in the wheat was amplified by in silico cloning.And the cDNA sequence had been confirmed by RT-PCR.The result indicated that a new sequence with 875 bp length was cloned，which contained an integrated ORF,encoding 229 amino acids,GenBank accession number is JK841279.Based on domain structure,it has GST domain structure in N-terminal and C-terminal.The trend of EST-3 expression by RT-PCR was very identity to the expression by SSH-cDNA,and their sequences have 98% consistency.As showed that the result of in silico cloning was right.The amino acid sequence showed highly comparability with the glutathione-S-transferase（GST） from GenBank，and their sequences have 97% consistency.Expression analysis revealed that the expression of GST in wheat was inhibited after infection by powdery mildew for 24 h,then it began to express after infection for 48 h and increased gradually.It reached the highest level after infection for 72 h,and decreased after infection for 96 h.The result suggested that GST belong to the gene induced by powdery mildew,and it might be involved in powdery mildew response of wheat.

Abstract:In order to obtain a new castor with low toxity,RNAi interference technology was used to regulate the expression of the RTA(ricin toxin A-subunit) gene.The RTA gene are amplified by Polymerase Chain Reaction technology,and then RTA transgenic expression vector(pBI-RTA-S-AS) was constracted successfully.Secondly,pBI121-RTA-dsRNA vector was transferred into cotyledonary node by Agrobacterium tumefaciens-mediated transformation.Transformed castor plants were identified by growth on medium containing 25mg/L Kanamycin and PCR.The results showed that 762 bp fragment was obtained.Three transformants were obtained and all of them were further identified as positive transgenitic plants by PCR.

Abstract:In order to elucidate the evolutionary characteristics of Neotorularia humilia,a pair of universal primers for Ethylene Receptor 1 (ETR1) gene in Brassicaceae was chosen to amplify the homologous ETR1 in N.humilia by PCR,and 14 homologous sequences were cloned.Sequences were aligned by Bioedit and the similarities among these clones at nucleotide level were from 93％ to 98％,and the similarities among these protein amino acid sequences were 78%.Nucleotide diversity was measured by DnaSP v5,and 14 DNA haplotypes were obtained in 1 644～1 661 bp fragments of BhETR1 in N.humilia.Furthermore,phylogenetic analysis revealed that 14 clones were classed into three clades,one representative clone from each clade (cloning 2,cloning 29,and cloning 35) was chosen to blast with ETR1 genes from Arabidopsis thaliana (L.) Heynh.and Arabidopsis lyrata.The nucleotide similarities were both 78％.These results suggest that BhETR1 is a ETR1-like gene,and the high heterogeneity among 14 BhETR1 sequences might be caused by the complex genome of N.humilia.

Abstract:In this study the expression analysis of PheTFL1 gene related to moso bamboo flowering provide the theory basis for the research of flowering mechanism of moso bamboo.PP2A gene was screened from nine candidate reference genes including UBC18,PP2A and EF1α,and so on,because of its stable expression in 11 kinds of different tissues and organs such as the leaves,immature inflorescence,inflorescence axis,branches and the cuticle of bamboo stem,and so on,which is used to correct the qRT-PCR results of PheTFL1 gene.The results showed that the low level expression of the PheTFL1 in leaves,branches and cuticle of bamboo stem of flowering bamboo was not significantly different from those of non-flowering bamboo,while there was high level expression in immature inflorescence and inflorescence axis.The expressions of PheTFL1 were detected at high level in leaves and roots of seedlings,but at lower expression in stems.Appreantly the PheTFL1 gene were abundantly expressed in young tissues which had meristematic ability,it may be involved in regulating the growth of the meristems,as well as in the development of flower.

Abstract:Arabidopsis PKS5 (protein kinase SOS2-like 5),a protein kinase,involves in the pathways responded to the tolerance of salt-alkali stress.To dissect the functions of distinct domains of PKS5 under the stress of external salt and alkali,the characteristics of various PKS5 were determined using the PKS5 point mutants.The results show that:(1)The distinct PKS5 point mutants display the distinguishable phenotypes of growth under the combined salt and alkali stress.In all the PKS5 mutants measured in this study,the pks5-4,pks5-5 and pks5-9 display no differenc of growth of the primary root compared with the wild type (WT) under the salt-alkali stress but the pks5-2,pks5-6,pks5-7 and pks5-8 exhibit the salt-alkali phenotype under the same conditions of salt-alkali stress.The pks5-2 and pks5-8 display the tolerant phenotype of growth of primary root and the pks5-6 and pks5-7 illustrate the sensitive phenotype of growth of primary root under the salt-alkali stress compared with the WT.(2)The RT-PCR analysis of the PKS5 and the point mutated versions demonstrates the point mutations in the PKS5 lead to the alterations of the PKS5 expression.The expressions of the PKS5-2,PKS5-6 and PKS5-7 decrease compared with the WT.(3)The sub-location of PKS5 point mutation versions exhibit no differences compared with the WT.Both the WT and the PKS5 point mutation proteins distribute ubiquitously in the nucleus,cytoplasm and membrane of cells in wild plants.(4)The contents of Na⁺ present the significant differences between the PKS5 point mutants and the WT.The pks5-2 accumulates the less contents of Na⁺ and the pks5-6 and pks5-7 possess the more Na⁺ ions compared with the WT.Taken together,the results in this study show the different point mutations in PKS5 cause the various responses of plants to salt-alkali stress and suggest the diverse domains of PKS5 confer to the distinct functions under the stress of salt and alkali in Arabidopsis.

Abstract:cDNA-AFLP approach was employed to analyze genes differential expression under cold stress using the three-five leaf stage leaves of Medicago ruthenica.The results showed that 549 differentially expressed transcript-derived fragments（TDFs） were identified by sixty-four primer combinations,and 43 up-regulated TDFs of them were sequenced and analyzed.Blastx-analysis and functional analysis indicated that 32 TDFs might participate in senescence and metabolism pathways,signal transduction,transcription regulation,stress responses etc,other 11 TDFs were showed homology to unknown and hypothetical function genes.The qRT-PCR results showed that it was accuately on the numerical value for expression of three different up-regulated TDFs were induced by low temperature stress.

Abstract:The aim of this work was to study the relationship between low potassium stress and the reactive oxygen species system.The tomato plants were grown in hydroponic systems to determine the role of reactive oxygen species (ROS) in the leaves response to low potassium stress.Parameters of oxidative stress superoxide (O^-·₂),malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) concentration and activities of antioxidant enzymes,such as superoxide dismutase (SOD),catalase (CAT),ascorbate peroxidase (APX) were investigated.The results indicated that:(1)The protective enzyme activities in the potassium-sensitive tomato were significantly depressed in the low potassium treatment compared to controls.While reactive oxygen species and MDA content showed significant differences between control and low potassium treatment.(2)The protective enzyme activities were increased in potassium-tolerant tomato compared with the control,and its reactive oxygen species and MDA content were increased.Relative expression levels of Cu/Zn-SOD,CAT and APX were analyzed in two kinds of tomato genotypes.The results showed that potassium-tolerant tomato had high protective enzyme expression under the low potassium stress,while potassium sensitive tomato was the opposite.These results show that higher protection enzyme activities probably scavenge H₂O₂ and O^-·₂,resulting in preventing the membrane permeability,and this can increase the adaptability to low potassium.

Abstract:‘Xinluzao 33’ (cold sensitive variety) and ‘Zhongmiansuo 50’ (high cold resistant variety) were selected as test materials in this study.The change of activity of antioxidant enzyme activities and osmotic adjustment substance contents in leaves of seedling were determined under simulating different stress-temperature gradient and time gradient of low temperature stress.The results showed that:(1)The responses to low temperature stress in two cotton cultivars intensified gradually with the decline of temperature and treatment period time,especially 15 ℃ and 10 ℃.(2)With prolonging of stress time,the relative electric conductivity (REC),POD activity,SP and Pro content of cotton leaves generally increased after 15 ℃ and 10 ℃ treatment,the variation trend in activity of POD and APX,content of MDA and SS was increased firstly until 24 h treatment.Under 5 ℃ and 0 ℃ treatment,REC,the activities of SOD and POD,the contents of MDA,SP and SS were increased significantly,the variation trend of APX and Pro increased to a certain degree and then decreased.(3)Compared with ‘Xinluzao 33’,the activities of antioxidant enzymes and the contents of osmotic adjustment substances of ‘Zhongmiansuo 50’ rose more steeply.Those results indicated that,under varying degree of low temperature stress,cotton seedlings could start the appropriate adjustment method to maintain the metabolic balance,and to improve resistance by the regulation and adaption of different indicators of antioxidant enzymes and osmotic adjustment substances.High cold resistant varieties could start the response mechanism of scavenging free radicals and osmotic regulation more rapidly and sensitively,which would enhance chilling adaptability.

Abstract:Seedlings of Salicornia bigelovii Torr.were treated with different concentrations of NaCl (0,100,200,300,400,500 mmol·L^-1).Three kind of polyamines and their different forms were investigated under NaCl and exogenous spermidine treatment.The results showed that:（1）three forms of the putrescine (Put) increased at first and then decreased under salt treatment.The free form of spermidine (Spd) and the bound state of spermine (Spm) increased all the time.The free form of Spd,the conjugated state of Spd and Spm,and the bound state of Spd both increased at first and then decreased.Finally,the total polyamines (PAs) of the free and bound were both increased all the time,while the conjugated state content increased at first and then decreased.（2）All the three forms of polyamines of (Spd+Spm)/Put ratio increased at first and then decreased,while the Put/PAs ratio was decreased first and then increased.（3）The conjugated and bound form of the polyamines contents increased with exogenous Spd treatment.At the same time,the free and bound states of (Spd+Spm)/Put ratio also increased.It indicated that exogenous Spd could be involved in the regulation of PAs metabolism and played an important role in enhancing salt tolerance of S.bigelovii seedlings.

Abstract:This study evaluated effects of foliar spraying 24-epibrassinoide (24-EBL) on the growth of salt-stressed canola and plant pigment role played in canola salt tolerance.The seedlings were grown in the presence of 150 mmol·L^-1 NaCl and sprayed with different concentration of 24-EBL (1 000,10,0.1,0.001 nmol·L^-1) for 15 days.The plant biomass,electrolytic leakage percentage (ELP),net photosynthetic rate (P_n),contents of photosynthetic pigments,phenolics,flavonoids and anthocyanins,and total antioxidant capacity (T-AOC) of these plant pigments were determined.The results showed that:(1)24-EBL could ameliorate these adverse effects induced by salt on biomass,P_n,contents of chlorophyll (Chl) and carotenoid (Car),MDA level and ELP.0.1 nmol·L^-1 24-EBL (EBL3) was chosen as the optimal concentration for growth promotion and used in a subsequent experiment.(2)The levels of β-carotene (β-Car) and lutein (Lut) in different parts of leaves were sharply decreased under salinity,but β-Car content in upper leaves,Lut content in upper and middle leaves were reversed with varying degrees by EBL3.The treatment of EBL3 could promote the contents of phenolics in all leaves and petioles,and the contents of flavonoids in petioles of seedlings under salt stress.However,the anthocyanin contents of all plant organs were increased significantly induced by EBL3.(3)The treatment of EBL3 induced the T-AOC of carotenoid (Car) extracts in the upper and middle leaves.However,it induced the T-AOC of phenolics extracts in all plant organs of canola seedlings under salt stress.(4)Correlation analysis indicated that the T-AOC of carotenoids’ extracts was all highly positively related to their contents of Car,β-Car and Lut.While,T-AOC of phenolics’ extracts showed a positive correlation with contents of phenolics and anthocyanins in upper leaves,a very positive correlation with contents of phenolics and flavonoids in stems,and anthocyanins’ contents of mid-leaves,petioles and stems.Sum up,foliar spraying 24-EBL could promote adaptation of the canola seedling to salt stress,which was due mainly to its increase of photosynthetic and antioxidant capacities induced by 24-EBL.Also,the increase of photosynthetic pigment and anthocyanin levels induced by 24-EBL played an important role in anti-oxidation of canola seedlings.

Abstract:In a nutrient solution hydroponic conditions,effect of foliar pre-application of 5% (V/V) methanol on the contents of H₂O₂ and MDA,and antioxidant enzyme activities (SOD,POD and CAT) in leaf and root of black soybean ［Glycine max (L.) Merrill］ were investigated under 50 μmol·L^-1 Al³⁺ stress,and to lay the foundation for further studying on the regulatory mechanism of methanol and antioxidant enzymes response to Al stress.The results showed that:(1)Under Al stress,the absorption amount of aluminum from root tips was more with increasing Al³⁺ treatment concentration,and the root growth was more seriously inhibited.(2)Al stress could induce the increasing of the contents of soluble protein,H₂O₂ and MDA,POD and CAT activities in leaf and root of black soybean,but SOD activity was no significantly change.(3)After foliar pre-application of 5% methanol treatment,under 50 μmol·L^-1 Al³⁺ stress the contents of soluble protein,POD and CAT activities were significantly ascend with increasing treatment time,while the contents of H₂O₂ and MDA in leaf and root were declined,and SOD activity was also no change.The study results have shown that foliar application of 5% methanol could significantly increase antioxidant enzyme activities (CAT and POD),and decline the accumulation of H₂O₂ and MDA in leaf and root of black soybean under Al stress.This may be an important mechanism for methanol taking part in response to Al stress by regulating antioxidant enzyme activities.

Abstract:The relations among rooting traits and contents of endogenous hormone,total phenolic acid,nutrient substance of four elite Japanese larch (Larix kaempferi) clones were studied.The results showed that:(1)There were significant differences in the rooting ability of cuttings amongst different clones.‘Rikuan17-3-1’ and ‘Rifu27-3-1’ were easy rooting clones,which the rooting rate reached 90%.While ‘Ricao103-3-1’ and ‘Ricao82-4-3’ was difficult rooting clones,which the rooting rate was lower than 20%.(2)The content of ABA in cuttings was increasing with time prolonging,and significant differences had been found between difficult rooting clones and easy rooting clones,there was a strong correlation between ability and ABA content.The content of Z and total phenolic acid was decreasing with time prolonging,and had a negative influence on the rooting.The content of total nitrogen was decreasing until stabilization with the time prolonging,while no significant relations with rooting ability.(3)(IAA＋Z)/ABA was decreased with the time prolonging,and the rate in easy rooting clones was lower than that in difficult rooting clones.(IAA＋Z)/ABA and total phenolic acid may be used as a standard to express the rooting ability of Japanese larch.

Abstract:Using HPLC technique,we studied the characteristics of the changes of the content of endogenous hormones (ZT,GA₃,IAA,ABA) in Lycium barbarum L..The results showed that:(1)The correlation between the seeds’ IAA contents and diameter and single fruit weight reached a significant positive correlation.The correlation between the seeds’ IAA contents and length reached a positive correlation.It indicated that IAA in seeds played an important role during the fruit development.(2)The content of GA₃ was the most in fruits and seeds.From the first rapid growth period (after flowering,2～8 d) to the slow growth phase (after flowering,8～25 d),the changes of GA₃ were similar to the changes of IAA in seeds;After the second period of rapid growth (after flowering,25～33 d),the content of GA₃ decreased rapidly.Otherwise,the content of IAA in seeds increased rapidly.The reason may be that GA₃ promoted the synthesis of IAA of seeds,and then IAA in seeds can help the elongation of the fruit cell.These results also showed that the endogenous hormone in seeds played an important role during the fruit development in L.barbarum L..There was a dynamic balance relationship among every kinds of hormones.The different hormones in fruits and seeds worked together to help the fruit development of L.barbarum L..

Abstract:The seeds of tartary buckwheat variety“Heifeng No.1” were used as experimental material in pot during 2012,in order to study the effect of soaked seed with four different chemical regulators on the growth of tartary buckwheat under different water conditions and to find the best chemical regulators to improve the drought resistance of tartary buckwheat,the four chemical regulators are:ZnSO₄,MnSO₄,SA and Pro.The main result showed that:（1）At normal irrigation,soaked seeds with the chemical regulators increased the leaf area,plant height,total root length,root volume,seedling index,leaf relative water content,proline content,soluble sugar content,root activity,SOD and POD activities and photosynthesis,while the treatment of ZnSO₄ is the most effective to the growth of tartary buckwheat,SA is the latter,both of them are significant difference from the CK at 0.01 level.Finally,the treatment of ZnSO₄ and SA can increase the number of spikes by 31.8% and 21.0%,grains per plant can be gained by 38.0% and 28.9%,and 100-seed weight can be added by 8.9% and 4.2%,respectively.However,the relative conductivity and MDA content of tartary buckwheat are dropped obviously.（2）Compared water stress and normal irrigation,the indexes of the leaf area,stem thickness,total root length,root volume,root weight,leaf relative water content,proline content,chlorophyll content,soluble sugar content,root activity,SOD and POD activities and photosynthesis are reduced,while relative conductivity and MDA content are increased by soaking with chemical regulators.The extents differed in the treatment of different chemical regulators,and soaked with H₂O is changed most in all indexes.（3）At water stress,soaked with ZnSO₄ and SA can significantly improve SOD and POD activities,photosynthesis,leaf area,total root length,chlorophyll content and root activity compared with CK.They can increase leaf relative water content by 79.9% and 70.9%,proline content by 32.2% and 36.6%,and soluble sugar content by 66.0% and 43.9%,respectively.The number of spikes,grains per plant and 100-seed weight can gained by 38.6% and 36.2%,40.4% and 39.0%,10.7% and 6.9%,separately.The research indicated that using chemical regulators can remarkable raise the photosynthetic physiological characteristics and drought resistance of tartary buckwheat under normal irrigation and water stress.The treatment of ZnSO₄ and SA are the best.

Abstract:To provide theoretical evidence to aid adaptive management of bamboo plantations operating under the background of climate change,we studied the effects of simulated increased atmospheric ozone concentrations on photosynthesis,lipid peroxidation and anti-oxidation enzymes in the leaves of Phyllostachys edulis (moso bamboo).The open-top chamber (OTC) test method was employed in conjunction with a split-plot design and ozone concentrations set to AA(40~45 nL·L^-1) and EO(92~106 nL·L^-1).The results showed that:(1)Compared with AA,ozone flux increased significantly in the leaves of Ph.edulis at the same treated time under EO;Ozone flux increased with the extension ozone exposure under AA and EO treatments.(2)Photosynthetic rate(P_n) and stomatal conductance(G_s) and soluble sugar content decreased significantly in the same treated time under EO,and chlorophyll(Chl) content and intercellular CO² concentration (C_i) decreased significantly in the treatment time of 60 d and 92 d respectively,while soluble protein content increased significantly after 60 d;With elongated ozone exposure,photosynthetic rate(P_n),intercellular CO₂ concentration(C_i),chlorophyll(Chl) content and soluble protein content decreased in the leaves of Ph.edulis,and soluble sugar content increased and then decreased.And we concluded the decline in P_n resulted from the stomatal conductance limitation.(3)Superoxide radical(O^-·₂) content and malondialdehyde (MDA) content and relative electrical conductivity increased significantly after the treatment time of 29 d,60 d and 60 d,respectively and shown a rising trend with the extension of processing time.(4)The activity of super oxide dismutase(SOD) increased significantly in the initial 60 days of ozone treatment,then decreased significantly and peroxidase activity(POD) increased significantly;The activities of SOD and POD increased and then decreased.The result illustrated that Ph.edulis responded in acclimation way in the initial O₃ fumigation period;but in the late period,the growth of Ph.edulis would be affected seriously.

Abstract:With four species of azalea as materials,we studied the growth and physiological indexes under pH 4.5,5.5,6.5,7.5,8.5 irrigation water,in order to analysis the growth conditions with different acidity and alkalinity irrigation water.The results showed that:(1)With the pH increasing,the chlorophyll contents,superoxide dismutase activities,catalase activities and new shoot growth rates of four species increased firstly and then decreased,while the relative conductivities were contrary;(2)Under pH 5.5,the chlorophyll contents of ‘Mevrouw.A’,‘Fugeer No.1’ and ‘Green Glow’,the CAT activities of ‘Mevrouw.A’,‘Spring Dance’ and ‘Green Glow’ were maximum.The same to SOD activities and new shoot growth rates of the four species,while the chlorophyll content of ‘Spring Dance’ with pH 4.5 treatment were maximum.The same to CAT activity of ‘Fugeer No.1’.Under pH 8.5,all relative conductivities were maximum,while the other indexes were contrary;(3)With pH 4.5～5.5,the cultivation matrix which initial pH value was about 5.0 could be maintained in the optimum pH range，about 5.0.Therefore,azalea can grow well with the irrigation water of pH 4.5～5.5 in the Southwest,and ‘Green Glow’ even can grow with the untreated water of pH 7.5.It is good for extension and breeding,also is a excellent resource for alkali tolerance rootstocks of azalea.

Abstract:To study the photosynthetic mechanism of submergence resistance in peach rootstocks,we studied the effects of water-logging on photosynthetic characteristics of peach rootstock seedlings ［Maotao (Prunus persica (L.) Batsch.),Shantao (P.davidiana (Carr.) Franch.)］ and Nemaguard with normal water supply as control.The results showed that net photosynthetic rate(P_n),relative water content(RWC),water use efficiency(WUE),transpiration rate(T_r),stomatal conductance(G_s),apparent quantum yield(AQY),carboxylation efficiency(CE) and maximal photosynthetic electron transport rate(J_max) in leaves were significantly lower than control,but the MDA content was opposite.Nemaguard had higher chlorophyll content under submergence stress in the late experiment period.Meanwhile,decrease amplitude of P_n,RWC,T_r,WUE and G_s of Nemaguard were the lowest among the 3 cultivars,Maotao took second place.The level of water-logging tolerance among the 3 peach rootstock seedlings was Nemaguard>Maotao>Shantao.As response to water-logging,membrane-lipid peroxidation was intensified,the stomatal aperture,water metabolism capacity,photosynthetic electron transport rate and photosynthetic capacity decreased.The chlorophyll biosynthesis of Nemaguard under water-logging enhanced and descending speed of RWC were slower,which led to higher light absorption and water metabolism capacity;Nemaguard had stronger resistance to photoinhibition and photooxidation because of the lowest membrane lipid peroxide level,there for,Nemaguard could keep the highest photosynthetic capacity among the 3 peach rootstock seedlings.

Abstract:In the present study,a three compartment-cultivation system was designed to investigate the development of common mycorrhizal network as mediated by different plant species and also the time effects.Medicago sativa as test plant was grown in two outer compartments,one as donor compartment receiving AM fungal inoculum and another as receiver compartment indicating development of hyphal network.In the first experiment,plants were harvested at 8,10,12 and 14 weeks after planting to test the time effects;while in the second experiment,the middle compartment was left for mediating plants,M.sativa,Leymus chinensis or Lepidium spetalum,which are known to exhibit different mycorrhizal dependency.The experimental results indicated that:(1)At 8 weeks after planting the external hyphae from donor plants penetrated the nylon meshes separating different compartments and colonized receiver plants.At 10 weeks after planting,mycorrhizal colonization rate of receiver plants reached the same level as that of donor plants.However,the plant biomass and shoot P concentrations were significantly lower for receiver plant,indicating asymmetric competition between different plants bridged by hyphal network.(2)Under experimental conditions,different plants in the middle compartment showed no significant effects on mycorrhizal colonization and biomass of receiver plants,but significantly decreased plant biomass and shoot P concentrations of donor plants.In case of L.spetalum or no plants in the spacer compartment,both shoot and root biomass of receiver plants were significantly lower than those of donor plants;while in case of M.sativa and L.chinensis,there were no significant differences in plant biomass between donor and receiver plants.The study demonstrated that both time and mediating plants are important factors influencing development of hyphal network between plant roots,and the established hyphal network could redistribute resources between plants and stimulate plant interactions.

Abstract:The characteristic of “stereoscopic” climates is fairly clear in Gongga Mountain,and various types of vegetation altitudinal belts ranging from subtropical vegetation to frigid zones vegetation were shaped along altitude.In this research,typical sample plot investigation method and allometric models were used to study the aboveground biomass and carbon storage of four typical vegetation altitudinal belts including evergreen and deciduous broad-leaved forest belt,mixed coniferous broad leaved forest belt,dark coniferous forest belt and alpine scrub belt in eastern slope of Gongga Mountain.The results show that:(1)The aboveground biomass of natural vegetation increased from lower to higher altitudinal zones until the maximum was reached and then declined as the altitude continued to increase.The aboveground biomass of the four vegetation altitudinal belts from low altitude to high was 233.49 t/hm²,524.55 t/hm²,415.81 t/hm²,20.86 t/hm²,respectively,indicating a maximum biomass of the mixed coniferous and broad leaved forest.The average individual plant aboveground biomass of the four vegetation altitude belts from low to high altitude was 320.11 kg,1 140.78 kg,623.15 kg,11.89 kg,respectively,which showed the same trend with the aboveground biomass of the vegetation altitude belts.(2)All the altitude belts analyzed as a whole,of the plant organs,leaf have the highest carbon content rate (48.52%),followed by branch (46.29%) and trunk (44.65%).The carbon storage of the four vegetation altitudinal belts from low to high altitude was 103.60 t/hm²,245.26 t/hm²,192.99 t/hm²,9.82 t/hm²,respectively.The correlation between aboveground biomass and mean annual precipitation reached a highly significant level,and mean annual precipitation was an important climate factor that affects the aboveground biomass distribution pattern in Gongga Mountain.

Abstract:The plant communities in Foping Natural Reserve were explored in this study.The diversity index and Huffman coding were used to examine the diversity and complexity of plant communities,as well as the relationship between complexity and species diversity.The results showed that:(1)The species diversity and complexity of plant communities presented a “low-high-low” pattern of skewed normal distribution as the altitude increased.The largest region of total complexity and diversity of plant community was concentrated from 1 300 to 1 500 m.The change pattern of total complexity and disorder complexity with altitude was similar to species diversity of communities (“low-high-low” pattern).However,the structure complexity had no regularity while the altitude increased.(2)Plant species diversity in the natural reserve was not only related with the altitude change,but also had close relationship with density of Bashania fargesii and Fargesia qinlingensis.The species diversity and species number significantly increased in the intersection of two bamboo groves.(3)The total complexity and disorder complexity of plant community had significant linear relations with the each index of species diversity,respectively.The variation of species diversity can totally express the changes of plant community complexity but can not be used to measure the structure complexity,because there is no significant correlation between species diversity and structure complexity.

Abstract:16 families,49 genera,87 species of rare and endangered plants in Shegyla Mountains were investigated in this paper.The “coefficient of endangerment” and the “value of superior conservation” were obtained through index quantification and weight allocation,thus the endangered levels and conservation priority classes were determined.The result showed that:(1)Of the 87 species studied,there were 1 critically endangered species,13 endangered species,55 vulnerable species,18 near threatened species;(2)23 species belonged to the first class protection,53 to the second,11 to the third.(3)The endangered level and conservation priority classes varied significantly between our research and the lists of endangered plants,most plants were threatened more severely in Shegyla Mountains.

Abstract:The purpose of this research was to establish a suitable two-dimensional electrophoresis system by optimizing the parameters including the different IPG strips,isoelectric focusing conditions,different gel concentrations and sample loading for intercellular washing fluid of cucumber leaves to analyze proteomics.Cucumber seedling leaves of the variety PI088 was used in the experiment,extracting the intercellular washing fluid and preparing for protein samples.(1)As shown by the results,with pH 3～10 nonlinear IPG strips,under the conditions of isoelectric focusing 70 000 Vh,10% separating gel concentration,sample volume 800 μg,we got a clear two-dimensional electrophoresis map.(2)The proteomics profiling of intercellular washing fluid of cucumber leaves in different inoculation time was analyzed by using the previous established protocol.We found 12 up-regulated and 10 down-regulated proteins with more than 1.5 times changes in 2 days after inoculating with Pseudoperonospora cubensis compared with control and one of the different protein spots were successfully identified.(3)Mass analysis showed that the different point is an acidic chitinase and the isoelectric point is 4.27.Reproducible profiles with high resolution were obtained by this 2-DE system.

Abstract:Paris cronquistii (Takht.) H.Li var.brevipetalata H.X.Yin et H.Zhang,a new variety of genus Paris from Sichuan Province,China is described.It is similar to P.cronquistii (Takht.) H.Li,but differs in having petals linear,1.2～3.1 cm long,much shorter than sepals,drooping,stamens 8～12,only double of the number of petals.The surface of leaf is dark green with light green stripe along main veins.

Abstract:Two genera and five species of plant are recorded to Gansu,China for the first time.The newly recorded genera are Maesa and Ardisia (Myrsinaceae).The newly recorded species are M.hupehensis,A.japonica,Apios carnea (Leguminosae),Impatiens sutchuenensis (Balsaminaceae) and Galinsoga quadriradiata (Asteraceae).

Abstract:The violaxanthin cycle (V-cycle),reversible conversion of violaxanthin (V) to zeaxanthin (Z) via the intermediate antheraxanthin (A),is a reversible switch of photosynthetic light-harvesting complexes between a light-harvesting state under low light and a dissipative state under high light.Xanthophylls such as zeaxanthin are known to play a crucial role in deactivating triplet chlorophyll (³Chl^*) and singlet oxygen (¹O₂^*).Violaxanthin cycle is further assumed to be involved either directly or indirectly in the non-photochemical quenching (NPQ) of excess light energy in the antenna of PSⅡ.Binding of xanthophylls by antenna proteins of both photosystems is essential to the regulation and function of the V-cycle.Because antenna proteins bind the substrates,V and Z,of the two Vx-cycle enzymes,VDE and ZEP,respectively,and antenna proteins are supposed to be the site for the Z-dependent dissipation of excess light energy.The lipid properties of the thylakoid membrane have a strong impact on xanthophyll conversion.The kinetics of violaxanthin de-epoxidation is likely to be limited by xanthophyll diffusion within the membrane.This assumption is supported by the fact that the first step of de-epoxidation (the V to A conversion) exhibits a 4～6 times higher rate constant than the second step (the A to Z conversion).The current knowledge supports the view that antenna proteins and thylakoid membrane lipids are essential modulators of violaxanthin cycle.Here a review is given on recent progress in the biochemical reaction and photoprotective functions of xanthophylls,structural properties of xanthophyll-cycle enzyme and cofactors,the regulation of xanthophyll cycle by antenna proteins and thylakoid membrane lipids.

Abstract:The gene expression in eukaryotic is regulated by chromatin structure.Epigenetic markers (like DNA methylation and histone modification) play an important role in the defense responses of plant.For example,plant DNA methylation patterns can be altered by pathogen infection,and pathogen-induced locus-specific demethylation can influence the expression of defense genes.Histone deacetylases (HDACs) promote defense responses against pathogens depended on jasmonic acid (JA) pathway.Furthermore,the chromatin remodeling complexes Swr1 may be targeted to gene promoters by the recognition of histone acetylation patterns and DNA motifs,which inhibited the expression of salicylic acid (SA)-sensitive genes.In this review,we focused on the underlying mechanisms of plant-pathogen interaction and the latest advances of epigenetics,such as DNA methylation,histone acetylation,histone methylation and chromatin remodeling.