Abstract:A DREB-like gene,designated as ThDREB2B (NCBI Accession No.EF653377) was isolated from Thellungiella halophila,a model plant for stress tolerance research.The result showed that:(1)The cDNA of ThDREB2B was 1 486 bp in full length,contained an open reading frame (ORF) of 954 bp that encoded 316 amino acid residues.The deduced protein was predicted to be 36.0 kD in molecular mass and pI 4.81.The region between residues 76 and 135 was a typical AP2/EREBP DNA-binding domain.(2)The phylogenetic analysis showed that ThDREB2B belonged to the A-2 group of DREB transcription factor subfamily.(3)The expression level of ThDREB2B was relative low in normal growth conditions,and was up-regulated under low temperature,salty,or drought stress.(4)The yeast one-hybrid analysis showed that ThDREB2B could bind to DRE element very specifically,but the transcriptional activate activity was very low.A post-translation modification might be necessary for ThDREB2B to activate the transcription of target genes.

Abstract:SGTl (suppressor of the G₂ allele of skp1) is a required component in some signaling pathways mediated by disease resistance (R) genes in many plant species.In this study,a full-length cDNA encoding the SGT1 protein was isolated from Ipomoea trifida by RT-PCR and RACE,designated ItSGT1.ItSGT1 has an open reading frame of 1 087 bp encoding putative protein of 361 amino acid residues.The molecular weight of putative protein is 40.1 kD and its pI is 5.05.The predicted SGT1 protein contained typical SGT1 domains of TPR,VR1,CS,VR2 and SGS.The deduced amino acid of ItSGT1 showed higher degree of similarities with their orthologs in other plant species.Southern blot analyses revealed that SGT1 was a multi-copy gene in the I.trifida genome.Analysis of ItSGT1 expression at the mRNA level by semi-quantity RT-PCR showed that ItSGT1 was expressed in different tissues.

Abstract:In the present study,a sialyltransferase-like proteins (STLP) gene,designated as DoSTLP1 (GenBank accession No.KC178574),was identified from a medicinally important species Dendrobium officinale,using RT-PCR and RACE methods.Sequence analyses showed that the full length cDNA of DoSTLP1 was 1 340 bp and encoded a 367 aa with a molecular weight of 41.66 kD and an isoelectric point of 8.64;The deduced DoSTLP1 protein contained the sialyltransferase and glycosyltransferase family 29 conserved domains (1~357,87~346),together with a signal peptide sequence (1~27) and two transmembrane helices (3~25,285~311).Multiple sequence alignment and phylogenetic analysis demonstrated that DoSTLP1 was highly similar (44.7%~53.7%) to STLPs genes from various plant species and was closely related to those from monocots.Real time quantitative PCR analysis revealed that DoSTLP1 was constitutively expressed in the leaf,stem and root organs.The transcription level of DoSTLP1 in roots was relatively higher than that of leaves with 2.857 fold.Molecular characterization of DoSTLP1 will be helpful for further functional elucidation of the gene involving in the development of D.officinale.

Abstract:In this research,the rapeseed rapid alkalinization factor gene RALFbn was initially cloned from Brassica napus by the NCBI (National Center of Biotechnology Information) database information.Structure analysis of RALFbn,its predicted protein RALFbn and the expression of RALFbn were done.The results showed that:(1)The full-length cDNA of RALFbn in B.napus was 510 bp,no intron,encoded 79 amino acids.(2)The RALFbn protein had the conserved “YIXY” domain and four conserved Cysteine residues which were the characters of RALF family members.It also had N-myristoylation site,tyrosine kinase Ⅱ phosphorylation sit,protein kinase C phosphorylation site,tyrosine kinase phosphorylation site,which indicated an active physiological activity of the potential RALFbn.(3)RT-PCR analysis results showed that RALFbn mostly expressed in rape stamens,no expression in pistil,petals and sepals,indicating that RALFbn was closely related to pollen development of B.napus.

Abstract:According to the ARP (Auxin-repressed protein) gene fragment sequence,which was obtained from the SSH (suppression subtractive hybridization) library constructed by iron-deficiency and normal leaves.The full length of ARP was cloned by the method of RACE (repeat amplification of cDNA end).The ARP expression levels were analyzed by qRT-PCR (real-time quantitative PCR) technology.The results showed that the IAA content in leaf was decreased gradually with the increasing of iron-deficiency degree;the full-length cDNA of ARP was 707 bp,its coding region covered 351 bp and encoded a polypeptide containing 116 amino acids.It was predicted that the ARP might positioned on the microbody in cell,was a nontransmembrane protein with non secretory type,had a conserved domains with auxin gene family;and its molecular weight was 12.82 kD;There were positive significant differences between ARP relative expressions in leaves with different iron-deficiency degrees.The ARP expression increased with the increasing of iron-deficiency degree.It was speculated that the endogenous IAA level was negatively regulated by the ARP in iron-deficiency leaves,to control the leaf growth and development.

Abstract:This experiment was studied on the effect of different selection methods and selection treatments on resistant protocorm-like bodies (PLBs),the selection and examination of transgenic plant regeneration in Dendrobium spp.The results showed that:(1)The method of retarding selection with the gradual enhancement of kanamycin (Km) concentration and selecting treatments with cutting under low Km after sterilizating PLBs mediated by Agrobacterium tumefaciens strain LBA4404 with antisense ACS gene and gus gene was optimal.The rate of transgenic resistant PLBs was up to 14.97%.(2)The multiplication of resistant PLBs was cultured on medium with gradual reduction of Km concentration and cutting under low Km concentration.The rate was 1.15 and the growth of PLBs was the best.(3)The differential rate of resistant PLBs cultured on the 1/2 MS medium supplemented with 0.5 mg/L 6-BA was 73.85%,13 resistant plantlets rooted on the 1/2 MS medium supplemented with 1.0 mg/L NAA and 50.0 mg/L Km and 100.0 mg/L Cefotaxime (Cef),the transgenic rate was 12.15%.(4)GUS histochemical assay and PCR assays proved that the T-DNA containing antisense ACS gene was integrated into the genome of these resistant plantlets.There was no morphological difference between transgenic plantlets and no-transgenic plantlets.Three transgenic plantlets transferred after 2 months were survival.

Abstract:The suspension cells and leaves of Liriodendron tulipifera were used as experiment materials to isolate protoplasts.The influences of different factors including pretreatment osmotic pressure,the kind and combination of enzymes,digestion time,culture medium were compared.The result showed that the pretreatment of leaves and suspension callus cells in the Cell Protoplast Wash containing 0.1% 2-(4-Morpholino) ethanesulfonic acid (MES) and 0.6mol/L mannitol (60M-CPW) for 1 h at 25 ℃ and light-resistant has the best effect in the protoplasts isolation.The best enzyme solution of suspension cells contained 60M-CPW+1% cellulase+1% hemicellulase+0.2% pectinase Y-23+0.1% MES,incubated at 25 ℃ for 6 h and the protoplasts yield was about 3×10⁶ per gram.The best enzyme solution of leaves contained 60M-CPW+2% cellulase+1% hemicellulase+0.2% pectinase Y-23+0.1% MES,incubated at 25 ℃ for 10 h and the protoplasts yield was about 11×10⁶ per gram.It was easy to culture the protoplasts of suspension callus cells and the culture KM8p was better than the modified MS.In the culture medium of KM8p containing 1.0 mg/L 2,4-D+0.5 mg/L 6-BA,the protoplasts of suspension cells will be formed visible callus in 25 days.

Abstract:Segregating population consisting of F₁,BC₁P₁,BC₁P₂ and F₂ were generated by crossing the resistant inbred line PI511890 with the susceptible inbred line‘Baipicui’.The resistance of segregating population and parental lines were evaluated by inoculating spore isolates of gummy stem blight at seeding stage.The results indicated that:(1)The resistance to gummy stem blight in PI511890 is controlled by a single dominant gene.(2)Using bulked segregation analysis,an unique 900 bp fragment was amplified in resistant materials with the primer ISSR-100.It was confirmed that the marker ISSR-100₉₀₀ was linked to the gene Gsb-3.(3)The polymorphic patterns of ISSR-100 in the 182 individuals of F₂ were scored and then calculated by the software of JoinMap 4.0.The results showed that the genetic distance between ISSR-100 and Gsb-3 is 8.3 cM.This ISSR band indicated that the marker could be useful for marker assisted selection in melon breeding for gummy stem blight resistance.

Abstract:Total DNA from 54 individual plants collected in 27 sample sites of 10 Oxytropis species in Inner Mongolia was extracted in this research,and the trnL-F sequence was amplied and sequenced.Then the sequences were analyzed by ClustalX and MEGA 5.0.The phylogenetic tree was constructed by Maximum Likelihood methods in MEGA 5.0.The results showed as follows:(1)In the 10 Oxytropis species,there were 54 variable sites,46 informative sites and 1.9% of the inter-specific difference,and the GC contents of the trnL-F region were between 30.69%~31.50%.(2)The Oxytropis sp.were monophyletic,clearly separating from the Astragalus sp..The bootstrap value was 99%.(3)The samples of Oxytropis glabra itself clustered a group which was relatively evolved independently.The samples of O.verticillaris,O.racemosa and O.ochrantha mixed.Therefore they showed a close relationship.We are congruent with the points in Flora of Intromongolica,which consensus putting the three species into Subgen.Euoxytropis Sect.Baicalia Stell.ex Bunge.(4)Different samples of O.aciphylla were divided into two major branches,and the taxonomic position of O.aciphylla at subgenus level needs further investigation.(5)The samples of O.ciliata and O.inschanica clustered a group,which also supported the consensus which put them into Sect.Xerobia Bunge.The investigation results indicated that trnL-F sequences provided the molecular evidences for the study of the phylogenetic relationships in the Oxytropis at subgenus,sects and species levels.

Abstract:In order to reveal the variation degree and variation patterns of the phenotypic in Michelia yunnanensis,we investigated 14 phenotypic traits for 180 individuals in 6 natural populations of M.yunnanensis from Kunming City in Yunnan Province of China and used nested analysis,correlation analysis,variance analysis,Shannon-Weaver diversity index and cluster analysis to analyze results.The results showed that:(1)There were significant differences in the phenotypic variation among and within populations.Phenotypic differentiation coefficient (VST) among populations (24.38%),was less than that of within populations (75.62%).The variation within-populations comprised a majority of total phenotypic variation.Coefficient of variation (CV) varied from 16.20% to 60.11% showing the high variation of the phenotypic traits.(2)The Shannon-Weaver index analysis shows that there were rich diversity in M.yunnanensis various populations and the total mean diversity index was 1.772.(3)According to the UPGMA cluster analysis,the po-pulations of M.yunnanensis in this study could be divided into three groups.These cluster results were not due to geographic distances.Utilizing of variation within and among populations is important significance for genetic improvement of M.yunnanensis.

Abstract:By using Brassica campestris ‘Longyou 7’,‘Longyou 9’,‘winter juncea’ and Brassica napus ‘vision’ as materials,statistical analysis on stoma guard cell perimeter and chloroplast number were performed,SSR marker was used to test accuracy of counting chloroplast number and measure perimeter in stomatal guard cells further.(1)The variation of stoma guard cell perimeter between parents and interspecific hybrid was very similar among the different leaf positions on the same plant.However,the variation was relatively similar at the down location in the same leaf.(2)Parents and interspecific hybrid had a clear dividing line for perimeter of stomatal guard cell at 58.90 μm,75.83 μm.The chloroplast number of ‘Longyou 7’ and ‘Longyou 9’ should be at the range of 10 to 12;the chloroplast number of ‘Longyou 9’בvision’,‘Longyou 7’בwinter juncea’ should be at the range of 14 to 16;the chloroplast number of ‘vision’ and ‘winter juncea’ should be at the range of 18 to 19.(3)The accuracy of this method for identification interspecific hybrid was 97.5% after SSR marker test.Obviously,there is a specific boundry between stomatal guard cells perimeter and chloroplast number of B.campestris,Brassica napus,‘winter juncea’ and their interspecific hybrid which can be used to identify interspecific hybrid.If guard cell perimeter is at the range of 58.90 to 75.83 μm,and at the same time chloroplast number is at the range of 14 to 16,the plant will be true hybrid.

Abstract:Male sterile individuals were discovered in the population of Erigeron breviscapus planted in Luxi Yunnan,and the frequency was about 1.06×10^-4.The morphology and the anther development of the newly male sterile individuals was examined and the pollen vigor and seed-setting percentage of the individuals were tested.It was shown that the modality of root,peduncle and leaf was similar between sterile and normal fertile plants,but sizes of tubular flowers and anthers and filament lengths were litter and no pollen grain or pollen without vigor in the male sterile plants.At the microsporocyte phase,tetrad phase,microspore phase and early uninuclear phase in the anther development,the microsporocyte and tetrad break down and form anther without pollen grain,or the microspore and uninuclear pollen break down and form sterile pollen grain with different forms and extine sculptures,which resulted from the premature degeneration of the tapetum.

Abstract:The chromosomic meiotic behavior of pollen mother cells (PMCs) of the hybrid progenies from Triticum timopheevi×Avena fatua L.var.glabrata Pat was researched by general cytology and genomic in situ hybridization (GISH) in the present study.The results showed that the PMCs meiotic index of the F₃ line was 87.46,indicating some genetic instability.4 pairs of red hybridization signals were found in the PMCs at the metaphase I by GISH analysis,and there was a red signal in each dissociative univalent.Some lagging chromosome,chromosome bridges and micronuclei were discovered at the anaphase Ⅰ,anaphase Ⅱ and telophase Ⅱ,with the percentage of 10.58%,1.92% and 12.36%,respectively.Wheat homologues or homoeologues normally pairing was interfered by the wild oat chromatin might lead to these abnormal phenomena.

Abstract:Gametophyte development of Egenolfia sinensis and E.bipinnatifida （Bolbitidaceae）were studied by the microscopy.The results indicate that both of them have similar features in spore germination and gametophyte development.The spores are bilateral,allmonolete.The spore germination pattern is the vittaria-type.The gametophyte development undergoes the filament and plate and finally forms the heart-shaped prothallus.Club-shaped,multicellular,marginal hairs are mostly found on the young prothallus towards the anterior end.The development of the prothallus is the drynaria-type.Sperms are produced in the young prothallus stage,while the archegonia are produced only in growing point under the large heart-shaped prothallus.Sex organs are the leptosporangiate-type.After fertilization,the zygotes develop into sporophyte.We discussed the phylogenetic relationship of Bolbitidacea,Dryopteridaceae and Lomariopsidaceae through comparisons of the gametophyte development.

Abstract:13 species belonging to 4 sections of the genus Lilium were crossed in 80 different cross combinations,their self- and cross-compatibility were studied.In order to overcome pre- and postfertilization barriers,2 different pollination methods and embryo rescue technique were used.The results indicated that self-compatibility of wild lilies was different,self-incompatibility of L.leichtlinii and L.davidi ‘unicdor cotton’ was investigated.Among the cross combinations within Sinomartagon section,only L.cernuum×L.pumilum,L.davidi ‘unicdor cotton’×L.cernuum and L.davidi×L.leichtlinii obtained hybrid embryos and seedlings with delaying pollination and embryo rescue technique.Cross compatibility between Sinomartagon and Lophophorum section was better than other cross combinations from different sections of the genus Lilium.Delaying pollination method was more effective than cut-style pollination for most of cross combinations.For the majority of selfed and crossed combinations,tissue culture could effectively prevent post-crossing barriers and obtained first filial generation seedlings.

Abstract:Nuclear divisions of Bangia conchocelis including vegetative and sporangial phases were systemically studied in this research.The Bangia sample was collected from the cultivation frames of Fujian Province.The results showed that Bangia conchocelis has a heterogenesis life history.Both the vegetative and sporangial branch cells of Bangia conchocelis were diploid with 2n=8 chromosomes and the nuclear division was mitosis.Homologous chromosome pairing could be observed till the late prophase in cells of both phases,which proved that somatic chromosome pairing was an important characteristic of nuclear division of Bangia conchocelis cells.

Abstract:An important step in the cultivation of super prematurity strawberry is how to determine the start of flow bud differentiation (FBD),and this is the premise of planting strawberry at the early stage.We conducted experiments Fragaria ananassa cv.‘Benihoppe’ at low-temperature treatment (nocturnal temperature was 17~20 ℃ with fluctuations) and short-photoperiod treatment (dark length was 16 h) from 23rd June through 24th August 2011.From the start of treatments we took samples every 3 to 5 days,separated apexes under anatomical microscopy,fixed all materials with FAA,dried at critical point,and observed them with scanning electron microscope.On the basis of the observed micro-morphological characteristics,we divided the whole process of strawberry flower bud differentiation into 7 phases:flower bud non-differentiation phase,FBD starting phase,reproductive apex swelling phase,inflorescence differentiation phase,top-flower sepal formation phase,flower petal formation phase,stamen formation phase and pistil formation phase.In the flower bud non-differentiation phase,the top bud was in the state of vegetative growth continually.In the FBD starting phase,the top bud turned gradually from sharp,narrow vegetative apex into smooth,broad reproductive apex.In the reproductive apex swelling phase,the reproductive apex uplifted and swelled.In the Inflorescence differentiation phase,top flower primordium and lateral flower primordium gradually appeared during top flower primordium differentiation process.In the top flower sepal and petal formation phase,the differentiation of sepal (including accessory sepal) and the petal was finished.In the stamen formation phase,two-wheeled stamen primordium appeared gradually by differentiation.In the pistil formation phase,a large number of pistil primordium uplifted gradually,the carpel primordium curled,and the FBD process was complete.This result revealed that the suitable time of strawberry planting is after the reproductive apex fully swellen.That is after the low-temperature and short-photoperiod treatment 15~20 days,the strawberry seedling can be planted on field.

Abstract:This research was conducted to provide theoretical evidence for bamboo cultivation during this time of possible climate change.Open-top chambers (OTCs) were employed to determine the effects of elevated O₃ （EO）and elevated CO₂（EC）alone and in combination on membrane lipid peroxidation and anti-oxidation system in the leaves of Phyllostachys edulis using a split-plot design with treatments of AA,EC ,EO,ECEO.The results showed that:(1)After 30 days of exposure,elevated O₃ can stimulate the activity of anti-oxidation enzymes(SOD,CAT,POD,APX) and the contents of osmotic adjusting substances(soluble protein and soluble sugar),which can balance reactive oxygen species production,resulting in no significant increase in malondialdehyde content.Along with the decline of antioxidant,intense the damage to membrane lipid and destroy the structure of cell membrane.(2)Short-term treatment of high concentration of CO₂ on membrane lipid peroxidation and antioxidant system in the leaves of P.edulis effect is not evident,and long-term treatment of high concentration of CO₂ will increase the antioxidant ability of P.edulis and osmotic adjustment function in a certain extent,and thus,alleviate the oxidative stress.(3)In combination of elevated CO₂ and O₃,the leaves of P.edulis can maintain high levels of antioxidant enzymes activities and osmotic adjustment substance contents to effectively regulate reactive oxygen species generation and clearing balance,indicating that elevated CO₂ could ameliorate the oxidative stress in some extent.

Abstract:With rapeseed roots of four different cold hardiness under continuously cool treatment (4 ℃ 24 h,0 ℃ 24 h,-3 ℃ 24 h,-6 ℃ 24 h,-9 ℃ 24 h,-15 ℃ 24 h,-21 ℃ 24 h) in the low temperature test boxes,testing the antioxidant enzymes activities (POD and CAT) and the POD isozymes electrophoresis and morphological variation characteristics of rape seedlings before and after the frozen treatments.To explore the correlation for changes of antioxidant enzyme activities at low temperatures and the ice formation in root cells of winter rapeseed and antifreeze mechanism of the winter rapeseed root.The result showed that:(1)The varieties of weak frost resistance rapeseed (‘Longyou 7’ and Vision) in the low temperature appeared a large number of water damage was on the surface of leaves,then the leaf blade atrophied until withered,root appeared water softening until dry death;strong frost resistance varieties (‘Longyou 6’ and ‘Longyou 8’) in the frozen did not produce water damage,or water damage was less,and the damage of its root was slighter.(2)Under continuously cool treatment,POD and CAT activities of the weak frost resistance rapeseed roots in early cooling had large changes,and then kept constant,indicating that the cells of roots had completely froze;POD and CAT activities of strong frost resistance rapeseed root in early cooling had small changes,which greatly increased in later period,indicating that the cells of roots remained solution state;The analysis of POD isozyme also reflected a similar change.Research showed that there were some correlations between changes of antioxidant enzyme activities of winter rapeseed root and the frozen stage of root cells in low temperature.Cell ice usually caused plant fatal damage,which stated that the key that strong cold hardiness rapeseed can winter safely was that avoiding intracellular ice formation,and the lower freezing temperature of its cells is,the stronger the cold hardiness of them is.

Abstract:In this study,the Al-sensitive black soybean (SB) was taken as experimental materials under Al stress to investigate the physiological and molecular mechanisms of the effect of the pretreatment with hydrogen peroxide (H₂O₂) on alleviating aluminum toxicity.The results show that:(1)The relative root growth of SB is promoted significantly with 0.1 and 1.0 μmol·L^-1 H₂O₂ pretreatment,but promoted first then inhibited with 10.0 and 100.0 μmol·L^-1 H₂O₂ pretreatment.(2)Exposure to different Al concentrations (50～400 μmol·L^-1) 3 weeks after pretreatment with 1.0 μmol·L^-1 H₂O₂,the total protein content was increased in both leaves and roots by 16.7%～41.2% and 10.0%～25.0%,respectively;the MDA content was significantly decreased by almost 50%;the activities of SOD and POD improved greatly in SB.(3)RT-PCR analysis showed that pretreatment with H₂O₂ also increased the expression level of SOD both in SB root and leaf under Al stress.Taken together,pretreatment with H₂O₂ can promote the growth of SB greatly and enhance the capacity to Al stress by the means of increasing the activities of antioxidant enzymes and their expression levels.

Abstract:To study the effects of physiological and biochemical characteristics and growth under water stress,we potted Liyu 18 seedlings under four different soil content levels:optimal water content (CK),mild water stress (LS),moderate water stress (MS) and severe water stress (SS),which were controlled by weighing the soil and pots.The results showed that:(1)With the increase of stress level,the maize biomass was significantly reduced,while root shoot ratio,root activity,proline content were increased.The influence of water stress on above-ground part was more than that of root.Soluble protein content was not significantly different and MDA content fluctuated.(2)Along with the period of water stress continued,root shoot ratio,root activity and proline content were increased and then decreased;soluble protein of roots was declined and then increased.MDA accumulation fluctuated in seedling of maize and MDA content in leaf were higher than that in root.(3)In preliminary stress,CAT was more sensitive than SOD and POD in leaf;root in moderate water stress mainly depends on CAT to reduce oxidation damage,while it also depends on CAT in severe water stress early and then through the CAT and POD common action to reduce the oxidation damage.POD synchronously reduced oxidation damage in leaf and root,while the complementary role existed between SOD and CAT in leaf and root.We can conclude that the growth of maize seedlings were negatively influenced by different degree of drought stress,but the protective enzyme system and osmatic adjustment substance could adjust themselves to avoid water drought harms.

Abstract:To further elucidate the relationship of spermidine and salt tolerance of halophyte Nitraria sibirica Pall.,under different levels of salinity in hydroponics condition,we studied the effect of spermidine on malondialdehyde (MDA),superoxide anion (O^-·₂) and the antioxidant enzyme system in leaves of N.sibirica seedlings.The result showed that in treatment groups (100 mmol·L^-1 NaCl and 200 mmol·L ^-1 NaCl),the activities of superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT) in leaves of N.sibirica seedlings and the activity of root system were significantly increased,while the content of the MDA and O^-·₂ in leaves were reduced in 5 d after foliage spray of spermidine (0.1 mmol·L^-1).In treatment groups (0,50 and 300 mmol·L ^-1 NaCl),there was no obvious effect on leaves of N.sibirica seedlings after treatment of exogenous spermidine.The results showed that under 100 mmol·L^-1 to 200 mmol·L ^-1 NaCl stress,exogenous spermidine can effectively reduce the injury to N.sibirica and enhance the adaptability in salt environment.

Abstract:To research the suitability of Tamarix chinensis seedlings to salt and drought stress,we studied the contents of osmotic adjusting substances in leaves of two years old T.chinensis seedlings under salt and drought stress by pot culture.The results showed that:(1)The soluble sugar content increased and then decreased with the stress intensified and kept higher than that of control under moderate and severe salt and drought stress.(2)The proline content increased with the stress intensified,but only significantly higher than that of control under the intercross stresses of severe salt and moderate and severe drought.(3)The contents of Na⁺ and Cl^- changed irregularly,and kept a significantly higher level than that of control under different stresses.(4)The contents of K⁺,Ca²⁺ and SO₄^2- decreased with the salt stresses intensified under light and severe drought stresses.Under moderate drought and salt stresses,the contents of K⁺ and Ca²⁺ had no difference with the control.Therefore,the osmotic adjusting substances played an active role on salt and drought resistance.In conclusion,T.chinensis seedlings showed some tolerance to salt and drought stresses,and appropriate drought stress could increase the resistance of T.chinensis to salt stress.

Abstract:Using the cork oak annual potted seedlings as experimental material,we studied the physiological and biochemical responses of Quercus variabilis seedlings under different soil drought stress systematically by way of weighing to control water content in soil.The result showed:(1)Under the CK stress (relative soil water content is 19.5%~21.5%),SOD,POD and CAT activities in the leaves of Q.variabilis seedlings kept stable,however,under the moderate and severe stress,with the time of drought stress,SOD,POD and CAT activities were increased firstly and then declined.But the ranges were different under different drought degrees.(2)In the whole process,the content of MDA kept an upward trend under different drought degrees,but the ranges were different.In addition,the content of soluble protein and the root activity raised firstly and then decreased with increasing of drought stress.(3)The content of proline become increased firstly and then declined,and the contents of chlorophyll a,chlorophyll b,chlorophyll in total and a/b were decreased in the process of drought stress.It was resulted that Q.variabilis seedlings improved the characteristic of resistance to soil drought stress by increasing the activities of protective enzymes,the content of soluble protein,proline content,root activity and so on in the short time and mild stress.Under severe stress,the metabolism in vivo and self regulation ability were in disorder and deprived,causing the protective enzyme activities,proline content,soluble protein content and root activity decreasing.

Abstract:To investigate the effect of salt stress on growth and ion distribution of Brachypodium distachyon (Bd21),we treated Bd21 seedlings with various concentration of NaCl,while the Arabidopsis thaliana seedlings were used as control.The results showed that:(1)The growth of roots and leaves of Bd21 was markedly inhibited under salt treatments.(2)Based on the results of root/leaf ratio,root growth of the Bd21 was better than that of Arabidopsis seedlings under the same salt treatments,suggesting that Bd21 is more tolerant to salt stress compared to the Arabidopsis seedlings.(3)Leaf Na⁺ content was lower than that in roots,and the K⁺,Cl^-,and the ratio of K⁺/Na⁺ in leaves were higher than those in roots under salt treatments,indicating that the transport of Na⁺ from the root to the shoot is effectively inhibited in Bd21.(4)Positive correlations of Na⁺ and K⁺ content were found in Bd21 and Arabidopsis roots,however,no correlations were found in leaves.These results implied that the same transporters are used to transport the Na⁺ and K⁺ in both plant roots and different channels are needed in leaves.

Abstract:The kinetic parameters of chlorophyll fluorescence and the photosynthetic rate of the different genetic background flue-cured tobacco varieties (‘K326’,‘Yunyan 87’,and ‘Zhongyan 103’) were studied under different altitude conditions,and their influencing factors G_s,C_i,T_r,WUE were investigated.The result showed that:(1)There were positive correlation between the average daily value of P_n,G_s,WUE and altitude and negative correlation between the average daily values of intercellular CO₂ concentration (C_i),transpiration rate (T_r) and altitude.(2)The diurnal variation of P_n,C_i,G_s,and T_r in the leaves presented a one-peak distribution and an unobvious midday depression occurred at altitude of 1300 m,and the diurnal variation of P_n,C_i,G_s,and T_r presented a bimodal pattern and an obvious midday depression occurred in the sunny noon.(3)The primary light energy conversion of PSⅡ (Photo-systemⅡ) (F_v/F_m) and potential activities of PSⅡ(F_v/F₀) of the three tobacco varieties increased with increasing altitude.(4)The daily photosynthesis (∑P_n) of the three tobacco varieties increased with increasing altitude,and the daily photosynthesis of ‘Yunyan 87’ varieties were significantly higher than the other two varieties.At altitude of 900 m,flue-cured tobacco’s leaves had the highest daily transpiration (∑T_r),and the lowest in 1 300 m.Obviously,the photosynthetic characteristics and photosynthetic capacity of flue-cured were affected and restricted by altitude factors,and the photosynthetic characteristics of tobacco varieties should be considered during distribution of varieties.

Abstract:To reveal the effects of different vegetation types of Zhifanggou watershed on soil microbial biomass and soil enzyme activities,we studied the microbial biomass,soil enzyme activities and the correlation between soil physicochemical factors and mentioned parameters,taking nine vegetations of this valley as the materials.The results showed that:(1)Compared with the abandoned land,soil physiochemical properties,microbial biomass and enzyme activities of arbor and shrub increased;the available nitrogen,microbial biomass P,soil urease activity and catalase activity of herbaceous decreased.(2)Soil microbial biomass C,microbial biomass N,invertase activity and alkaline phosphatase activity of different vegetation types were consistent with the law of shrub>arbor>herbaceous,while the microbial biomass P,urease activity and catalase activity were consistent with the law of arbor>shrub>herbaceous.(3)The soil microbial biomass C,N and P were significant positively correlated with soil organic material,total nitrogen and total phosphorus,and there were significant positive correlations between enzyme activities and soil organic material,total nitrogen and alkali-hydrolyzed nitrogen.It indicated that soil microbial biomass and enzyme activities were influenced by vegetation types and soil physicochemical properties collectively,and the artificial shrub had a better effect on plant recovering than those of artificial arbor and herbaceous.

Abstract:Aimed to study the dynamics of the biomass and allocation of the Pinus massoniana plantations with different stand ages (5a,15a,21a,32a,60a) in Guangxi,South of China,we established fifteen plots,each with a size of 20 m×50 m,at different sites.By using the investigation data of 21 Pinus massoniana trees with different ages and diameters at breast height,the regression model of the biomass relating with D (diameter at breast height,1.3 m) was established.And other biomass components were sampled in different quadrates in fifteen 1 000 m² research plots:shrubs (three 4 m² quadrats),herbs (three 1 m² quadrats) and litterfall (three 1 m² quadrates).This method applied to estimate the biomass and allocation characteristics of biomass with stand age.Results showed that:(1)The biomass of the stands increased with stand age,being 15.03 Mg/hm² in 5a stand,125.93 Mg/hm² in 15a stand,183.51 Mg/hm² in 21a stand,191.53 Mg/hm² in 32a stand,405.31 Mg/hm² in 60a stand,and living biomass and litter made up 75.01%~94.19%,0.86%~24.99%,respectively.(2)Most biomass (90.20%~98.35%) of Pinus massoniana plantation was concentrated in the tree layer,and grown with stand age,next was the litter layer,made up 0.86% to 24.99%;Shrub and herb biomass contributed small,made up 0.47% to 34.85%,0.32% to 27.00%,respectively,and decreased with stand age.(3)The biomass of the trunk occupied the greatest proportion of tree layer,made up 49.93% to 83.10%,increased with stand age;Root had a relatively stable biomass,accounted 6.97% to 12.82%;Branches and leaves made up 11.75% to 14.83%,1.33% to 23.65%,decreased with stand age.The biomass allocations of shrub were branch>leave,except root>branch>leaves in young (5a) forest.The above-ground biomass was higher than under-ground biomass in middle-aged (15a) and near mature (21a) forest,but opposite to that of other stands.(4)The litter biomass ranged from 3.48 to 6.68 Mg/hm²,the law was not obvious.(5)Biomass of all tree organs and stand of Pinus massoniana plantation showed a good growth model.Compared with other forest,the total biomass of 32a Pinus massoniana plantation was higher than that of the Phoebe bourmei Plantation,but lower than that of tropical rainforests,and it is the fast growing forest tree species with higher photosynthesis efficiency and potential carbon fixation.

Abstract:28 endophytic fungi isolated from the root,stem,leaf and fruit of Berberis thunbergii cv.atropurpurea were cultivated in liquid medium and the cultures were dried,grinded,and then extracted with acetone.The antifungal activities of the acetone extracts to five species of botanical pathogenic fungi were tested.The strain with wider antimicrobial spectrum was identified by molecular biological technology.The antifungal activities of the strain’s mycelia and fermentation broth were determined respectively.The results showed that:(1)Five endophytic fungi (R₃,S₄,L₆,F₂ and F₆ ) has a wider antifungal spectrum in the tested endophytic fungi that isolated from B.thunbergii cv.atropurpurea.The S₄ strain that isolated from the stem exhibit the best antifungal activity,which provided more than 90% inhibition of mycelium growth rates in five test fungi species,93.06% inhibition of Fusarium solani.(2)S₄ was identified as Paraphaeosphaeria by molecular biological technology.(3)The inhibition of mycelium growth rates for F.solani was significantly positively related to the tested concentration (volume) of mycelium acetone extracts from S₄(r=0.99,y=15.334x+14.618).The inhibition rates for F.solani was significantly negatively related to the tested concentration (volume) of fermentation broth of S₄(r=0.99,y=-20.196x+64.984).In that way,fermentation broth of S₄ promotes the growth of F.solani at high concentration.The compound with antifungal activities of S₄ mostly consisted of mycelia.

Abstract:New cytological methods in ferns by using embryo and young sporophyte were provided with details.Cytological methods of using root-tip and spore mother cell were compared with the new ones.It was supported that:(1)Several aspects limited the success rate of cytological observation by using field root-tips,for the mitotic phase cells of field root-tips only existed in the spring season,about one month,less root-tips numbers (<20 per rhizome),more viscous materials in the field root-tips,and slowly growth and difficulties in manipulating root tips after their collection.Based on above reasons,a low success rate (<40%) existed in the cytological experiment by using field root-tips of one rhizome.(2)Meiosis phase cells of spore mother cells only existed in the formation period of sporangia,about one week,which restricted the success rate of cytological observation of ferns.(3)New cytological materials:embryo and young sporophyte have more than 300 root-tips or embryos in unit areas (d=15 cm dish),more mitotic cells and less viscous materials in root-tip or embryo cells,and few restrictions in experiment season and time.The success rate of cytological experiment is more than 80% by using embryo and young sporophyte.For these reasons,new cytological materials and methods could raise the success rate of the cytological experiment in ferns.

Abstract:In the process of the investigation,collection and study of Bryophytes from the Dagu Glacier of Heishui County in Sichuan Province,discovered a new geographic distribution records of Andreaea densifolia.This paper describes its morphological characteristics and pictures is taken under the microscope.Description and drawing of the past had been corrected.Enriched our study information on Andreaea densifolia and it has an important significance on the study of diversity of moss flora of China.

Abstract:RNA editing is a post-transcription phenomenon of gene processing and modification at specific nucleotide sites,which including nucleotide insertion/deletion or nucleotide conversion.RNA editing mainly occurs at genomic of mitochondria and chloroplast in higher plants.It has many important biology functions,but the mechanism of this phenomenon is still unclear.During recently years,the PPR proteins,might be as trans-acting factor of RNA editing,has been put forward and become a research focus in molecular biology.In this review,we introduced PPR proteins,RNA editing and possibility interaction pattern between PPR proteins and RNA editing.

Abstract:The research progress about anthocyanin biosynthetic genes cloning,application and exogenous gene transformation of Petunia hybrida were reviewed in this paper.At least 12 enzymes were involved in the petunia anthocyanin biosynthesis.Except AAT and AMT,the most of synthetic enzyme genes,regulatory genes An2,An4 and enzyme activity regulation gene difF,have been cloned.A variety of exogenous color genes such as DFR,F3′5′H,CHS,CHI,CHR and Lc were introduced into petunia,the changes of flower color were observed.Some researchers also reported that the transformants with CHS were male sterility.The application prospects about petunia anthocyanin biosynthetic genes were also discussed.