Abstract:To investigate the function and expression patterns of sucrose synthase gene,we used cDNA reverse transcript from total RNA of stem tissue of Populus tomentosa as DNA template.The specific-primers were designed according to PtrSS2 CDS on Phytozome v9.0 database for PCR amplification.The sequencing results indicated that PtSS2 was 2 412 bp in full length which encoded a protein of 803 aa.Its molecular weight and isoelectric point (pI) were 92.14 kD and 6.00,respectively.The result showed that the PtSS2 in P.tomentosa belonged to acidic protein.The deduced protein sequence of the PtSS2 shared 100% and 98.63% highly identify with PtrSS2 and PtrSS1,respectively.Conserved domain searching results showed that this protein contained two conserved function domains,5~552 and 554~744.Tissue differential expression detected with qRT-PCR indicated that the PtSS2 transcripts were more abundant mRNA products in vegetative bud and stem tissue,and relative lower transcripts in root,it belong to constitutive expression patterns.RT-PCR showed that levels of mRNAs to drought stress were significantly higher than that in control group.The results suggested that PtSS2 gene play a role in the development of P.tomentosa plant.

Abstract:Primers were designed based on homologous sequences of previously reported Arabidopsis thaliana and Brassica napus L..BcHSP70-1 was isolated from Brassica campestris ssp.chinensis.The physical properties of BcHSP70-1 gene,together with subcellular localization and transmembrane domain were analyzed with bioinformatics.The results showed that:BcHSP70-1 contains 1 950 bp (ORF) nucleotides and encodes 649 amino acids,which is hydrophilic protein and localized in the cytoplasm.BcHSP70-1 has one intron and two exons,the intron is 324 bp.Comparison of orthologous exons and introns of HSP70-1 from different species showed that introns have more significant differences.Using real-time quantitative PCR analysis showed that BcHSP70-1 expressed differently among the different heat resistant cultivars.The heat sensitive cultivar (NHCC002) had no constitutive expression of the gene.The qRT-PCR results showed that,compared to 38 ℃ high temperature stress,BcHSP70-1 had higher expressed levels at 4 ℃ low temperature stress in non-heading Chinese cabbage.

Abstract:Using RT-PCR and RACE methods,we cloned a SPS gene from a medicinally plant Lycium barbarum L.,named as LbSPS (GenBank number:KC834608).Sequence analyses showed that the full length cDNA of LbSPS was 3 677 bp and the 3 165 bp ORF encoded 1 033 amino acids with a molecular weight of 118.457 5 kD and an isoelectric point of 6.05.Phylogenetic analysis showed that the amino acid sequences of LbSPS were 66%～98% identical to the sequences of melon,tomato,potato,etc.qRT-PCR analysis showed that the LbSPS gene was highly expressed in flower.The expression level reached the lowest in leaf.Molecular cloning of LbSPS will be useful for further functional elucidation of the gene involving in the development,stress response in L.barbarum L..

Abstract:Verticillium wilt caused by the fungus Verticillium dahliae Kleb.is a serious soilborne disease in eggplant.The eggplant cultivars are susceptible,but wild Solanum torvum is highly resistant to Verticillium wilt.A forward suppression subtractive hybridization library was established using roots of S.torvum,and the cDNAs from the fungus inoculated seedlings were used as the tester and the normal uninoculated seedlings as the driver.(1)170 positive clones were randomly selected and sequenced,and 109 non-redundant ESTs were obtained,among which 61 ESTs share sequences homology with stress resistance related genes of other plants.Such as chitinase,cytochrome P450,peroxidase,protease inhibitor Ⅱ,etc.Moreover,a EST in SSH was used as a querying probe to blast the EST database in GenBank.(2)Based on the assembled homologous cDNA sequences and RT-PCR,a universal stress gene was cloned,designated StUSP1.(3)Expression pattern revealed that StUSP1 was up-regulated in roots while S.torvum was infected by Verticillium wilt.This SSH library is helpful to understand the resistance mechanism of wild eggplant to Verticillium wilt.

Abstract:In order to elucidate the enzyme mechanism of starch biosynthesis in wheat endosperm and provide theoretical basis to enhancing wheat yield,we identified the isozyme forms,organ localization and subunits constitution of AGP in nine wheat cultivars from different provenances by using native polyacrylamide gel electrophoresis (Native-PAGE) and SDS polyacrylamide gel electrophoresis (SDS-PAGE).Results of the present study showed that:(1)There are six AGP isozymes in wheat,ie,AGPp,AGPs,AGPe1,AGPe2,AGPe3 and AGPe4.(2)AGPs localized in leaf and seed coat of wheat,but AGPp was solely in seed coat.AGPe1,AGPe2,AGPe3 and AGPe4 were exclusively present in wheat endosperm.AGPe1 expressed first,following by the AGPe2 and AGPe3.The AGPe4 expressed last.(3)Every AGP isozyme of endosperm was all composed of both large and small subunits.The molecular size of large and small one were approximately 51~54 kD and 50 kD,respectively.(4)Spatial localization of the AGP isozymes manifests organ specificity.AGP isozymes of endosperm exhibit rich genetic polymorphism,and expresse according to different developing periods of grain.AGPe3,AGPe1 and AGPe2 could be the key isozymes of AGP,and be a very important determinant for total AGP activity,play an major role in starch biosynthesis in late filling period of wheat grain.

Abstract:In order to make clear the genetic background of Notopterygium forbesii,and provide theoretical basis for its protection,we assessed the genetic diversity and genetic structure of 138 individuals from 14 natural populations of N.forbesii,an endangered and endemic species in Qinghai,Gansu and Sichuan,using cpDNA trnS-trnG noncoding sequences.The results showed that:(1)Sequence length varied from 509 bp to 515bp and base composition was with high A+T content of 67.6%;(2)31 haplotypes were identified based on nucleotide variation.Among them,nine haplotypes(H5,H1,H9,H10,H16,H17,H19,H20,H22) were shared by different populations,and H5 was the most frequent haplotype and represented 48.56% of the total samples;(3)Relatively high level of haplotype diversity(Hd=0.750 3) and nucleotide diversity(Pi=0.007 11) were detected in 14 populations of N.forbesii.However,31 haplotypes from different populations mixed together and did not form distinct geographically separated clades.(4)Investigations of population differentiation(F_ST=0.602 4),gene flow(N_m=0.330) and AMOVA(60.24% genetic variation was partitioned among regions) all demonstrated that high genetic differentiation existed among population.(5)The genetic distance of 14 populations of N.forbesii ranged from 0.000～0.007,with an average of 0.003,indicating that the genetic relationship between populations of N.forbesii was relative far.And there was no significant correlation between genetic distance and geographic distance,illustrating that there was no obvious geographical trends of the distribution of the population genetic variation in N.forbesii.Many factors might attribute to the high level of genetic differentiation,such as:limited gene flow;genetic drift;geographical isolation.Based on our results,we proposed some conservation strategies.

Abstract:Eleven pairs of simple sequence primers were used to analyze genetic diversity and genetic structure of wild Prunus tomentosa Thunb.including 104 ecotypes,11 subpopulations and 5 populations from Qinling Mountain,in order to make clear of cherry germplasm resources in China,and provide theoretic reference for cherry breeding and cherry root stock modifying.The results showed that:(1)A total of 110 alleles of 11 loci were detected from 104 individuals and 5~13 alleles could be detected from each primer.The observed average number of alleles (A) was 10;the effective number of alleles (Ae) was 7.586 3.(2)The percentage of polymorphic loci (PPB) was 69.55% in Tianshui Valley,76.53% in Chang’an Valley,81.36% in Taibai Valley,85.00% in Huayin Valley,92.17% in Meixian Valley,and the total PPB was 81.62%.The higher level of expected heterozygosity (He) was 0.864 0.(3)The coefficient of gene differentiation (Gst) was 0.081 2,about 91.88% of gene differentiation was observed within the population,and 8.12% among the populations.Gene flow (Nm) was 2.827 3.The total Nei’s genetic distance was 0.489 7 and Shannon’s information index was 2.101 9.The research indicated that higher level of genetic diversity existed in wild P.tomentosa Thub.in Qinling Mountain.The genetic differentiation within population was higher than that among populations,and gene exchange was not hindered.It was not sensitive to genetic drift in the existing level of genetic diversity within population.However,moderate gene exchange existed among populations may reduce the redifferentiation of entire populations.

Abstract:In order to select the cross-combinations with better compatibility,we made reciprocal crosses in this study between Paeonia×lemoinei ‘High Noon’ (HN) and P.ostii ‘Fengdanbai’ (FDB),22 P.rockii hybrids (RHs),29 cultivars of P.×suffruticosa Zhongyuan Group and Japan Group (SUFs) from 2006 to 2011.Meanwhile,AFLP markers were employed to identify early the nature of some offsprings from crosses of HN and RHs.Main results were as followed:(1)When HN was used as male parent,FDB as female parent was fertile annually,the average setting-seed ratio was 2.88 each flower in five years,showing they are compatibility in crossing,and the fertility in crosses RHs as female parent,1 and 9 of RHs have displayed more compatibility with higher setting-seed ratio,29.17 and 26.86 each flower,respectively.(2)When HN was used as female parent,all 38 cross combinations using SUFs as male parent were almost infertile as there were only 4 seeds harvested from 4 single combinations,which indicated a very weak fertility of HN.(3)From 64 pairs of AFLP primer combination 9 pairs of primers were screened for amplification to identify the nature of 22 offsprings from the cross.The results showed clearly they are all real hybrids,most of which (86.36%) for partial maternal type,a few (13.64%) for partial male parent type.According to the above results and the characteristics of matroclinal inheritance in tree peonies,we think that FDB,1 and 9 of RHs can be recommended as female parent for crossing and introgression should be the main breeding strategy in this type of cross,but,when HN was used as female parent,it is needed to test more combinations with other various cultivars to select suitable parents for the crosses ,and suggested that AFLP markers could be practiced as an essential step in peony breeding through distant crosses to play an important role in identifying hybrids early.

Abstract:Using Yunnan potato varieties including ‘Jianchuanhong’ mother plant and its 70 inbred seedlings from one berry,and 100 seedlings of B20 hybrid [CIP010(♀)×CIP004(♂)] as materials,we studied their genetic diversity with 12 pairs of SSR primers,for the purpose of finding the consistent progenies as mather plant (parent) at the molecular level and providing the basis for long-term preservation of germplasm resources.The results showed that:(1)The polymorphism rate of ‘Jianchuanhong’ seedlings population was 81.6%,which was higher than that of B20 with 72.8%,which indicated that the polymorphism rate of two groups were higher.(2)The cluster analysis indicated that the offsprings of both inbred or hybrid populations had high genetic similarity coefficient,the range from 0.74 to 0.96.Two groups had different degrees of genetic segregation which were small,most of amplified bands were consistent.(3)We did not found one plant from a berry which was as same as ‘Jianchuanhong’ mother plant at the molecular level in all the tested materials.So it was very difficult to find the seedling populations which was not separated completely.We must be further evaluate the field performance of similar lines compared with mother plant (parent) at the molecular level,and determine whether they can recover the sources by similar or poles near lines.

Abstract:The allelic compositions of high-molecular-weight glutenin subunit (HMW-GS) and the alleles on Glu-A3 and Glu-B3 loci of low-molecular-weight glutenin subunit(LMW-GS) in the wheat cultivars and lines in Southern Shaanxi were identified by SDS-PAGE and STS molecular markers,respectively;and the partial allelic results of HMW-GS from SDS-PAGE were validated by STS specific marker.The results showed that:(1)There were nine types of allelic variations of HMW-GS in 64 cultivated materials in Southern Shaanxi.The frequencies of the Null and 1 alleles at Glu-A1 locus were 53.12% and 46.88%,respectively;the alleles of 7+8,7+9,14+15 and 17+18 at Glu-B1 locus are 26.56%,48.44%,21.88% and 3.13%,respectively;the alleles of 2 +12,5+10 and 4+12 at Glu-D1 locus were 71.88%,15.63% and 12.49%,respectively and the 9 HMW-GS alleles formed 17 types of permutations in which “1,7+9,2+12” and “null,7+9,2+12” were the major styles.(2)The frequencies of the allelic variations of Glu-A3a,Glu-A3c and Glu-A3d at Glu-A3 locus of LMW-GS are 10.94%,62.50% and 26.56%,respectively;and the alleles of Glu-B3a,Glu-B3b,Glu-B3d,Glu-B3e,Glu-B3f,Glu-B3g,Glu-B3i and Glu-B3j at Glu-B3 locus of LMW-GS are 6.25%,4.69%,29.69%,1.56%,3.13%,18.75%,4.69% and 31.25%,respectively.(3)The validated results from 2 STS specific markers for the allelic compositions of HMW-GS by SDS-PAGE could demonstrate that STS specific markers might efficiently overcome the misreading for the alleles of 7 and 7^*,8 and 8^* and 2 and 2^*.

Abstract:In the present study,a total of 327 F₂ lines from the cross between two common wheat Chinese Spring(female)×Lankaodali were planted in Qianxian,Qishan and Yangling of Shaanxi Province,respectively.Test weight,hardness,protein content and bound moisture content were evaluated.A genetic map was constructed based on 167 SSRs and 2 EST markers.QTL analysis was conducted with single environment model and multi-environment model by the software QTL-ICIMapping V.3.2.The results showed that:(1)In two mapping models,6 QTLs(QTW-6B-6,QTW-7B-6,QTW-7B-9,QTW-5D-2,QTW-6D-1,QTW-6D-4) were found for test weight,explaining 1.99%~6.57% of phenotypic variance in single-environment model,whereas accounting for 3.66%~20.07% of phenotypic variance in multi-environment model.And Q_MTW-7B-9,Q_MTW-6D-1 and Q_MTW-6D-4 showed major QTL in multi-environment model;(2)3 QTLs (QHD-4A-5,QHD-7A-1 and QHD-7B-9) were detected for hardness,and in single-environment model it explain phenotypic variance from 6.00% to 6.95%,while in multi-environment model it explain phenotypic variance account for 5.43%~9.64%;(3)1 QTL（QPR-6D-1） for protein content was mapping on 6D chromosome,explaining 5.39% and 10.06% of phenotypic variance in single-environment model and multi-environment model,respectively;(4)1 QTL for moisture content was detected explaining 39.20% and 75.01% of phenotypic variance in single environment model and multi environment model,respectively;(5)The QTLs controlling test weight,hardness,protein content and bound moisture content were mapping on 1B chromosome,indicating the big influences of 1B on these traits.Test weight,seed hardness,protein content and moisture content are mainly controlled by additive effects.The identified molecular markers related to these quality traits in this study will benefit for marker-assisted selection in breeding programs.

Abstract:To elucidate the biological mechanism of Polygonatum sibiricum seed propagation,we applied paraffin sections technology and safranine-fast green dyeing in studying mature seed morphology and morphological changes and the anatomy structure characteristics of germinating seeds.The result showed:(1)Mature P.sibiricum seed consists of seed coat,endosperm and embryo.The seed coat is a layer of lignified cells;the endosperm occupies most of the seed containing a large number of starch;the embryo stays in the club-shaped stage.(2)In germinating seed,sections near the embryo hilum would differentiate into haustorium,cotyledon coupling and cotyledonary node.Sections near the micropyle would differentiate into radicle,hypocotyls and germ.(3)At germination,cotyledon coupling stretch and push out the germ and radicle,then hypocotyl swells and forms newborn rhizome,haustorium degraded and absorbed nutrient substance of the seed.Cotyledon coupling are connected with haustorium and newborn rhizome,which transferred nutrient materials from endosperm to newborn rhizome.This pathway provides material assurance for the differentiation of the germ and radicle on the newborn rhizome.P.sibiricum seed germination rates is low under natural conditions,and it does not emergence until the next year.In summary breeding characteristics of P.sibiricum is an important mechanism adapting the environment.

Abstract:The megasporogenesis,microsporogenesis and development of female and male gametophyte of Tricyrtis maculata (D.Don) Machride were observed by the method of paraffin sections.The main results as follows:(1)The anther is four sporangiate and the development of anther wall is the monocotyledonous type.The anther wall is composed of epidermis,endothecium,middle layer and tapetum.The epidermise consist of one layer of cells and still existed until the anther matured.The endothecium developed banding-shaped thickenings when the anther matured.The young anther wall has 2～3 layer middle layers and degenerated when maturity of the anther.The tapetum belongs to secretory type and degenerated at the time of anther matured.(2)The cytokinesis of the microspore mother cells in meiosis is successive type.The microspore tetrads are tetrahedral and isobilateral spore.The mature pollen grain is the 2-celled type.(3)The ovary has three chamber which has more ovule that is double integuments,tenuinucellate and anatropous.The archesporium directly functions as the megaspore mother cell.After meiosis,the megasporocyte divides into linear or T-shaped type tetrads.The megaspore in chalaza end usually is functional one.The embryo sac is a polygonum type.(4)There are some abnormal phenomena in the development of the anther that bring about the pollen degeneration.

Abstract:The morphology of spores of 25 species of Selaginellaceae from China was examined using scanning electron microscope (SEM).The results show that:(1)The megaspores are tetrahedral-globose,with a trilete,each of which has a length of about 1/2~3/4 of the spore radius.The megaspores are often rounded triangular or suborbicular in polar view,and suborbicular,fan-shaped or nearly elliptic in equatorial view.The length of polar axis is about 158~548 μm.The length of equatorial axis is about 196~675 μm.(2)The microspores are also tetrahedral-globose,with a trilete,each of which has a length of about 1/2~3/4 of the spore radius or almost equal to radius of the spores.The microspores are always suborbicular or rounded triangular in polar view,and suborbicular,nearly fan-shaped in equatorial view.The length of polar axis is about 10~40 μm.The length of equatorial axis is about 17~63 μm.(3)The ornamentation of the spores includes granulate,tuberculate,verrucate,spinate,baculate,reticulate,lamellate,verrucate-rugulate,and cerebriod.The spore morphology characteristics can be used as the criterions for the classification of subgenus and species of Selaginellaceae.

Abstract:To explore the defense mechanisms involved in disease resistance of grafted watermelon to Fusarium oxysporum,we compared the histological responses using microscope and expression of defence genes of grafted and self-rooted watermelon infected by F.oxysporum.The results showed that:(1)F.oxysporum caused a quick defense response by formatting gums and tylosis in infected xylem vessels,and the thickening of xylem parenchyma cell wall in roots of grafted plants.These histological changes appeared later in roots of self-rooted plants.Serious infection resulted in wall disintegration of xylem parenchyma cell,the diseased vascular finally became hollow and plants developed wilt symptoms,which did not observed in grafted watermelon.(2)Highly induced expression of defence genes were observed in grafted plants than that in self-rooted plants,among which,the transcription of CHI,APX and PPO genes in grafted watermelon accumulated along the F.oxysporum inoculation,while transcription of PAL significantly increased and then sharply declined,but still with high expression level than base level.Different from the expression manner in grafted watermelon,only the transcription of PPO gene was up-regulated after F.oxysporum inoculation,in self-rooted watermelon,whereas expression of CHI,APX and PAL genes increased first and then sharply declined,which is consistent with PAL gene expression pattern in grafted watermelon.These results indicating that the resistance mechanism of grafted plants to F.oxysporum infection is because of the quick response in histological level and the high expression of defence genes in transcription level,which finally protect the grafted plant from infection by F.oxysporum;and that the significantly responses of defence genes in the interaction between grafted plants and F.oxysporum might be one of the important molecular mechanisms involving the resistance of grafting plants.

Abstract:In order to determine the difference of small heat shock protein (sHSPs) expression in four maize (Zea mays L.) varieties with different endurance under combined drought and heat stress,and the effect of abscisic acid (ABA) and H₂O₂ on their expression,we used ‘Zhengdan 958’ with drought endurance,‘Xundan 20’ with heat endurance,‘Longyu 602’ with endurance to combined drought and heat stress,‘Zhuyu 309’ with sensitiveness to three stresses as experimental material.ABA and ABA synthesis inhibitor Flu (F),H₂O₂ scavenger KI (I) and sodium pyruvate (P) were used to study the influences of ABA and H₂O₂ on sHSPs expressions induced by combined drought and heat stress in maize leaves.The results were as follows:(1)The increases of six sHSPs such as sHSP16.9,sHSP17.2,sHSP17.4,sHSP17.5,sHSP22 and sHSP26 induced by heat stress and combined drought and heat stress were all more than that induced by control and drought;(2)sHSP17.2 was only expressed in ‘Zhengdan 958’,while the increase of sHSP16.9,sHSP17.4 and sHSP26 gene expression was all the highest in ‘Longyu 602’,but the lowest in ‘Zhuyu 309’ among four maize varieties;the increase sHSP17.5 and sHSP22 gene expression was the highest in ‘Zhengdan 958’,but the lowest in ‘Zhuyu 309’;(3)The pretreatment with ABA,F,I and P,all slightly affected the increase of six sHSPs genes expressions,but significantly affected the increase of sHSP26 protein expression by heat stress and the combination of drought and heat stress.Our results showed that there was great difference of six sHSPs expression among maize varieties with different endurance.ABA and H₂O₂ slightly improve these sHSPs genes expressions,but significantly improve sHSP26 protein expression under the combination of drought and heat stress.These results lay a foundation for further investigating the mechanisms of plants tolerance to combination stress.

Abstract:The seed germination,seedling growth and physiological and biochemical indexes of stress resistance of Medicago sativa were discussed in this paper as the different treatments (CK,10% PEG,0.03% FA+10% PEG and 0.05% FA+10% PEG) were carried out in the experiments.The results showed that:(1)M.sativa seed germination rate,germinating energy,germination index,vigor index and seedling chlorophyll content,membrane stability indexcatalase (MSI) and root activity were downward trend.The growth rate of stem length and biomass were decreased,but the contents of malondialdehyde (MDA),hydrogen peroxide (H₂O₂),proline and soluble sugar of seedling leaves increased with the increasing of treatment duration.The activities of catalase (CAT) and glutathione reductase (GR) decreased firstly and secondly increased and finally decreased.The activities of superoxide dismutase (SOD) and peroxidase (POD) and superoxide anion (O^-·₂) increased firstly and then decreased under the simulated drought stress.The growth and development of M.sativa were inhibited significantly under the simulated drought stress and the seedling suffered from drought stress.(2)As being treated with the fulvic acid,the M.sativa seed germination rate,germinating energy,germination index,vigor index,and seedling’ stem length,biomass,proline and soluble sugar contents were increased significantly.The treatment of fulvic acid also significantly alleviated the decline in the content of chlorophyll,root activity and MSI,promoted the activities of SOD POD,CAT and GR relatively,and even reduced the contents of MDA,H₂O₂ and the level of reactive oxygen species.It is thus clear that the seed germination and seedling growth and development of M.sativa were significantly inhibited under 10% PEG solution simulated drought stress.In soaking seeds with fulvic acid,the content of osmotic adjustment substances was increased and enzyme activities were protected to effectively reduce oxidative damages caused by drought stress to the seedling of M.sativa,enhanced overall drought resistance of plants and maintained their normal growth.Besides,relatively significant effects were achieved by 0.05% FA in maintaining the seed germination and seedling growth of M.sativa under drought stress.

Abstract:To study the resistant potential of Quercus variabilis seedlings under NaCl stress,we examined the biennial cork oak seedlings grown on containers with four soil NaCl concentrations (0%,0.4%,0.6% and 0.8%).Growth index and protective enzyme activities,proline content,root activity and other physiological indexes were systematically measured and analyzed under different stress conditions and at different stress time.Results showed that:(1)With NaCl stress increasing,fresh weight and dry weight of each organ,plant height and secondary root length all increased then decreased.But the mainroot length increased and the leaf number showed a gradual reduction.（2）With the extension of stress time,three protective enzyme (SOD,POD,CAT) activities were increased before decreasing,but the variation ranges were different.Malondialdehyde (MDA) content was increased,and it grew faster at higher stress level.(3)The organic substances for osmotic adjustment such as proline and soluble protein increased at the lower stress and then decreased at the higher stress;While the content of soluble sugar was continuously increased.(4)With the NaCl concentration rising,root activity increased and then decreased;Chlorophyll a and b both showed a downward trend.It was resulted that Q.variabilis seedlings improved the characteristic of resistance to soil salt stress by increasing the activities of protective enzymes and organic substances for osmotic adjustment in low and medium NaCl stress;Under severe NaCl stress,the metabolism in vivo and self regulation ability were in disorder and deprived,causing the protective enzyme activites,soluble protein content and root activity decreasing.

Abstract:Seeds of Medicago sativa L.cv.‘Gannong No.3’ were used as test material to study the effects of different cadmium concentrations on seed germination and physiological and biochemical characteristics.The results showed that:(1)Cadmium significantly inhibited seed generation and bud growth.The germination energy,germination rate,bud and hypocotyl lengths,and dry weight decreased significantly.The inhibition effect on germination energy was found stronger than that on germination rate,and on hypocotyl length was found stronger than that on bud.(2)On the 4^th day of germination,proteolytic enzyme activity in seeds was significantly inhibited,together with the significant decrease of soluble protein and soluble sugar contents(P<0.05).(3)On the 10^th day of germination,the activities of SOD,APX and GPX increased firstly and then decreased,CAT activity decreased continuously,while superoxide radical generation rate,H₂O₂ and MDA contents increased significantly,indicating that low cadmium concentration promoted the scavenging capacity of anti-oxidative system in seedlings while under high cadmium concentration,the anti-oxidative system activity decreased,and lipid peroxidation accelerated.The excessive accumulation of reactive oxygen was the main reason for seedling damage and biomass decrease.

Abstract:The calcicole,Eurycorymbus cavaleriei,and calcifuge,Rhododendron decorum,were used as experimental materials to compare the responses of growth,chlorophyll content,osmoregulation and mineral element accumulation to different exogenous Ca²⁺ by addition 0,5,10,25 and 50 mmol/L Ca²⁺ in the Hoadland solution for culture medium.The results showed that:(1)Several parameters of E.cavaleriei such as plant height,leaf dry weight,leaf length,leaf width,leaf index,stem diameter,contents of chlorophyll and protein were promoted,and contents of proline and soluble sugar had no significant changes,with the increase of exogenous Ca²⁺ concentration.However,for R.decorum,these parameters appeared opposite trend and shown a restrained result.The contents of chlorophyll and protein decreased and the contents of proline and soluble sugar increased.The contents of chlorophyll and protein of E.cavaleriei were 2.99 mg/g and 17.10 mg/g,respectively,while the contents of chlorophyll and protein of R.decorum were 1.39 mg/g and 14.30 mg/g,respectively with 50 mmol/L Ca²⁺ in the Hoadland solution.(2)E.cavaleriei have Ca,K homeostasis and higher P,N absorption,while R.decorum is remarkable calcium accumulation and constraint of P,N absorption at lower calcium concentration.

Abstract:The physiological and photosynthetic indexes of 2-year-old seedling of Camellia oleifera clones including Changlin 4(C₄),Changlin 23(C₂₃) and Changlin 53(C₅₃) were measured under different gradients sustainable drought stress in greenhouse,and then the drought resistance was comprehensively evaluated by correlation analysis,principal component analysis and subordinative function.The results showed that:(1)As the drought stress proceeding,the relative electric conductivity and TBARS content were increasing.(2)The activities of SOD and POD increased at first,and then decreased.The antioxidant enzyme activities were the highest after drought stress for 15 d.(3)Chlorophyll content,net photosynthetic rate,stomatal conductance and transpiration rate in leaves of C.oleifera were decreased in various degrees.(4)The order of drought tolerance was Changlin 53>Changlin 4>Changlin 23,which was accordance with the damaged symptom of C.oleifera after drought stress.

Abstract:Germination characteristics,dormancy causes,dormancy types and methods of breaking dormancy of Gynostemma pentaphyllum seeds which were collected from Jinxiu county in Guangxi,were investigated in this paper,so as to provide scientific basis for the seed propagation of G.pentaphyllum.The results indicated that:（1）The viability of G.pentaphyllum freshly mature seeds was 91%,but when incubated at 10 ℃～35 ℃ constant temperature and 15 ℃/25 ℃ alternating temperature,germination percentages of them were less than 10%.The viability of freshly seed was significantly greater than the germination percentage,which indicated that there was obvious dormancy phenomenon in freshly collected G.pentaphyllum seeds.（2）G.pentaphyllum seed coat is water permeable,the embryo fully developed,the germination percentage of in vitro embryos was (78.0±4.8)%,and in vitro embryos could produce normal seedlings,which indicated that in vitro embryos of G.pentaphyllum seeds were non-dormant.（3）Water extract of whole seeds and crushed seeds had inhibitory activity on seed germination rate,height of seedling and root length of seedling of cabbage.The inhibitory effect enhanced significantly with the increase of water extract concentration,and the inhibitory effect of crushed seeds was greater than that of whole seeds;When water extract of crushed seeds at a concentration of 5%,seed germination rate,height of seedling and root length of seedling of cabbage were only 18.0%,0.1 cm and 0.1 cm respectively,77.1%,97.3% and 95.8% lower than that of control.These indicated that there were water-soluble germination inhibitory substances in seed coat and endosperm of G.pentaphyllum,which was one of the main causes of seed dormancy.（4）GA₃ and 6-BA could not improve the germination of G.pentaphyllum seeds,but cold stratification could promote seed dormancy release.These results indicate that G.pentaphyllum seeds possess non-deep physiological dormancy.（5）Low-temperature dry storage was the best way for seed conservation of G.pentaphyllum,which could also break seed dormancy.

Abstract:Using Sophora alopecuroides and Thermopsis lanceolata as materials,under 25 ℃,the imbibed seeds were taken out as a sample every 24 h.The non-imbibing seeds after 10 d were regarded as hard seed (H).Imbibing seeds and hard seeds that imbibed for 24 h after treated with sulfuric acid were all subjected to germination test and several vigour tests.The results indicated that:(1)The numbers of the seeds newly imbibed in one day were gradually decreased along with time.The hard seeds of S.alopecuroides had a relative slow rate of imbibition,which was decreased below 1% after 10 d,while the imbibition rate of T.lanceolata was at the same level after 3 d,another decrease happened after a sudden increase in 9th to 10th day.(2)The germination rate,germination index,vigour index,the activity of dehydrogenase,respiration rate and SOD activity of hard seeds were significantly higher than those of non-hard seeds in both species,while the relative conductivity,the contents of soluble sugar and malondialdehyde of hard seeds were lower than those of non-hard seeds.Studies showed that the vigour of hard seeds were higher than that of imbibing seeds,and the vigour of imbibing seeds were increased gradually with the initial imbibing time postponed.

Abstract:Green walnut fruit of ‘Zhonglin 5’（early mature）,‘Liaoning 4’ (middle-mature),‘Xifu 1’ (middle-late mature) were harvested on three stages of early,middle and late August,and stored at 0~1 ℃.Physiological indices and preservation effect during the storage were measured and valued.(1)Respiration intensity of fruits from each harvest stage and each variety all showed two-peak curve trend.Those harvested in middle August appeared the earliest respiration peak,also presented one more Cx activity peak during the first period of storage and the earliest increase of PG activity,which resulted in the most decrease in acid value of kernel and the highest decay rate of fruit after storage.(2)Among fruit of three varieties,the physiological indices changed almost in the same way.After 54-day storage,the decay rate of ‘Liaoning 4’ was the highest,followed by ‘Zhonglin 5’,and ‘Xifu 1’ was the lowest.(3)Kernel of ‘Liaoning 4’ with higher soluble protein content showed more decline rate than those with lower content.In conclusion,walnut fruit harvested on mid-August are less tolerant to store due to its vigorous postharvest physiological metabolism.

Abstract:In order to get high fresh-keeping botanical materials and develop new botanical preservativation,we determined the fresh-keeping activities of 35 Chinese herbal medicine bought in the market and optimal concentrations on the 28th day after storage in room temperature (RT) against tomatoes.Plants were extracted with ethanol by ultrasonic wave extraction.The fresh-keeping activity of the each plant extracts was assayed on Jinpeng tomato by spraying method.The control group (CK) was treated with clear water.The drug control was treated with 1-methylcyclopropene (1-MCP) fumigating 24 h airtightly.The results indicated that Litsea cubeba extract,pomelo peel extract and lotus leafs extract had higher fresh-keeping activities of them significantly during the storage,and the optimum concentrations were 2.0,2.0,1.0 mg·mL^-1 dry matter respectively.The treatments significantly reduced the weight-loss rate and the number of rotted tomatoes,slowed down the decrease in the flesh firmness effectively,titratable acidity,flavor,Vc,delayed the increase in total soluble solids,increased the superoxidae dismutase,catalase and peroxidase activities,restrained the increase of relative electric conductivity.The preservation effects were not significantly difference with antistaling agent 1-MCP and require further research.

Abstract:Studies of cryopreservarion and regeneration of Saposhnikovia divaricata callus were conducted for avoiding the variation by subculture and exploring the new way to preserve plant germplasm resources.Three-weeked callus were used as the materials to explore appropriate procedure of cryopreservation by vitrification in the method of single variable.The results showed that:(1)The procedure in which callus were precultured in solid medium MS+1.0 mg/L 6-BA+1.0 mg/L NAA+5% DMSO for 3 d at 4 ℃,and loaded with 60% PVS2 for 20 min under room temperature,then dehydrated with 100% PVS2 for 45 min at 2 ℃,and putted into the liquid nitrogen are appropriate for preservation.(2)The highest survival rate of callus reaches 79.24%.Preculture and dehydration are the key points of cryopreservation.After defrosting,callus should be embathed by MS+1.0 mol/L sources and cultured in dark for 14 d,which are conductive to the recovery and plant regeneration.Cryopreservation by vitrification can be used as a method to preserve S.divaricata callus.Cryopreserved callus were able to regenerate and differentiate to healthy plantlets.

Abstract:Molluginaceae is reported as a new record to Inner Mongolia.The family is mainly distributed in both tropical and subtropical regions of hemispheres.The voucher specimens are hold in HIMC.

Abstract:During investigations on the crustose lichens from China,Trapeliopsis granulosa,Megaspora verrucosa var.mutabilis and Placynthium nigrum are revealed as new to China or mainland China.Placynthium is also reported from China for the first time.The detailed descriptions and illustrations are provided for the newly reported taxa.

Abstract:Ultraviolet-B(UV-B) radiation is a key environmental signal that is specifically perceived by plants to promote UV acclimation and survival in sunlight.In contrast to phytochrome-,cryptochrome- and phototropin-sensing systems,with considerable knowledge accumulated,the UV-B photoreceptor UV Resistance locus 8 (UVR8) was only recently described at the molecular level.UV-B perception was thought to induce dissociation of the UVR8 homodimer,allowing its subsequent interaction with Constitutively Photomorphogenic 1(COP1) and activation of UV-B responsive genes.Here,we review the recent studies of the UVR8 photoreceptor in the context of UVR8 discovery,UVR8 structure,UV-B perception mechanism,UVR8 redimerization and the commonalities and differences between UV-B and visible light signaling.

Abstract:Seed vigor is an important index of seed quality and a main part of seed value.Seed vigor is one of the research focus in seed science.In this article,the recent advances on seed vigor were reviewed,including the evolution and extension of seed vigor concept,genetic analyses,new determination methods,miRNA and proteomics analyses related seed vigor,and the mechanism of enhancing seed vigor by priming.Moreover,the research directions in future of seed vigor were also proposed in this article.