Abstract:Catalase plays important roles in plant salt tolerance.HcCAT1,a catalase gene from the perennial shrub Halostachys caspica,which distributes in saline-alkali arid land in Xinjiang,was isolated by homologous sequence cloning method.Sequence analysis showed that the ORF of HcCAT1 was 1 479 bp,encodes 492 amino acids with a molecular mass of 56.7 kD and a pI of 6.84.HcCAT1 shared high similarity with those from other plant species.Semi-quantitative PCR results showed that the expression of HcCAT1 gene was up-regulated by salt stress.The recombinant plasmid pET32a-HcCAT1 was constructed and transformed into E.coli BL21(DE3),The fusion protein His-HcCAT1 was expressed by IPTG induction.SDS-PAGE and Western blotting showed that His-HcCAT1 was 77.7 kD,same size to the expected.Under low temperature,His-HcCAT1　was expressed in soluble form,and had certain catalase activity.Salt stress experiments showed that E.coli carrying the recombinant plasmid pET32a-HcCAT1 exhibited better growth phenotypes and higher growth rates than the control bacteria in the LB medium supplemented with 400 mmol/L NaCl,400 mmol/L KCl and 300 mmol/L mannitol,demonstrating that HcCAT1 could enhance the salt stress tolerance for E.coli cells.These results will help to understand the molecular mechanism that H.caspica for salt stress and oxidative stress.

Abstract:During differentiation,the Lepidium perfoliatum seed coat epidermal cells produce copious amounts of mucilage that is extruded from the seed coat upon imbibition.Mucilage is composed primarily of pectin,a polysaccharide that is a main component of the cell wall.To validate the function of a mucilage related gene MUM4 (MUCILAGE-MODIFIED4,encodes a putative NDP-l-rhamnose synthase in Arabidopsis),LpMUM4 from L.perfoliatum,which is myxospermous,was characterized in the present study.Sequence analysis revealed that the protein is highly homologous to AtMUM4 from Arabidopsis.Analysis of qRT-PCR showed that LpMUM4 was expressed in various parts of L.perfoliatum,and the transcription level was relatively high in silicles and root and the expression level gradually increased with the development of silicles.Moreover,the immunolocalization analysis showed that LpMUM4 was strongly expressed in both outer and inner integument layers at the earlier stage,then was observed more strongly in the epidermal and subepidermal layers of outer integument,finally was concentrated in between the epidermal and subepidermal layers,which corresponded to the process of the outer integument (testa) differentiation and the mucilage production of seed in L.perfoliatum.Overexpression of LpMUM4 in Arabidopsis showed a remarkable inhibition in the transcription level of AtTTG1 gene (which locates upstream of the AtMUM4 in the mucilage synthesis pathway) in silicles.However,the inspection of the morphology and mucilage release behavior of seed coat revealed no evident difference between LpMUM4 overexpressed transgenic line and WT.The possible explanation may be that the differentiation of the seed coat and production of the mucilage are complex processes in L.perfoliatum,and which is regulated by an interaction network of numerous genes with function redundancy.Therefore,the increasing expression of one gene (LpMUM4) during development may not cause evident phenotype change.

Abstract:In order to improve the rice blast resistance of ‘Yunzijing 41’and‘Yunzijing 43’,we transformed bivalent expression vector pCAMBIA1300-Pi-ta⁺-Bchi into rice calli using the agrobacterium- mediated method.Regeneration seedlings through tissue culture are tested through CPR assay,PCR and rice blast resistant assay method and a part of these are determined to be transgenic plants.This experiment laid the foundation for breeding the longer and higher blast resistance rice variety in future.Results show:(1)Resistant callus passed through differentiation and rooting cultivation,we received 137 T⁰ generation of rice seedlings,including 14 ‘Yunzijing 41’,82 ‘Zhonghua 11’,41 ‘Yunzijing 43’.(2)After CPR assay and PCR,the conversions of ‘Yunzijing 41’,‘Yunzijing 43’ and ‘Zhonghua 11’transgenic positive rice plants were 66%,43% and 55%,respectively.Transgenic plants were confirmed that two exogenous genes had been integrated into the rice genome.(3)After be identified by inoculation with rice blast strain 66 b,transgenic plants enhanced clearer resistance to rice blast than non-transgenic plants;at the same time,transgenic plants of Pi-ta⁺ gene and bean chitinase gene had more obvious ability of resistance to rice blast than transgenic plants of Pi-ta⁺ gene or bean chitinase gene.(4)CPR assay results existed in some false positives,PCR detection results are more reliable.But CPR assay is more convenient,faster and the results is more intuitive.This can be used for preliminary screening.The research indicates that transgenic plants of Pi-ta⁺ gene and bean chitinase gene had a higher ability of resistance to rice blast.

Abstract:In this paper,we isolated the diacylglycerol acyltransferase (DGAT) from Brassica napus and named BnDGAT1 gene.The amino acid sequence,protein domains and phylogenetic tree were analyzed.The BnDGAT1 protein was predicted that the amino sequences were composed of several completely functional domains,and eight hydrophobic transmembrane structures were detected by SOSUI.Phylogenetic tree analysis indicated that BnDGAT1 were closer with BjDGAT1,AtDGAT1 and TmDGAT1 than with other plant.In addition,expression profiles of BnDGAT1 were respectively analyzed using real-time PCR assays for different organization tissues and development stages of rape pod.Tissue-specific expression showed that the transcription expression levels in leaf and flower were higher than that in root and stem.Moreover,the expression levels of RNA transcription of pod were gradually down-regulated at different developmental stages of pod maturation.

Abstract:The dimensional electrophoresis profiles with good resolution and repeatability was got by separating the proteins of alfalfa on the bud of male sterile (Ms-4) and fertile plants(MF) of bud emergence stage.By using ImageMaster 2D software to analyze silver stained 2-DE gel,the protein spots of Ms-4 and MF mainly scattered in the isoelectric point of 5~7 with maximum distribution of molecular weight in 20~60 kD.There were about 6 000 expressed protein points in bud for Ms-4 and MF,and about 98 spots were differential expressed.The 22 protein spots were successfully identified by mass spectrometry analysis.The ribulose bisphosphate carboxylase small chain,UTP-glucose-1-phosphate uridylyltransferase and others played an important role in photosynthesis,carbohydrate metabolism and the development of multicellular organisms by using Blast2GO program to analyze function and metabolic pathway of the 22 proteins.Meanwhile,they were involved in the composition of cytoplasm,cell wall and other parts,which has some functions,including binding,catalytic,combining and hydrolysis and others.It concluded preliminary that the lack of protein and the changes of expression levels might lead to male sterility,which may attributed to the loss of energy and the change of material synthesis in the development process of alfalfa pollen.

Abstract:The phylogenesis of thirty-three tobacco germplasms belonging to different brown spot resistance analyzed by six SSR markers which linked to the tobacco brown spot resistant genes and twenty-one random SSR markers were reported in this study.The results of cluster analysis based on the six tobacco brown spot resistant linked SSR markers flanking the three tobacco brown spot resistant QTLs showed that thirty-three tobacco varieties could be clustered into four groups at a relative low level of GS (genetic similarity coefficient) 0.44.The tobacco varieties which had the resistant resource to tobacco brown spot from the Jingyehuang (China) and Beinhart-1000 (USA) were clustered into group Ⅰ;the tobaccos which belong to CV series and are resistant to tobacco brown spot were clustered into group Ⅱ;N.suaveolens belonging to wild tobacco was in an unique group Ⅳ;while the left which belong to susceptible varieties such as Changbohuang,G140,and NC82 were clustered into group Ⅲ.The results of cluster analysis showed that the SSR markers linked to the tobacco brown spot resistant genes (flanking the resistant QTLs) could cluster the species into resistant and susceptive while the random SSR makers could not.

Abstract:Using cytochemical technique,we observed the distribution of polysaccharides and lipids during the anther development of Michelia figo:(1)A few lipids were accumulated in sporogenous cells.At microspore mother cell（MMC）stage,a few lipids were still located in the MMCs which had formed a callose wall.At the same time,a few lipids were accumulated in tapetal cells,but many polysaccharides appeared in other cells of anther wall.After MMC meiosis,tetrad microspores still had a few lipids.(2)After released from tetrad microspores,the free microspores began to accumulate polysaccharides and the number of lipids decreased.At this time,polysaccharides in anther wall cells decreased and endothecium cells enlarged from radial direction.In late microspores,there were still many polysaccharides and a few lipids in the cells.Tapetal cells began to degenerate at this time and many lipids appeared in the cells.(3)In early bicellular pollen,the vacuoles disappeared,and the number of polysaccharides increased evidently.In nearly mature pollen of M.figo,though the lipids had been less,there were still many polysaccharides and some lipids accumulated in the vegetative cells as the storage material of pollen.The study suggested that tapetal cells at microspore mother cell stage contained little number of lipids and no polysaccharides.It appeared that tapetal cells transported nutriment to chamber actively,or transported lipids from middle layer cells without converting to polysaccharides.

Abstract:The leaf anatomical structure of Nitraria tangutorum Bobr.from three natural populations(WMX,ZGL,JGC) of different habitats along Hexi corridor were researched.The leaves were anatomically observed,and indexes including leaf length,width and thickness,upper and lower pubescence length,width and density,upper and lower stoma length,width,area and density,upper and lower cuticle thickness,upper and lower epidermal cell thickness,palisade tissue thickness,spongy tissue thickness,diameter of main vein,diameter of lateral vein,diameter of crystal cell,mucilage cell length,width and aqueous tissue length,width were measured.At the same time,the ratio of palisade tissue thickness to spongy tissue thickness (P/S),tightness (CTR) and looseness of leaf tissue structure were statistically analyzed.The differences of one index among three populations were compared to explore the adaptive response mechanism of leaf morphology anatomy features to different habitats.The results are as follows:(1)The indexes had different degrees of differences except some indexes including leaf length,width,ratio of length to width and lower pubescence width,the indexes such as leaf thickness and area,upper and lower pubescence length and density,upper and lower stoma length and density,upper epidermal cell thickness,upper and lower palisade tissue thickness,spongy tissue thickness,but P/S,CTR,diameter of vascular bundle,mucilage cell length and width all had significant differences among three populations.(2)The rank of variation coefficients and plasticity indices of aggregative indicators from three populations were the same,the order was JGC＞WMX＞ZGL.It showed that the ecological adaptability of N.tangutorum Bobr.was JGC＞WMX＞ZGL.(3)The plasticity indices of palisade tissue,spongy tissue,pubescence,cuticle of N.tangutorum Bobr.from three populations were relatively high.These organizations played a dominant role in response to different environment.The results above may be the adaptive response mechanism of leaf anatomical characteristics to different habitat conditions.

Abstract:Crystals in vegetative and reproductive organs of Pinellia pedatisecta (Araceae) were systematically examined and their morphology and distribution were determined with light microscopy.(1)Crystals were found in every organ.Raphides were most common,but druses,crystal sand and styloids were also found.(2)Leaf contained a variety of crystal,including raphides,druses,crystal sand and styloids.Raphides were distributed primarily within the upper mesophyll,with only occasional raphides coming into focus lower in the leaf.Crystal sand and stellate druses were also common crystal type in leaves,and occasionally styloids were seen.(3)Bulbs had many raphides bundles,giant druses near their conducting tissue.Adventitious roots had highly irregular raphide bundles and rare giant druses.(4)Spathes contained raphides,druses and crystal sand.Raphides were distributed primarily within the upper and the lower mesophyll,while crystal sand was distributed primarily on the upper and the lower epidermis.(5)Raphide bundles were found in anther wall,aligned perpendicular to the surface.The pollen sacs contained only small druses.(6)Raphides were found in pericarp and seed capsule.Based on acid solubility,all crystals appeared to be composed of calcium oxalate.In light of these findings,we conclude that calcium oxalate crystals of all types play an important role in protecting the plants against herbivory.

Abstract:Three walnut cultivars (superior line),‘Xiangling’,‘Lu W06-1’ and ‘Xiluo 3’,were used as experimental materials to study their cold-tolerance and the effect of different low temperatures and times on walnut’s osmolytes content and protein expression.Results showed that:(1)The ratio of xylem of ‘Lu W06-1’s 1-year-old twigs was the largest,and thickness of phloem of ‘Xiluo 3’ was significant larger than that of others.(2)With the temperature decreasing,relative electric conductivity (REC) increased gradually,and the REC of ‘Xiluo 3’ was almost larger than that of other two walnut cultivars (superior line) under every treatment.(3)The contents of soluble sugar (SS),free proline (FP) and soluble protein (SP) increasing firstly and then decreasing.However,the temperatures that increased to maximum value were still different.The SP contents of ‘Lu W06-1’ increased faster and larger,and its SS and FP contents were always larger than that of others under treatments.There were significant positive correlations between any two osmolytes of the three osmolytes,especially the correlation coefficient between SS and FP,which was 0.844.These indicated that their respond to cold stress were linked by a close relationship.(4)Electrophoretic protein patterns showed similar among different treatments,but there were significant accumulation existed in 6 protein bands of walnut branches when exposed to low temperature,which was from 38.9 kD to 87.9 kD.The cold tolerance abilities were ranked in the following order:‘Lu W06-1’>‘Xiangling’>‘Xiluo 3’.When exposed to low temperature,SP content of walnut branches accumulated rapidly,then SS and FP increased.In addition,more accumulated protein bands were detected in walnut branch which was more cold-tolerant.

Abstract:The leaf structure of different bitter melon cultivars resistant to powdery mildew was compared and studied.They mainly included thickness of upper and lower epidermis;thickness of palisade tissue and spongy tissue;compactness and porosity of leaves structure;waxes content;leaf weight ratio;density of stoma and fuzz,etc.The result indicates that:(1)The waxes content of resistant cultivars is significant higher than that of susceptible one and significant negative correlation with disease index.Wax layer is an important structure barrier to resist and delay the pathogen invading.(2)The stomatal number and hair densities of abaxial leaves of susceptible cultivars are significant more than that of resistant ones.The stomatal number and hair densities of abaxial leaves are significant positive correlation with disease index.It indicates that the less stoma and fuzz,the more resistance.(3)The palisade and spongy tissue of resistant bitter melon cultivars arranged closely and in good order,but the leaf tissue section of high susceptible cultivars present lots of pores and hard to observe whole cells.(4)The thickness of leaves,lower epidermis and palisade tissue and leaves structure compactness of resistant cultivars is significant higher than that of susceptible ones,but the thickness of spongy tissue and porosity of leaf structure is opposite.To the powdery mildew resistance ,the leaf weight ratio count for little.Wax content,the stomatal number and hair density of abaxial leaves can be the reference designators to identify the resistance to powdery mildew for bitter melon.

Abstract:The effects of 2 species AM fungi (G.mosseae,G.versiforme) on salt tolerance of processing tomato were studied in pot culture under different NaCl concentrations (0,50 and 85 mmol/L).The results showed that:(1)Under 0 mmol/L NaCl conditions,compared with non-mycorrhizal plant,mycorrhizal plant can enhance root activity,promote the accumulation of soluble sugar,soluble protein in leaves and proline content in roots,promote SOD and POD activities in leaves and reduce accumulation of MDA content,but no significant difference.(2)Under 50 mmol/L and 85 mmol/L NaCl stress,compared with non-mycorrhizal plant,mycorrhizal plant significantly enhanced root activity,promoted the accumulation of soluble sugar,soluble protein in leaves and proline content in roots,promoted SOD and POD activities in leaves and reduced accumulation of MDA content.(3)Expression of H⁺-PPase (AVP1) gene was studied by qRT-PCR and it was regulated by AMF and salt stress jointly.With the increasing of the concentration of salt,the AVP1 gene expression decreased.AVP1 gene expression of mycorrhizal plant is higher than that in non-mycorrhizal plant distinctly.We concluded that inoculation G.mosseae and G.versiforme to processing tomato can enhance the seedlings osmotic adjustment mechanism of salt tolerance,raise the activities of antioxidant and AVP1 gene expression.So the damage of salt stress on the plant would be alleviated and the adapt ablity of processing tomato seedlings to salt environment would be improved.

Abstract:In this study,the pear cultivar ‘Yali’,‘Chili’ and ‘Balixiang’ were used to determine the dynamic change of fruit organic acids accumuation and related enzyme activities during fruit development,the correlation of organic acids contents and the activities of related enzyme were also explored.The results demonstrated that:(1)The contents of organic acids decreased gradually during fruit development.The total organic acid content of ‘Chili’ was the highest,followed by ‘Yali’,and the ‘Balixiang’ is the least at the period of fruit ripening.Furthermore,the total organic acid content showed significant difference among three cultivars.(2)At the later stage of fruit development,the content of citric acid of ‘Yali’,‘Chili’ and ‘Balixiang’ was almost the same,but the content of malic acid showed significant difference among three cultivars,which indicated that malic acid played an important role in the difference of organic acid content of different cultivars.(3)NADP-ME activity showed significant difference during late stage of fruit development,however,NAD-MDH and PEPC activities showed no significant difference in synthesis of malic acid,so the NADP-ME was an important enzyme involved in the difference of malic acid content among ‘Yali’,‘Chili’ and ‘Balixiang’.(4)The related enzymes of CS,Cyt-ACO,Mit-ACO and NAD-IDH in synthesis pathway of citric acid showed same trends in different cultivars,but no significant difference at late stage of fruit development,which suggested that they were not main factors leading to the difference of citric acid content.(5)The correlation analysis between organic acid content and activities of related enzymes during the fruit devlopment revealed that both of enzyme activities in malic acid and citric acid synthesis pathway affected the total level of the organic acid content together.

Abstract:At 0 ℃ low temperature stress,the dynamic process of protective enzyme system (POD,SOD and CAT),osmotic regulation substances (soluble sugar and soluble protein) and malondiadehyde (MDA) as well as relative electric conductivity were determined in Isoetes sinensis Palmer submerged leaves.The results showed that the relative electric conductivity,soluble sugar and activity of CAT increased at the beginning then decreased.The SOD activity gradually increased with the process of low temperature stress.The activity of POD,soluble protein and chlorophyll content decreased in the whole process of low temperature stress.MDA content were lower than the control group during the whole low temperature stress process and fluctuated within a certain range.We can concluded that the I.sinensis Palmer submerged leaves were negatively influenced by 0 ℃ low temperature stress,but the osmotic regulation substances,protective enzyme system,plasma membrane permeability could adjust themselves to avoid low temperature harms,which led to some tolerant ability of I.sinensis Palmer to the low temperature condition.

Abstract:We studied the effects of exogenous 5-aminolevulinic acid(5-ALA)on germination of seeds,the content of soluble sugar,malondialdehyde(MDA)and antioxidase activities in Isatis indigotica seedlings under salt stress with sand culture.The results showed that:(1)There were significant inhibition of seed germinating and seedling growth in 100 mmol·L^-1 of NaCl stress.Germination rate,germination vigor,germination index,vigor index of seeds and water content were significantly decreased under salt stress,while malondialdehyde (MDA),content of soluble sugar,Cu-Zn superoxide dismutase (SOD)and peroxidase (POD) activies were increased significantly.(2)Under salt stress,appropriate concentration ALA could improve germination rate,water content,activities of SOD,POD and CAT,meanwhile reduce the contents of soluble sugar and malondialdehyde (MDA),in which the germination rate and germination vigor of seeds were the maximum,and the activities of SOD,POD,CAT were the maximum by the treatment of 16.7 mg·L^-1 ALA.It indicated that salt stress could obviously inhibit the seed germinating and seedling growth.Appropriate concentration ALA could effectively alleviate the damage to seed germinating and seedling growth of I.indigotica under salt-stress and promote the salt resistance,especially the effect of 16.7 mg·L^-1 ALA was the most significant.

Abstract:In order to study the water tolerance of Quercus variabilis in seed germination stage,the effects of different concentrations (0%,5%,10%,20%,30%) of PEG stress on seed germination,growth,protective enzyme activities and the organic osmoregulation substances were measured with choosing fresh cork oak seeds and using Petri dish and filter paper germination method.The correlation analyses were done between seed germination,radicle growth rate and PEG stress.The results showed that:(1)With the increasing of drought stress,seed germination rate,vigor index,germination index and radicle length of cork oak were all increased then decreased,showing that low concentration PEG stress (5%,10%) can promote the cork oak seed germination and growth,whereas high concentrations (20%,30%) had inhibition effects.(2)The regression equation between seed germination,radicle growth rate and PEG stress showed that the critical and the maximum value of the seed germination of Q.variabilis were 32.01% and 36.99%,while the corresponding radicle growth rates were 30.1% and 33.35% under the PEG stress.(3)With the increase of PEG concentration,three protective enzyme (SOD,POD and CAT) activities and contents of three kinds of organic osmoregulation substances were presented different responses,but had a same rising trend.Thus it can be seen that cork oak seeds increased protective enzyme activities and contents of osmotic regulation substances in vivo to adapt to the water stress,making the inhibition degree of germination and growth to the minimum.

Abstract:To explore the responses to salt stress in germinating stage and seedling stage of Silybum marianum (L.) Gaertn.(white rind type,HW;black rind type,SD),and compare the salt tolerances of two S.marianum cultivars.Treating the seeds and seedlings of two S.marianum cultivars by different concentrations of NaCl,germination energy,germination rate,bud seedling,seedling growth condition and physiological and biochemical characteristics were observed.Results showed that:(1)The germination energy,germination rate decreased under NaCl stress.The low density NaCl showed promting function and high density NaCl expressed inhibitory function(HW:NaCl concentration≥0.5%,SD:NaCl concentration≥0.3%) on the bud seedling growth.NaCl has great influence on radical,plumular axis length and fresh weight,and has no significant effect on dry weight.(2)The content of malondialdehyde (MDA) increased in young leaves,while photosynthetic pigment contents decreased.The low density NaCl showed promting function and high density NaCl expressed inhibitory function(HW:NaCl concentration≥0.9%,SD:NaCl concentration≥0.7%) on the seedling growth.The soluble sugar,soluble protein contents and activities of protective enzymes (including SOD,POD and CAT) increased at first and then decreased in young leaves,among them,soluble sugar and protein contents decreased significantly than that of control when NaCl concentration was 0.9%,while the activities of protective enzymes decreased significantly than that of control when NaCl concentration was 0.7%.Proline content increased continuously.It was found that NaCl effected bud seedling growth by altering the ability of seed imbibition at the seed germination stage,and S.marianum seedlings could promote the osmotic substance contents and activities of protective enzymes to relieve the damage of NaCl at seedling stage.The ability of salt tolerance at seedling stage was significantly stronger than that at germinating stage of S.marianum,and the ability of salt tolerance of HW was stronger than that of SD.

Abstract:The effects of different cadmium levels（0,200,400,600 mg/L）on stem diameter,height,weight of hundred leaves,weight of stems and flowers,malondialdehyde (MDA),relative conductivity (REC),superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX),as well as photosynthetic parameters (Chl a+b,Pⁿ,G^s,T^r,WUE) were studied in six marigold cultivars.The results showed that:(1)No reduction in the stem diameter and height were noted when the plants were grown at Cd²⁺ supply levels up to 400 mg/L.However,fresh weight of hundred leaves stems and flowers of all cultivars were decreased with the increase of Cd²⁺ concentrations.Moreover,‘Great Hero’ and ‘Durango’were more sensitive than other cultivars.(2)MDA and REC were increased gradually as Cd²⁺ concentration increasing.However,the activities of antioxidative enzymes significantly changed with the increasing of Cd²⁺ concentrations from 0 to 600 mg/L.(3)Cadmium stress also caused Chl a+b and Chl a/b decrease,especially in Cd stress-sensitive cultivars.Moreover,Net photosynthetic rate decreased significantly under Cd stress,while the decrease of stomatal conductance (G^s),transpiration rate (T^r) and WUE were little.It was concluded that there was significant different response to Cd among marigold cultivars.The physiological characteristics of marigold responding to Cd might be important factors for the tolerance of cultivars.The photosynthetic efficiency and activities of antioxidative enzymes in sensitive cultivars were all decreased under Cd stress,which may cause lipid peroxidation to increase.In summary,‘Janie’and ‘Gate gold’had adaptation mechanism to Cd stress.The two cultivars are recommended for the heavy metal contaminated soils.

Abstract:With cucumber varieties ‘Jinyou No.4’ and peanut vine straw,corn straw and rice husk of after 1 year rotten as test materials,the effects of different crops straw returning on growth and photosynthesis characteristic of cucumber were investigated in protected cultivation.The results showed that:(1)Crop straw returning not only could significantly increase root activity and leaf nitrate reductase activity of cucumber,but also could improve leaf chlorophyll content,F^v/F^m,Ф^PSⅡ and photosynthetic rate of cucumber leaves,compared with the control.So light use efficiency of cucumber leaves was increased,net photosynthetic rate significantly enhanced,thereby promoting growth and development of cucumber.(2)The plant height and stem increased,the fresh and dry weight of cucumber increased,and significantly improved the yield of cucumber.(3)One of the best straw returning is maize straw returning,its yield reached 5 765.74 g·m^-2,the treatment yields 43.8% higher than compared with the control;followed by peanut vine straw returning,rice husk straw returning less effective.We concluded that straw returning promoted root absorption capacity,significantly improved leaf nitrogen metabolism,light energy use efficiency,net photosynthetic rate of cucumber,so as to promote the growth of the cucumber plant,improve the production,and the effect of corn straw returning was the best.

Abstract:In this study,we collected the data from 30 plots and 30 groundwater level monitoring wells in the middle reaches of Tarim River.According to the data from monitoring wells,we divided the groundwater levels into 6 gradients:0~2 m,2~4 m,4~6 m,6~8 m,8~10 m,>10 m.Then we analyse the coverage of vegetation and biodiversity at different groundwater levels,in order to investigate the relationship between the frequency of plants distribution and groundwater level,as well as to determine the reasonable ecological water level of the desert riparian forest in middle reaches of Tarim basin,and to provide a basis to ecosystem restoration in middle reaches even the whole basin-wide of Tarim basin.The result shows that:(1)There are 15 species in middle reaches of Tarim basin and the dominant species is Populus euphratica.(2)With the reduction of groundwater depth,the coverage of vegetation decreases gradually;As the groundwater level between 2~4 m,the average coverage is 39.14%;When the groundwater level between 6~8 m,the coverage of vegetation is less than 20%;The coverage is only 7.65% when groundwater level less than 10 m.(3)Along with the lowering of groundwater level,the changing trend of species diversity is increased firstly,and then decreased;The species diversity is maximum when groundwater level between 2~4 m,followed by 4~6 m and 0~2 m;When groundwater depth under 6 m,the species diversity decreases rapidly.The species diversity is precious little when groundwater level under 10 m,only P.euphratica and Tamarix chinensis still remaining.(4)Average depth of groundwater level for the species in middle reaches of Tarim river are:P.euphratica 4.58 m,T.chinensis 3.53 m,P.communis 2.34 m,Alhagi sparsifolia 4.10 m,Karelinia caspica 3.18 m,Lycium ruthenicum 2.98 m;P.communis can be suitable for the shallow level of groundwater only,the suitable water level of the rest is about 3~4 m.In summary,in the middle reaches of Tarim River,the most suitable groundwater level to the growth of plants is 2~4 m and the reasonable groundwater level to ensure the normal growth of plants is 2~6 m.It indicates that the groundwater level should be above 6 m in order to ensure the restoration of vegetation and the normal growth as well.

Abstract:From May to October 2011,sample-plot survey and soil sampling analysis have been carried out in 128 quadrats of vegetation in 33 sample areas in the middle and lower reaches of the Fenhe River.TWINSPAN was applied to classify the phytocoenosium,and canonical correspondence analysis (CCA) was used to analyze the distribution relation between soil factor and phytocoenosium,in order to reveal the relationship between species diversity and soil factor of phytocoenosium in the middle and lower reaches of the Fenhe River.The results shows that:(1)In the middle and lower reaches of the Fenhe River,121 kinds of plants have been discovered which belong to 33 families and 81 genera,of which Compositae,Gramineae,Chenopodiaceae and Polygonaceae plants are the most,accounting for 24.79%,14.05%,8.26% and 7.43% of the total number,respectively.The distribution frequency of Phragmites australis is the highest which reaches to 49%.(2)TWINSPAN indicates that 33 sample areas in the middle and lower reaches of the Fenhe River are divided into 8 coenotypes (Ⅰ~Ⅷ).(3)Patrick richness index and Shannon-Wiener index variation tendency of phytocoenosium in the middle and lower reaches of the Fenhe River are similar,while Simpson index shows a contrary tendency with the change pattern of Patrick richness index and Shannon-Wiener index;the variation tendency of Pielou evenness index is different from other three indexes.(4)Most of the content differences of soil water content and rapidly available potassium content in the middle and lower reaches of the Fenhe River reach significant level among different sample areas of different coenotypes.The soil nutrients are characterized by apparent moderate nonuniform spatial distribution.(5)The content of soil organic matter and species Simpson index,soil total nitrogen and Pielou evenness index have significant negative correlation in the middle and lower reaches of the Fenhe River basin.(6)The result of CCA ranking demonstrates that soil water content,rapidly available phosphorus and rapidly available potassium content are the most important environmental factors which influence vegetation type distribution.

Abstract:Set 11 plots in the southern slope of Qinling Mountains in Shaanxi Province,the characteristics of Patrick richness index,Simpson dominance index,Shannon-Wiener diversity index and Pielou evenness index are studied,in terms of the species comprise,diversity index differences and gradient ordination between diversity indices and environmental factors of Pinus tabuliformis and Quercus aliena var.accuteserrata mixed forest,to reveal the relationships between community diversity characteristics and environmental factors.Results indicated that:(1)11 plots record 112 species vascular plants,belong to 45 families 77 genera.The wide distribution species include Rosaceae,Asteraceae,Liliaceae,Pinaceae,Poaceae and Caprifoliaceae.(2)The dominant positions of P.tabuliformis and Q.aliena var.accuteserrata are significant.The auxiliary species in tree layer are less with average only 4.8 and the biodiversity level is low.The species compositions of shrub layer are rich,average 11.4.The herb layer takes second place,average 9.(3)One-way ANOVA analysis indicates difference of diversity indices from 4 different forest layers all reaches extremely significant level (P<0.01),LSD multiple comparison illustrates the values of diversity indices from community overall are the highest,while diversity level of tree layer is the lowest.(4)CCA method divides the distribution of diversity indices from different layers along 12 environmental indicators (terrain factors and soil nutrients) gradient into 3 sectors,they are Ⅰ (medium concentration of soil phosphorus and organic matters restricted area),Ⅱ(non- environmental factors restricted area) and Ⅲ(high concentration of soil phosphorus restricted area);community overall diversity indices are mainly influenced by shrub layer,meanwhile influenced by tree layer evenness indices,but environmental factors nearly have no restrictive roles on tree layer diversity.(5)The main factors causing diversity difference among different layers of community in study area are soil available phosphorus,total phosphorus and organic matter,while elevation,slope and other terrain factors have no significant effects on community diversity.It may be due to soil nutrients direct influence weakens indirect ecological role of terrain factors.Studies show that keeping moderate soil nutrients and improving tree layer evenness by upbringing is an effective measure for maintaining P.tabuliformis and Q.aliena var.accuteserrata mixed forest biodiversity in the southern slope of Qinling Mountains.

Abstract:We conducted a systematic research on the diversity and ecological characteristics of wild liana in Hunan Huangsang National Nature Reserve,by means of field survey,sample collection and indoor investigation.The study results showed that:(1)There are 45 families,113 genera and 250 species of liana in Hunan Huangsang,accounting for 21.13%,13.33% and 12.32%,respectively,of overall liana plants in the same region.Among all these liana,there are 3 families,3 genera and 3 species of pteridophyte,and there are 42 families,110 genera and 247 species of angiosperm.For the angiosperm,dicotyledonous liana dominate and have 37 families,105 genera and 223 species,while monocotyledonous liana contain only 5 families,5 genera and 24 species.(2)For all the liana in this region,the families and genera which have less than 10 species accounts for 82.22% and 97.35% of entire families and genera,respectively.The dominant families contain Vitaceae,Ranunculaceae,Papilionaceae,Rosaceae,Celastraceae,Convolvulaceae,Dioscoreaceae,Cucurbitaceae and etc.The dominant genera contain Clematis,Rubus,Actinidia,Vitis,Smilax,Dioscorea and etc.(3)In the ornamental view,the majority of liana own at least 2 types of ornamental characteristics.Foliage plants have the most species,accounting for 92.80% of overall species,while stem-viewed plants have the least species,accounting for 2.00% of overall species.(4)In terms of climbing style,the majority is twining liana,accounting for 46.40% of overall species,while the minorities include curling,hooking and adhering liana,accounting for 24.40%,18.00% and 11.20% of overall species,respectively.(5)In terms of life-form,phanerophyte liana dominates,accounting for 80.80% of overall species,while the minorities include annual plant,geophytes,and chamaephytes,accounting for 10.80%,7.60% and 0.80% of overall species,respectively.(6)In terms of breeding system,hermaphrodite flowers dominate.Of all unisexual flowers,dioecious plants have more species than the monoecious ones.Hermaphrodite,unisexual flowers and polygama account for 70.40%,28.40% and 1.20% of overall species,respectively.(7)There are 72 tropical genera,which dominates the floristic composition and accounts for 63.72% of entire genera.

Abstract:The bryophyte communities were preliminarily studied by the method of transect sampling from four peak clusters and three slope sections (lower slope,middle slope,upper slope) of karst rock desertification which were influenced by human actions in valley of Siya River,Guizhou Province.The distribution of the bryophyte communities in different peak cluster and different slope section was studied.The results are as follows:(1)The bryoflora of this site includes 8 families,19 genera and 40 species.There are 19 types of bryophyte communities in the area.Among them,14 types are pure communities.The dominant communities are E.julaceum,B.argenteum and H.involuta.(2)There are two very important life-forms,which are wefts and short turfs occurring on the area owing to dry and barren environment affected by human actions.(3)The richness of the bryophyte communities is reducing with the expansion of human action area in this special environment.(4)The results indicated that the E.julaceum has the potential value to control rock desertification contribution which was made by human actions to its highest summed dominance ratio.

Abstract:N²O emission dynamics and its microbial mechanisms within alfalfa grassland in arid areas were previously unclear.Accordingly,gas collection was performed on a 3-year old alfalfa (Medicago sativa L.cv.Longdong) grassland in Qingyang,on the Loess Plateau,using a static,enclosed chamber.N²O emission flux was measured using High Performance Gas Chromatography.Quantities of nitrifying and denitrifying bacteria in soils at a depth of 0～30 cm were determined using the most probable number (MPN) method.The results showed:(1)The N²O emission flux of alfalfa grassland ranged from -0.099～0.085 mg·m^-2·h^-1 through all phonological stages.N²O emission peaked at flowering stage of the first cut and at the re-growth stage before overwintering,whereas the grassland absorbed N²O at re-growth stage of the second cut and during overwintering,which became the N²O repository.(2)The amounts of nitrite bacteria,nitrate bacteria and denitrifying bacteria varied among different phenological stages and soil layers.(3)Significant linear correlation was found between N²O emission flux and soil moisture content and soil pH value and the amounts of nitrate and denitrifying bacteria.(4)Longdong alfalfa grassland in Qingyang was found to be a weaker N²O emission source than other agricultural sources as reported in similar research and the international average of emission level.

Abstract:With the stem segments as explants,we studied the technique about the tissue culture for rapid propagation and in vitro bulbils regeneration system of Dioscorea opposita Thunb from Wen County,Henan Province.The results showed that:(1)The disinfection efficacy which combing 70% alcohol 30 s with 5% NaClO 15 min was the best.The optimal axillary buds induction medium was MS+0.5 mg·L^-1 6-BA+0.1 mg·L^-1 NAA with the maximum multiple buds ratio and buds height.After 20 d,the multiple buds ratio were 2.22 and buds height were 3.3 cm.The optimal subculture medium was MS+1.5 mg·L^-1 6-BA and the propagation coefficient could reach 4.1.The optimal rooting medium was 1/2MS+0.2 mg·L^-1 6-BA+1.0 mg·L^-1 NAA+0.02% activated carbon,with 12 d for the average rooting day,100% rooting rate and 1.04 cm root length.(2)The cultural method of the explants with single bud,was significantly (P＜0.05) higher than the cultural method of the single bud in the inductivity and average number of bulbils,which the inductivity,average number and size were 88.9%,1.50 and 0.38 cm×0.54 cm,respectively.1%~3% sucrose concentration was helpful to inducing the bulbils with had regular shape and the colour of the plantlets leaves were dark green.The optimal bulbils germination medium was MS+1.5 mg·L^-1 6-BA+0.2 mg·L^-1 NAA.The bulbils germinated at 18~22 d and inductivity reached 83.3% at 30 d.These results had a great potential application value for test-tube plantlet factory production of D.opposita Thunb.

Abstract:Temperature and light conditions were explored to find out the optimum conditions of spore germination of Polytrichum commune and Haplocladium microphyllum.To find the suitable method for rapid detect of spore viability of mosses,I²-KI reaction method,TTC reaction method,red ink staining method,and methylene blue staining method were studied based on six species of mosses by comparing the spore viability with the germination results.The results indicated that methylene blue staining method got the most similar results with the germination rate of moss spores and showed clear staining effect,which can be used for the rapid detection of the viability of bryophyte spores.The correlation between spore viability (x) detected by methylene blue staining and germination rate (y) in vitro reaches a very significant level（r=0.976）.The regression equation between spore germination ratio (y) and viability (x) can be obtained:y=-8.547+1.069x(P<0.01).The germination rate can be detected conveniently by spore viability.

Abstract:During the investigation of diatoms from Xingkai Lake,more than one hundred samples were collected and studied.Totally,7 taxa from Cymbellaceae and Gomphonemataceae were newly recorded in China.They are:Cymbella peraspera Krammer,Cymbopleura cuspidata (Kützing) Krammer,Encyonema obscurum var.alpina Krammer,Encyonema silesiacum var.lata Krammer,Gomphonema auritum Braun & Kützing,Gomphonema clava Reichardt and Gomphonema exilissimum (Grunow) Lange-Bertalot & Reichardt.The morphological characteristics of these taxa and comparison with similar species are given.The basis information of algae from Xingkai Lake is provided.

Abstract:Sciuro-hypnum ornellanum (Molendo) Ignatov & Huttunen (Brachytheciaceae,Bryophyta) from Altai Mountains,Xinjiang was found and firstly recorded in China.The history of Sciuro-hypnum （Hampe） Hampe was introduced.Morphological characters and distribution of S.ornellanum,and the differences among allied species were discussed.The key to the Chinese species of Sciuro-hypnum was also given.Not only do the results provide new references to Brachytheciaceae in China,but further confirm the relationships between Xinjiang,China,Russia,Middle Asia,and Europe in flora.

Abstract:Grass pea (Lathyrus sativus L.),a leguminous crop,has very long history of cultivation and been widely cultivated.Because of its high protein content and a strong drought tolerance,it has become major sources of feed and food for the vast populations of drought-prone and marginal areas,and it has also been considered as a model crop for sustainable agriculture.With more food,protein and new food resources are needed for the growing human demand,researches on grass pea have attracted the attention of scholars around the world.In this review,we firstly summarize the recent progress made in the understanding of stress resistance in grass pea,including the resistance of drought,salinity,heavy metal and biotic stress.Meanwhile,mainly morphological characteristics adapted to drought stress are also briefly introduced.Finally,aspects of the particularly important research in the future are suggested.