Abstract:In this study, the expression of CELL GROWTH DEFECT FACTOR 1 (CDF1)like protein encoding gene P1 was detected in different developmental stages of Arabidopsis thaliana leaves by realtime PCR. The results showed that P1 is expressed in all developmental stages of rosette leaves, but its expression was the highest in senescent leaves. GUS staining showed that P1 promoter has high driven activity in leaves. In seedlings and the vegetative stage plants (4-5 weeks old), GUS staining can be detected in all rosette leaves, but after the plants entered into reproductive stages (after 6 weeks old), the rosette peripheral leaves began to yellowing and GUS staining was centralized to the senescing leaves and increased with leaf senescence progress, but the stain in younger leaves was weaker. GUS fluorescent quantitative analyses further confirmed the staining results. By searching cisacting elements in P1 promoter, the elements related to MeJAresponsiveness, heat stress responsiveness, droughtinducibility and salicylic acid responsiveness which have been previously proved to induce leaf senescence reactions were found. These results indicate that P1 as a membrane protein in leaves is possibly participate in the cell response to leaf senescence signals. This study lays a foundation for the molecular function verification of P1 during leaf senescence process in future.

Abstract:In this research, a gene named NtACOY2 encoding a novel ACC Oxidase ( ACO ) protein was isolated using RTPCR from ‘Yunxiang’ (Narcissus tazetta var. ‘Yunxiang’). The full length cDNA of NtACOY2 consisted of an open reading frame (ORF ) of 936 bp, and encoded a 35.83 kD protein with 311 amino acids. Bioinformatics analysis indicated that NtACOY2 contained a typical DIOX_N and 20GFeⅡ_Oxy binding domain. Evolutionary analysis indicated that the amino acid sequence encoded by NtACOY2 was highly conserved. Realtime fluorescence quantitativePCR results revealed that the expression of NtACOY2 in the petal and deputy crown is increasing with the senescence of ‘Yunxiang’. The expression of NtACOY2 in petals in each period was higher than that in the deputy crown, and the highest expression in petals is at bud stage. So it is inferred that NtACOY2 may be involved in the development of ‘Yunxiang’ and related to flower senescence. The expression vector of NtACOY2 was successfully constructed by PCR and identified by restriction enzyme digestion reactions. And the sense plant express vector of NtACOY2 was used to transform the tobacco through Agrobacteriummediated procedure. PCR detection showed that a total of 15 transformed plants were amplified fragments with the same size as the positive controls. The result of RTPCR identification showed that 12 transgenic tobacco plants were obtained. Two randomly selected transgenic plants (Z1, Z2) and wild type (WT) exactly the same condition of transplanting under greenhouse cultivation, the results showed that the flowering time of Z1, Z2 were 8 d and 7 d earlier flowering compared with control plants, and the flower number of transgenic tobacco were more than the wild type, it is showed that NtACOY2 could normally expressed at the transcriptional level. The experimental results laid the foundation for further research on the function of NtACOY2 gene.

Abstract:A total 84 pyrroline5carboxylate synthetase (P5CS) genes were identified from 31 genome sequence available plants by using bioinformatics methods, and their phylogenetic analyses were performed. The results revealed that: (1) P5CS had a large difference in intron length, but there was no significant difference in amino acid length, exon number, isoelectric point, and molecular weight. (2) Due to the occurrence of gene duplication, there were two P5CS in most monocot and dicot plants. (3) Moreover, in both monocot and dicot plants, P5CS1 genes were clustered in one group, while P5CS2 genes were clustered in another group, supporting that P5CS1 and P5CS2 of independent origin and the duplication event occurred before the divergence of monocot and dicot plants. In some plants (such as Medicago truncatula and soybean) there were 3-7 P5CS genes, indicating that the duplication events of P5CS genes also occurred several times after the divergence of monocot and dicot plants, and totally four different evolutionary patterns were revealed. (4) There were two P5CS genes in cassava. Expression analysis revealed that MeP5CS1 and MeP5CS2 were expressed in leaf, petiole, stem, fibrous root and storage root. (5) Of which, MeP5CS1 was highly expressed in leaf, while MeP5CS2 was highly expressed in stem and storage root. Under drought stress, MeP5CS1 was significantly induced in the first fully expanded leaf, while MeP5CS2 was significantly induced in the first fully expanded leaf and bottom leaf. Under cold stress, both MeP5CS1 and MeP5CS2 were significantly induced in different tissues, but they exhibited different expression patterns. These results indicated that MeP5CS1 and MeP5CS2 were involved in the regulation of abiotic stresses (e.g., drought and cold) at the transcriptional level.

Abstract:In this study, we selected the EST sequence of CiABR17 from the suppression subtractive hybridization (SSH) library of Caragana intermedia under drought stress via blastn. Through RACE, we obtained the 594 bp cDNA fragment of ABR17. The open reading frame is 471 bp, which encodes a polypeptide of 157 amino acid residues, with a calculated molecular weight of 16.44 kDa and a pI of 4.93. The average hydrophobic index of ABR17 is -0.126, which is a hydrophilic protein. The quantitative realtime PCR analysis indicates that the transcript level of CiABR17 was induced differently by dehydration, NaCl and heat treatments, which showed that CiABR17 gene was related to stress response of C. intermedia. Significant difference between CiABR17 overexpression lines and wildtype in fresh weight, dry weight and rosette diameter was found.

Abstract:The genetic diversity of 6 wild Dactylis glomerata accessions contained 90 individuals was analysis with AFLP technique. (1) A total of 208 polymorphic bands were amplified with 4 primer pairs, thus the percentage of polymorphism was 59.86% and polymorphism information content was 0.205 3. The Neis genetic diversity varied from 0.201 9 to 0.233 6, which total and average were 0.335 8 and 0.230 9, respectively. The Shannon information index was from 0.235 5 to 0.293 5, which total and average were 0.399 4 and 0.266 4, respectively. (2) The UPGMA trees for individuals and accessions, STRUCTURE analysis and principal coordinate analysis indicated that materials which sampling from same region were clustered together, revealing distinct regionalism. AMOVA revealed 63.30% of genetic differentiation was occurred within accessions and 36.70% was among accessions, while the variance of two sampling regions was 23.51%. The tested germplasm collections revealed abundant genetic variability and high level of differentiation, and population genetic diversity was affected by not only geographical isolation, but also environmental factors like altitude, temperature and monthly precipitation.

Abstract:In the present study, the cDNA of C. reticulata (floral leaf and green leaf) were sequenced based on Illumina HiSeq2500 to analyze the leaf color mechanism. In total, 228 862 unigenes were obtained and 4 851 differential expressed genes (DEGs) were selected. 2 291 DEGs were divided into 31 GO terms, 1 826 DEGs were divided into 23 COG major functional categories. Most of these genes are related to its growth and metabolism. 1 363 DEGs were annotated into KEGG database, 15 pathways of DEGs most annotated were screened out, GluRS, δALAD, ALAS, in the pathway of porphyrin and chlorophyll metabolism; ANS, LAR, CHS in the pathway of flavonoid biosynthesis, are the key genes in its floral leaf formation. The coloration of the leaves was caused by a large amount of gene expression changes related to leaf color metabolic pathways, not caused by single gene mutations, the silencing of homologous genes induced by C. reticulata mosaic virus in Yunnan is probably the main reason for the formation of C. reticulata leaf coloration. These results greatly enriched genetic information of C. reticulata, and provide some reference for the cultivation of the colorful leaf varieties.

Abstract:In this study, the genomic library of G. elata was set up by means of the second generation of DNA sequencing, and the microsatellite loci in genomic sequences was screened. The types, abundance, length and preference of microsatellite locus were analyzed and compared. Primer pairs for 60 microsatellite loci with high repetition were designed, PCR and polyacrylamide gels electrophoresis were carried out on 80 individuals sampled from 4 populations in order to test the polymorphism of the markers. (1) 61 048 sequences of G. elate were gotten in the genomic sequencing, 12 107 microsatellite loci were detected out, occupying 8.16% of total sequences. (2) Among these SSR loci, the repetition of dinucleotide was the highest. 20 loci among those 60 were detected amplifiable, stable, and polymorphism after PCR and electrophoresis; the number of polymorphic alleles of each locus (N_a) ranged from 4 to 14 with the average of 8.40, while the average of polymorphism information content (PIC) was 0.77. The microsatellite markers developed for G. elate in this study can make good basement for its genetic study, germplasm identification.

Abstract:In order to solve the problem of susceptibility of rice stripe disease (RSD)long growth period and poor eating quality in the major rice cultivars in Shanghai, we crossed female parent ‘Wuyunjing 7’, a Japonica rice variety with high yield and wide adaptability, and ‘Wu 2699’, a Japonica rice strain with high RSDresistance. Subsequently, the F₁ of (‘Wuyunjing 7’בWu 2699’) was crossed with male parent ‘Taihuxiangjing’, an earlymaturing and high quality Japonica rice variety. Genotypic detection of QSTV11b and the fragrance gene Badh2 was performed by using molecular markers, which linked to the RSDresistant gene QSTV11b and cosegregated with the fragrance gene Badh2, respectively. By associated with resistance identification and fragrance determination, a fragrant, earlymaturing, high RSDresistant, high yield and excellent eating quality Japonica rice variety named ‘Huxiangjing 151’ was obtained.

Abstract:In order to understand the genetic mechanism of carbon isotope discrimination (Δ) and water use efficiency(WUE) in wheat, we used recombinant inbred lines (RILs) of wheat to study the genetic basis of Δ under different water treatments, based on QTL mapping and environmentspecific assistive effect analysis. The results show that: (1) Δ value in the RILs population showed a normal distribution, indicating that Δ is a quantitative trait. (2) We detected 11 majoreffect Δ QTLs in 2B, 3B, 7B, 1D, 3D and analyzed their phenotypic variation rate between 10.83%-46.87%, 9 additive × environment interactions QTLs and analyzed their phenotypic variation rate between 1.02%-3.15% were detected. (3) We detected 5 pairs of epistatic QTLs which include 3 pairs of epistatic QTLs and their interactions rate between 0.86%-2.01%. (4) Additive effect and contribution rate were larger than epistatic effect and contribution rate, AQTL and AQTL × environment contribution rate were larger than AAQTL × environment contribution rate. The results indicated that the genetic variation of Δ in the RILs population was mainly affected by additive effect QTLs, the majorgenecontrolled Δ has a greater effect than the water environment.

Abstract:The growth and development characteristics and relationship between the galls and Haloxylon ammodendron were studied through the observation of the morphology and microstructure of the leafy galls in H. ammodendron and the enrichment analysis of differentially expressed genes based on transcriptome sequencing, for the aim to provide a theoretical basis for the coevolution of insect and plant and the pest control of H. ammodendron. The results showed: (1) the growth stage of the leafy galls can be divided into 3 periods: growth period, formation period and decay period. (2) There were obvious differences in the anatomical structure of the leafy gall and the assimilating branch and scale leaf of H. ammodendron in the growing period and the formation period: In the growth period of leafybracted gall, the cuticle is damaged outer epidermal cells, but epidermal cells intact, little morphological differences and tightly stacking, it no palisade cells and kranz anatomy, only spongy tissues with high water content, and the cells are small and dense than that of the assimilation branches and scales, the number of cells is about 2 times the scale, and the diameter of the vascular cylinder is smaller than that of the assimilating branch and scale leaf; In the formation period of leafybracted gall, the cuticle is severely damaged outer epidermal cells, the shape of large differences, loose arrangement, sponge tissue water content is seriously reduced, vascular tissue is not obvious. (3) The expression of gene enrichment related to the normal development of plant cells and photosynthesis in H. ammodendron was downregulated, while the expression of stressrelated enrichment was upregulated. It is considered that the leafy galls of H. ammodendron only promote the growth and development of psyllids, and have no effect on improving the photosynthesis of H. ammodendron.

Abstract:Gathering mature trees as experimental materials, we observed the anatomical structure of scale and needle leaves of Sabina vulgaris by using the handsliced method. The aim is to explore the relationship between droughtresistant adaptation and anatomic structure of scale and needle leaves of S. vulgaris, to reveal the ecological significance of heterophylly mechanism of S. vulgaris, and to provide a theoretical basis on widespread use of vegetation restoration and reconstruction of S. vulgaris in the arid and semiarid areas of China. The results show as followed, (1) corneum thickness (CT) of scale leaves was significantly higher than that of needle leaves, while the thickness of abaxial side epidermis(TAB) and adaxial side epidermis(TAD) of scale leaves were both significantly lower than those of needle leaves. That meant scale leaves mainly prevented water loss by thick cuticle, while needle leaves mainly maintain water through the whole thick epidermal system. (2) Opening stoma ratio (OS), stoma aperture(SA), stoma length (SL) and stoma width (SW) of scale leaves all were significantly higher than those of needle leaves, while stoma density (SD) of scale leaves was significantly smaller than that of needle leaves. The results showed that scale leaves had stronger drought tolerance, and needle leaves relied on higher SD and sensitive stomatal closure to react against drought stress. (3) Leaf thickness (LT) and midrib thickness (MT) of scale and needle leaves both had no significant difference, nevertheless thickness of palisade tissue (TP), thickness of spongy tissue (TS), palisade tissue and spongy tissue ratio (P/S)，tightness of leaf palisade tissue (TLP) and area of resin duct (AR) of scale leaves all were significantly higher than those of needle leaves, and xylem thickness (XT), xylem thickness and midrib thickness ratio (X/M) and looseness of leaf spongy tissue (LLS) of scale leaves all were significantly less than those of needle leaves. The observed results indicate that scale leaves adapt to drought by higher P/S and compactness of leaf structure, while needle leaves react against drought by strengthening conducting tissue. The study showed that drought tolerance of scale leaves was stronger than that of needle leaves, and compared with scale leaves, needle leaves mainly chose an avenue of escape to react against drought.

Abstract:The shading net can affect the growth of fruit tree and the development of berry by adjusting the microclimate. Experiments were conducted in Heshuo (Xingjiang) in 2015, using Vitis vinifera L. cv. Cabernet Sauvignon and Vitis vinifera L. cv. Syrah as materials. Treating time was from verasion (August 5th) to 12 days before harvest (September 5th). The results showed that: (1) the shading net decreased the daily average temperature, illumination intensity and photosynthetically active radiation, and increased the daily average humidity, effectively improving the microclimate of grapevine growing. (2) The transverse diameter, the vertical diameter and the fruit weight of grape berry treated with shading net were increased. The shading net effectively inhibited the excessive accumulation of sugar and the rapid degradation of organic acids in grape berry, and reduced the alcohol content in wine. The contents of total phenol and tannin were increased, and the contents of total anthocyanin and flavonoid in grape berries and wines were decreased in treatment group. (3) Nine kinds of monomeric anthocyanins were detected in grape and wine with HPLC. Except anthocyanin3glucoside, the other 8 kinds of monomeric anthocyanins in Cabernet Sauvignon berry and wine were lower in shading treatment than those in the control, while in Syrah berry and wine, the monomeric anthocyanins were also lower in shading treatment, except dimethoate3coumaroylated glucoside. Due to global warming, this study is helpful to alleviate the problems of rapid ripening of grape berry, and high alcohol content of wine in hot wine regions，and is meaningful to improve the qualities of grape and wine.

Abstract:The objective of this experiment was to compare the concentration of Resveratrol and its precursors and the activity of important metabolic enzymes in Cabernet Sauvignon grape. The relationship was analyzed between the rootstocks and resveratrol synthesis. The results provide a reference for selecting resistant rootstocks with eight different rootstocks suitable for Xinjiang. In this experiment, the eight rootstock cultivars (Fercal, 5C, 140R, 3309M, 3309C, SO4, Kangzhen3, 5BB) grafted with scions of Cabernet Sauvignon grapes were used as experimental materials. Selfrooted ‘Cabernet Sauvignon’ plants were used as the control (CK). The content of transresveratrol, transpiceid and phenylalanine, cinnamic acid, and coumaric acid were determined by HPLC technique. The activities of the following enzymes in the phenylalanine pathway of resveratrol production were also determined: peroxidase(POD), polyphenol oxidase(PPO), phenylalanine ammonia lyase (PAL),cinnamic acid4hydroxylase(C4H) and 4coumarate coenzyme A ligase(4CL).The results showed: (1) resveratrol and piceid concentrations in the Cabernet Sauvignon leaves were 11% to 46% greater in scions with grafted rootstocks than that of selfrooted one. (2) Leaf resveratrol concentrations were the greatest in scions with 140R as the rootstock(18.24 μg/g) in the scion combinations of rootstocks. Scions with 140R rootstock had the highest phenylalanine concentration (38.61 μg/g) and coumaric acid concentration (1.06 μg/g). (3) In the scion combinations of rootstocks CS/3309C had the highest PAL activities. Leaf C4H activities and 4CL activities in scionrootstocks were greater than that in selfrooted. Leaf POD activity and PPO activity in CS/Fercal were the highest. The conclusions were that these resistant rootstocks could significantly increase the resveratrol concentrations in the leaves of Cabernet Sauvignon grapes. The contents of resveratrol in grapes were significantly associated with the metabolic enzyme C4H and the PPO. CS/140R was the most advantageous combination for increasing resveratrol in Cabernet Sauvignon grape leaves.

Abstract:In order to clarify the effect of AMF on the resistance of muskmelon to compound stress, and to explore its physiological mechanism, we investigated the effects of arbuscular mycorrhizal fungi (AMF) on the growth and the antioxidant activities of melon under low light and salt stress by pot experiment in greenhouse. The results showed that: （1） the growth of melon seedlings was significantly inhibited. The plant height, the dry weight and the fresh weight were significantly reduced. Soluble protein, soluble sugar, proline, malondialdehyde (MDA) contents and antioxidant enzymes activities (SOD, POD and CAT) in melon seedlings under low light and salt stress were higher than those in control group. （2） The inoculation with Glomus could significantly promote the growth of muskmelon seedlings, and the rate of mycorrhizal infection was negatively correlated with salt stress with the extension of stress time.（3） The inoculation with Glomus improves the physiological parameters of inoculated seedlings compared with nonAM seedlings; the contents of soluble sugar, soluble protein, starch, proline and antioxidant enzymes activities (SOD, POD and CAT) increased significantly, while MDA content decreased, and mycorrhizal infection rate with stress duration was negatively correlated with the salt concentration; the contents of SOD and POD in leaves were more active than those in roots, while CAT activity was less than that in roots. We propose that AM symbiosis can protect melon plants from low light and salt stress by improving their antioxidant activities and bidirectional transport of carbohydrates.

Abstract:The dynamic variation of ultraweak luminescence(UWL) and photosynthetic characteristics, and their relationship under drought stress of 20% PEG treatment and drought stress with regulating of reactive oxygen by carrying out four treatments of PEG, PEG + hydrogen peroxide (H₂O₂), PEG+ sodium benzoate and distilled water (CK) in Sedum hybridum seedling to supply theoretical basis for understanding the generation of UWL. The results showed:（1） in process of drought stress by PEG treatment, net photosynthesis (P_n), transpiration rate (T_r), intercellular CO₂ concentration (C_i), stomatal conductance (G_s), chlorophyll a (Chla), chlorophyll b (Chlb), chlorophyll (Chl) and UWL intensity all decreased; above photosynthetic characteristics and UWL intensity of PEG treatment decreased more quickly and had a bigger drop.（2） In drought stress with regulating by H2O₂ and sodium benzoate, P_n, T_r, G_s, C_i, Chla, Chlb,Chl and UWL intensity of treatments of PEG+ H₂O₂ and PEG+ sodium benzoate all decreased along with stress time as well as PEG treatment. However, above photosynthetic characteristics and UWL intensity of PEG+ H₂O₂ were lower than those of PEG treatment, while above photosynthetic characteristics and UWL intensity of PEG+ sodium benzoate were higher than those of PEG treatment. The results indicated that sodium benzoate treatment played the role of relieving drought stress and increasing UWL intensity.（3） Correlation analysis showed UWL intensity was positively correlated with photosynthetic index under drought stress and drought stress with regulating of reactive oxygen. In conclusion, under drought stress and drought stress with regulating, photosynthesis parameters decreased more quickly than that of CK, UWL intensity decreased more quickly than that of CK too; UWL intensity decreased along with the decline of photosynthetic efficiency.Which stated that the generation of UWL in plants positively related to extent of photosynthesis of plants, UWL intensity reflected the extent of adversity stress in plants.

Abstract:Using quinoa variety “Longli 1” as material, we pretreated the seeds and seedlings with different NaCl concentrations (100, 200, 300, 400, 500 mmol/L), determined the seed germination indexes, the contents of chlorophyll, soluble sugar, proline, MDA and the activities of antioxidant enzymes in different period of seedlings to study the effects on seed germination, seedling growth and physiological characteristics of Chenopodium quinoa under salt stress. The results showed: (1) With the concentrations of NaCl increased, seed germination rate, seed energy, seed index and vigor index were increased and then decreased, when the seeds were treated with 200 mmol/L NaCl, the four indexes were increased 6.40%, 28.18%, 20.77% and 30.91% than that of CK; (2) root and stem growth of quinoa seedlings were inhibited when the seedlings were treated with different NaCl concentrations, and the inhibiting effects on stem growth were stronger than that of root; (3) with increasing the NaCl concentrations and prolonging the treatment time, chlorophyll contents of seedling leaves increased and then decreased, soluble sugar, proline and MDA contents increased, and the activities of SOD, POD, CAT and APX also increased. We concluded that the salt threshold value of quinoa was 200-300 mmol/L.

Abstract:One year seedlings of Calligonum arborescens from Minqin in Gansu province were treated with different concentrations of NaCl (0,50,100,200,300 mmol·L^-1). We analyzed the photosynthetic characteristics and made the gray correlation analysis between physiological indexes and aboveground biomass, to explore the salt tolerance mechanism of desert plants, provide a theoretical basis for C. arborescens to better adapt to the virtual environment and to protect and restore the stability and sustainability of desert ecosystems. The results showed that, with the increasing of NaCl concentration, proline content gradually increased, in opposition to the change in soluble sugar. the photosynthetic parameters increased obviously under 50 mmol·L^-1 NaCl, and the net photosynthetic rate, stomatal conductance and transpiration rate reached the maximum, and significantly increased by 33.3%,68.0% and 60.8% compared with the control, the net photosynthetic rate, stomatal conductance and transpiration rate decreased when the concentration was more than 50 mmol·L^-1 compared with 50 mmol·L^-1 NaCl. The content of chlorophyll b decreased with the increasing of NaCl concentration while chlorophyll a and chlorophyll increased first and then decreased. Gray correlation analysis showed that transpiration rate, stomatal conductance, intercellular CO₂ concentration and chlorophyll b were significantly correlated with aboveground biomass. The research showed, low NaCl concentrations improving the growth of plants by activating certain mechanisms of plants. Through the adjustment of proline and soluble sugar contents, reducing chlorophyll content, net photosynthetic rate and transpiration rate, plants could maintain growth under high salt concentration.

Abstract:To investigate the response mechanism of Halamphora veneta (Kützing) Levkov to heavy metal stress, we analyzed the effects of different concentrations of four heavy metal, including Cu²⁺，Hg²⁺，Cd²⁺ and Pb²⁺ treatments on its cell density, chlorophyll a, malondialdehyde content and morphological changes. The results showed that：(1) low concentration of heavy metal treatment promoted the growth of H. veneta (Kützing) Levkov, while high concentration of heavy metal inhibited the growth of H. veneta (Kützing) Levkov. (2) The results of chlorophyll a showed that the H. veneta (Kützing) Levkov was sensitive to low concentration of Cu²⁺, Hg²⁺, Cd²⁺ and Pb²⁺, thus the chlorophyll a content of diatoms could be an effective index for the heavy metal monitor. (3) It is showed that the effect of low concentration of Cu²⁺，Hg²⁺，Cd²⁺ and Pb²⁺ on the malondialdehyde (MDA) content in H. veneta (Kützing) Levkov was not obvious, while the content of MDA in the H. veneta (Kützing) Levkov was promoted by the high concentration of heavy metal. (4) The morphological changes of the cells showed that Cu²⁺, Cd²⁺and Pb²⁺ treatment did not cause obvious deformation of H. veneta (Kützing) Levkov, and Hg²⁺ treatment could cause the expansion and deformity of the cells. The above results showed that the H. veneta (Kützing) Levkov possess tolerance mechanism for heavy metal stress, meanwhile, its chlorophyll a content and morphological changes could be used as the water monitoring index for heavy metal pollution.

Abstract:Five kinds of seeds of beardless Iris species were used as materials. The purpose of this study was to understand the reasons of seminal dormancy and germination method through conducting the absorbent and germination experiments. This can provide technical support for the protection and application of Iris germplasm resources. The results are as followed: (1) the results of waterabsorbing of five wild Apogons Iris seed showed that the water permeability of I. ensata Thunb. and I. setosa Pall. was the best, followed by I. laevigata Fisch, while the water permeability of I. sanguinea Donn. ex Horn. was poor. The permeability to water and gas and density of the endosperm is one of the main reasons for the inhibition of seed germination of I. lactea Pall. var. chinensis Kodiz.. In contrast, the dense endosperm is the main factor affecting the germination of the seeds. and the alternating temperature can increase the permeability of the seed coat and endosperm. (2) There was a strong inhibitory effect on seed coat of I. lactea Pall. var. chinensis Kodiz. and I. sanguinea Donn. ex Horn. for germination, while the inhibition of seed cost of I. laevigata Fisch.,I. ensata Thunb.and I. setosa. Pall.was not significant. The tipped micropylar endosperm is the main factor in the dormancy of five wild Iris. (3) The effects of temperature influenced seed germination of Iris greatly, alternating temperature significantly or very significantly increased seed germination rate of I. lactea Pall. var. chinensis Kodiz., I. sanguinea Donn. ex Horn., I. ensata Thunb., and the optimum alternating temperature was 30 ℃/20 ℃, 8 h light/16 h dark, but seed germination rate, germination energy of I. setosa Pall.and I. lactea var. chinensis Kodiz. had not significant difference, therefore, the single factor could not break the seed dormancy of I. laevigata Fisch. and I. setosa Pall.. A study found that seed dormancy and germination characteristics in five species of wild Apogons Iris were different, the main influencing factors were different, but the tipped micropylar endosperm is the main factor in the dormancy of five wild Iris. It needed to adopt comprehensive measures with cold stratification combined alternating temperature 30 ℃/20 ℃, which was the effective measures on breaking seed dormancy to greatly enhance the wild Apogons Iris seed germination rate.

Abstract:In order to reveal the effect of exogenous Ca²⁺ on the characteristics of the sprout tumble, we sprayed the plant cultivated for two years with bulbs by different concentrations of CaCl² solution (5, 10, 15, 20 and 25 mmol·L^-1), using the equal distilled water as the control, then measured the changes of the rate for sprout tumble and the physiological characteristics of underground part on sprout tumble stage. The results showed that: （1） the different concentrations of exogenous Ca²⁺ had effect on the plant sprout tumble characteristics， effectively extending the growth period of Fritillaria przewalskii to increas the bulb yield. The effect of the concentration of CaCl² on delaying the stage of sprout tumble was 15 mmol·L^-1>20 mmol·L^-1>25 mmol·L^-1>10 mmol·L^-1>5 mmol·L^-1> CK. （2）The different concentrations of CaCl² have significantly effected phenology of sprout tumble, and the greatest effect was found in the pretreatment sprayed by 15 mmol·L^-1 CaCl².Compared with the control, the phenology delayed 3~7 d at the fastigium of sprout tumble and 3～6 d to finish the fastigium of sprout tumble.（3）10~25 mmol·L^-1CaCl² can enhance the root TTC vigor and the activities of SOD,POD and CAT, and the bulbs have the highest levels of the root TTC vigor and activities of antioxidant enzymes by 15 mmol·L^-1 CaCl².（4）The results of comprehensive analysis of membership function show that, the resistance and viability of bulbs in F. przewalskii at sprout tumble stage by different concentrations of CaCl² from strong to weak are 15 mmol·L^-1>20 mmol·L^-1>25 mmol·L^-1>10 mmol·L^-1>5 mmol·L^-1> CK. All above suggest that 15 mmol·L^-1 CaCl² is the best treatment to delay phenology of sprout tumble,enhance the plant vitalities and the resistance, and increase bulbs yield.

Abstract:Our aim is to investigate biseasonal flowering phenology and reproductive features of Tamarix ramosissima. The study was conducted in wilderness region of Mosuowan which is located at the southern edge of Gurbantunggut Desert. We observed the flowering phenology index, flower characteristics changes of the flowering course and fruit set characteristics in the wild population of T. ramosissima. The results showed that: (1) the spring flowering period of T. ramosissima. was from the late May to early June, exhibiting a “massflowering” pattern. The summer flowering period was from the middle June to early September, exhibiting an “extendedflowering” pattern. (2) In the spring flowering period and the summer flowering period, the flowering duration of the population, individuals, inflorescences and single flower were 14, 10, 3, and 1 d, and 85, 77, 2, and 1 d, respectively. (3) There were significant correlation among first flowering date, flowering duration, flower number and fruit number at inflorescences of the summer flowering period. (4) There was no significant differences in the flowering process and morphological structure between two flowering periods. (5) The fruit rate and seed rate in spring flowering period are same higher than that in the summer flowering period, but there was no significant difference between two flowering periods. (6) Pollination times in spring flowering period is significantly higher than that in summer flowering period. (7) There was no significant differences in the pollen vitality between two flowering periods, the stigma receptivity in spring flowering period is longer than that in summer flowering period. The survival conditions in wilderness region of Mosuowan is poor, biseasonal flowering phenology and reproductive features of T. ramosissima raise the possibility of their reproductive success.

Abstract:Achnatherum splendens is a constructive species in arid or semiarid grassland, vegetation composition and community stability of its community can affect the desertification degree of grassland, which represents successional dynamics and development direction of community. The aims of this study is to explore the relationship between vegetation composition, interspecific association and community stability by analyzing the composition, and diversity of species, functional group biomass composition, Raunkiaer frequency coefficient, and Spearman rank correlation of A. splendens and Stipa communities in Songshantan grassland in Gansu Tianzhu. The results indicated that, (1) the species diversity of Stipa community was richer than that of A. splendens community，and the degree of species replacement was similar in these two communities. (2) The two communities were degraded, with the grassland degradation increased, A. splendens and Stipa communities dominated by grasses and forbs, respectively. (3) The positive to negative association ratio of speciespairs in two communities was less than one, and the interspecific association was loose, and they had a low community stability. (4) The high species diversity was not benefit for the stability of Stipa community. The study suggests that biomass composition of functional group, evenness of species and drought disturbance had higher effects on the community stability than that of the species diversity.

Abstract:Plant functional traits reflect the response and adaptation of plants to the growth environment, linking the environment, plant individuals and ecosystem structures, processes and functions. Grazing as the main land use of grassland ecosystems, play an important role in community structure of grassland ecosystems and changes in ecosystem functions. In this study, the functional traits of Stipa breviflore were studied under different grazing intensities of Siziwang banner, Inner Mongolia. Meanwhile the effects of grazing on grassland community structure were discussed. The results showed that: (1) with the increase of grazing intensity, the traits, individual biomass, plant height and breadth of crown were significantly smaller and shorter. (2) Through the trait plasticity change spectrum, we found that the plasticity indices of the functional traits were the highest in the heavy grazing area and the lowest in the light grazing area. The plasticity responses of stem mass, leaf mass, biomass of whole plant to grazing were the sensitive, but that of stem base diameter, crown and leaf mass were inert. (3) The variability of plant functional traits increased with grazing response intensity, the coefficient of variation (CV) and response degree (PI) of S. breviflora were consistent with the exponential equation y=0.08+0.18e^1.61x (R²=0.53, P＜0.05), the variability of plant functional traits and the response intensity of traits to grazing were proportional. (4) Among the factors affecting aboveground biomass, phenotypic functional traits including width of clump crown, average leaf length, leave number and total leaf area contribute to 72.93%. With the increase of grazing intensity, the variability of S. breviflora increased, and the plasticity was enhanced, which provided a mechanical explanation for the reason why Stipa breviflora is still a constructive species under the conditions of longterm grazing.

Abstract:Taking the Populus euphratica forest as the research object, we analyzed the two sections of Xinshajilike and Kanbaiwusitan, and the characteristics of the radial growth of P. euphratica in the middle reaches of the Tarim River. In the middle of the Tarim River, based on the temperature data of the long time series of the weather station near the cross section, the correlation analysis and the MannKendall mutation test were used to study the response of the temperature change of the radial growth of P. euphratica.Research showed that: （1）the radial growth and temperature changes of P. euphratica showed an increasing trend along the riverside of the middle reaches of the Tarim River. The MannKendall mutation analysis was used to analyze the change of radial growth of P. euphratica along 2 profiles.The result showed that the mutation of radial growth of P. euphratica along the profiles of Xinshajilike and Kanbaiwusitan occurred in 1993 and after 1998, respectively. And the radial growth of P. euphratica in this region had a lag to temperature. (2) From the time analysis, it was found that the temperature of June to September had the greatest effect on the radial growth of P. euphratica.The temperature of June to September might be a limiting factor for the radial growth of P. euphratica in this area. (3) P. euphratica growth temperature in 13-33 ℃, would greatly promote their growth. Although more than 33 ℃, the temperature of P. euphratica growth promoting role, but had a tendency to decrease. Temperature too high or too low would inhibit the growth of P. euphratica.

Abstract:Caragana liouana, C. microphylla and C. korshinskii are three of the most common species which are widely planted in an agropastoral transition zone in the arid and semiarid area of northern China. However, the ecology effect of these types of vegetation planting on soil properties and bacterial communities in salinealkali soil has received far less attention. The root with any adherent soil particles and bulk soils from replicated plots representing three different species of Caragana were collected at a research site in Ningxia, China. The rhizosphere soil was washed from the roots, and community diversity and structure of rhizosphere and bulk soil bacterial were analyzed by using barcoded pyrosequencing of the 16S rRNA gene amplicons. Our results showed that: (1) soil pH and EC were decreased significantly in bulk soils of the three Caragana species when compared with control soil, while the opposite patterns were found in total P and N. (2) Across all samples, Proteobacteria， Cyanobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Gemmatimonadetes, Planctomycetes, Chloroflexi, Acidobacteria and Euryarchaeota were the most dominant bacterial phyla which represent 81.7%-97.5% of all taxon tags. Shannon index indicated that the αdiversity of the soil bacterial community did not affected by short term of Caragana plantation. (3) A principal coordinates analysis found that the bacterial community structure in rhizosphere of C. microphylla obviously distinct from that of C. liouana and C. korshinskii. Meanwhile, the same pattern was detected in the bacterial community of bulk soil under C. microphylla. At the genus level, the relative abundance of 12 dominant bacterial genera, such as Alysiosphaera, Entotheonella, Haliangium, Mesorhizobium, Ensifer, Pseudoxanthomonas, Rhizobium, Phyllobacterium, Phenylobacterium, Novosphingobium, Luteimonas, Brevundimonas and Chitinophaga, were significantly accumulated in the bulk soil of C. microphylla. (4) Distance based redundancy analysis indicated that soil EC, total P and N exerted strong influences on the structure of the bulk soil bacterial community and explained 23.5%, 25.4% and 22.2% of community variances between samples, respectively. Our results suggest that shortterm plantation of Caragana did not affect the α diversity of bulk soil bacterial community and different species of Caragana exerted distinct effects on the structure of the bulk and rhizosphere bacterial community.

Abstract:Based on 53 occurrence records of five Schistidium species from Xinjiang, which is a desiccationtolerant moss genus, and 7 bioclimatic variables, the present study employed both the maximum entropy (Maxent) model and the spatial analysis method in the ArcGIS 10.2 to predict the suitable distributions of Schistidium in Xinjiang under current and future climate scenarios, in order to provide basis for exploring the influence of climate change on bryophyte species distributions in arid and semiarid zones. The results indicated that: (1) the Maxent model gave a high accuracy (i.e. AUC=0.957) in habitat predictions for Schistidium; (2) The annual precipitation, precipitation of driest quarter and mean temperature of warmest quarter were the major climatic factors influencing the distribution of Schistidium in Xinjiang; (3) The suitable distribution of Schistidium in Xinjiang mainly located along Altai and Tianshan Mountains. Under the future (i.e. 2061-2080) climate scenarios, the range of Schistidium was predicted to decrease by 10.39% and most current habitats in south of Xinjiang would lost.