Abstract:20 ARF genes were identified from the capsicum genome by bioinformatics, and these genes were not welldistributed on 12 chromosomes of pepper. The results of the phylogeny relationship showed that ARF genes of pepper could be divided into ClassⅠand Ⅱ, and could be further divided into seven subgroups: Ⅰa, Ⅰb, Ⅰc, Ⅰd, Ⅰe, Ⅱa andⅡb. The results of gene structure showed that ARF gene family members were composed of 1~15 exons, and for each gene expression level of different tissues in different developmental stages revealed that the gene family had certain expression specificity. The qRTPCR uncovered that high salt stress could significantly activate and inhibit the expression of ARF gene family.

Abstract:A MADSbox gene, NtPI2, was cloned from the flower bud of Narcissus tazetta var. chinensis using RTPCR and rapid amplification of cDNA ends. NtPI2 is 810 bp in length with an open reading frame 627 bp which encoded 208 amino acids. Phylogenetic analysis indicated that NtPI2 belongs to the PI/GLO family. Realtime quantitative PCR demonstrated that NtPI2 was expressed in all tissues of ‘Jinzhanyintai’. The expression pattern of NtPI2 was different in different organs of flower in single and double narcissus. We compared the expression pattern of NtPI2 in single and double narcissus, and found that the expression of the NtPI2 of the stamen petaloids and corona in double narcissus ‘Yulinglong’ were significantly higher than that of in single narcissus ‘Jinzhanyintai’. This indicates that the increased expression of NtPI2 in the petaloid stamens may be the direct cause of the occurrence of the double narcissus. Plant express vector of NtPI2, pCAMBIA1302NtPI2, was constructed and used to transform the tobacco through Agrobacteriummediated procedure. The result of molecular identification showed that 8 transgenic tobacco plants were obtained. The results will lay a foundation for the further study of the NtPI2 gene function and its relationship with the formation of the double narcissus.

Abstract:In order to clarify the information of CmTPS gene family and the patterns of response to environment cues, we identified seven TPSs in melon genome in this work. These TPSs distributed on seven chromosomes and designated CmTPS1-7. Phylogenetic analysis indicated that CmTPS genes would be classified into classⅠand classⅡ. CmTPS4 and CmTPS7 belong to classⅠwith 16 introns and their proteins probably possess TPS activity. The other five CmTPS genes, containing two to four introns, were classified into class Ⅱ. CmTPS3 consists of only TPS domain, whereas the remaining TPSs comprise TPS, TPP and UDPforming domains. CmTPS proteins have low similarity (15.90%-57.31%) within family members. Subcellular localization prediction indicated that CmTPS1, CmTPS2 and CmTPS6 were localized to the nucleus and the others in cytoplasm. The expression of CmTPS genes under various abiotic stresses showed that CmTPS4 might be main gene encoding TPS in melon leaves under low temperature stress, while melon TPS family genes were more sensitive to salt stress and might be involved in regulation of ABA signal pathway. Our results lay the foundation for functional characterization of melon TPS family genes in the future.

Abstract:In this study, miR166a with differential expression was candidated from the small RNA libraries of the halophyte Halostachys caspica roots established under high salinity (600 mmol·L^-1 NaCl), some work was carried out as follows. miR166atargeted gene was predicted from this species transcriptome by bioinformatic analysis; the miR166atargeting was identified with the technology of 5′ RLMRACE; miR166a precursor and full length of ATHB8like were obtained by PCR and RACE methods and fully analyzed by bioinformatic softwares. The results showed that predicted target was ATHB8like; 5′ RLMRACE validated the accurate cleavage site of the target by H. caspica miR166a between 14^th to 15^th base of its mature miRNA; H. caspica mature miR166a was highly conserved compared to different plant species; the miR166a precursor could be folded into complete hairpin structure and was met with various indexes of miRNA precursor and did not reflect the conservation in evolution by aligning with plant species available; the full length cDNA of ATHB8like is 2 786 bp that open reading frame is 2 526 bp with putative 841 amino acids containing a HDZIP III domain and H. caspica ATHB8like was conserved compared to those ATHB8 of different plants. This work will lay the foundation for further studying biological functions of H. caspica miR166a and its target.

Abstract:In order to study the synergistic mechanism of multigenes in regulation on high accumulation of carbon eighteen unsaturated fatty acids in sea buckthorn (Hippophae L.) seed oil, the line ‘Suiji 1’ with low seed oil content and the line ‘Xine 3’ with high seed oil content were selected as samples, in which these two lines had closed genetic relationship. Seeds of these two lines were harvested in six different developmental stages. Changes of the fatty acid components and relative contents in seed oils were determined by the method of gas chromatograph coupled with time of flight mass spectrometry, the expression patterns of KAR, FATB, Δ9D, KASⅡ, SAD, FAD2, FAD3, FAD7 and FAD8 genes involved in fatty acid biosynthesis were tested using qRTPCR analysis, and the effects of expression changes of multigenes on the accumulation of carbon eighteen unsaturated fatty acids were analyzed. The result showed that: (1) high accumulation of carbon eighteen unsaturated fatty acids were found in seed oils of the lines ‘Suiji 1’ and ‘Xine 3’, which were about 87.71% and 88.68% of total fatty acids, respectively. During seed development, the relative contents of oleic acid of these two lines had shown an uptrend; the relative contents of linoleic acid first decreased at initial stage of aging, then increased and finally trended nearly stable; and the relative contents of linolenic acid first increased, then decreased, and finally trended relatively stable. (2) the downregulation expression of FATB coordinated with the low expression of Δ9D genes decreased the metabolic biosynthesis of palmitic and palmitoleic acids transformed from C16∶0ACP. Relatively high expressions of KAR and KASⅡ genes improved the biosynthesis of stearic acid, which provided more precursors for the synthesis of carbon eighteen unsaturated fatty acids. (3) the continuous high expression of SAD gene catalyses stearic acid desaturation to synthesize oleic acid, and the continuous increased radio of SAD to FATB gene expressions directly improved the fatty acid desaturation rate. The expression peaks of FAD2, FAD3, FAD7 and FAD8 genes simultaneously appeared in the periods of rapid biosynthesis of linoleic and linolenic acids, and then the oleic acid was gradually desaturated to linoleic acid and linolenic acid. Our data showed that the high accumulation of carbon eighteen unsaturated fatty acids in sea buckthorn seeds are from the low expression of FATB and Δ9D genes coordinated with the high expression of KAR、KASⅡ, SAD, FAD2, FAD3, FAD7 and FAD8 genes. These results provided scientific basis for understanding the biosynthesis and accumulation mechanism of carbon eighteen unsaturated fatty acids in seeds oil, which is significant for improving ratios of different unsaturated fatty acid in plant oils.

Abstract:In this study, chloroplast genomes of 22 species belonging to 22 genera were compared to reveal the general characteristics and structural variation of chloroplast genome of Brassicaceae. The results showed that：(1) the genome size was about 150 kb, and there were 1-5 kb differences among the chloroplast genomes of different plants. The differences in genome size were mainly caused by the difference of LSC length. (2) The gene order of Brassicaceae species was basically the same, no gene rearrangement and inversion event was found. (3) trnY, trnG, ycf15, rps16 genes were lost in some species, petB, petD intron sequences were also lost in individual species. (4) The four boundaries of the genome was relatively conservative, IRaLSC boundary located in the rps19 gene, the IRaSSC boundary located in the ycf1 gene in all species, but the length of rps19 and ycf1 was different on each side of the boundary in different species. The IRbSSC boundary located in the overlap area of the ycf1 and ndhF genes in most species, whereas this boundary changed in Alyssum desertorum and Arabis alpina, lied in ycf1 pseudogene and ndhF genes, respectively. (5) Gene length of 29 proteincoding genes varied among the 22 cp genomes, and the variation was from the differences of intron or the coding sequence. Large fragment deletions were observed of ycf1 gene in the three species. The length of some genes revealed obvious phylogenetic signals. (6) The phylogenetic tree of Brassicaceae which was constructed based on the cp genome data had good resolution, and the evolutionary branched were of high supports. The results of this study showed that the cp genome can provide more evidence for the systematics and phylogeny of plant groups that are with faster evolution and low phylogenetic resolution.

Abstract:In this research, the 4 retrotransposons that belong to Oryza, including active, low copy number: Tos17/Osr21 (Ty1copia) and RIRE7/Osr31 (Ty3gypsy); inactive, high copy number: Osr34 (Ty3gypsy) and Houba/Tos5/Osr13 (Ty1copia). Were used to design primers form the long terminal repeat region (LTR) of the two lateral wings. In the mean time, PCR amplifications were carried through to 37 Oryza sativa L. ssp. japonica cultivated varieties (strains) in Xinjiang. Rice LTR retrotransposons that applies to the interretrotransposon amplified polymorphism (IRAP) markers were evaluated and identified, and the genetic diversity of 37 varieties (strains) were analyzed. (1) The results of PCR amplification showed that Tos17/Osr21, RIRE7/Osr31, Osr34 and Houba/Tos5/Osr13 were in turn obtain 73, 63, 107 and 560 bands, of which polymorphic bands were 36, 63, 70 and 523, the polymorphic rate was 49.3%, 100.0%, 65.4% and 93.4%, respectively. (2) Comprehensive evaluation and comparison polymorphism, heterogeneity, the total number of bands and the average number of polymorphic bands, indicated that Houba/Tos5/Osr13 is suitable for the IRAP marker method to construct the DNA fingerprint database. (3) Based on the genetic similarity coefficient of Houba/Tos5/Osr13, clustering analysis through unweight pair method using arithmetic averages (UPGMA) method. According to 0.55 threshold value that 37 O. sativa L. ssp. japonica cultivated varieties (strains) in Xinjiang were divided into 6 groups, and most of the varieties (strains) have been clearly distincted. The genetic similarity among varieties was high, and the degree of diversification was low. The strains ‘2018’ and ‘9616’ were clustered into separate classes, indicating that the genetic background between cultivars and varieties is far away and the degree of diversification is high. In summary, IRAP molecular marker was suitable for genetic relationship analysis of O. sativa L. ssp. japonica germplasm resources in Xinjiang, identification and determination of genetic distance of breeding, the construction of DNA fingerprint database as well as the research of related fields. In the actual breeding, different varieties and strains of rice were selected for cross breeding, the success rate was high, which could greatly shorten the breeding process of fine varieties.

Abstract:‘Minihongyou’, a new pummelo mutant was used as material in this study. Morphological survey, SEM (scan electron microscopy) observation and ISSR molecular marker technology were conducted to confirm the taxonomic status of ‘Minihongyou’. (1) According to morphological survey results, the ‘Minihongyou’ fruit is similar with ‘Duncan grapefruit’, but there were a great of differences between ‘Minihongyou’ and ‘Guanximiyou’. Moreover, morphology of young leaves of ‘Minihongyou’ was different from ‘Guanximiyou’ and ‘Duncan grapefruit’. (2) The scanning electron microscopy results showed that pollen size and exine mesh of ‘Minihongyou’ were distinct with ‘Guanximiyou’ and ‘Duncan grapefruit’, howerver, the apertures were the same with the other two species. (3) The cluster results indicated that ‘Minihongyou’ could be classified into the same group with ‘Duncan grapefruit’ in a little genetic distance, which means the genetic relationship between ‘Minihongyou’ and ‘Duncan grapefruit’ was closer than that with other species. It was concluded that ‘Minihongyou’ was a novel pummelo, which was different from ‘Guanximiyou’ and ‘Duncan grapefruit’.

Abstract:Five different melon materials (P10 and 36 with hard flesh, 417 and 205 with crisp flesh and Charentais with soft flesh) which had three different tastes were analyzed by texture profile analysis (TPA) and puncture method to evaluate the texture characteristics of melon flesh. The cell microstructure of melon flesh were observed by tissue section method, and the cell size (area, perimeter, length and width) and shape (aspect and roundness) parameters were measured by Imagepro plus 6.0 software in order to make clear the variation characteristics of flesh cell microstructure of different melons during ripening. The relationships between cell morphological parameters and texture of melon flesh will provide the theoretical basis for quality breeding of melon. The results showed that: (1) the cells of P10 and 36 with hard flesh were smaller, and arranged closely; the cells of 417 and 205 with crisp flesh were larger, and arranged more loosely; and the cells of typical climacteric type Charentais which had soft flesh were the largest and extremely irregular. (2) Cell area and perimeter of melons with different tastes were significantly different in maturation, and had a significant negative correlation with taste. During fruit ripening, cell size parameters showed an increasing trend, but the cell aspect and roundness showed a decreasing trend, that is, the cells were more and more round. (3) The taste of melon flesh had significant or highly significant correlations with texture and cell size parameters. Significant or highly significant positive correlations were found between the cell size parameters and adhesiveness (0.951^*-0.983^**). But cell area was found to exert a significantly negative influence on TPA hardness and crispness (-0.910^* and -0.926^*, respectively), and cell length and width also had a significant influence on crispness (-0.884^* and -0.894^*, respectively). In the cell shape parameters, the correlation between cell roundness and adhesiveness was also significant (0.936^*). These results indicated that melon flesh with different tastes had significant different texture and cell microstructure, and the melon taste was closely related to flesh texture and cell size, that is, the melon flesh texture will be harder with smaller cells.

Abstract:The experiment took Malus robusta Rehd. as rootstock, on which grafting M9, M7, SH38, T337, SH6, SH1, JM7, GM256, ‘Liaozhen 2’, M26, B9. To analyze the correlation among different indexes by determining grafting survival rate, germination rate, plant growth, leaf anatomical data, we studied these 11 dwarf rootstocks by principal component analysis(PCA) and hierarchical cluster analysis(HCA). To learn grafting affinity of different dwarf interstocks with M. robusta Rehd and evaluate their dwarfing traits, we investigated the growth characteristics and leaf anatomical structure of 11 dwarf rootstocks on M. robusta Rehd.. The results showed that: (1) 11 dwarf rootstocks had affinity with M. robusta Rehd, which M26 and SH38 had the strongest affinity. (2) The correlation analysis showed that dwarfing of plant have a negative relatoin with plant height, length of plant internode, diameter ratio, the ratio of upper epidermis thickness, stoma density, thickness of spongy tissue, and its positive with leaf length to width ratio, palisade tissue to spongy tissue ratio, thickness of leaf, thickness of palisade tissue. (3) PCA got four principal components and represented 91.573% of the total variability. The PC1 was related to thickness of leaf, thickness of spongy tissue, thickness of palisade tissue, and the PC2 included length to width ratio, related to plant height, length of plant internode, and the PC3 consisted of palisade tissue to spongy tissue ratio, diameter ratio, and the PC4 was stoma density. (4) According to the result of PCA, 11 dwarf rootstocks were divied ino four types by HCA. The first types includes SH1, SH38, SH6, M7, M26 and the second covers B9, JM7, The third class contains T337, M9, GM256 and the fouth is ‘Liaozhen 2’, which was consistent with the results of PCA. As a result, 11 apple dwarf rootstocks had a better affinity with M. robusta Rehd., which the ranking of dwarf was: ‘Liaozhen 2’ > GM256 > M9 > T337 > JM7 > B9 > M26 > M7 > SH6 > SH38 >SH1.The plant of dwarfing was estimated by plant height, length of plant internode, diameter ratio, the ratio of upper epidermis thickness, stoma density of leaf, thickness of spongy tissue, thickness of palisade tissue, palisade tissue to spongy tissue ratio and thickness of leaf.

Abstract:The salt tolerant germplasm Crossostephium chinense and the two wild species of Chrysanthemum, Chrysanthemum indicum (Tiantangzhai) and (Shennongjia), along with two cultivars of Chrysanthemum (‘Fanhuasijin’ and ‘Hanluhong’) were treated with 1/2 Hoagland nutrient solution containing 200 mmol·L^-1 NaCl and their physiological response that changed with the increase of saltstress time were compared. The related physiological indexes of each material were measured at 0, 5, 10 and 15 days after salt stress and the physiological responses of each material were compared, in order to preliminarily explore the physiological salttolerance mechanism of C.chinense. The results showed that the contents of chlorophyll (Chl), net photosynthetic rate (P_n), stomatal conductance (G_s), transpiration rate (T_r) and the peroxidase activity (POD) in five species decreased with the increase of saltstress time, while C. chinense had the minimum decrease or a significantly different changing trend from other 4 Chrysanthemum species. In the meantime, the content of malondialdehyde (MDA), proline and the activity of superoxide dismutase (SOD) increased with the time, and among them the MDA of C. chinense increased least. The changing trend of intercellular CO₂ concentration (C_i) varied in different germplasms. The study has shown that the chlorophyll content and the membrane system were relatively stable under salt stress, and the net photosynthetic rate maintained at a certain level, which may be the main reasons that the salt tolerance of C. chinense was stronger than that of other Chrysanthemum species.

Abstract:In this paper, a pot experiment was used to test the response of reactive oxygen scavenging enzymes (SOD, CAT, POD，APX) and membrane damage (MDA) of nine coexisting species under three water deficit levels (severe, moderate and mild water deficits, corresponding to 45%-50%, 60%-65% and 75%-80% of field water capacity, respectively) in three months of growing season, to understand the subsequent community level effect from the perspective of ecophysiological mechanism of vegetation succession. The nine species routinely coexist in middle secondary successional stages in Loess Hilly Region. They are Artemisia scoparia, Cleistogenes chinensis, Oxytropis glabra, Agropyron cristatum, Cleistogenes songorica, Artemisia sacrorum, Lespedeza davurica, Artemisia giraldii and Bothriochloa ischaemum. The results showed that: (1) treatments of species, growing season and water deficit all had significant effects on SOD, CAT, POD, APX activities and MDA content. (2) For species treatment, SOD activity of L. davurica, CAT activity of B. ischaemum, POD activity of C. chinensis, CAT, POD and APX activities of O. glabra were relatively high, whereas MDA content of L. davurica was comparatively low. SOD, CAT and POD activities declined from August, and MDA content in leaves was observed fell in October. That implied that the above indexes in leaves were ordinarily higher in quick growth month. The activities of SOD and APX responded positively to water deficit, i.e., their values under severe water deficit were higher in comparison with the ones under moderate and mild water deficits; and no such significantly positive responses were observed for the activities of POD and CAT. This meant that SOD and APX activities took more active and positive role for water stress tolerance. (3) The relative high SOD activity and low MDA content in L. davurica and high APX activity of O. glabra showed that they could tolerate water deficit well, subsequently when soil moisture declined, their fitness and abundance might go rise. (4) The activities of SOD and APX of the nine coexisting species were positively correlated with their successional niche positions, i.e., species dominated in late successional stage had better drought tolerant traits. This really act in local community succession accompanied by soil drying in Loess Hilly Region wherein, e.g., species of L. davurica and O. glabra that behaved well in water deficit condition, dominate in later successional stage.

Abstract:The photosynthetic characteristics of Bothriochloa ischaemum and Lespedeza davurica in the loess hillgully was investigated under potted condition, the photosynthetic gas exchange parameters of two species during the heading period, flowering period and mature period were studied under three soil water regimes (HW, 80％±5% of field capacity(FC); MW, 60％±5% of FC; LW, 40％±5% of FC) and seven plant mixture ratios (i.e. 0∶12, 2∶10, 4∶8, 6∶6, 8∶4, 10∶2 and 12∶0, respectively). The objectives were to determine the leaf photosynthetic characteristics of two species across their growth periods under different mixture ratios, and to identify their coexistence mechanisms of two native species under lower water availability. The results showed that: (1) the net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) of two species were decreased under water stress, and the photosynthetic response of B. ischaemum was more sensitive to water stress; water stress decreased photosynthesis of both species during growth periods were caused by stomatal limitation, except for the species of L. davurica in the mature period under LW soil water regime; (2) under HW soil water regime, the averaged P_n values of B. ischaemum in mixtures were significantly improved, whereas adversely affected L. davurica throughout the growing season; Under MW or LW soil water regimes, P_n in mixtures showed higher values when B. ischaemum in heading period or flowering period and L. davurica in mature period, compared to respective monoculture, and the water use efficiency (WUE) of B. ischaemum were significantly higher than that of L. davurica in different growth periods; (3) when the B. ischaemum and L. davurica at a mixture ratio of 10∶2, the P_n and WUE of B. ischaemum in different growth periods under LW regime, and the P_n and WUE of L. davurica in mature period under the MW or LW regimes, which were significantly higher than that of the species in monoculture. These results suggested that the B. ischaemum and L. davurica at a mixture ratio of 10∶2 improved the leaf photosynthesis and water use efficiency of both species under low soil moisture condition.

Abstract:The effects of different temperature (5-45 ℃) and NaCl (0-300 mmol·L-1) on seed germination index and antioxidant enzyme activities of Cynanchum thesioides(Freyn). K. Schum were studied. The results showed that: (1) with the increase of temperature, germination index of seed all increased first and then decreased. The low or high temperature inhibited significantly seed germination. The optimum temperature for germination was 25 ℃, and its recovery germination ratio was over 95% at 5 ℃ and 35 ℃. (2) As NaCl concentration went up, the germination ratio, germination potentiality, vigor index of seed decreased, but relative salt injury rate increased and germination was completely inhibited at 300 mmol·L-1. The root vigor of seed was inhibited significantly only at high NaCl concentration(>150 mmol·L-1), the seed could recover germination after the salt stress was relieved, but it was still inhibited by salt stress. The higher salt concentration, the more prohibitive, and the appropriate content of salttolerant was 65.25 mmol·L-1(the salt content is 0.38%). (3) Under salt stress, the germination ratio was positively correlated with POD and APX, but negatively correlated with O-·2 generation rate and MDA, the vigor index was negatively correlated with CAT. Therefore, the seed germination was significantly inhibited by salt stress, protective enzymes POD and APX played a major antioxidant role during seed germination under salt stress, Cynanchum thesioides(Freyn). K. Schum was suitable for germination in moderate saline soil.

Abstract:By using the leaves of bean seedling, we studied the effects of alternative respiratory pathway on the chlorophyll content and the chlorophyll fluorescence characteristics under NaCl stress， to investigate the physiological effects of altemative respiratory pathways under stress and the regulation of photosystem Ⅱ(PSⅡ) in plants under salt stress. The results showed that: (1) the treatment of NaCl with increased concentration (0、100、200、300 mmol/L) caused significant decrease of the chlorophyll content in bean seedling leaves. The ratio of Fv/Fm (the potential maximal photochemical efficiency of PSⅡ), F_v′/F_m′ (the maximum quantum efficiency of PSⅡ photochemistry at illumination), Y(Ⅱ) (effective photochemical quantum yield of PSⅡ photosynthetic), and qP (photochemical quenching coefficient). However, the levels of NPQ (nonphotochemical quenching) were significantly decreased. Meanwhile, the capacity of the alternative respiratory pathway was increased significantly. (2) The NaClstressed leaves, which were pretreated with salicylhydroxamic acid (the specific inhibitor of the alternative respiratory pathway, SHAM), exhibited lower levels of chlorophyll content, F_v/F_m, F_v′/F_m′, Y(Ⅱ) and qP, but higher levels of NPQ than the leaves subjected to NaCl stress alone. These results suggested that NaCl stress can cause a decrease of the photochemical efficiency of photosystem Ⅱ and an increase in dissipation of light energy in the bean leaves, and the alternate respiration pathway could play a role in alleviating the decreas of chlorophyll content and photochemical efficiency of photosystem Ⅱ (PSⅡ) under NaCl stress.

Abstract:The study was to discuss the relationship between Ultraweak photon emission (UPE) and senescence of strawberry fruit to supply theoretical basis for understanding the relationship between plant senescence and UPE. The study layout the experiment by soaking respectively postharvest ‘Hongyan’ strawberry fruit with hydrogen peroxide (H₂O₂) and tea polyphenol(TP), uncoupler 2,4dinitrophenol (DNP) and adenosine triphosphate(ATP),then analyze contrastively the variation of fruit ageing process and UPE under promoting reactive oxygen and eliminating reactive oxygen conditions, inhibiting energy formation and increasing energy conditions in postharvest strawberry fruit. Therefore the study aim to understand the relationship between UPE and senescence in strawberry fruit. The result showed that: (1) during fruit ageing process, fruit firmness of CK, H₂O₂ and TP treatments, DNP and ATP treatments decrease continuously weight loss rate and decay rate of above treatments increase continuously. Meanwhile UPE intensity of five treatments decrease. Based on above results, in fruit ageing process, UPE intensity decline along with the ageing of postharvest fruit. (2) In whole fruit ageing process, the fruit firmness of H₂O₂ and DNP treatments are all lower than those of CK and weight loss rate and decay rate are all higher than those of CK, meanwhile UPE intensity of H₂O₂ and DNP treatments are all lower than those of CK. (3) The fruit firmness of TP and ATP treatments are all higher than those of CK and weight loss rate and decay rate are all lower than those of CK, meanwhile UPE intensity of TP and ATP treatments are all higher than those of CK. Above results indicated that regulating reactive oxygen level and energy level can effect on ageing process and UPE intensity of fruit. Promoting reactive oxygen accumulation lead to speed up the ageing extent and to intensify the decline of UPE intensity of fruit, and eliminating reactive oxygen lead to delay the ageing extent and to relieve the decline of UPE intensity in fruit; inhibiting ATP formation lead to speed up the ageing extent and to intensify the decline of UPE intensity of fruit, and increasing ATP lead to delay the ageing extent and TP relieve the decline of UPE intensity in fruit. Above results indicated that UPE intensity decline along with the fruit ageing process, UPE intensity reflect the ageing course of strawberry fruit.

Abstract:In order to elucidate the effect mechanism of stand characteristics on seed germination and natural regeneration of Rhododendron protistum var. giganteum, we investigated the effect of fresh and litter leaf, forest litter and forest moss aqueous extracts on its seed germination percentage and germination index. We also discussed the autotoxicity and litter allelopathy effects on the species natural regeneration. The results indicated that: (1) both fresh and litter leaf aqueous extracts inhibited seed germination, the inhibiting effect of litter leaf aqueous extracts is relatively lower than that of fresh leaf. Seed germination percentage and germination index dramatically decreased with increasing fresh leaf aqueous extracts concentrations. When the fresh leaf aqueous extracts concentration reached 10%, seed germination percentage decreased to only 8%. Thus, the species has obvious autotoxicity effect on its germination. (2) Forest litters collected under the plant canopy with different distance (0, 2, 5 and 10 m) to adult individuals have allelopathic effects on seed germination. However, the effect varied among different distances and forest litter aqueous extracts concentrations. Forest litters collected from canopy 5 m distance have the strongest allelopathic effects on seed germination percentage and germination index. When the concentration of forest litter aqueous extracts reached to 2%, seed germination percentage and germination index decreased to 77.33% and 21.35, respectively. These indictors significantly reduced 18.32% and 20.5% compared to control, respectively. (3) The aqueous extracts of moss which collected under the plant canopy also inhibited seeds germination percentage of R. protistum var. giganteum. Based on above results, we concluded that the plant has autotoxicity effects on its seed germination, which may further influence its natural regeneration. The forest litters also have inhibited allelopathic effects on seed germination. Thus, we can reasonable to assume that the autotoxicity and allelopathic effects would affect the natural regeneration of R. protistum var. giganteum populations.

Abstract:13 species of urban greening plants in Hohhot were selected for study. The photosynthetic physiology and ecology indexes of plants were measured by using LI6400 portable photosynthesis system and the carbon fixation capacity of the plants were quantitatively studied. The effects of plant photosynthesis on the carbon fixation were studied. The factors affecting the efficiency of carbon sequestration were analyzed. The order of carbon sequestration efficiency was determined. The result indicated that: (1) different plants had different trends in daily carbon fixation, Poa pratensis, Hemerocallis fulva, Paeonia lactiflora an single peak curve， and Platycladus orientalis, Picea asperata, Sabina chinensis, Pinus tabuliformis, Sabina vulgaris, Forsythia suspensa, Syringa oblata, Sophora japonica, Salix babylonica, Populus alba var. pyramidalis had doublepeak curve. From June to November, the trend of carbon sequestration of each plant was basically the same that the high value of carbon sequestration appeared around June, and before or after September. (2) Carbon sequestration of plants: Forsythia suspensa> Sophora japonica> Populus alba var. pyramidalis> Syringa oblata> Pinus tabuliformis> Sabina vulgaris> Sabina chinensis> Paeonia lactiflora> Hemerocallis fulva> Salix babylonica> Platycladus orientalis> Picea asperata> Poa pratensis； (3) there was a significant correlation between carbon sequestration and photosynthetic rate, transpiration rate and air temperature. According to the main species of carbon dioxide fixation and oxygen release analysis showed that the plant configuration, carbon fixation and oxygen release of relatively strong plants as the preferred plant (the arbors optimum with Sophora japonica, evergreen arbors with Pinus tabuliformis, the shrubs optimum with Forsythia suspensa, the herbaceous plants optimum with Paeonia lactiflora), while carbon fixation ability could be used as a longlived species and ornamental species, which were suitable for selection for a large area of green．The purpose of this study was to provide reference for the selection of urban greening plants, to provide theoretical support for the construction of urban greening plant communities, and to provide scientific basis for the construction of urban ecological gardens．

Abstract:The observation data of 59 phenotypic (Quantity traits 24, Quality traits 35) of Taraxacum koksaghyz and its 10 sympatric species were analyzed through Variance Analysis, Factor Analysis and Cluster Analysis to reveal the phenotypic diversity of genus Taraxacum and the relationship between the species was also studied. The results showed that: （1）the coefficient of variation of quantitative characters of 13 germplasm resources was 7.50%-55.00%, and the average value was 28.25%, and the diversity index was between 1.157-2.032, with an average of 1.663. （2）The variation range of the coefficient of variation was between 20.40%-67.44%, and the variation range of diversity index was between 0.271-1.672, with an average of 1.136. The morphological diversity index of quantitative traits was greater than that of quality traits; （3）the cumulative contribution rate of the first 7 principal components is 84.767%, in the principal component analysis of 59 traits, and traits the floral morphological variation was a major factor contributing to the phenotypic differentiation of Taraxacum. （4）The results of Wards cluster analysis using Euclidean distance, 13 collections were divided into 4 groups at a genetic distance 7.5. The species collected from the same region tended to be clustered into the same groups, indicating close relationship, while the 3 collections of T. koksaghyz were clustered into 2 different groups showing distant relationships. The results showed that Taraxacum was a genus rich in both quality and quantitative trait variation, resulting phenotypic diversity.

Abstract:Plant functional traits could respond to the variation of habitat and directly influenced ecosystem function. In order to explore the underlying mechanisms of how fencing and grazing affected species coexistence and community assembly, we analyzed effects of fencing and grazing on plant functional traits and functional diversity in an alpine meadow on the Tibetan Plateau. The results showed that: (1) grazing significantly decreased specific leaf area and plant height at the community level. Under grazing, specific leaf area tended to decrease for forbs at the species level, however, there was no significant difference for sedges and grasses compared with fencing. (2) Leaf dry matter content was significantly negative correlated with specific leaf area. Leaf dry matter content and plant height was significantly quadratic functional correlation in the grazing treatment. Plant height decreased first and then increased with the increase of leaf dry matter content in the grazing treatment. Leaf dry matter content were lesser for grazing than that for fencing in the case of equal specific leaf area. Plant height was lesser for grazing than that for fencing in the case of equal leaf dry matter content. (3) Grazing decreased the average dissimilarity of traits among species, caused traits convergence on the whole. Dissimilarity of leaf dry matter content and plant height among species was significantly lesser for grazing than that for fencing. Functional evenness significantly increased, and functional divergence significantly decreased after grazing. The results indicated that different species had different response modes to grazing and fencing treatments. Grazing decreased competition for light among neighboring while could increase competition for soil nutrient. Soil nutrient was a key factor in the process of community assembly driven by grazing. Therefore, the influence of grazing on species coexistence attributed to competition for multiple resources.

Abstract:Dominant species and natural rattan populations in secondary lowland rain forest of Ganshilin Natural Reserve Area in Hainan Island were as test materials. According to contrastively analyzing important values of rattan and dominant species in the community, we conductedto identify utilization and competition relationships of rattan interspecies with dominant species at layers,niche breadth, niche proportional similarity and niche overlap to explore the mechanism of rattan and dominant species at forest layer, so as to provide some theoretical references for protection to rattan resource. The results were presented as follows:(1)Vatica mangachapoi and Hopea reticulata were constructive species, 5 kinds of rattan hadrelatively upper IV in community,but there was quite a difference.Calamus rhabdocladus (Cr) had maximum IV, was 0.286. Plectocomia microstachys(Pm)had the minimum, IV equal to 0.053, sorting as follow: Cr> Cf> Dj> Ct>Pm. (2) Rattan had greater niche breadth, in which the greatest one was Cr, B_iand B_awere 2.900 and 0.612, respectively, obviously greater than the species at herb layer and had little difference with other layers. (3)The results of niche proportional similarity were indicated that the lower similarity was showed between rattan and dominant species in layers, only excepted for Dj and Callerya nitida, basically the species at layers of the largest similarity with rattan palms were same, which were Alpinia oxyphylla, Millettia reticulata, V. mangachapoi and H. reticulate. The similarity of Cr had the highest ratio with other rattan, on the contrary, Pm hadthe lowest ratio. (4) L_ik and L_ki between rattan and dominant species in layers were generally lower. All of those were less than 0.1, and niche breadth and overlap were not positively correlated. The value of overlap between 0-0.023 accounted for 63.5%, 36.0% of quantity were focused on 0.023-0.046, only 0.5% left for the rest. The study indicates that rattans in the region have relatively higher resource utilization capacity among the community species. However, great interspecies discrepancies and niche differentiations are showed among rattan interspecies and with dominant species, tending to resource sharing.

Abstract:In this paper, we set an object of study in the desert steppe in Ningxia, based on the field sampling and laboratory analysis. The characteristics of the fractal dimension of the soil and the relationship between fractal dimension and soil properties were studied. The results showed that:（1）there was more fine grained soil after enclosure. The clay（＜2 μm）content increased significantly in 0-10 cm, 10-20 cm and 20-40 cm soil layers（P＜0.05）.The silt sand（2-50 μm）content increased significantly in 0-10 cm soil layer（P＜0.05）. The sand（50-250 μm）content decreased in 0-10 cm, 10-20 cm soil layer（P＜0.05）.（2）Soil nutrients accumulated after enclosure. The organic carbon, TN, TP, alkalihydrolyzable nitrogen, available phosphorus content of soil were higher. In 0-10 cm soil layer, the organic carbon, TN, TP, alkalihydrolyzable nitrogen, available phosphorus content increased by 177.70%, 155.70%, 60.11%, 120.42%, and 179.40%, respectively. In 10-20 cm soil layer, the soil organic carbon, TN, TP, available phosphorus content increased by 202.80%,36.50%, 27.78% and 37.30%, respectively. The soil nutrient change is not significant in 20-40 cm soil layer（P＞0.05）. Obviously, enriched nutrients were distributed mainly in the 0-20 cm layer and concentrated in 0-10 cm layer（P＜0.05）.（3）In the enclosed plot, the fractal dimension of soil is of between 2.64-2.69, and the fractal dimension of the outside fence is 2.59-2.64. Compared with outside fence, the fractal dimension of soil in the enclosed plot increased significantly in 0-10 cm and 10-20 cm（P＜0.05）.（4）The soil fractal dimension and soil particle size distribution, the organic carbon, TN, TP, alkalihydrolyzable nitrogen, available phosphorus content all showed a linear relationship. The results show that fractal dimension can be used as a comprehensive index to measure soil fertility, soil structure and soil restoration.

Abstract:In order to discuss the change mechanism of soil organic carbon during the recovery of desertification grassland, we studied the soil organic carbon of coarse sand, soil organic carbon of fine sand, soil organic carbon of clay and silt, heavyfraction organic carbon (HFOC), lightfraction organic carbon (LFOC) and total nitrogen under different restoration of desertification grassland in Yanchi Country, north and middle region of Ningxia (mobile dunes, semifixed dunes, fixed dunes and grasslands). The results showed that: (1) to compare with mobile dunes, soil organic carbon of coarse sand, soil organic carbon of fine sand, soil organic carbon of clay and silt in grassland, fixed dunes and semifixed dunes were increased by 67.7%, 69.8% and 212.1%; 48.8%, 35.3% and 99.9%; 33.6%, 23.0% and 48.9%, respectively. (2) The content of LFOC, the proportion of LFOC and the content of HFOC showed that mobile dunes< semifixed dunes< fixed dunes< grassland; the proportion of HFOC decreased gradually in the process of grassland restoration in desertification grassland. (3) The content of fine sand, clay and silt, HFOC, LFOC, soil organic carbon of coarse sand, soil organic carbon of fine sand and soil organic carbon of clay and silt were significantly positively correlated to the content of SOC and soil total nitrogen (TN), were significantly negatively correlated to the content of coarse sand. The content of LFOC and soil organic carbon of clay and silt have significantly effected on SOC, and the content of LFOC, HFOC, soil organic carbon of coarse sand, soil organic carbon of clay and silt have significantly effected on soil total nitrogen, which indicated that the restoration of desertification grassland is beneficial to reduce soil erosion and improved soil structure and quality.

Abstract:Hoya acuminata (Wight) Benth. ex Hook. f. is reported as a new record species of Apocynaceae, Asclepiadoideae from China. H. acuminata has been recorded in Bhutan, Sikkim, Khasia and Myanmar and it was found on a tree of dense moist forest in Medog County, China at the altitude of 1 577 m in 2015. It is related to H. chinghungensis, but differs in its branches quite glabrous, umbels 3-5 flowered, with corollas up to 5 cm in diameter and lobes 2 cm. The voucher specimens are preserved in the herbarium of Guangxi Botanical Garden of Medicinal Plants (GXMG).