Abstract:In this study, we analyzed the transcriptional activity and interacting proteins of AtWRKY61 transcription factor through dualluciferase(LUC), yeast twohybrid (Y2H) and bimolecular fluorescence complementation (BiFC) experiments. qRTPCR was used to analyze the response characteristics of AtWRKY61 to various abiotic stress. They lay the foundation for further revealing the function and molecular regulation mechanism of AtWRKY61. Subcellular localization through green fluorescence protein (GFP) shows that AtWRKY61 is localized in the nucleus only. A dualLUC assay in Arabidopsis protoplasts and yeast experiment reveal that AtWRKY61 has transcriptional repression activity. qRTPCR results indicate that transcription of AtWRKY61 responded to multiple abiotic stresses and hormone stimuli, suggesting AtWRKY61 may participate in multiple signaling pathways. Y2H test demonstrated that AtWRKY61 interacted with itself and two closely related paralogs AtWRKY9 and AtWRKY72, which were further confirmed by BiFC. This implies that AtWRKY61 might perform its transcriptional repression function via forming a complex with itself and two other closely related homologs.

Abstract:We cloned a MYB transcription factor named CsMYB123 from the tea plant (Camellia sinensis) cultivar ‘Zijuan’ using RTPCR. Bioinformatics analysis of CsMYB123 gene showed that it contains a 915 bp ORF that encodes a protein with 304 amino acid residues, an estimated molecular weight of 34.07 kD and an isoelectric point of 8.69. Based on an analysis that utilized BLAST online tools, we conclude that CsMYB123 belongs to the MYB gene family and is a R2R3MYB protein. Our molecular evolutionary tree analysis of the CsMYB123 protein and all of the MYB transcription factors in Arabidopsis thaliana indicates that the CsMYB123 protein is most closely related to AtMYB123 and is a member of subgroup 5, which is one of the 22 R2R3MYB subgroups. CsMYB123 is not predicted to have an Nterminal signal peptide or a transmembrane domain. CsMYB123 is predicated to be a hydrophilic protein that is localized to the nucleus. The qPCR results indicated that the expression level of CsMYB123 gene in different tissues was as following: the first leaf and a bud > the second leaf > the third leaf > the fourth leaf > old stem > tender stem, with the expression of CsMYB123 gene in the first leaf and a bud was 15.68 fold higher than that in tender stem；However, expression of CsMYB123 was downregulated under the treatment of IAA, ABA, ETH and GA₃. We detected anthocyanin content in different tissues of ‘ Zijuan’ tea plant, which was listed as below: the second leaf > the first leaf and a bud > the third leaf > the fourth leaf > tender stem > old stem, and the content in the second leaf and the first leaf and a bud were 15 times and 11 times higher than that in old stem, respectively. Based on the study above, we found that CsMYB123 gene was highly expressed in tender shoots of ‘Zijuan’ tea plant, and the expression level of CsMYB123 gene was positively correlated with the content of anthocyanin in different tissues. Thus, CsMYB123 may promote the accumulation of anthocyanins in tea plant.

Abstract:In this study, we cloned a WRKY transcription factor encoding gene WRKY75 from Caragana intermedia. The sequence analysis shows that the open reading frame of CiWRKY75 is 570 bp and encodes 189 amino acids, contains one WRKYGQK motif and a C2H2type zinc finger, belongs to group II WRKY family. CiWRKY75 localized in the nuclei by transforming the GFP fusion constructs into Arabidopsis thaliana mesophyll protoplast. The transcripts of CiWRKY75 was induced by NaCl and ABA treatments. Overexpression of CiWRKY75 in Arabidopsis thaliana resulted in sensitivity to salt tolerance, and the germination rate of the transgenic lines decreased under both NaCl and ABA treatments compared with wild type. These results indicates that CiWRKY75 is an important regulator in plants response to salt and ABA treatments.

Abstract:On the basis of transcriptome data, the expression of bHLHs of Lepidium apetalum seeds which can tolerate low temperature germination and not between the two groups, were compared, and the family of class bHLH transcription factors in the seeds transcriptome is analyzed in this paper, the laICE1 was one of the bHLH transcription factor gene family members whose relative level of expression in seeds was different between the twogroups significantly. The gene was cloned and its expression was analyzed in response to low temperature stress in L. apetalum seedling. The results showed that: (1) there were 83 family members of bHLH transcription factors in L. apetalum seeds at least. Compared with the low temperature germination stagnation group, there were 17 down regulation, 13 up regulation and 60 bHLH transcription factors with no significant difference in the low temperature germination tolerance group seeds. Among them, the expression of c20009_g1 was down regulated remarkably, and it had an open reading frame composed of 1 503 bp. The sequence was annotated in the GO database with known plant cold related ICE1 genes. C20009_g1 was named laICE1 in this article. (2) Sequence analysis showed that laICE1 encodes a protein consisting of 500 aa with a molecular weight of 54 635.19 kD, a theoretical PI of 5.45, a formula of C₂₃₆₄H₃₇₄₂N₆₈₈O₇₅₈S₂₂, and a conserved domain bHLH. (3) Quantitative analysis by realtime fluorescence showed that the expression of laICE1 was significantly lower in the seeds of the germination tolerance group than that in the seeds of the germination stagnation group. This is consistent with the data of the transcriptome. After low temperature treatment, the expression level of the gene was increased significantly in seedling stage. These results suggest that laICE1 may be related to the ability of the L. apetalum seedlings to tolerate low temperature.

Abstract:The stearoylACP desaturase (SAD) gene from Paeonia ostii was cloned using RTPCR and RACEPCR strategies, named as PoSAD (GenBank accession number: KY038819). The full length of FAD3 cDNA is 1 559 bp, contains a 1 197 bp open reading frame (ORF) encoding a putative protein of 398 amino acids. The noncoding districts of 3′ and 5′ end are 172 bp and 123 bp. Multiple sequence alignment results showed that it contains two conserved domains of PoSAD gene. Phylogenetic tree analysis showed that the P. ostii had the closest evolutionary relationship with Ricinus communis. Subcellular localization analysis of TMHMM and TargetP indicated that it might be targeted to the endoplasmic reticulum without transmembrane region. PoSAD gene was expressed in the root, stem, leaf, petal, pistil, stamen and seed of P. ostii by the tissuespecificity expression. The expressive content of PoSAD gene in different tissues of P. ostii was different: the highest was petal, the next was pistil, and the lowest level was in root; in different periods of seeds, the highest expression was in seeds of 60 d, the next was 80 d. The expression level of 10 d was the lowest.

Abstract:In order to further verify the function of cotton GhVHAA gene, we constructed the GhVHAA gene into the prokaryotic expression vector pET28a and induced by IPTG in E. coli BL21 (DE3) for resistance analysis. The results indicated that: (1) semiquantitative RTPCR analysis showed that the expression level of GhVHAA gene in cotton seedlings was induced by dehydration and salt stress. (2) A 1 872 bp coding region was ligated into the prokaryotic expression vector pET28a. The prokaryotic expression vector pET28aGhVHAA was successfully constructed. The SDSPAGE electrophoresis results show that there was a specific protein band at about 70 kD, which was identical with the expected molecular weight of the recombinant protein. (3) The resistance of recombinant bacterium BL21 (pET28aGhVHAA) to PEG6000 (20%) and NaCl (0.5 mol/L) was significantly higher than that of the control strain BL21 (pET28a), and indicating that the expression of GhVHAA gene in E.coli can enhance the resistance of the strain. The results provided a theoretical basis for the application of GhVHAA gene in plant stressresistant genetic engineering.

Abstract:Using the core fragment screened by mRNA differential display technology in our laboratory preliminary study, which is about 414 bp length deserved from the Conringia planisiliqua L. under drought stress, we cloned the full length cDNA by RACE technology and sequence analysis showed it has higher similarity to AtNSP5, so it was named CpNSP5. The length of CpNSP5 is about 1 228 bp and with an open reading frame of 966 bp. It encodes a protein composed of 321 amino acids whose molecular weight is 35.034 5 kD and the isoelectric point is 5.41. The secondary structure of the CpNSP5 protein contained 26 βsheets and had the Kelch repeat conserved domain. According to phylogentic tree analysis, CpNSP5 kept close relationship with Brassica rapa. Realtime quantitative PCR analysis showed that the transcript of CpNSP5 was induced strongly under 20% PEG6000 stress and 200 mmol·L^-1 NaCl stress. These results indicated that CpNSP5 might be involved in stress responses of C. planisiliqua L. which can provide a candidate gene for crop drought stress breeding.

Abstract:Core leptosporangiatae is a major fern group in the Filicinae. The origin of the wall cell on archegonium has not been specifically reported yet. Combined with research on sexual organs of Cyatheaceae and other 10 more groups, this paper takes Dryopteris goeringiana (Kunze) Koidz. as an example, at the condition of artificial environment, observed the development of the archegonium by paraffin section method. The results show that: （1） the archegonium originates from an initial cell and a plurality of vegetative cells on the gametophyte; （2） Initial cell gives rise to a column of three cells by two unequal divisions, from outside to inside, there are neck wall cell, central cell and basal cell; （3） Central cell ultimately developed into an egg cell, ventral canal cell and neck canal cell;（4） Basal cell divided into 1-4 wall cells under the ventral wall of the archegonium; (5) The wall cells around the ventral of the archegonium are directly transformed from the vegetative cells adjacent to the egg cell. It is the first time to propose that the archegonium of the core leptosporangiatae is multicellular origin, the morphological basis is provided for the study of the evolution of sexual reproduction in the archegonium plants.

Abstract:Micromorphological characters of pollens and seeds of six sect. Daghestanica (Tscholok.) N.Friesen species were observed and analyzed by using light microscopy (LM) and scanning electron microscope (SEM), and the taxonomic value and the significance of evolutionary biology of these characters were discussed for the first time. These studies provide some theoretical support for interspecific taxonomy. Study results showed that: (1) the pollen shapes of Daghestanica species were prolate with the size of (17.84-29.84) μm × (12.23-19.18) μm, and the equatorial view shapes were elliptical, the polar view shapes were round, bilateral symmetry. The exine ornamentation were rugulate and reticulate. The pollen exine ornamentation and perforation characteristics among the six species were significantly different. (2) The species with largest pollen size was A. rude, which was accompanied with longer polar axis than other congeners, and the species with smallest pollen size was A. herderianum. (3) The seeds of the Chinese Allium sect. Daghestanica were ovate and the ornamentation of seed coat is scalariform. The cell is polygon, cellular arrangement is relatively loose with verrucate on the periclinal walls, anticlinal walls are straightarched. (4) The cell shape, arrangement and secondary of convex testa cells have predominant differences among species. So differences of morphorlogical characters in seeds and pollens can provide some evidence for classification of the Chinese Allium sect. Daghestanica species.

Abstract:With the cultivar Chardonnay grapevine (Vitis vinifera L.) as material, the methods of paraffin section and CFDA dye labeling were used to observe the structure of grape berry and the cell death in grape berry skin, berry quality and relative physiological indexes were also measured, in order to make clear the effects of sunburn on grape berry quality and berry structure. The results showed that: (1) The sunburn of berry was characterized by light brown lesions from initial phase, and then the lesions increased in size and depth of color with the increasing of sunburn severity. For the severe sunburn in chardonnay grapes, the dark brown lesions were seen and associated with cell death in the berry skin. (2) When the berry was damaged by sunburn, berry firmness and water contents decreased, but the cell wall contents increased. The epidemic cell size of grape berry with sunburn was smaller than that with no sunburn, but the epidemic cell wall of sunburn berry was thicker than that with no sunburn. (3) With the increase of sunburn severity, the epidemic cell wall broke, and the cell activity decreased. Due to the loss in protecting function of berry skin, the grape berry shrunk gradually with the increasing of sunburn severity. In addition, for the grape berry with severe sunburn, the xylem vessel in dorsal vascular bundle cracked. (4) The occur of sunburn was associated with the water loss of grape berry, TSS (total soluble solids) and total sugar content of grape berry increased, but the content of organic acids decreased. Sunburn induces the changes in grape berry anatomy and disorder of physiological function, with the increase of sunburn damage to berry, the cells of berry skin died gradually. Because of water loss in grape berry, the TSS and sugar contents also increase in grape berry, but the impacts of sunburn on the wine quality should be further studied for the wine grape production.

Abstract:In order to study the effects of high temperature on grain development and crystal properties of wheat (Triticum aestivum L.), we selected the main varieties of XC11 and XC39 with different qualities and maturity stages. They were treated at the early (T₁) and middle (T₂) stage after anthesis under high temperature, respectively. The results showed that: (1) T₁ treatment significantly reduced grain length and grain weight of two varieties, while T₂ treatment had greater effects on grain width and thickness. Although the grain filling rate was decreased by high temperature treatment, the maximum peak time of the two varieties appeared at 18 day after anthesis (DAA). (2) For morphology of starch grains, the influence on the Atype starch granules morphology is more serious under high temperature treatment. Under T₁ treatment, pores of Atype starch granule of XC11 can be observed in surface at 10 DAA, Atype starch granule size significantly less than the same period controlled starch granule size at 15-20 DAA, starch granule surface indentation increased at 20-25 DAA and A and Btype starch granule surface significantly constricted. However, the shape and size of starch granule of early maturing XC39 were less affected by the high temperature after anthesis. (3) Under different high temperature treatments, the diffraction peaks of starch grains were the same, but the peak intensities of starch grains were different between the two varieties. The results showed that high temperature stress did not affect the crystal type of starch grains, but changed the lamellar structure of starch grains. The early high temperature after anthesis not only has a great influence on the grain morphology, but also affects the morphology and crystal characteristics of starch grains in the grains.

Abstract:Taking two flowering cultivars ‘YS205 ’and‘ HZ88’ and nonflowering cultivar YS304 of potatoes as materials in this study, we observed the anatomical characteristics of flower bud differentiation by paraffin method, and analyzed the IAA, GA₃, ZR and ABA dynamic changes in leaves of flowering and nonflowering varieties by ELISA to investigate the relationship between the contents, ratio of endogenous hormones in leaves and flower bud differentiation, which provided theoretical basis for regulation, cultivation and cross breeding of potatoes. The results showed that: (1) there was a relatively stable temporal correspondence between the internal development and the external morphology of flower bud. It took only a week to complete the whole flower bud differentiation which from the initial stage that the growth cone was gradually upward to the formation of pistil and stamen primordium. In this period, the microscopic characteristics of‘ YS205’ and‘ HZ88’ had no significant difference, but ‘YS304 ’did not flowering. (2) With the continuous development of floral organs, the ovary of HZ88 formed two locules with several ovules in each, but the ovary of YS205 had mutated which formed a complete three locules. Afterwards, ‘YS205 ’and HZ88 have carried out selfpollination and fertilization process successively, and HZ88 had a certain selfseeds rate, but YS205 was not. (3) During the early period of flower bud differentiation, the contents of IAA, GA₃, ZR and ABA of three varieties were low which no significant difference. Subsequently, the IAA and GA₃ contents of three varieties increased first and then dropped which showed a singlepeaked curve, but the rate of rise and fall of YS304 was faster than that of two varieties. Conversely, the ZR and ABA contents of‘ YS205’ and HZ88 were higher than those in‘ YS304’ during the whole flower bud differentiation. (4) The ratios of ABA/GA₃, ABA/IAA, ZR/IAA and ZR/GA₃ in YS205 and‘ HZ88’ were higher than those in nonflowering YS304, and the variation trends were different. Thus, lower levels of IAA and GA₃, higher levels of ABA and ZR were beneficial to potato bud differentiation, on the contrary, the formation of flower primordium was inhibited.

Abstract:To explore the possible mechanism of high rates of ammonium nitrate (NH₄NO₃) in the regulation of root hair formation, we grew wild type (WT), auxininsensitive and ethyleneinsensitive mutant seedlings on vertically oriented agar plates. Our study found that: (1) high rates of ammonium nitrate (NH₄NO₃) supply stimulated the branched root hair formation and inhibited root hair elongation. (2) The effect of NH₄NO₃ on root hair formation were blocked by reactive oxygen species (ROS) and diphenylene iodonium chloride (DPI), suggesting that ROS was involved in NH₄NO₃induced branched root hair formation. (3) The treatment of auxin or ethylene under high NH₄NO₃ condition completely inhibited high NH₄NO₃ induced branched root hair formation. (4) Either eir13 seedlings treated with auxin or aux17 and axr13 treated with ACC, the NH₄NO₃ induced branched root hair formation was inhibited. The results above showed that ROS, auxin and ethylene involved in high NH₄NO₃induced branched root hair formation. Auxin played a compensating role in the absence of an ethylene response and ethylene played a supplemental role in the absence of an auxin response. A higher level of auxin was required for preventing branched root hair formation in the absence of ethylene signaling.

Abstract:Using nonwoven bag, white paper bag, kraft paper bag separately covered the ‘Pollock’ avocados after the second physiological drop, we measured regularly the changes of internal and external quality indexes such as fruit color parameters, fruit shape index, and the content of pericarp pigment, soluble sugar, soluble solids, Vc, fat, soluble protein. The purpose is that studies on the effect of different bagging materials on the growth and development process of avocado fruit in the appearance quality and internal quality. It aims to provide a theoretical basis for high quality cultivation of avocado. The results showed that: (1) the three kinds of bagging materials could significantly promote the growth of avocado fruit.They significantly increased the single fruit weight of mature fruit, but there is not significant effect on the growth and development and maturity on avocados. (2) Nonwoven bags could significantly improve the fruit shape index of avocados, while the other two bagging materials did not. Although the kraft paper bag could significantly increase the brightness of fruit, but would make the pericarp turn yellow. White paper bags and nonwoven bags could increase fruit brightness, but they were not significantly different from the control group. (3) Nonwoven bags and paper bag processing could significantly improve carotenoids and chlorophyll in pericarp, soluble sugar, soluble solids, VC, fat and soluble protein contents in pulp of avocado. Kraft paper bag also could significantly improve soluble solids, soluble sugar, soluble protein and fat contents in pulp of avocado, while reducing the chlorophyll content in pericarp and Vc content in pulp, inhibition of carotenoid synthesis and accumulation in pericarp. (4) All bagging materials could also change the avocado pericarp thickness. The kraft paper bags could significantly improve the pericarp thickness, while nonwoven bags and white paper bags have reduced the pericarp thickness. All bags had no significant effect on pulps density. (5) According to the comprehensive analysis of membership function method, the results indicated that nonwoven fabric bags are optimum bagging materials, and the white paper bags are the second. These results greatly enriched the suitable bagging materials can significantly promote the avocados growth and development, improving the appearance quality and internal quality of avocado fruit. In this experiment, the effect of nonwoven bag bagging is the best.

Abstract:In order to study the effects of physiological, morphological indexes and the physiological mechanism on drought stress for Fagopyrum tataricum cultivars, we took the pot experiment of artificial water control and three water treatments included normal irrigation, moderate water stress, and heavy water stress. The experimental materials included ‘Diqing’, ‘Xinong9909’, ‘Heifeng1’ and ‘Xiqiao1’. Three results were drawn from this experiment. (1) Compared to the normal water treatment, the main root length of ‘Diqing’ and ‘Xinong9909’ increased under the heavy water stress; The plant height, stem diameter, leaf area, shoot dry weight, root dry weight, root volume, root area of ‘Heifeng1’ and ‘Xiqiao1’ decreased, and the decrease of drought tolerant cultivars were less than those of nondrought tolerant cultivars. Besides, the drought stress made root/shoot ratio increased of ‘Diqing’ and declined of other cultivars. (2) Drought stress could make chlorophyll content, leaf relative water content, F_m, F_v/F_m, root activity and soluble protein content significantly decreased, but superoxide dismutase (SOD) activity, peroxidase (POD) activity, malonaldehyde (MDA) content, soluble sugar content and free proline content increased. Also, there were differences of up or down for different varieties. (3) Subordination function method and principal component analysis were used to synthetically evaluate the drought resistance of different F. tataricum genotypes. We found out that the resistance ranking (‘Diqing’＞ ‘Xinong9909’＞ ‘Heifeng1’＞ ‘Xiqiao1’). The results of correlation analysis showed that plant height, root dry weight, dismutase (SOD) activity, soluble protein content were significantly correlated with D value and the proline content and soluble sugar content were very significantly correlated with D value. The study has shown that ‘Diqing’ and ‘Xinong9909’ had the best performance for the indexes of various aspects under two kinds of drought conditions, thus we could conclude that these cultivars had better adaptability under drought environment. ‘Heifeng1’ and ‘Xiqiao1’ had the poor performance, which showed low drought resistance. At the same time, plant height, root dry weight, dismutase (SOD) activity, soluble protein content, proline content and soluble sugar content can be used as indicators for the rapid determination of drought resistance.

Abstract:Low light intensity environment remarkably affected growth, development and metabolism in tobacco plants and quality of tobacco leaves. In the present study, by spraying different concentrations of calcium chloride ［3.0 (C₁) and 6.0 (C₂) mmol/L CaCl₂］, gibberellins ［100 (G₁) and 200 (G₂) mg/L GA₃］ , salicylic acid ［1.0 (S₁) and 2.0 (S₂) mmol/L SA］ and paclobutrazol ［100 (P₁) and 200 (P₂) mg/L PP₃₃₃］ on tobacco (Nicotiana tabacum L.) seedlings, we investigated the effects of these pretreatments with the abovementioned four chemical regulators on growth, development, low light tolerance and photosynthetic characteristics of tobacco seedlings under low light intensity stress（80 μmol·m^-2·s^-1）, and carried out comprehensive evaluation by subordinate function. The results showed that: (1) as compared with the control spraying with distilled water (CK), the pretreatments with the four chemical regulators all enhanced dry weight, root vigor, contents of total chlorophyll and proline, and photosynthetic capacity of tobacco seedlings, and improved the seedling quality. (2) After exposed to low light stress for 6 days, as compared with the CK, the pretreated seedlings with the four chemical regulators relatively enhanced dry weight, root vigor, total chlorophyll content and photosynthetic capacity, reduced the electrolyte leakage and MDA level, and delayed the decline level of relative growth rate and dry matter accumulation rate of tobacco seedlings, which in turn enhanced the tolerance of these tobacco seedlings to the low light stress. (3) Comprehensive effects of these treatments with four chemical regulators on improving the quality of tobacco seedlings were S₁ > S₂ > C₁ > C₂ > P₂ > G₂ > P₁ > G₁, respectively, and SA and CaCl₂ pretreatments received better effects than those with spraying GA and PP₃₃₃. In addition, the relieving effects of these treatments with different concentrations of the four chemical regulators on the low light stress were demonstrated from strong to weak was S₁ > C₁ > S₂ > P₁ > P₂ > G₂ > G₁ > C₂, respectively, after exposing to low light condition for 6 days. The results indicated that these pretreatments with the four chemical regulators all improved growth and quality of tobacco seedlings, and enhanced their low light tolerance and photosynthetic capacity to some extent, and 1.0 mmol/L SA displayed the optimal effects in this study.

Abstract:In this study, Cu tolerance and accumulation characteristics in Melissa officinalis were investigated by some indexes, such as biomass, chlorophyll contents, antioxidant enzyme activities, soluble protein (SP), malondialdehyde (MDA) and Cu contents in plants under different concentrations of Cu²⁺ (0, 200, 400, 800, 1 000 mg·kg^-1) through pot experiments was measured after 0, 7, 14, 21 and 28 days. The results show that: (1) at the same treatment time, there was a similar trend that a significant increase at low doses (200 and 400 mg·kg^-1), while an inhibitory at high doses (800 and 1 000 mg·kg^-1) in most of indexes except MDA content. Furthermore, the statistical results showed that differences were significant between high doses group (800 and 1 000 mg·kg^-1) and those of low dose groups (200 and 400 mg·kg^-1) (P<0. 05). Unlike these changes of other indexes, the variation trend of index MDA was growing 14 days ago and decreasing at 1 000 mg·kg^-1 Cu²⁺ concentration. (2) As the Cu²⁺ dose increasing, the total Cu concentration in plants reached up peak at 400 mg·kg^-1 (0.71 mg each pot) then declined. (3) Throughout the experiments, these indexes of tolerance and the bioconcentration factors of M. officinalis were more than 0.5 and 1, respectively. Both the index of tolerance and the bioconcentration factor decreased with the Cu²⁺ concentration increasing after 28 days, which explored that M. officinalis has some certain of tolerance ability and accumulation capacity for Cu. The results suggested that M. officinalis has the potential to be a promising plant for phytoremediation in Cucontaminated soil.

Abstract:Water is the main limiting factor for plant growth in the waterwind erosion area of the Loess Plateau. Liudaogou watershed was taken as a study area in consideration of its typical representative of the Loess Plateau. Caragana korshinskii and Salix psammophila, two kinds of typical shrubs, were chosen as the objects of the study to measure the δD of their stem water and soil water in different soil depths and δ¹³C of the leaves. And the IsoSource model was used to calculate the probable contributions of soil water to these two shrubs. In addition, the leaf water potential, stomatal conductance, photosynthetic rate and transpiration rate were measured to compare the different water sources and ecophysiological adaption of the two shrubs in different seasons. The results showed that: (1) the water use strategies of C. korshinskii and S. psammophila changed with seasonal fluctuations, and the soil moisture utilization ratio of different depths in different seasons were significantly different. (2) In the dry season, C. korshinskii and S. psammophila mainly used the water from 40-80 cm layer, and the ratio was 48.1% and 49% respectively. (3) In the wet season, C. korshinskii used more than 57.5% water from the surface soil layer (0-10 cm) and shallow layer (10-40 cm), while S. psammophila used more than 76% water from shallow layer (10-40 cm). (4) The soil water deficit of the two shrubs were serious in the dry season, and the leaf water potential, stomatal conductance, photosynthetic rate and transpiration rate were less than those in the wet season. It indicates that the C. korshinskii and S. psammophila can obtain higher carbon assimilation rate by reducing stomatal conductance to decrease water loss. And they can maintain higher water use efficient to adapt the arid condition.

Abstract:This study focused on the parameters of root architecture among four dominant species at three different stages of vegetation succession in a Karst peakcluster depression by the method of whole digging sampling. (1) Root forms forked branches and the topological index (TI) tends to close to 0.5 with the secondary forest 0.57, the primary forest 0.49 and the shrub 0.46. It is indicated that forked branches are beneficial for root to expand living space in poor and shallow soil. (2) The average root length of the dominant species in three various vegetation restoration was 37.01 cm, all above 34.29 cm. The increasing of connection length is beneficial for plants to survive better in nutrientpoor Karst soil. (3) Due to different adaptative strategies of plants under different succession stages, the root branching rate in secondary forest is lower than that in shrub and primary forest. (4) The area of the cross sections under the dominant species in three succession stages conform with the Leonardo da Vinci theory and do not change with diameter of branches. (5) There was no significant difference in soil nutrient, moisture acquisition, and soil space expansion among three vegetation restoration processes. It suggested that the same ecological adaptation strategies that root forms forked and longer root link length, lower branching rate were adopted under the dominant species in three succession stages despite the high variability in Karst peakcluster depression.

Abstract:Distylous plant is a special group of angiosperm which has reciprocal stigma and anthers within a species. Comparative investigations of breeding system of distylous species on different elevations can be revealing the relationship between distylous plant evolution and their environments. Primula nivalis is a native primrose in the northern Xinjiang, NW China. In order to investigate the comparative effect of habitat heterogeneity on frequency of morphs in different sexual morph plants and differentiation of floral characters were quantified at seven lowelevation forest (1 657-2 013 m) and seven highelevation grassland populations in this research. The study results will clarify the reproductive strategies and adaptation mechanisms of P. nivalis at different elevational environments. (1) The investigations on effect of heterogeneous habitats on P. nivalis floral phenotype suggested that frequency of LS (long style) morph individuals in high elevation grassland population was higher than that of SS (short style) morph individuals; (2) The floral morphological characters of LS among populations in different ecological conditions were significant different, but no significant difference for SS morphs with different ecological conditions; (3) The length of corolla tube and stamen, and stamenstigma spatial distance, herkogemy and relative reciprocity of LS flowers in high elevation grassland population are the main factors for floral trait differentiation in P. nivalis at heterogeneous environments; (4) This revealed that variation of LS floral characters at different population decreased the herkogamy level of both morph flower sexual organs in high elevation grassland populations. Therefore, changes of floral trait of LS plants are the main factors for floral trait differentiation and relative reciprocity of both morph flowers in heterogeneous environments.

Abstract:In order to find a reasonable density to maintain a stable community structure and improve species diversity, we studied the effects of different stand densities on community structure and species diversity of Eucalyptus robusta plantation in Puxing Town, Xinjin County, Sichuan Province, using typical sampling method, setting 3 plots in each stand density (A. 625 trees·hm^-2; B. 750 trees·hm^-2; C. 875 trees·hm^-2; D. 1 000 trees·hm^-2; E. 1 125 trees·hm^-2). The results showed that: (1) a total of 96 plants were recorded, belonging to 51 families and 79 genera. The number of species in the vegetation of every kind of stand density arranged from greatest to least was: the herb layer, the shrub layer, and the tree layer. When the density was 1 000 trees·hm^-2, there were 6 species in the tree layer, which was the maximum. And the maximum was 17 species in the shrub layer when the densities were 750 and 875 trees·hm^-2 , there were 32 species in the herb layer under the stand density 625 trees·hm^-2.（2） In general, the species richness index D, ShannnonWiener index H, Simpson index H′ and Pielou uniformity index Jsw of the E. robusta plantation community in all kinds of stand densities were all expressed as: herb layer＞shrub layer＞tree layer. The maximum of the D and H′, H, J_sw value of the tree layer was respectively from the density C, A, B; each index of the shrub and herb layer had the maximums respectively at the density 750 and 625 trees·hm^-2. (3) Seen from the community structure, the diameter class of the five kinds of stand densities showed a single peak type distribution, and the trees were mostly distributed in the middle diameter classes(7.0≤d＜23.0 cm); the height class was different from the diameter class, the trees in the density of A, B, C and D, E were concentrated respectively in the height classes Ⅱ to Ⅴ(6.0≤h＜18.0 m), Ⅲ to Ⅴ(9.0≤h＜18.0 m), Ⅱ to Ⅲ(6.0≤h＜12.0 m), Ⅳ to Ⅴ(12.0≤h＜18.0 m). (4) The dominant tree species varied among different layers. It was E. robusta in the tree layer, and the important value of Broussonetia papyrifera in each density was second only to E. robusta in general. In the shrub layer, E. robusta seedlings only appeared in density E, and the dominant position of B. papyrifera in each density was significant. In density B-D, both Alangium chinense and Ligustrum lucidum existed, in which they grew well with the important value of 0.118 4 and 0.183 2 under density B, having great potential for renewal. As the dominant species of herb layer, Artemisia carvifolia and Arthraxon hispidus both grew under the five kinds of stand densities. The results showed that the stand density 750 trees·hm^-2 was the optimum for the E. robusta plantation, which was more conducive to the stable and sustainable development of community structure and species diversity of E. robusta plantation in this area.

Abstract:Allium wallichii Kunth., mainly distributed in the Hengduan Mountain (HDM), was researched in this study. Based on the MaxEnt and ArcGIS, we simulated the distribution trends of A. wallichii in the Last Glacial Maximum, MidHolocene, Current and Future. In addition, we detected the distribution pattern of which A. wallichii responded to climate change following the Last Glacial Maximum. The results indicated that: (1) environmental parameters such as Precipitation of Warmest Quarter, Temperature Annual Range, Temperature Seasonality and Altitude largely influenced the distribution of A. wallichii. (2) Evaluation by ROC curve showed that MaxEnt could accurately predict the species distribution (AUC=0.98). (3) According to the distribution change in all periods, we revealed that the distribution of A. wallichii in the Last Glacial Maximum was expanded compared with the distribution of Current, which is similar to some subnival plants. It can be inferred that the distributions of A. wallichii will move westward in the future.

Abstract:Lejeunea patersonii (Steph.) Steph. was reported for the first time from North Vietnam and Guangxi Province, China. The species is characterized by the orbicular leaves with crenulate margins; small, distant underleaves with indistinctly crenulate margins, 1-2 times stem width; leaf cell with smooth cuticle, cell walls with small trigones and without intermediate thickenings. Morphological descriptions and illustrations were provided, and a discussion was given for L. patersonii and its allies. The distribution of L. patersonii was recomfirmed by the correction of current confusing information.

Abstract:Anthocyanins, carotenoids and alkaloids are three major classes of pigments in plant. Among them, anthocyanins impart vivid colors to most angiosperm tissues and organs. It is synthesized through flavonoid biosynthetic pathway, which has been well characterized and studied. Recently, researchers have found that, besides chalcone synthase (CHS), chalcone isomerase (CHI) and flavanone 3 hydrolase (F3H), which are very important enzymes participating in the flavonoid biosynthesis pathway, dihydroflavonol 4reductase (DFR) also plays a vital role in the anthocyanins biosynthesis. It can catalyze three different kinds of dihydroflavonols and two kinds of flavanones to produce five different anthocyanins precursors, and different members from the DFR gene family confer different catalytic efficiency. Thus, DFR determines the category and content of anthocyanins leading to different colors of plant tissues. In the present review, we summarized the function and regulation characterization of DFR in anthocyanin biosynthesis, those include the feature, evolution and the mechanism of DFR reaction. Moreover, we aslo discussed the relationship between DFR and environment, transcription factors and some structural genes, aiming at providing new insights for further research on DFR and basis for using genetic engineering to change the color of plant tissue and organ.