Abstract:Chlorophyll biosynthesis is catalyzed by a series of enzymes. Among them, the chlorophyll synthase (CHLG) catalyzes the synthesis of chlorophyll a and b, the last step of the pathway. In this study, Medicago truncatula (ecotype R108) and Medicago sativa with fall dormancy of 4 or 8 were used. The evolutionary relationship of plant CHLGs and their gene structure were analyzed using bioinformatics; the expression of MtCHLG under light/darkness, abscisic acid (ABA) or polyethylene glycol (PEG) treatment was studied by realtime quantitative PCR; the transcript level of MtCHLG was tested in mtcao mutant; and the correlation coefficient between the expression level of MsCHLG and plant height or yield in Medicago sativa was analyzed. The results showed that: (1) CHLGs shared common conserved domains and a relatively uniform gene composition. It seems that several terrestrial plants possess one more CHLG with much longer introns. (2) MtCHLG open reading frame (ORF) of 1 137 bp was cloned encoding 378 amino acids and the protein was highly identical (99.2%) to MsCHLG. (3) qRTPCR demonstrated that MtCHLG was predominantly expressed in young leaves of Medicago truncatula with a lightinducible or darkrepressed pattern showing a significant increase in the daytime and a continuous decline at night. Moreover, under 100 μmol·L^-1 ABA treatment of 2 h, MtCHLG in leaves decreased to about 26% of the control (P<0.05). 5% PEG treatment within 24 h repressed the expression of MtCHLG, which decreased to about 42% of the control (P<0.05) at the end of the treatment. (4) When transiently expressed in tobacco epidermal cells, the recombinant protein MtCHLGGFP was detected mainly in chloroplasts. (5) qRTPCR showed that in mtcao mutant with no obvious expression of MtCAO, the expression level of MtCHLG was about 44% of the wild type, indicating that MtCAO lossoffunction resultes in a decrease of MtCHLG, which suggests that MtCHLG is downstream of MtCAO in the chlorophyll biosynthesis pathway. (6) The plant height of the alfalfa accessions with FD of 8 was about 2.5-3.5 times of the ones with FD of 4. The average yield of the former was about 2.1 times of the latter, and the expression level of MsCHLG showed a similar pattern (1.2-1.5 times). According to the correlation coefficient, the expression level of MsCHLG was significantly correlated with both plant height and yield. The findings suggest that MsCHLG transcriptional level might be useful for preliminary prediction of alfalfa yield at early stage, and CHLG may serve as a candidate gene to improve yield of legume forages by breeding.

Abstract:Racomitrium canescens is a bryophyte with extremely strong desiccation tolerance. The gene RcPLD from R. canescens was annotated coding a phospholipase D protein performed significant expression responses in the desiccation and rehydration processes, and supposed maybe participated in the strong desiccationtolerance function of R. canescens. In this study, the cloned coding sequence of RcPLD was used for constructing the overexpression transgenic Arabidopsis thaliana lines rcpldoe, the mechanism of the drought resistance in A. thaliana enhanced by RcPLD was preliminary analyzed by determining the drought stress tolerance and related physiological and biochemical indexes. The results showed: (1) the cloned coding sequence of RcPLD was used for constructing plant overexpression vector, the RcPLD overexpression transgenic A. thaliana lines, rcpldoe, were successfully constructed, and many T₃ generation homozygote rcpldoe lines were obtained. (2) Under normal condition, T₃ generation homozygote rcpldoe lines performed smaller size, longer vegetative period, delayed bolting, and slower aging of rosette leaves comparing with wildtype plants; under the condition of drought treatments, rcpldoe plants performed significantly better droughttolerance than the wildtype A. thaliana. (3) In the process of drought treatments, it was found the water loss rate was lowered in rcpldoe plants, damage on membrane integrity and inhibition of photosynthesis maybe decreased to a certain extent, but little was affected on the content of osmotic regulation substance. According to the research, under the condition of drought stress, water loss and photosynthesis inhibition in the rosette leaves of rcpldoe plants were decreased, then performed the drought tolerance which was stronger than the wildtype A. thaliana. This laid research foundations for further researching more functions of RcPLD and discovering more droughtresistance function related genes in R. canescens.

Abstract:The Arabidopsis ABI5 subfamily transcription factors AtDPBFs (DC3 promoter binding factors)/ABFs (ABRE binding factors) are composed of 9 highly homologous members, which are involved in seed maturation and dormancy, flowering time, root growth, ABA signal transduction and stress responses. This study used the qRTPCR method to analyze the relative mRNA content changes of 9 genes of ABI5 subfamily in different tissues and growth stages, and the response to ABA, high salt, hypertonicity and low temperature in seedling stages in order to clarify the similarities and differences of the biological functions of the nine genes in Arabidopsis. The results showed that: (1) 6 genes were expressed significantly and abundantly when Arabidopsis seeds just germinated compared to 5dayold seedlings; during the vegetative growth stage, the signal of At5G42910 gene was not detected, and the remaining 8 genes were detected as the seedlings grew. The relative content of mRNA of them were also increased correspondingly, and the increase of AtDPBF2 and AtDPBF4 was the largest; the relative content of ABF3 in 13dayold seedlings was the highest, about 59 times that of ABI5. (2) In the reproductive growth stage, 9 genes are expressed in a small amount in stems and roots, but in large amounts in flowers and seeds, and the expression level of ABI5 is the highest, which is about 122 times and 730 times of that in roots, respectively; ABF2 expression was the highest in leaves, and AtDPBF2 expression was the highest in fruit pods, The expression levels of the two were about 10 and 12 times higher than that in roots; At5G42910 was highly expressed in flowers and fruit pods, which was about 5 times of the expression in other organs. (3) After being treated with 100 mmol·L^-1 NaCl, 50 μmol·L^-1 sorbitol, and 10 μmol·L^-1 ABA for 8 days, the growth and development of seedlings in each treatment was significantly slower than that of the control, and the inhibitory effect was increased as the treatment concentration increased further. (4) After 13dayold Arabidopsis seedlings were treated with 20 μmol·L^-1 ABA, the relative mRNA contents of ABF1 and ABI5 genes increased the most, and the increase of both was close to 30 times; after 100 mmol·L^-1 sorbitol treatment, the relative mRNA contents of ABF1 and ABI5 genes increased the most, and the increase rates of the two were close to 120 times and 30 times, respectively; 100 mmol·L^-1 NaCl treatment resulted in the downregulation of most ABI5 subfamily genes, but only the ABF3 gene was significantly upregulated; low temperature treatment at 4 ℃ increased the relative mRNA contents of ABF1 and ABI5 genes by about 110 times and 25 times, respectively. These results indicate that the expression of 8 members of the ABI5 subfamily increases gradually during the vegetative growth stage, and the expression of each gene rises sharply after entering the reproductive growth stage, and they are tissue differences. 9 genes are expressed in large quantities in flowers and seeds, but low in roots and stems. ABFs genes in leaves play a major role, and ABI5 and AtDPBF2 genes play a major role in seed formation and maturation; in response to abiotic stress, ABF1 and ABI5 mainly respond to ABA and osmotic stress, and ABF3 mainly responds to salt stress. In addition to ABF1, ABI5 also plays an important role in response to cold stress. It is speculated that At5G42910 gene plays an important role in seed formation and maturation.

Abstract:To reveal the function of the maize transcription factor KNOX, this study used the bioinformatics method to identify the KNOX family members at the maize genome level and analyzed the expression profile of family gene response to stress and the tissuespecific. The results showed that: (1) there were 22 ZmKNOX genes in the maize genome named ZmKNOX1ZmKNOX22 according to their positions on the chromosome. The subcellular localization prediction of coding proteins showed that all the other family proteins located in the nucleus, except ZmKNOX5, ZmKNOX11, ZmKNOX12, and ZmKNOX15, found in mitochondria and ZmKNOX7 in the cytoplasm. The phylogenetic tree analysis showed that most ZmKNOX and sorghum were clustered in the same branch, indicating that the phylogenetic relationship between the two species was close. There was a specific correlation between the gene structure and the protein evolutionary classification. (2) The tissue expression profile analysis of the whole growth period showed that ZmKNOX had different expression patterns. The expression patterns of the genes during the growth period were correlated with the evolutionary classification of proteins. ZmKNOX13, ZmKNOX20, ZmKNOX1, and ZmKNOX21 were constitutively high in the whole growth period, while ZmKNOX3, ZmKNOX5, ZmKNOX6, and ZmKNOX14 were constitutively low in the whole growth period. ZmKNOX4, ZmKNOX8, ZmKNOX9, and ZmKNOX1719 expressed in certain stages and tissues of plant growth and development, including the embryo, seed germination stage, germ sheath, shoot tip, shoot internode, apical meristem, and inflorescence. Further coexpression analysis of the growth period data showed that the module in which ZmKNOX13 was closely related to the biological process of ubiquitination. (3) Eight ZmKNOX family genes showed different response patterns under salt, cold, heat, and UV treatments, while the gene expression levels did not change significantly. Among them, ZmKNOX6 was significantly upregulated under cold treatment, ZmKNOX14 was significantly downregulated under heat treatment, ZmKNOX13 was significantly upregulated, while ZmKNOX3 and ZmKNOX14 were significantly downregulated under salt stress. All the above three genes were low expression during the growth period. (4) The sequencing data analysis showed that the expression patterns of upregulated ZmKNOX3 and ZmKNOX13 genes in leaves and downregulated ZmKNOX3, ZmKNOX6, and ZmKNOX17 genes in roots were the same under salt treatment. ZmKNOX3 was stable in leaves and roots at different treatment time points, but the expression patterns were opposite. These results showed that ZmKNOX family genes play an essential role in maize growth, development and stress response.

Abstract:In order to reveal the function of NAC gene in pepper, we cloned the fulllength gDNA sequence and cDNA sequence of CaNAC55 gene with pepper CM334 as the experimental material. Bioinformatics analysis showed that the full length of CaNAC55 gDNA was 4 164 bp, the full length of CaNAC55 cDNA and the complete open reading frame (ORF) were 1 299 bp, and the protein encoded by the gene was composed of 432 amino acid residues. The results of gene sequence alignment and homology analysis showed that CaNAC55 shared 99.87%, 93.37% and 92.62% homology with Capsicum annuum (XM016722474), Solanum lycopersicum (XM004241285) and Solanum tuberosum (XM006361027) respectively. Realtime fluorescence quantification showed that drought, heat shock and high salt could induce the expression of CaNAC55 gene and the expression of CaNAC55 gene reached the peak at 24 h, 24 h and 12 h after drought, high salt and heat shock treatment, which were 3.01, 20.92 and 8.84 times of the control, respectively. The relative expression of CaNAC55 gene in ABA treatment was significantly lower than that in control, indicating that the expression of CaNAC55 gene was inhibited by ABA. The results showed that the response of CaNAC55 transcription factor to different stresses was different. It was speculated that CaNAC55 gene might be an important regulator in response to stress in C. annuum.

Abstract:The goal of this study was to research the cyanobacterial diversity and distribution in algal crusts of Gurbantunggut Desert by the clone library method. In this paper, 10 representative algal crust soil samples were collected in different regions of the Gurbantunggut Desert, and the cyanobacterial 16S rRNA and psbA gene clone libraries were constructed and performed phylogenetic analysis. Moreover, the correlation of cyanobacterial diversity and abundance with environmental factors was analyzed to acquire the distribution characteristics and influencing factors of cyanobacteria. The results showed: (1) the cyanobacterial 16S rRNA gene belonged to 10 genera of 6 families (accounted for 94.85% of the total library) and an uncultured cyanobacteria by phylogenetic analysis. Oscillatoria and Microcoleus accounted for 42.54% and 37.16% of the library respectively, which were the dominant genus of cyanobacteria in Gurbantunggut desert. Only 4 genera of 4 families cyanobacteria were identified with the psbA gene by phylogenetic analysis, but the dominant genera were consistent with the former results. (2) The species of cyanobacteria in algal crusts were different from each other in the 10 sample sites, but Oscillatoria and Microcoleus were found in each sample site, which proved that they were the dominant genera in algal crusts of Gurbantunggut Desert. In addition, there were more cyanobacteria species in Gur2 and Gur17, and fewer cyanobacteria species in Gur3, Gur5 and Gur9. However, the relative geographical locations of Gur2, Gur3, Gur5 and Gur17 were relatively close, indicating that geographical location was not the main factor affecting the distribution of cyanobacteria. (3) Redundancy analysis results showed that microbial biomass nitrogen (MBN) and soil organic carbon (SOC) have the greatest impact on the diversity of cyanobacteria, followed by nitrate nitrogen (NO^-₃N), microbial biomass carbon (MBC). Total phosphorus (TP) and total potassium (TK) have the least impact. The research showed that the cyanobacteria diversity and physicochemical properties of the soil in different regions of the Gurbantunggut Desert are spatially heterogeneous. The algae crusts in the middle, south of the desert are the most nutritious and the diversity of cyanobacteria is higher, while the algae crusts in the east, west are poor in nutrition, and the cyanobacteria richness and diversity are lower.

Abstract:Baolia Kung et G. L. Chu was established on the basis of Baolia bracteata Kung et G. L. Chu described in 1978 from Diebu County on the border between Gansu and Sichuan provinces, China. However, its systematic position has not been resolved at the molecularlevel. This study analyzed the nuclear DNA (ITS) and chloroplast DNA (atpBrbcL, rbcL) markers of 48 species belonging to 32 genera (including Baolia) of the family Amaranthaceae, constructed the molecular phylogenetic trees of Amaranthaceae and discussed the biosystematic relationship of Baolia. The results indicate that: 1. Baolia is nested within the subfamily Chenopodioideae Burnett; 2. Corispermum L. and Baolia diverged from each other from the Late Oligocene to the Middle Miocene; 3. Corispermeae Moq. and Chenopodieae Dumort. have a close relationship.

Abstract:Tamarix ramosissima is one of the most widely distributed Tamarix species in extremely arid areas. It can inhabit sandy wasteland, arid salinealkali land, and salinealkali wetland, etc., and it plays an important role in maintaining the stability of a specific ecosystem and protecting the diversity of plant germplasm resources. In this study, by using 14 ESTSSR markers, we analyzed the genetic diversity and genetic structure of 12 natural T. ramosissima populations (191 individuals) in the Ejina wetlands of the Alxa area. It provides a theoretical basis for the management, protection, and utilization of Tamarix germplasm resources in the region. The results showed that: (1) a total of 79 alleles (N_a) were amplified from 14 ESTSSR markers. The average number of alleles per locus was 5.6, the average expected heterozygosity (H_e) was 0.55, the average observed heterozygosity (H_o) was 0.29, and the average polymorphism information content (PIC) was 0.51, indicating that the investigated populations had abundant information of genetic variation. (2) the average polymorphic loci ratio, the average Shannons information index (I), and the average fixed index (F) of the 12 T. ramosissima populations were 97.0%, 0.862, and 0.332, respectively, which indicated that the T. ramosissima populations in this area processed a high level of genetic diversity. (3) The mean inbreeding coefficient (F_is) within the populations was 0.366, and the average genetic differentiation coefficient (F_st) and gene flow (N_m) between the populations were 0.079 and 4.425, respectively. These results suggested that the genetic exchange between the populations existed widely, and the genetic variation within the investigated populations was significantly higher than that between populations. (4) The genetic structure analysis showed that the 12 T. ramosissima populations could be divided into four subpopulations, and the genetic distances between these populations were uncorrelated with their geographical distances (r=0.194, P=0.120). The present study identified that the investigated T. ramosissima populations had rich genetic diversity, while they all showed a certain degree of heterozygote deficiency and inbreeding, which had a potentially adverse effect on the longterm maintenance of genetic diversity of T. ramosissima in this area.

Abstract:In this test, the endodermis and Casparin strip of vegetative organs of five species of Equisetaceae were comparatively observed by paraffin section method. The morphological characteristics and distribution of two layers of endodermis and its Casparin strip were reported for the first time, and the various types of Casparin strip and their cooperative defense mechanisms with sclerenchyma were also discussed. The results showed that: (1) there was only one Casparin strip in the rhizomes and roots of five species of horsetail, and there were two Casparin strips in the aerial stems of four species of horsetail. (2) There were three types of Casparin strip in the vegetative organs of horsetails, namely, one Casparin strip on each of the two common endodermis, one Casparin strip on one scattered endodermis, and one Casparin strip on one common endodermis. (3) The rhizomes and roots of horsetails had developed sclerenchyma or dense epidermis. (4) There were complex endodermis cells in the outer endodermis of the aerial stem of Equisetum arvense L.. It was suggested that the number of Casparin strip of horsetails can not be used as a basis for classification. Although there was only one Casparin strip in the rhizomes and roots, there were developed sclerenchyma or (and) epidermis closely connected with them in the underground part. It is speculated that sclerenchyma or (and) epidermis may have the same function as Casparin strip. The defense ability of the three types of Casparin strip from strong to weak is as follows: Casparin strip on two common endodermis > Casparin strip on one scattered endodermis > Casparin strip on one common endodermis.

Abstract:In order to explore the physiological basis of the leaf color variation in Cymbidium hybrid, we used ‘Purple Element’ (K21) and its three new strains (K211，K212，K213) as materials to analyze the changes of leaf photosynthetic pigment content, chlorophyll synthesis precursor substance content, chlorophyll synthesisrelated enzyme activities and chlorophyll fluorescence parameter. Furthermore, their microstructure and ultrastructure were observed in this study. The results showed that: (1) the contents of chlorophyll a, chlorophyll b, carotenoid in the variegation leaves of three different strains were significantly lower than those in the corresponding green leaves. Compared with the corresponding green leaves, UrogenⅢ were accumulated in the variegation leaves of K211 and K212 and PBG were abundant in the variegation leaves of K213. The maximum photochemical efficiency of photosystem Ⅱ (F_v/F_m) and the actual photochemical efficiency ［Y(Ⅱ)］ in the variegation leaves of three different strains were significantly lower than those in the green leaves, while their photochemical quenching coefficient(qP)exhibited an inverse state. (2) In the comparison of the microstructure and the chloroplast ultrastructure, the cells in the variegation leaves contained less chloroplasts than that in the green leaves. Meanwhile, the mature degree of chloroplast in the variegation leaves was lower, even K213 presented a cavity structure. It is speculated that the inhibition of chlorophyll precursor synthesis, the underdevelopment of chloroplast structure and the decrease of chlorophyll content are the reasons for the formation of the leaf art in three new strains. This study preliminarily explained the possible reasons for the formation of the leaf art from the physiological and cellular level, which laid a theoretical foundation for further research on related molecular mechanisms and rational utilization of germplasm resources.

Abstract:This experiment used ‘Ershuizao’ as the material, detected dynamic changes in the contents of five auxins and their analogs, four cytokinins and abscisic acid in the inflorescence axis (EX), callus (CA), primary embryogenic callus (PC), late embryogenic callus (LC) and globular embryo (GE) stages of garlic by LCMS/MS, combined with the dynamic changes of genes expression related to hormone synthesis and signal transduction. The regulatory effects of the three types of hormones in garlic somatic embryogenesis was discussed. We hope to provide a theoretical basis for the hormone regulation of garlic somatic embryogenesis, and lay a foundation for further research on the molecular mechanism of plant somatic embryogenesis. The results showed: (1) during the garlic somatic embryogenesis, the contents of auxin and its analogs all increased first and decreased later, reaching the highest in the PC stage and the lowest in the GE stage. The contents of N6isopentenyladenine(IP), transzeatin(tZ), and ABA were the highest in the EX stage, and these contents in the other four stages were significantly lower than that in the EX stage, while the content of ciszeatin(cZ) was higher in the CA and PC stages and the lowest in the GE stage. (2) In the PC stage, the expression of the IAA synthesis genes AsYUCCA1, AsTA1, and the extraauxin transport gene AsABCB1 increased. In the LC stage, the expression of auxin transportrelated gene AsAUX1 increased. the expression of auxin response genes AsARF1 and AsARF2 decreased. The expression of the cZ synthesis genes AsLOG1 was the highest in the CA stage. The expression of classifier transportrelated gene AsENT2 and signal transductionrelated genes AsORRA1 and AsORRA2 were the highest in the PC stage. (3) In the last four stages of garlic somatic embryogenesis, the expression of the ABA synthesis ratelimiting enzyme genes AsNCED1 and AsNCED2 were significantly lower than those in the EX stage. The expression of ABA signal transductionrelated genes AsPP2C increased in PC stage, AsABI1 increased in LC stage, and AsPYL1 increased in GE stage. This study suggest that: during garlic somatic embryogenesis, the accumulation of indole3carbaldehyde (ICAld), indole3butyric acid (IBA), and cZ can promote the formation of garlic callus. High levels of auxin and its analogs and low levels of IP and tZ can help the formation of garlic primary embryogenic callus, Low levels of auxin and its analogs, CTK, and ABA may be more conducive to the formation of garlic globular embryo (GE). Hormone synthesisrelated genes regulate the changes in endogenous hormone content, and hormone signal transductionrelated genes were involved in the occurrence of garlic somatic embryos.

Abstract:The seeds of cotton ‘Dalingmian No.69’ were used as the material in the pot experiment. We inoculated two species of arbuscular mycorrhizal fungi (AMF) including Rhizophagus intraradices (RI) and Funneliformis mosseae (FM) into the cotton roots respectively, in order to investigate the effects of AMF on cotton growth, root characteristics, cell membrane permeability, antioxidant enzyme activities and the accumulation and transfer of arsenic in cotton under different soil arsenic concentrations (0, 100, 200 mg/kg). It provided the theoretical basis for the reasonable application of AMF in the remediation of arsenic contaminated soil. The results showed that: (1) cotton growth, root development, root activity, antioxidant system (SOD, POD, CAT) and osmotic regulation system (soluble sugar, soluble protein, proline) were inhibited with the aggravation of arsenic stress. (2) Inoculating RI or FM significantly increased the plant height, biomass, rootshoot ratio and root activity of cotton. The arsenic content of the aboveground and underground parts and transfer coefficient of cotton were reduced. The root morphological indexes (such as total root length, root surface area, root volume, root tip number and root branch number) were also enhanced by RI or FM inoculation. The root length percentage of 0-0.2 mm diameter class was decreased, but the root length percentage of 0.5-1.0 mm and >1.0 mm diameter class were increased. With RI or FM inoculation increased, the contents of osmotic regulatory substances (such as soluble sugar, soluble protein and proline) and the activities of antioxidant enzymes (such as SOD, POD and CAT) in the cotton leaves and roots at different levels. The relative conductivity and malondialdehyde(MDA) content were decreased by RI or FM inoculation, and the effects of F. mosseae inoculation was greater than that of R. intraradices inoculation. It was concluded that AMF inoculation reduce arsenic toxicity to cotton, and enhance the tolerance of cotton under soil arsenic stress by promoting cotton growth and root development, reducing arsenic concentration in cotton, inhibiting its transfer to the ground, and activating antioxidant system and osmotic regulation system, and the inoculation effects of F. mosseae was better than that of R. intraradices.

Abstract:To reveal the effects of salinealkali stress on Toona sinensis seedlings, we treated the potted 1yearold seedlings of _{Toona sinensis} with three alkali levels, A_Ⅰ (pH=7.16), A_Ⅱ (pH=8.47), A_Ⅲ (pH=9.91), and four salt concentrations, S₅₀(50 mmol/L), S₁₀₀(100 mmol/L), S₁₅₀(150 mmol/L), S₂₀₀(200 mmol/L). The photosynthetic parameters, chlorophyll content, membrane damage degree, protective enzyme activity and osmotic regulation substance content under different treatments were examined to provide theoretical basis for developing cultivation of Toona sinensis on saltalkali lands. The results showed that: (1) under A_Ⅰ S₅₀ and A_Ⅱ S₁₀₀ treatments, the aboveground part of Toona sinensis seedlings grew well. (2) With the increases of salt and alkali stress concentration, net photosynthetic rate, transpiration rate, stomatal conductance and chlorophyll content of Toona sinensis leaves were decreased, while the intercellular carbon dioxide concentration appeared increasing. Under the salt concentration of S₅₀ and S₁₀₀, the photosynthetic index of Toona sinensis seedlings treated with A_Ⅰ alkali level did not show significant differences from that of the control (P > 0.05), while the photosynthetic efficiency of seedling leaves decreased significantly under A_Ⅱ and A_Ⅲ levels. Under the salt concentrations of S₁₅₀ and S₂₀₀, each level of alkali treatment significantly inhibited the photosynthetic efficiency in leaves. (3) With the increased salinealkali stress, the relative conductivity, the content of malondialdehyde and the content of proline increased, while the SOD activity, the contents of soluble protein and soluble sugar demonstrated early increase and late decrease. So, the seedlings of Toona sinensis were more sensitive to alkali stress than salt stress, and soil pH is an important factor affecting seedling growth of Toona sinensis. Salinealkali stress significantly inhibited the leaf photosynthesis of Toona sinensis seedlings. However, Toona sinensis can adapt to the salinealkali stress environment by regulating the antioxidant system and osmotic regulation substances, so that it has a certain tolerance to salinealkali conditions.

Abstract:In this study, we used an opentop chamber method to control the environmental CO₂ concentration. Environmental CO₂ concentration (Ca, 390 μmol·mol^-1) and elevated CO₂ concentration (Ce, 700 μmol·mol^-1) were set from 2018 to 2019. The effects of CO₂ concentration increase on the activities of key enzymes of photosynthetic carbon assimilation, net photosynthetic rate and grain yield of functional leaves of maize and peanut were investigated, and the mechanism of the effects of CO₂ concentration increase on the photosynthesis of maize and peanut intercropping system was clarified. It provides a theoretical basis for high yield and high efficiency of maize and peanut intercropping in the future CO₂ concentration increasing environment. The results indicate that: (1) compared with Ca, the activities of PEPC, PPDK, NADPMDH, Rubisco, GAPDH and Ru5PK in functional leaves of intercropping maize under the condition of Ce were increased. In particular, PEPC, NADPMDH, and PPDK at 43 days after seedling, Rubisco, GAPDH and Ru5PK 59 days after seedling reached a significant level of difference. Under the condition of Ce, phosphorus application has a positive regulatory effect on it. (2) The activities of Rubisco, GAPDH, Ru5PK and FBPase in functional leaves of intercropping peanuts increased by Ce. At 43 days after seedling and 59 days after seedling, the difference reached a significant level. Phosphorus application significantly improved the activities of Rubisco and FBPase of intercropping peanut under the condition of Ce. (3) The net photosynthetic rate of intercropping maize and intercropping peanut increased significantly under the treatment of Ce. The yield of intercropping maize, intercropping peanut and intercropping system increased by 4.4%-52.0%, 10.3%-24.0%, and 5.7%-47.0%, respectively, all reached significant different level. It indicted that Ce could enhance the grain yield of maize and peanut, the key lies in the improvement of enzyme activities of PEPC, PPDK, Rubisco, GAPDH, Ru5PK and Ru5PK of intercropping maize, as well as the Rubisco, GAPDH, Ru5PK and FBPase of intercropping peanut, to strengthen the carboxylation of CO₂ fixation ability, thus improve the photosynthetic rate of intercropping maize and intercropping peanut. Phosphorus application has a positive regulatory effect on them.

Abstract:In this study, the species and quantity of plants in the water source areas of Mountain Kalamaili Nature Reserve were counted through quadrats survey. TWINSPAN and DCA were used for quantitative classification and ordination of plant communities, the relationship between diversity index and soil physical and chemical properties of typical water source areas were analyzed by CCA. The results showed that: (1) according to the investigation of 32 typical water sources, there are 53 species belonging to 41 genera, 15 families of plants was statistically obtained. (2) Community classification showed there are 7 communities, Ass. Halimodendron halodendron, Ass. Calligonum mongolicumEphedra distachya, Ass. Nitraria schoberi+Tamarix chinensisEphedra distachya+Aristida pennata, Ass. Achnatherum splendens+Seriphidium teraealbae, Ass. Kalidium foliatum, Ass. Nitraria schoberi, Ass. Tamarix chinensis+Kalidium foliatumAchnatherum splendens. (3) It was found that organic matter and total nitrogen have great influence on the distribution of plant communities. It is considered that the typical water source area is an important functional area, it also has important link to maintain the ecological balance of Mountain Kalamaili Nature Reserve.

Abstract:Based on the tree species of forest community in Caohai National Nature Reserve, the forest was divided into four types: Pinus yunnanensis forest, Pinus yunnanensisAlnus cremastogyne forest, Alnus cremastogynePopulus yunnanensis forest, Alnus cremastogynePinus armandii forest. The age structure, survival curve and static life table of the dominant tree species in different communities were analyzed by using the method of space instead of time, and the development trend of the dominant tree species in four communities was predicted by using the time prediction model. The species diversity of the community was analyzed to provide theoretical basis for forest protection and sustainable management in the study area. The results showed that: (1) the diameter structure of dominant tree species of Pinus yunnanensis forests and Pinus yunnanensisAlnus cremastogyne forests showed a partial normal distribution, and the decline trend was obvious, while Alnus cremastogynePopulus yunnanensis forest and Alnus cremastogynePinus armandii forest showed an inverted “J” type, and the decline trend was relatively weak. (2) The analysis of static life table and survival curve showed that different forest communities in the study area were unstable, and the survival curve deviated from Deevey III curve in different degrees. (3) The time series analysis showed that the number of the population increased after the second, fourth and sixth instars in the study area, but the number of middle and young age individuals decreased, and the number of old age individuals increased first and then decreased, the population will inevitably decline. (4) There are 83 species belonging to 70 genera and 35 families, including 29 species belonging to 23 genera and 17 families of shrub layer and 54 species belonging to 48 genera and 21 families of herb layer. The species richness index (S) was herb layer>shrub layer, and the Pielou index (J_sw) was shrub layer > herb layer in three types of forest community, the Alnus cremastogynePinus armandii forest showed the opposite trend, and there were obvious differences in species diversity.

Abstract:Agrobacteriummediated transient gene expression has become an effective method for studying gene function and producing active proteins due to its simple operation, high reproducibility and low experimental cost. In this study, the transient expression of the reporter gene GFP in the leaves of five Chinese herbal herbs ［Glycyrrhiza uralensis Fisch., Scutellaria baicalensis Georgi, _{Astragalus membranaceus} var. mongholicus (Bge.) Hsiao, Rheum officinale Baill., Isatis tinctoria L.］ was conducted by means of leaf osmotic method, which was mediated by nonviral (vector I), viral binary vector (vector Ⅱ) and two kinds of Agrobacterium tumefacients (EHA105, LBA4404). The factors affecting the expression were analyzed in order to identify the suitable materials for the application of transient expression technology in Chinese medicinal materials. The results showed that: (1) the transient transformation efficiency of Agrobacterium tumefaciens in the leaves of five Chinese herbal medicines was affected by vectors, strains and plant species types. (2) Among the five selected Chinese herbal plants, compared with the strains without transformation vector, when the OD₆₀₀ of Agrobacterium resuspend was 0.8 and the leaves were infected for 5-7 days, the fluorescence intensity of EHA105 strain containing nonviral binary vector was the highest in Glycyrrhiza uralensis Fisch. leaves, followed by Rheum officinale Baill.. The strain LBA4404 containing the virustype binary vector had the highest fluorescence expression of GFP in the leaves of Scutellaria baicalensis Georgi. Fluorescence or almost no fluorescent protein expression was detected in the leaves of Glycyrrhiza uralensis Fisch. and Astragalus membranaceus var. mongholicus (Bge.) Hsiao membranaceus infected by different bacterial fluids containing different vectors, that is, they were not diffused to the surrounding areas. Weak fluorescence or no fluorescence intensity was detected in the leaves of Isatis tinctoria L.. The results showed that the leaves of Glycyrrhiza uralensis Fisch. and Scutellaria baicalensis Georgi could be used as materials for Agrobacteriummediated transient gene expression.

Abstract:Liparis petraea is reported from China for the first time. The detailed morphological description and photos were also provided. This species is similar to L. nervosa, it can be distinguished by silvergraygreen leaves, flat leaf surface, short cylindrical projections of the callus at the base of the lip and plants usually have bulbil. The individuals in Liparis petraea population are gathered, which is related to their bulbil propagation mode.

Abstract:This study identifies one diatom species as Neidium beatyi after examining the specimens collected from East Dongting Lake National Nature Reserve by using light and scanning electric microscopy. The observation results demonstrate that N. beatyi possesses the following diagnostic features: (1) linearelliptic to lanceolate valve outline; (2) 3-5 longitudinal lines along two valve margins; (3) Two proximal raphe ends deflected in opposite directions, distal raphe ends forming forked two fissures and triangular apical flap present at each apex; (4) Striae 16-18/10 μm and areolae 14-18/10 μm; (5) 4-7 renilimbi surrounded each internal opening of some areolae. The study results are consistent with the morphological characteristics and quantitative characters of the type population of N. beatyi, hence it is confirmed to be N. beatyi; and add a new geographical distribution region of N. beatyi — Dongting Lake, China.