Abstract:In this study, the PAL genes of three Dracaena (D.cochinchinensis, D. cambodiana and ‘Aizong’) plants were cloned by homologous cloning using the DNA and total RNA. Bioinformatics of PAL gene were analyzed with DNAMAN and MEGA7 software. The purpose of this study is to explore the molecular identification methods of three Dracaena plants, and provide a theoretical basis for the identification of different Dragons blood sources. The result show that: (1) three 718 bp PAL gene segments were obtained from D.cochinchinensis, D. cambodiana and ‘Aizong’, respectively. The homology of this 3 PAL genes was 99.69%, and just only 5 base mutations in base sequence. Phylogenetic analysis showed that the PAL gene of three Dracaena plants clustered with Liliaceae plants. (2) PAL gene was expressed in roots, stems and leaves of three Dracaena plants by RTPCR analysis. The difference of PAL gene expression in different tissues of Dracaena plants is small, and higher in ‘Aizong’ and lower in D.cochinchinensis and D. cambodiana. (3) Gene sequencing showed that PAL gene sequences were completely consistent in the same species, and just only 5 base mutations among three Dracaena plants. The PAL genes of three Dracaena plants are highly conserved. (4) Molecular identification method for three Dracaena plants was established based on the mutation site. Further molecular identification results indicate that GCGGG base site for D.cochinchinensis, CTGGC for D. cambodiana and GTTTG for ‘Aizong’. The research of molecular identification method is beneficial to the traceability and quality control of dragon’s blood.

Abstract:FT (Flowering Locus T) and its homologous gene were considered to be important genes which related to plants blossom and flower development. To better study the function of the FT homologous gene and flowering mechanism of Oncidium ‘Jinhui’, we isolated the FT homologous gene named OnFT and its GenBank accession number was MK967676 on the basis of transcriptome sequencing results in this study. OnFT contains a 537 bp open reading frame which encoding 178 amino acids. Bioinformatic analysis showed that the molecular weight of OnFT protein was 19.99 kD and this protein might be a unstable hydrophilic protein. Besides, the OnFT protein belonged to the PEBP family. The phylogenetic analysis showed that Oncidium was closely related to Phalaenopsis equestris from Orchidaceae. qRTPCR results indicated that the relative expression of OnFT gene were different in four tissues, with the highest expression was in flowers and almost no expressed in root. The expression level of OnFT gene in young flower buds was low and increased gradually during flower maturation. The expression of OnFT gene in leaves and pseudobulbs increased first and then decreased with the growth of maturity, highly expressed in leaves of middle seedling stage and pseudobulbs of budding stage.

Abstract:Glycosyltransferase can maintain the hormone balance in plants and widely participate in plant growth and development and stress response. PhUGT74E2, the homologous gene of UGT74E2 and its promoter sequence were cloned from petunia (Petunia hybrida var. Mitchel diploid). The sequence characteristics and protein structure characteristics were analyzed，to study the function of petunia UGT74E2, and laid a theoretical foundation for further research on the function of PhUGT74E2 and its molecular mechanism regulating the stress tolerance of petunia. The results showed: (1) the homologous gene of UGT74E2 was cloned from petunia (Petunia hybrida var. Mitchel diploid), named PhUGT74E2. (2) The full length of PhUGT74E2 was 1 986 bp, encoding 448 amino acids. The molecular formula of the protein was speculated to be C₂₂₇₈H₃₅₄₄N₅₈₆O₆₇₆S₁₈. The molecular weight was 50.53 kD and the isoelectric point was 5.18. No signal peptide and transmembrane domain were found in PhUGT74E2, and the protein was mainly located in chloroplast. The promoter sequence of 2 083 bp upstream of PhUGT74E2 gene was also cloned. The sequence contains abscisic acid, gibberellin, light and stress response elements. (3) Phylogenetic tree analysis showed that PhUGT74E2 had the same origin as other species, but was most closely related to tobacco NtUGT74E2. (4) Fluorescence quantitative PCR analysis showed that PhUGT74E2 gene was expressed in leaves, stems, roots, axil and apical. The expression level of PhUGT74E2 in axil was the highest, while the lowest in stems and roots. Both PEG6000 and NaCl treatments caused significant upregulation of PhUGT74E2 expression, and the expression level increased with time. The result indicated that PhUGT74E2 was involved in drought and salt stress response of petunia.

Abstract:ABF transcription factor (TF) is a basic leucine zipper protein, which involved in the growth, development and stress regulation in plants. In this study, a DcABF1 gene encoding ABF transcription factor was cloned from the carrot cv. ‘Junchuanhong’. The amino acid sequences, phylogenetic evolutionary relationships and physicochemical properties of DcABF1 were analyzed. The relative expression levels of the DcABF1 gene under different abiotic stress treatments were detected by quantitative realtime PCR. Sequence analysis indicated that the length of DcABF1 gene was 1293 bp and encoded 430 amino acids. The relative molecular mass of DcABF1 and theoretical pI were 104.96 kD and 4.850, respectively. The sequence alignment and phylogenetic analysis of the DcABF1 with the ABF TFs from other plants showed that the DcABF1 had the closest relationship with ABF from durian. The prediction of protein functional domain revealed that DcABF1 protein contained 28.84% αhelix and 56.05% random coil. There were some cis elements in the region of DcABF1 promoter. Quantitative realtime PCR analysis indicated that the DcABF1 gene had response to high temperature, low temperature, and salt stress treatments. The expression levels of DcABF1 were upregulated under salt treatment and peaked at 4 h. The expression level trend of DcABF1 under high salt treatment was first increased and then decreased. However, the expression of DcABF1 gene was downregulated compared with the control under drought treatment.

Abstract:We used the Chinses old garden rose Rosa chinensis ‘Old Blush’ as test material and designed the degenerate primers according to the conserved domains of the FT/TFL1 gene family members of Arabidopsis thaliana and Fragaria vesca. We cloned and sequenced the genomic DNA of R. chinensis ‘Old Blush’, and did the sequence alignment based on database sequence and double haploid genomic information. We obtained a total of 8 FT/TFL1 gene family sequences, and the 8 sequences were respectively annotated as 2 FT genes (RcFT1 and RcFT2), 1 BFT gene (RcBFT), 1 ATC gene (RcATC), 2 MFT genes (RcMFT1 and RcMFT2), and 2 PEBP genes (PEBP1 and PEBP2). Phylogenetic tree analysis divided these 8 genes into 3 subgroups. Structural analysis showed that the introns of 8 genes ranged from 1-5. qRTPCR expression analysis FT/TFL1 genes in different tissues of R. chinensis ‘Old Blush’ showed that RcFT1, RcPEBP, RcMFT1, RcMFT2 and RcBFT have the highest expression in leaves, followed in stem tips. RcFT2 had the highest expression level in stem tips and second in leaves. The expression of RcATC in stem tips was the highest, while lower in other tissues. RcPEBP gene has expression in root tissues, other genes have no expression in roots. In addition, the expression level of RcFT1 and RcFT2 in the leaves and stem tips of R. wichuriana ‘Basyes Thornless’ during the reproductive growth period were significantly higher than those during the vegetative growth period. We speculated that the R. chinensis ‘Old Blush’ with continuous flowering may have multiple flowering time (FT) gene loci, and FT may be used as a marker gene for reproductive transformation of rose.

Abstract:In this study， we isolated the flavonoid 3Oglucosyltransferase gene named HvtUF3GT from ‘Heilaoya’ grain， and obtained a 1 449 bp sequence. HvtUF3GT gene contained a 1 434 bp open reading frame (ORF)， encoding 478 amino acids. The theoretical isoelectric point (pI) was 5.45 and the predicted protein molecular weight was 52 912.58 Da. Protein sequence analysis showed that HvtUF3GT was a hydrophilic unstable acidic protein containing a typical 44 amino acids PSPG box at the Cterminus and a βαβαβ Rossmann folded structure in the spatial structure. HvtUF3GT was a member of UDP glycosyltransferase_GTB _type superfamilies. Phylogenetic tree analysis showed that HvtUF3GT and the glycosyltransferase of Trib. Triticeae such as Hordeum vulgare， Triticum urartu， Aegilops tauschii and Brachypodium distachyon were clustered into one branch. HvtUF3GT was closely related to H. vulgare， while far away from Oryza sativa (indica rice) and Oryza brachyantha belonging to Trib. Oryzeae. Semiquantitative and quantitative PCR results showed that the HvtUF3GT gene was not expressed in‘INB0N7’with blue grain coat and‘Kunlun 12’ with white grain coat，while the expression level in the grain of black and purple coat was‘Heilaoya’ (black grain)>‘Kunlun 17’ (black grain)> ‘Dazhangzi’ (purple grain)> ‘Nierumuzha’ (purple grain) during the late stage of grain grouting in Tibetan hulless barley. Thus，it was speculated that the HvtUF3GT gene could play an important role in the process of grain coloration in Tibetan hulless barley.

Abstract:In this paper, the morphological structure of leaf middle rib cells of 26 species of Pottiaceae from the retreating site of No. 1 Glacier in Tianshan Mountain, Xinjiang, China, was studied by optical microscopy and segregation method. The results showed that: (1) the length and width of the middle rib cells, the thickness of the cell wall, and the number of pit fields and the end and tail of the cells reflected that there were some difference of the function and water conduction of the costal cells in same genus and among different genera. (2) The end tail of the middle rib cells and the wavy structure of the cell wall could strengthen the connection between cells and improve the mechanical fixation and supporting function. (3) In different habitats, the number of pits on the side wall of the middle rib cells could effectively control the speed of water diversion and material exchange. which might be the positive response of bryophytes in glacier areas to harsh habitats, and had certain ecological and taxonomic significance.

Abstract:In order to explore the effects of high temperature stress on tomato seedling growth and flower bud differentiation, we subjected ‘Zhongza 9’ tomato seedlings to high temperature treatments with 37 ℃/27 ℃ (day/night) when it grew to the critical point of flower bud differentiation, 25 ℃/15 ℃ (day/night) was set as control. The indicators related to the growth and flower bud differentiation of tomato seedlings were determined. The results showed that the plant height and internode length of tomato seedlings were significantly longer than that of the control from the third day of high temperature stress, and the stem diameter was significantly smaller than that of the control, that is, the plants appeared to be long. The leaf area and root surface area of tomato treated with high temperature were always significantly lower than that of normal temperature control, while the root volume, total root length and number of roots were significantly lower than that of control from the 3rd day. The flower bud differentiation process at high temperature treatment accelerated significantly from the 1st day, and the number of flower bud differentiation decreased significantly on the 9th day of high temperature treatment, while the flower bud size was larger than that of control 5 days before high temperature treatment, and the flower bud size of the high temperature treated plant was significantly lower from the 7th day. This study clarified that high temperature inhibited the vegetative growth of tomato seedlings, accelerated the flower bud differentiation process, reduced the number of flower bud differentiation, and reduced the size of flower buds, eventually leading to a decrease in yield.

Abstract:The threeyearold delayed cultivation of Red Globe grape was used as material. At the later stage of growth, soil water content was controlled at 0.20 (T₁), 0.25 (T₂) and 0.30 m³·m^-3 (T₃). The common management methods of fruit growers were used as control (CK). The changes of water transport structure and water consumption of fruits were studied by means of slicing and field stem flow measurements during fruit ripening. The results showed that: (1) at the early stage of grape fruit color change, the xylem structure of the fruit stalk vascular bundle was intact and the pipe wall was clearly visible. In the middle stage of fruit color change, the wall of the xylem part of the fruit stalk become blurred, the cross sectional area of the central vascular bundle of the fruit brush in the middle stage was smaller than that in the early stage. In the later stage, the guide tube wall of fruit brush and fruit stem xylem were blurred and broken. (2) When the soluble solids content of grape fruit was 7%, the epidermal cells of fruit stalk were closely arranged and the intercellular space was small, and the vascular bundle of fruit brush were clearly visible. When the soluble solids content reached 11%, the number of central vascular bundles of fruit brush was larger than that of ovule vascular bundles, and the distribution was different. When soluble solids content increased to 15%, the fruit stalks were visible.Epidermal cells arranged loosely, epidermal cells elongated, some cells ruptured, and the central vascular bundle and ovule vascular bundle of fruit brush collapsed. (3) On September 11, the stem sap flow of different soil moisture treatments(CK, T₁, T₂ and T₃) reached the maximum, with the peak values of 3.51, 3.95, 4.37 and 4.59 d·L^-1, respectively. In the middle stage of grape color change, stem sap flow of T₁ was significantly lower than that of T₂ and T₃ (P < 0.05) under the influence of low temperature, but there was no significant difference between T₁ and CK. From October 15 to October 26, there was no obvious extreme low temperature, and the sap flow rate of the trees decreased among different treatments. With the continuous decrease of temperature in late November, the sap flow rate of each treatment decreased rapidly. It was found that the excessive soil moisture resulted in the decrease of stem sap flow at low temperature, and the increase of soil water supply could delay the accumulation of soluble solids in grapes, thus delaying the ripening of grapes.

Abstract:Tartary buckwheat (Fagopyrum tataricum) sprouts is a newly healthy food. Tartary buckwheat sprouts were treated with different photoperiod (0, 4, 8, 12, 16 and 20 h·d^-1). The biomass, the contents of chlorophyll and main nutritional components, and the expression level of genes related to flavonoids synthesis were measured in order to clarify the mechanism of the effect of different photoperiod on the quality of Tartary buckwheat sprouts, the results showed that: (1) with the increase of growth time of Tartary buckwheat sprouts, the biomass of Tartary buckwheat sprouts increased as a whole, and the growth state of sprouts was the best and the fresh weight was the highest at 16 h·d^-1 photoperiod. (2) The effects of different photoperiod on the contents of nutrients in Tartary buckwheat sprouts were different. The content of soluble sugar began to decrease gradually on the second day of germination, and the content after 10 days was only 13.5% and 14.5% of that on the second day. The anthocyanin content was the highest (2.16 mg·g^-1) when the photoperiod was 12 h·d^-1 on the second day of sprouting, and decreased after 4 to 10 days of different photoperiod treatments. Rutin is the main flavonoids in Tartary buckwheat sprouts. The content of rutin changed after different photoperiod treatments, and proper light was beneficial to its synthesis and accumulation. The highest content (59.60 mg·g^-1) was obtained when the photoperiod was 16 h·d^-1 on the 4th day of treatment. (3) qRTPCR analysis showed that the expression of flavonoids synthesis related genes in Tartary buckwheat sprouts treated with different photoperiod was the highest on the second day, and decreased with the growth cycle. However, the expression of the key enzyme gene FtFLS1 and the anthocyanin branch gene FtDFR2 increased, and showed strong lightinduced characteristics. The results showed that photoperiod had a great effect on the biomass of Tartary buckwheat sprouts, darkness was beneficial to Hypocotyl elongation, and long photoperiod (16 h·d^-1) was beneficial to the increase of fresh weight. During the germination of Tartary buckwheat, the contents of soluble sugar, anthocyanin and rutin in Tartary buckwheat sprouts decreased as a whole, and the contents of soluble sugar and anthocyanin were the highest on the second day when the photoperiod was 16 h·d^-1. The content of rutin was the highest on the 4th day after treatment when the photoperiod was 16 h·d^-1. It was suggested that Tartary buckwheat sprouts should be fed at 16 h·d^-1 for 4 days.

Abstract:The gas exchange and chlorophyll fluorescence parameters of lanceolate, oval and serrated broadoval leaves of Populus euphratica in Tarim basis were measured with chlorophyll fluorometer (PAM2100) and LI6400 Portable Photosynthesis System. The characteristics of solar radiation utilization, energy allocation and dissipation in three different leaf shapes of P.euphratica were analyzed by comparing the differences in photosynthetic parameters, in order to elucidate the ecophysiological adaptation mechanisms. The result showed that: (1) under strong solar radiation of desert region, the net photosynthetic rate (P_n), PSⅡ effective, actual photochemical quantum efficiency (F_v′/F_m′ and Φ_PSⅡ) and photochemical quenching coefficient (qP) decreased, and excitation pressure (1qP), relative limitation of photosynthetic function (L_PFD) increased obviously, and F_v′/F_m′, Φ_PSⅡ, qP, energy of PSⅡ photochemistry transport (P) could go to near the mining level, which indicated that strong solar radiation could cause the photoinhibition of photosynthesis. However, this constituted reversible destruction to PSⅡ reaction center in three heteromorphic leaves, their PSⅡ function downregulation were an adaptation to avoid strong solar radiation damage. (2) Three typical heteromorphic leaves of P.euphratica taken different ways to adapt strong solar radiation in desert area. The oval leaves improved F_v′/F_m′, Φ_PSⅡ, P to maintain higher photosynthetic capacity, in order to dissipate excess light energy and reduce the effects of excess excitation energy on photosynthetic apparatus. The serrated broadoval leaves maintained high electron transport rate (ETR) to relieve the reduced pressure of photosynthetic membrane and dissipate thermally to protect the photosynthetic apparatus avoiding light damage together, and maintain higher P_n. However, lanceolate leaves had weakness resistance for strong light, reduced F_v′/F_m′, Φ_PSⅡ and allocated more absorb light energy to dissipate more excess excitation energy, further to better adapt strong solar radiation and survive. (3) Stepwise regression analysis indicated that photosynthetic capacity of serrated broadoval leaves were mainly affected by ETR and NPQ, the oval leaves and lanceolate leaves were mainly affected by F_v′/F_m′, Φ_PSⅡ and NPQ, respectively. Overall, Three typical heteromorphic leaves of P.euphratica adopted different ecological strategies to adapt the desert environment with development.

Abstract:In this experiment, the‘Hongyan’strawberry fruit (Fragaria ananassa Duch.) was used as test material, and salicylhydroxamic acid (SHAM) was used to inhibit the mitochondrial alternative pathway to make the cytochrome pathway run alone. The mitochondrial extract was treated with electron transfer and oxidative phosphorylation coupling accelerators ［adenosine diphosphate (ADP) and succinic acid disodium salt (C4H₄Na₂O₄)］ and inhibitors ［2,4dinitrophenol (DNP) and sodium vanadate solution (NaVO₄)］. Under the condition of promoting and inhibiting respiratory metabolism, the changes of mitochondrial respiratory metabolism and ultra weak luminescence (UWL) and the relationship between them were compared and analyzed in strawberry fruit.The results showed that: (1) the mitochondria of strawberry fruit were treated with accelerator, the key enzymes activity of respiratory metabolism including succinate dehydrogenase (SDH), cytochrome oxidase (COX), ATP synthase (H⁺ATPase), respiration rate and adenosine triphosphate (ATP) content increased with the increase of concentration, and the intensity of UWL increased with the increase of concentration. The respiratory metabolic index and UWL intensity at each concentration were higher than those of the control. After treatment with inhibitor, the changes of respiratory metabolism indexes and UWL intensity were opposite to those of accelerator, and all of them were lower than those of the control. (2) The correlation analysis showed that all indexes of respiratory metabolism were positively correlated with UWL.The above results showed that the mitochondrial UWL intensity of strawberry fruit changed with the change of respiratory metabolism; the accelerator promoted the respiratory metabolism and led to the increase of UWL intensity; on the contrary, the inhibitor inhibited respiratory metabolism and led to the decrease of UWL intensity; It suggested that mitochondria was one of the organelles that produced UWL, and UWL was stimulated in the process of mitochondrial respiration and metabolism.

Abstract:The effects of different photoperiod treatments (6, 8, 10 and 14 h/d) on the plant growth, endogenous hormones contents, and sex differentiation of luffa (Luffa cylindrica Roem.) seedling were studied by artificial shading method, which will provide the theoretical basis for artificial light regulation of this plant species. The results showed that: (1) with the extension of the photoperiod, the plant biomass was increased gradually. The total Chl a+b contents, SOD, POD and CAT activities, soluble sugar, soluble protein and free amino contents were first increased, then decreased, and reached to maximum under the treatment of 10 h/d. (2) The GA₃, IAA, ZT contents of 8 and 10 h/d were lower than those of 6 and 14 h/d, the ABA contents were the contrary. (3) The 1^st female and male flowers of 10 h/d were the lowest, the number of female flowers and yield were the highest of all photoperiod treatments. Overall, 10 h/d photoperiod was more beneficial to the growth and cultivated health seedling of luffa.

Abstract:The study used seeds of Paeonia rockii treated with different concentrations of gibberellic acid (GA₃) to investigate the effects of rooting and the variation of nutritious substances, enzyme activity and endogenous hormones content during different rooting stages to provide a basis for clarifying the mechanism of seed germination. The results showed that: (1) GA₃ treatment could effectively promote the rooting of seeds. 300 mg/L GA₃ treatment was the best to promote rooting with the highest rooting rates of 71.00% and made the first seed rooting time shorter 14.67 days than control treatment. (2) Compared with the control, GA₃ treatment could promote hydrolysis of the starch, soluble sugar accumulation and soluble protein consumption of seeds in the first 15 days. It also could accelerate improvement of activity of peroxidase (POD) in the first 30 days. (3) During sand stratification process, abscisic acid (ABA) content decreased gradually, gibberellic acid (GA), zeatin riboside (ZR) and indole3acetic acid (IAA) contents increased first and then decreased. Compared with the control, GA₃ treatment could increase the contents of GA, ZR and IAA which significantly improve dormancy breaking. The study found that GA₃ treatment can regulate the contents of endogenous hormones, POD activity and the transformation of nutrients, thus seeds of Paeonia rockii can break dormancy and germinate in advance.

Abstract:To verify the response of different concentrations of 5aminolevulinic acid (ALA), we sprayed alfalfa (cv. Nongmu 806) seedlings with 15% PEG6000 and ALA with different concentrations (0, 5, 10, 15, 20, 25 mg·L^-1), and 1/2 Hogland nutrient solution was used as control. Then, the physiological, biochemical indexes and secondary metabolite of ‘Nongmu 806’ seedlings were determined. Results revealed that: (1) compared with the control, 15% PEG simulated drought stress reduced the contents of chlorophyll a, b, carotenoid and chlorophyll in alfalfa leaves, increased the content of osmotic adjustment substances and the activities of antioxidant enzymes. (2) After ALA and 15% PEG treatment, the contents of chlorophyll a, b, carotenoid and chlorophyll of alfalfa seedling leaves increased, the activities of CAT, POD, SOD and the contents of soluble protein, proline, flavonoids and saponins increased, whereas the contents of malondialdehyde, H₂O₂ and·OH decreased compared with 15% PEG treatment. The results showed that spraying ALA can effectively improve the tolerance of alfalfa to drought stress. However, different concentrations of ALA have different recovery effects on 15% PEG, and 10 mg·L^-1 ALA had the most significant effect.

Abstract:Taking ‘Heiqi No.1’ and wild Lycium ruthenicum Murr. as research subjects, we determined and analyzed their total phenolics, total anthocyanins. total tannins, individual anthocyanins and individual nonanthocyanin phenolic compounds. The results showed that: (1) the total phenolics, total anthocyanins and total tannins of ‘Heiqi No.1’were 14 250, 390 and 3 330 μg/g higher than those of wild L. ruthenicum. (2) There were 4 individual anthocyanins in ‘Heiqi No.1’ and wild L. ruthenicum, including 1 diglucoside, 2 coffee acylated glucosides, and 1 coumaryl glucoside. The 4 individual anthocyanins of ‘Heiqi No.1’ were all significantly higher than those of wild L. ruthenicum. The content of individual anthocyanins in ‘Heiqi No.1’ was 116.88% (5 672.8 μg/g) higher than that of wild L. ruthenicum. The content of malvidin3O(6caffeoyl)glucoside in ‘Heiqi No.1’ was 14.93 times than that in wild L. ruthenicum. (3) There were 29 individual nonanthocyanin phenolic compounds in ‘Heiqi No.1’ and wild L. ruthenicum, including 7 flavan3ols, 4 hydroxybenzoic acids, and 18 flavonols. And the content of protocatechuic acids was the highest. However, the content of individual nonanthocyanin phenolic compounds in ‘Heiqi No.1’ was 51.42%(2.71 μg/g) lower than that of wild L. ruthenicum.

Abstract:On the basis of a comprehensive survey of the artificial mixed forest of Cunninghamia lanceolata and Mytilaria laosensis in the Daqingshan Experimental Field in Guangxi, we selected a typical fixed plot of 90 m × 110 m by a typical method to measure the coordinates of the center of each standing tree. The scale of each plant is measured, includes the diameter, the height and the width of the tree. We analyzed the population dynamics of the mixed forests, the spatial distribution pattern of main woody plant populations and the interspecific association of main populations in order to explore the interactions between species in the artificial mixed forest of C. lanceolata and maintaining population stability and succession by using diameter class replace the age class and the Ripleys L(r) function of spatial point pattern. It provides a theoretical basis for tree species selection, spatial structure adjustment and tending management for subtropical mixed forests. The results showed that: (1) there were 49 species and 3 361 viable standing trees with a breast diameter of ≥1 cm in the plot, including the important values of seven species of C. lanceolata, Mytilaria laosensis, Evodia lepta, Castanopsis hystrix, Psychotria rubra, Ficus hispida, and Wendlandia uvariifolia. Of all are above 4%, which has a large advantage and is the main tree species of the forest. (2) All living stands (DBH≥1 cm) in the mixed forest of C. lancenlata and M. laosensis showed clustering distribution on the scale of 0-40 m, among which: saplings (1 cm≤DBH<5 cm) were on the scale of 0-40 m. The degree of aggregation is higher than that of all living trees in the community. Small trees (5 cm≤DBH<10 cm) are randomly distributed on the scale of 0-5 m, and the degree of aggregation is weak on the scale of 6-40 m, while large tree (DBH≥10 cm) exhibits a uniform distribution on a scale of less than 5 m and a random distribution on a scale of 5 to 40 m. (3) In addition to the random distribution of the seven old populations in the community, except for the M. laosensis and C. hystrix, the other populations are subject to aggregate distribution, and the degree of aggregation increases with the scale. (4) The large trees and the small trees in the plot are independent of each other, and there is a positive correlation between the small trees and the saplings, the large trees and the saplings in the research scale. (5) There is no correlation or negative correlation among the main populations (21 species pairs) in the study area, and only a small number of populations (5 pairs) are positively correlated, indicating that the stability of the structure of the artificial mixed forest of C. lanceolata and M. laosensis in the Daqingshan experimental field in Guangxi is weak, and it has not reached the top stage of community succession.

Abstract:Subalpine forests in Western Sichuan suffered from longterm continuous deforestation in the second half of the 20th century, and a series of secondary forests on logging land have been formed by natural restoration, which provides the good natural experimental site for studying the forest vegetation succession and structure. In this study, by using the method of replacing space with time, we analyzed the changes of dominant species composition along vegetation restoration and their influencing factors in Miyaluo of western Sichuan. Our results showed that: (1) a significant difference in soil nutrient was found among different succession stages. The content of soil total nitrogen, soil total phosphorus, soil available phosphorus and soil available nitrogen were the highest in coniferousbroadleaved mixed forest stage. Soil pH values among different restoration stages were 5.42-7.39. Soil organic carbon presented an exponential growth pattern along time. The mean soil C/N value was about 15 and only soil C/N in coniferous forest was 18.62. (2) We recorded 16 major arbor tree species in research area. The dominant species in coniferous forest were Picea asperata and Abies faxoniana. While Betula albosinensis and Acer davidii were the dominant species in broadleaved forest. The analysis of community similarity showed that there was a significant difference in the composition of dominant species in arbor layer along the different recovery stages (R_ANOSINM = 0.439, P <0.001). (3) The analysis of the multivariate regression tree revealed that the variations of dominant species in arbor stratum were mainly influenced by forest age, soil organic carbon (SOC) and total nitrogen (TN). The interspecific competition is the dominant factor affecting the difference of community composition in arbor layer before the 80 years of succession. However, environmental selection affects the tree species composition after 80 years. (4) The analysis of sequential tests showed that the variations of dominant trees species were primarily affected by soil TN, altitude, available phosphorus (AP) and SOC. The results can provide scientific basis for the restoration of degraded forests and secondary forest ecosystem management in the alpine region of western Sichuan.

Abstract:In this paper， herbaceous communities in the Loess Plateau were taken as research object， four vegetation belts from Yuyang， Yulin， Shaanxi to Fuxian， Yanan， Shaanxi were selected to measure species diversity and biomass of herbaceous communities， combined with the meteorological data of the last 20 years in the study area. The distribution characteristics of species diversity and biomass of herbaceous communities in the four vegetation belts and their response rules to precipitation changes were analyzed， so as to provide references for vegetation restoration and ecological construction of soil and water conservation in the Loess Plateau. The results showed that： (1) Margalef index， Pielou index and ShannonWiener index of herbaceous communities in the four vegetation belts were the smallest values in the grassdesert belt and the largest values in the forest belt. The values increased first and then decreased with the increase of annual average precipitation， and the maximum values all appeared in the forestgrass belt. (2) The order of aboveground， underground and total biomass is grassdesert belt< forest belt< grass belt< forestgrass belt. With the increase of annual average precipitation， they showed a trend of “single peak curve”， and the inflection points of the curves all appeared in forestgrass belt. There is a significantly positive correlation between underground/aboveground biomass and annual average precipitation.

Abstract:In the present study, we selected 54 natural Miscanthus lutarioriparius populations to study their geographical distribution pattern and phenotypic diversity. These selected populations evenly distributed in the naturally occurrence range of M. lutarioriparius across China. Their phenotypic traits were measured during the field investigation conducted at the end of 2017 growing seasons, including the plant height, stem diameter, pitch number, length of the longest stem, branch number, shoot density, dry weight per stem and dry matter yield. And the soil pH and soil fertility were also determined. The effects of soil factors on these phenotypic traits and correlations between these phenotypic traits were further studied. Results showed that: (1) eight phenotypic traits were significantly (P＜0.01) different between and within the 54 natural M. lutarioriparius populations, and the phenotypic variation mainly came from within the population. (2) There were significant correlations within these eight phenotypic traits. For example, the plant height positively correlated (P＜0.01) with the pitch number and stem diameter, while significantly negative correlations existed between the shoot density and the other phenotypic traits. Length of the longest stem only had significant correlations with the plant height. (3) Information of the eight phenotypic traits were summarized to four principal component factors, namely the yield factor, plant type factor, shoot density factor and longest stem factor. These four principal component factors could reflect 84.436% phenotypic information of the 54 natural populations. (4) The 54 natural M. lutarioriparius populations were clustered into two groups based on the cluster analysis of their phenotypic traits. The first group contained 23 populations naturally distributing at the lower reaches and the northeast of the Yangtze River. The second group contained 31 populations mainly from the Dongting Lake area, the middle reaches and the northwest of the Yangtze River. Plants in the second group generally had higher plant height and biomass yield, smaller shoot density, thicker stem than that from the first group. (5) The natural M. lutarioriparius populations mostly grow on the infertile soil with a nearly neutral pH. The soil organic matter content and available potassium content had the greatest influence on the plant height of M. lutarioriparius, which was suggested by their high direct path coefficients of 0.443 and 0.318, respectively. That was also true for their effect on the biomass yield with their direct path coefficients of 0.259 and 0.429, respectively.

Abstract:Molineria prainiana Deb (Hypoxidaceae), a species previously known from India and Butan, rencetly found growing under the moist forest in Yunnan Tongbiguan Provincial Nature Reserve, Dehong, Yunnan Province, China in 2019. It was characterized by rhizomatous herb up to 170 cm tall, blade 60-107 cm long, raceme elongated up to 30 cm long, densely tomentose, yellow flowers and ovary without beak belongs to the genus Molineria. Vouchers are kept in the Herbarium of Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences (HITBC).

Abstract:During a survey of freshwater diatoms from Shibadukeng stream in the Xianju National Park, Zhejiang Province, China, a newly recorded diatom, Encyonema ventricosum var. hankensis (Skvortzov) Rodionova & Pomazkina was recorded. Based on the application of light microscope (LM) and scanning electron microscope (SEM), E. ventricosum var. hankensis was identified and described here in details. The morphological differences between Zhejiang population and two Russia populations and other similar Encyonema species were compared. In addition, the habitat characteristics of Encyonema ventricosum var. hankensis in Shibadukeng stream were supplied in our paper. The results show that: (1) E. ventricosum var. hankensis valves strongly dorsiventral, dorsal margin broadly arched, ventral margin moderately undulant, apices capitate, deflected to the ventral margins. (2) E. ventricosum var. hankensis Zhengjiang population has a stigma on the dorsal side of the center area, while the Lake Khanka population and Lake Baikal population are no recorded. (3) E. ventricosum var. hankensis is found in Lake Khanka and Lake Baikal, and this is the first report from the freshwater in China.

Abstract:Moss peristome is located at the mouth of the capsule with complex structure, and it is derived from three layers of cell or cell wall of amphithecium. The function of peristome is mainly to dominate and protect spores dispersing, and also serves as an important basis for determining the phylogenetic status and classification of mosses. At present, the structural diversity, functional diversity and molecular biology of moss peristome are the weaknesses in China. This advances reviews the study of development, structure and function in moss peristome at home and abroad in recent years.