Abstract:The serine protease inhibitors (SPIs) are involved in regulating the balance of endogenous proteins by inhibiting the activities of target proteins and play an important role in plant development and defense mechanisms. In this study, the fulllength ApSPI gene was cloned from Agapanthus praecox ssp. orientalis by using RACE technology. The recombinant E.coli Transetta (pET32aApSPI) was constructed, and the abiotic stress tolerance of the recombinant bacteria was tested. The results showed that: (1) the ApSPI gene was comprised of 652 nucleotides with a 366 bp ORF encoding 122 amino acids. ApSPI was characterized as a Kazaltype serine proteinase inhibitor containing a Nterminal signal peptide and a single putative Kazaltype domain. (2) The optimal induction temperature, duration, and IPTG concentration were 37 ℃, 6 h, and 0.1 mmol·L^-1, respectively. The recombinant ApSPI was mainly expressed in the form of soluble. (3) Analysis of abiotic stress tolerance of the recombinant bacteria showed that the tolerance of recombinant bacteria Transetta (pET32aApSPI) to NaCl (200-400 mmol·L^-1), KCl (200-400 mmol·L^-1) and PEG6000 (5%) was significantly higher than that of the control strain Transetta (pET32a). In summary, overexpression of ApSPI enhanced the resistance of E. coli to salt and drought stress, which laid a foundation for further research on the role of ApSPI in plant stress resistance.

Abstract:To elucidate the biosynthetic pathways of potato terpenoids, we identified a terpene synthase gene named as StHcS from potato genome data. StHcS was successfully cloned from potato variety ‘Feurita’ with infection of Phytophthora infestans by RTPCR. Bioinformatics analysis, biochemical characterization and gene expression pattern analysis were conducted for StHcS. The results are as follows: (1) the coding sequence length of StHcS is 1 497 bp and it eventually encodes 498 amino acids with a molecular mass of 74.78 kD; (2) the encoded StHcS contains the conserved DDXXD catalytic motif, and exhibits the highest similarity to the hedycaryol synthase in Camellia maliflora; (3) in vitro assay and E. coli metabolic engineering experiments reveal that StHcS can react with trans farnesene pyrophosphate (FPP) to produce the sesquiterpenehedycaryol; (4) RTPCR analysis indicates that StHcS can be induced by infection of P. infestans in potato tubers and the highest expression was observed at 72 h post inoculation. Hedycaryol was also successfully detected in the infected potato tubers by GCMS analysis. The identification of StHcS biochemical function provides diversity for the studies regarding sesquiterpene synthase, and it is also the first hedycaryol synthase found in potato, which provides a reference for the analysis of potato terpene biosynthesis.

Abstract:DREB gene is called the main regulator of abiotic stress response. In order to explore the function of DREB in the stress resistance process of Dryopteris fragrans (L.) Schott, a perennial medicinal herb, this study cloned and analyzed the DfDREB gene with bioinformatics. The expression patterns of DfDREB gene under different hormones and stress treatments of drought, NaCl, high temperature and low temperature were studied by realtime quantitative polymerase chain reaction. The results showed that： (1) the DfDREB gene, with a total length of 1 203 bp, encodes 401 amino acids. The relative molecular mass is 43.66 kD and the isoelectric point is 6.13, which is a hydrophilic nonsecreted protein. This protein has an AP2 conserved domain and belongs to the AP2 family. (2) Realtime PCR analysis showed that DfDREB gene was expressed in the roots, petioles and leaves of D. fragrans, among which the highest expression was in the leaves and the lowest expression was in the roots. When SA, MeJA and ETH were treated, the expression of DfDREB was upregulated, and the expression reached the peak at 1 h. During ABA treatment, the relative expression of DfDREB was upregulated only at 12 and 24 h, and downregulated during the rest of the time. Under drought, NaCl and high temperature treatments, DfDREB expression was upregulated. The expression of DfDREB was significantly upregulated at 0.5 and 12 h under low temperature treatment, and there was no significant change at 1 to 6 h and 24 h. It shows that DfDREB can respond to hormone and abiotic stress treatments, and gene expression is induced by stress. The results provide a scientific basis for further study on the stress resistance mechanism of D. fragrans.

Abstract:In this study, the primers were designed based on the conserved sequences of other plant NBSLRR genes in GenBank. The fulllength cDNA (PbNBSLRR) sequence of NBSLRR gene in Picea balfouriana was cloned by RTPCR. Analysis of the information of PbNBSLRR and its encoding protein were carried out and the expression characteristics of the gene in spruce was studied. The results showed that: (1) PbNBSLRR gene is 2 616 bp with a 2 508 bp ORF, encoding 836 amino acids, which has the typical NBARC domain and LRR domain of NBSLRR resistance genes, and gene accession number is MK044348. (2) At the amino acids level, the similarity of the PbNBSLRR protein to the corresponding sequence in Picea sitchensis NBSLRR protein is 98%. Molecular evolution analysis further indicated that PbNBSLRR was closely related to the NBSLRR of P. sitchensis. (3) Quantitative realtime PCR analysis showed that the expression of NBSLRR was observed in all tissues of P. balfouriana, P. asperata, and P. likiangensis, and the highest expression level was found in the roots of P. balfouriana and P. asperata and the trunk phloem of P. likiangensis. In addition, the expression of NBSLRR was upregulated by infection with Lophodermium piceae. The highest expression of NBSLRR gene in P. balfouriana and P. asperata was found in May and P. likiangensis was found in Steptember (1.73fold, 2.11fold and 90.49fold higher than that in control, respectively), which indicated that the NBSLRR gene is involved in the defense response of the needle cast disease in spruce.

Abstract:Metal tolerant protein (MTP) maintains metal homeostasis in plants by absorbing and expelling metals from the cytoplasmic sol. In this study, we used a variety of bioinformatic methods to identify and analyze the TaMTP genes in the wheat genome, and qRTPCR to analyze the expression of TaMTP genes under the stress of various heavy metals, so as to provide theoretical basis for indepth study of the regulatory mechanism and stress resistance of this family of genes on the growth and development of wheat. The results showed that: (1) TaMTPs all had cationic Efferent family domain, and most members had zinc transporter dimeric domain. Phylogenetic and cluster analysis showed that TaMTP proteins were divided into seven groups: G1, G5, G6, G7, G8, G9 and G12. Analysis of gene structure and motif revealed that most TaMTP genes had relatively conservative exonintron arrangement and conserved motif composition. (2) Gene expression profile analysis of RNASEQ data showed that different TaMTP genes had their own unique expression mechanism, among which TaMTP11Bb and TaMTP11D had higher expression levels under abiotic stress, TaMTP11A, TaMTP11Bb, TaMTP11D, TaMTP113Ab, TaMTP113B and TaMTP113D had higher expression levels under biological stress. (3) qRTPCR analysis showed that when wheat was subjected to heavy metal stress of zinc (Zn), copper (Cu), cobalt (Co), cadmium (Cd), manganese (Mn) and iron (Fe), the expression levels of TaMTP11A、TaMTP84A、TaMTP84D、TaMTP113Aa and TaMTP113B were increased. The results showed that each metal ion could induce the expression of these TaMTP genes in roots and leaves. However, the expressions of TaMTP11A and TaMTP84A under Fe³⁺ and Cu²⁺ stress were completely opposite, and the expression levels of the two genes in wheat leaves and root tissues were low under Fe³⁺ stress. It was speculated that TaMTPs might be involved in the tolerance or transport of corresponding trace elements, but different TaMTP had different transport functions for different metals.

Abstract:Recovery the juvenile characteristics of mature wood by rejuvenation treatment is an important approach to improve the adventitious rooting capacity of difficulttoroot woody plants. However, the mechanism of rejuvenation is still unclear. In this study, rejuvenated and mature cuttings of walnuts were used as materials, DNA methylation pattern of both cuttings was detected at the genomewide level by methylation modificationdependent endonuclease sequencing technology (MethylRADSeq). And then, the expression level of genes which is related to differential methylation sites were analyzed. The results showed that： (1) rejuvenation treatment could significantly reduce the level of DNA methylation in walnut cuttings. (2) Functional enrichment analysis showed that genes related to differential methylation sites were mainly involved in brassinolide signal transduction, secondary metabolite biosynthesis and lignin biosynthesis. They participated in metabolic pathways such as photosynthesis, MAPK (Mitogenactivated protein kinase, MAPK) signaling pathway, fructose and mannose metabolism, cAMP (cyclic AMP, CAMP) signaling pathway and phenylpropane biosynthesis pathway. (3) qRTPCR analysis showed that key regulatory genes (NAC1, ARF5, ARF6 and WRKY22) had different expression patterns in rejuvenated and adult materials. It indicated that the rejuvenation treatment affected the expression of core regulatory genes of adventitious root formation, through reduced the genomic DNA methylation level in walnut cuttings. It may be an important regulatory pathway for rejuvenation to regulate adventitious root formation in walnut.

Abstract:Cytoplasmic male sterility (CMS) was one of the important ways to create hybrid by using heterosis in Brassica napus. The selection of restorer line and the study of restorer gene was helpful to improve the application value of CMS line. In this study, we used the cytoplasmic male sterile line 1193A and restorer line 15R1 of Brassica napus as parents to construct a hybrid pool of two extreme characters in F₂ population. The restorer gene was located and analyzed by BSAseq technology. The results showed that： (1) 33 883 nonsynonymous SNPs between 1193A and 15R1, and 7 996 nonsynonymous coding mutations between mixed pools were obtained . (2) The results of indel detection and annotation showed that there were 2 918 mutations between parents and 840 mutations between mixed pools. (3) Based on the correlation analysis of SNP and indel, the restorer gene was located in the 0-880000 region of C09 chromosome, with a total length of 880 kb. (4) Through the SNP and indel annotation of candidate regions, we found that there were 40 SNPs with nonsynonymous mutations between parents, 65 SNPs with nonsynonymous mutations between mixed pools, 7 indels with frame shifting mutations between parents and 11 indels with frame shifting mutations between mixed pools. The coding genes in the candidate region were annotated. The results showed that 162 genes were annotated, including 11 nonsynonymous mutations and 5 frame shifting mutations. These genes may be related to fertility restoration.

Abstract:Cushion plants are important elements in alpine subnivalbelt flora, which are recognized as the production of adaptive convergence to cold and extreme environment in alpine zone. In this study, the seeds of five cushion plants of Caryophyllaceae were chosen asexperimental materials. These seeds that collected from the alpine subnival belt in Xizang and Yunnan, germinated on wet filter papers. Roottipsquashmethod was used for cytological observation. The present study aims to accumulate karyological data for cushion plants in QinghaiTibet Plateau (QTP), and then further to provide the basis for the exploration on karyotypic evolution mechanism of special life form plants in extreme environment of QTP. The results showed that five species are all diploid, and their karyotype formulae were showed as followed: Arenaria densissima, 2n = 2x = 20m + 2sm, 2A; A. oreophila, 2n = 2x = 22m, 1A; A. polytrichoides, 2n = 2x = 20m + 2sm, 2A; A. smithiana, 2n = 2x = 20m + 2sm, 1A; Thylacospermum caespitosum, 2n = 2x = 18m + 4sm, 2A. The chromosome numbers of T. caespitosum is consistent with that of Arenaria subg. Dolophragma. The results provide the karyological evidence for the independence of the new clade composed by abovementioned two taxa in the molecular phylogeny framework of Caryophyllaceae. Moreover, we discussed the association between the evolutionary history of paleopolyploid speciation exhibited by five studied cushion plants and the uplift of QTP and its surrounding region during the Miocene period.

Abstract:Under artificial culture conditions, we observed the whole process of gametophyte development of Drynaria roosii Nakaike in Polypodiaceae by scanning electron microscopy in order to reveal some fine structures in different stages of the gametophyte in three dimensions, and provide the evidence for further supplement of classical morphological theory. The results were as follows: (1) two rhizoids of prothallium metrocytes were earliest and simultaneous formed in the process of spore germination. (2) Most rhizoids of the gametophyte of D. roosii were bulging and bifurcate with two cell walls, and the base of the rhizoids was round. (3) The trichomes extensively developed in venter and margin of prothallium, mastoid and acicular singlecelled trichome mixed together. (4) When the antheridia released sperms, the anterior and posterior dehiscence of the cover cells were different. (5) The cytomembrane which attached clastic materials, might be restrictive structure from the sperm to the antherozoid. (6) The disintegration process of ventral canal cells started from the membrane of archegonium opening. (7) It was found that the abnormal archegonium, sex organ that did not distinguish between male and female and sex organ which were vesicular and abortion.

Abstract:In this study, the watermelon cultivar ‘Zaojia 8424’ and pumpkin cultivar ‘Weizhen No. 1’ were used as materials, and two grafting combinations including watermelon/pumpkin (W/P) and pumpkin/pumpkin (P/P), were set up, using the onecotyledon splice grafting method. The pumpkin seedlings without grafting (P) were used as control. The effects of watermelon scion on root growth and sugar metabolism of grafted seedlings were measured. The results showed that: (1) in W/P, the watermelon scion caused significantly lower root growth index (fresh quality, dry mass, and root volume), root vigor, and shoot growth index (fresh quality, dry mass, and leaf area) of the grafted seedlings than those of the P/P and P seedlings. (2) The contents of total sugar, soluble sugar, reducing sugar, starch, as well as sucrose, glucose and fructose in the roots increased in this order: W/P < P/P < P, and there were significant differences between the treatments at 18 d post grafting. (3) Compared to the P/P and P treatments, watermelon scion caused lower activity of cell wall invertase (CWIN) and hexokinase (HXK) in the roots of W/P grafted seedlings at 18 d post grafting, and accordingly, the expression levels of CWIN and HXK were significantly reduced. The results indicated that watermelon scion could repress the sugar accumulation in the roots of grafted seedlings and inhibit the enzymatic activities of CWIN and HXK, and thus suppress the root growth and vigor of grafted seedlings.

Abstract:Canopy structure plays a significant role in growth, development and highquality and yield of fruit trees. In this study, we compared twentyyearold pears (Pyrus bretschneideri ‘Yuluxiang’) of OpenCentral Canopy (OCC) with three boughs (OCC_3b), four boughs (OCC_4b) as well as five boughs (OCC_5b) with those of the large and layered canopy (CK) for the canopy light interception, foliar gas exchange, chlorophyll fluorescence quenching, photorespiration and fruit quality characters, aiming to explore the effects of different light environment within canopy on foliar photosynthesis and fruit quality and elucidate the mechanism of photosynthetic regulation and fruiting regularity and thus provide an important theoretical basis for standardization of fruit trees training and pruning in the Loess Plateau of China. The results demonstrated that: (1) photosynthetically active radiation (PAR) intercepted by OCC_3b, OCC_4b and OCC_5b at different orientations and timing of the day were greater than those by CK significantly. Compared to CK and OCC_5b, the leaf maximum net photosynthetic rate (P_nmax) and carboxylation efficiency (CE) of OCC_3b and OCC_4b were significantly increased. (2) Under high light stress, leaves of OCC can efficiently dissipate excessive light energy by increasing the ratio of photorespiration rate (P_r) to gross photosynthetic rate (P_g) (i.e. P_r/P_g) and reversible component in NPQ ［r(qE)］ while decreasing irreversible component in NPQ ［r(qI)］. (3) The single fruit weight (SFW), coloring area at fruit surface (CA), anthocyanidin content in fruit skin (AC), soluble solids content (SS) and total soluble sugar content (TSS) increased significantly while titratable acid content (TA) decreased significantly in OCC_3b and OCC_4b than those in OCC_5b and CK. (4) At the significant level of P < 0.01, PAR was positively correlated with CA and AC but negatively correlated with TA, while P_nmax was positively correlated with SFW but negatively correlated with TA. In summarize, OCC_3b and OCC_4b could increase light energy interception by the canopy, leading to the increased foliar photosynthetic performance and the enhanced photoprotective capacity via more effective thermal dissipation with photorespiration. Accordingly, the improvement of light environment within canopy and leaf photosynthetic capacity after the OpenCentral Canopy pruning resulted in the improved fruit quality.

Abstract:In this study, the purpose was to understand the effect of the interaction between bacillus ZJMP5 and phosphate fertilizer on the root development and yield of adzuki bean. The pot experiment was conducted in 2016 and 2017 using ‘Jinhong No.5’ adzuki bean (Phaseolus angularis Linn.). The experiment consisted of two factors: phosphate fertilizer and bacillus ZJMP5. Three levels of P₂O₅ ［50 (P₁), 100 (P₂), 200 (P₃) mg·kg^-1］ and four levels of bacillus ZJMP5 ［10⁶ (A₁), 10⁷ (A₂), 10⁸ (A₃), 10⁹ (A₄) cfu·mL^-1］ were designed. Moreover, no P fertilizer and bacillus ZJMP5 was designed as control, and there were 13 treatments in our study. The root morphology, physiological characteristics and yield of red adzuki bean seedlings under different interaction levels of P fertilizer and bacillus ZJMP5 were analyzed. The results showed that: (1) the bacillus ZJMP5 and compound phosphate fertilizer treatments (phosphorus bacteria interactions) were significantly increased adzuki bean seedling taproot length, root area, root volume (P < 0.05). The seedling root length and root cap ratio are the highest under P₁A₃ treatment, 83.1% and 50.9%, respectively, compared with the CK significantly increased. The root area and root volume were the highest under P₂A₂ treatment, 69.7% and 54.2%, respectively, compared with the CK significantly increased. (2) The root SOD and POD activities, root activity and soluble protein content in the roots of rhododendrons seedlings were significantly increased by the interaction of each phosphorus bacteria, and all reached the peak value at P₂A₂ treatment, while MDA and soluble sugar contents in the roots of rhododendrons seedlings were significantly reduced, and all reached the minimum value at P₂A₂ treatment. (3) The P content of rhododendrons seedlings was significantly increased and the acid phosphatase activity of the roots was significantly decreased by the interaction of phosphorus bacteria. With the increase of phosphorus application, P content of plants increased gradually, and acid phosphatase activity of roots decreased gradually. As the concentration of bacterial solution increased, the P content of plant and the activity of acid phosphatase in root system both first increased and then decreased, and were the highest at the concentration of A₂. (4) With the increase of phosphorus application level or concentration of bacterial solution, the 100grain weight and grain yield of adzuki bean increased first and then decreased. In addition, under the P₂A₂ treatment combination, the yield increase was the best, which increased by 141.60% and 210.40%, respectively, compared with the control group. It was found that bacillus ZJMP5 could improve the grain yield of adzuki bean by changing root configuration, increasing root activity and improving root physiological function, and the optimal effect of growth promotion and yield increase could be achieved under the interaction of 100 mg·kg^-1 phosphorus application and 10⁷ cfu·mL^-1 bacterial liquid concentration.

Abstract:Using annual Astragalus membranaceus(Fisch.)Bge.var.mongholicus(Bge.)Hsiao (A. mongholicus) and Astragalus membranaceus (Fisch.) Bge (A. membranaceus) seedlings as materials, we used potting to simulate drought for 12 days and then resume watering. The effects of drought stress on the physiological status of A. mongholicus and A. membranaceus and the contents of calycosin7OβDglucoside and calycosin in the roots, stems and leaves were investigated. The results showed that: (1) drought stress significantly inhibited the growth of shoots in A. mongholicus and A. membranaceus, but had little effect on their roots. The relative water content of soil decreased after 4 days of continuous drought treatment, but the relative water content of the leaves of A. mongholicus and A. membranaceus decreased only after moderate drought stress (8~12 days of continuous drought), and the degree of decrease of A. membranaceus was larger than that of A. mongholicus. (2) Under drought stress, the activities of SOD and POD in the roots and leaves of A. mongholicus and A. membranaceus both increased first and then decreased, and the activities of SOD and POD in the roots and leaves of A. mongholicus were lower than that of A. membranaceus. (3) The content of calycosin7OβDglucoside in different organs of A. membranaceus was leaf> stem> root, while the content of calycosin7OβDglucoside of A. mongholicus in the roots, stems and leaves was not significantly different. The content of calycosin in A. membranaceus was expressed as leaf> stem, but in A. mongholicus, the opposite trend was found (stem>leaf). There are also differences between the content of flavonoids in the same organ of A. mongholicus and A. membranaceus. The drought resistance of A. mongholicus is higher than that of A. membranaceus. Moderate drought stress can promote the accumulation of calycosin7OβDglucoside and calycosin in the organs of Astragalus.

Abstract:We explored the response of photosyntheticCO₂ response curve and fruit medicinal components of Lycium ruthenicum cultivated in arid areas to nitrogen(urea, N, 46%) application. The experiment had five different N application rates ［0(CK), 50, N2:100, 150 and 200 g·strain^-1］. The net photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), water use efficiency (WUE), intercellular CO₂ concentration (C_i) and the contents of total polysaccharides, total flavonoids, anthocyanins, proanthocyanidins in the fruit were measured, and the parameters including carboxylation rate (η), maximum net photosynthesis rate (P_nmax), photorespiration rate (R_p), CO₂ compensation point (CCP) and CO₂ saturation point (CSP) were obtained by fitting a rightangle hyperbolic correction model. The results showed as follows: (1) appropriate N application rate had certain effects on η, P_nmax, R_p, CCP and CSP in leaves of L. ruthenicum. When N application rate was 100 g·strain^-1, η and R_p were the largest, and CCP was the smallest. When N application rate was 100~150 g·strain^-1, CSP was the largest. When N application rate was 150-200 g·strain^-1, P_nmax was the largest. (2) Appropriate N application rate had certain effects on the contents of the main medicinal components in fruits of L. ruthenicum. When N application rate was 200 g·strain^-1, the total polysaccharide content was the largest. The total flavonoid content was the largest when N application rate was 150-200 g·strain^-1. The anthocyanin content was the largest when N application rate was 50-150 g·strain^-1. The proanthocyanidin content was the largest when N application rate was 100-200 g·strain^-1. For comprehensive consideration, the best L. ruthenicum planting conditions in arid areas are the optimum of η, R_p, CCP, CSP, contents of polysaccharides and total flavonoids when N application rate at 100-150 g·plant^-1, and the optimum of P_nmax, contents of anthocyanins and procyanidins when N application rate at 150-200 g·plant^-1per year.

Abstract:In this study, we evaluated the phenotypic diversity of 40 natural populations from 3 species (O. kokonoricus, O. thoroldii and O. intermedius) of Orinus using 22 phenotypic traits. According to index of VIF, we filtered altitude (ALT) and 9 climatic factors like mean annual precipitation (MAP), adopted dbRDA analysis (Distancebased redundancy analysis) to explore the relationship between multigeographical climatic environment and phenotypic diversity of different species of different populations, to investigate the mechanism of plant phenotypic diversity of Orinus. The results showed as follows: (1) based on ward clusting of 22 traits, it generated 2 clusters at ward 55 by squared error of within populations, and the spatial autocorrelation among populations were not significant (P > 0.05). Our results showed that its pattern responded to the habitats was unique, the ShannonWiener (H) index of 17 qualitative traits ranged from 1.045 to 2.734, the average coefficient of variation was 47.84%, the color of spikelet was the lowest phenotypic diversity among populations (H: 0.170). (2) Nested analysis of variance revealed that both within and among populations are abundant variation (F > 10, P < 0.01), principal component analysis also showed that flag leaf and glumes and lemmas traits were important components of total variation, indicating the variation of phenotypic traits among populations (71.10%) was much greater than that within population by V_st(28.90%). The phenotypic variations derived from intrapopulations of Orinus. (3) Furthermore, dbRDA proved that ALT and annual mean wind speed were crucial factors for driving the phenotypic dissimilarity between O. kokonoricus and O. thoroldii populations, and extreme climate promoted phenotypic similarity like mean temperature of driest quarter (Bio9) and precipitation of driest month (Bio14) among populations, inversely aridity index (AI) and vapor pressure (Vapr) promoted effects of phenotypic dissimilarity. Phenotypic variation of O. intermedius populations were limited by MAP, potential evaporation (PET) and Vapr. Phenotypic variance of Orinus accounted for a lot of tendency along geographic and climate change among populations, were remarkable indicators for environmental suitability of alpine plant.

Abstract:Based on field investigations, collecting literature, and collating plant databases, we analyzed the flora composition and distribution types of Firminana danxiaens Nature Reserve in Guangdong Province, and the similarities between three neighboring study areas. The results showed that: (1) there were 84 species of pteridophytes belonging to 51 genera and 28 families in Nanxiong Firminana danxiaens Nature Reserve, with a single family structure and a low level of differentiation. Most of them belonged to oligo families, but the origin of the flora was ancient and the evolutionary relationship was coherent. (2) The fern flora in this area was widely geographically related, and had a high degree of kinship with the tropics at the family and genus levels. It was mainly distributed in the pantropical and subtropical regions, and at the species level in terms of tropical Asia and East Asia. Mainly, it had a permeable transition from tropical to temperate zones. (3) Geographically, the fern flora of Firminana danxiaens Nature Reserve was closely related to the fern flora of Guanyindong, followed by Guanzhai Mountain, and distanced from Danxia Mountain. The similarity coefficient between this Firminana danxiaens Nature Reserue and Guanyindong was above 0.83, and the floristic homogeneity was obvious, which consistent with the fact that the modern natural conditions of the two were similar. The results provide an important basis for discussing the origin and development of ferns in Danxia landform, and have reference significance for the rational development and utilization of plant resources in Firminana danxiaens Nature Reserve in Guangdong Province.

Abstract:We reported a species of Mallomonas collected from Yichun City, Heilongjiang Province. Its main characteristics, such as scales and bristles, were observed by transmission electron microscope and scanning electron microscope. And a phylogenetic tree was constructed based on the SSU rDNA and LSU rDNA gene sequences. Combining morphological characteristics with molecular biological data, we identified this species as a new record species in China and Asia——Mallomonas intermedia. The systematical relationship between M. intermedia and other species which belong to the other series of the same section and its world distribution and dispersal were also discussed. This study provided new data for the geographical distribution of M. intermedia and the dispersal of Chrysophyta and other microalgae.

Abstract:During the study of the Grimmiaceae of Xinjiang regions, four species of Grimmia, including G. capillata De Not., G. plagiopodia Hedw., G. crassiuscula H. C. Greven & C. Feng, and G. incurva Schwaegr. are newly recorded in the Xinjiang, and among them the first species is also found in China for the first time. In this paper, the taxonomic features, geographical distribution and characteristic comparison of related species are described.

Abstract:Gastrodia flexistyla T. C. Hsu & C. M. Kuo and Gastrodia shimizuana Tuyama, two newly recorded species of Gastrodia R. Brown are reported from Mainland, China. G. flexistyla T. C. Hsu & C. M. Kuo resembles G. nipponica (Honda) Tuyama, but it differs from the latter by its perianth tube long, indistinctly verruculose, lip greenyellow, etc. And G. shimizuana Tuyama is similar to Gastrodia pubilabiata Sawa, but it can be distinguished from the latter by its perianth tube pale yellowbrown to pale redbrown, lip triangular, white, etc. The form description and photos of the newly recorded species are provided in the article.

Abstract:As a key signal molecule in plants, nitrate modulates a series of biological processes during plant growth and development. Nitrate and its signal directly affect the nitrogen use efficiency (NUE), yield and quality of crops. Therefore, intensive study of nitrate signal transduction is the key to sustainable agriculture. In recent years, with the rapid development of plant molecular genetics, biochemistry and other disciplines, scientists have already made many breakthroughs in nitrate signal perception, transmission as well as longdistance signal transduction, which will provide insight into how nitrate signal regulates various aspects of plant growth and development. In this review, we disscussed the recent advances in nitrate signal transduction in Arabidopsis thaliana, which is expected to provide theoretical basis for the construction of new crops with high NUE.