Abstract:In the study, the RbohC and RbohF gene sequences of rapeseed (Brassica rapa L.) were cloned from ‘Long you 6’ by RTPCR. And realtime quantitative PCR was used to analyze the expression of RbohC and RbohF genes under different tissues and abiotic stresses, which provided a basis for further study on the biological functions of RbohC and RbohF genes in rapeseed. The results indicated: (1) two fulllength 3 050 bp and 2 995 bp rapeseed RbohC (GenBank accession number: XM_009134386) and RbohF (GenBank accession number: XM_009114548) gene sequences were successfully cloned. (2) Bioinformatic analysis showed that RbohC and RbohF contained 2 733 bp and 2 847 bp ORFs, encoding 910 and 948 amino acid residues, respectively. It is predicted that the molecular mass of RbohC and RbohF proteins were 103 kDa and 108 kDa which isoelectric points were 9.47 and 9.21. The amino acid sequences encoding RbohC and RbohF of rapeseed have high homology with the amino acid sequences of various plant corresponding proteins such as radish. These sequences are highly conserved and contain a typical conserved domain of NADPH oxidase, including two the EF chiral motif structures, which can bind to Ca²⁺, the six transmembrane domains, the flavin adenine dinucleotide binding domain, the NAD pyrophosphate binding domain, and the NADP ribose conserved binding site in the Cterminal region. (3) RTPCR analysis showed that RbohC and RbohF were expressed in root, stem, leaf and hypocotyl of rapeseed with nontissue specificity. However, RbohC had the highest level expression in roots, while RbohF gene in hypocotyl. (4) Low temperature, drought, salt, ABA and H₂O₂ all induced the expression of RbohC and RbohF, indicating that RbohC and RbohF play an important role in rapeseed adaptation to stress. However, the RbohC and RbohF genes of ‘Long you 6’, which is highly resistant to cold, are more sensitive to stress, and the expression of RbohC gene is higher than that of RbohF gene. (5) After treatment with H₂O₂ scavenger DMTU, NADPH oxidase inhibitor DPI and IMD, MAPKK inhibitor U0126, the expression of RbohC and RbohF in rapeseed decreased, indicating that U0126 and DMTU can inhibit the expression of RbohC and RbohF. Studies have shown that RbohC and RbohF genes have an important role in adapting to stress in rapeseed. The expression of both genes is regulated by MAPK kinase signaling pathway, and is regulated by H₂O₂ feedback. The RbohC and RbohF genes in the cultivar, the coldresistant ‘Long you 6’, are more sensitive to the H₂O₂ and MAPK kinase signaling pathways.

Abstract:In this study, we successfully cloned four POD genes, named as GjPOD4, GjPOD5, GjPOD7 and GjPOD42 (GenBank accession numbers are MH708528, MH708531, MH708529 and MH708530), from Gerbera jamesonni cv. ‘Linglong’ using RTPCR. Their characteristics were then analyzed using series of bioinformatics methods. Moreover, to provide basis for the understanding of their function and their future application in gerbera resistance breeding, we investigated their expression patterns together with POD activities under SA, PEG, cold stress and Phytophthora cryptogea treatments. Results showed that: (1) the coding sequence length of these PODs ranged from 966 bp to 1 005 bp, encoding 321-334 amino acids. Bioinformatic analysis showed that all the four PODs belong to the class Ⅲ plant hemedependent peroxidase superfamily containing conserved domains and motif, signal peptide, transmembrane structure and phosphorylation sites. (2) Phylogenetic analysis revealed that GjPOD4, GjPOD7 and AtPRX52, GjPOD5 and AtPRX47, GjPOD42 and AtPRX42 shared close relationship. (3) These gene expression and POD activities were all found to be significantly or very significantly influenced by the treatments of SA, PEG, cold stress and gerbera root rot pathogen. While the expression pattern of GjPOD4 differed from other GjPODs. (4) Correlation analysis showed that the expression of GjPOD42 was significantly positive correlated with POD activity in different organs (P<0.05). Notably, all the gene expression were significantly induced and positively correlated with the POD activity under the Phytophthora cryptogea treatment. Results obtained in this study indicated that GjPODs played an important role in stress responses of gerbera, especially during the gerberaP. cryptogea interaction. And, the function of GjPOD4 might differ from other GjPODs.

Abstract:A rice lateral rootless mutant k209 with high temperature sensitivity was isolated from an ethylmethane sulfonate (EMS)mutagenized rice library. After growing under normal (day 32 ℃/ night 22 ℃) and high (day and night 34 ℃) temperature for 7 days, phenotype analysis and lateral root primordia examination by methylene blue staining were conducted. The F₂ populations from crossing of k209 with wild type (WT) Kasalath and Nipponbare were used for genetic analysis and gene mapping, respectively. Results showed that under normal temperature there was no significant difference in the plant height, primary root length and adventitious root length between k209 and WT, but the length and number of lateral roots of k209 were decreased. However, under high temperature, k209 showed significantly shorter shoots, primary roots and adventitious roots and no lateral root. Furthermore, methylene blue staining analysis revealed that normal lateral root primordia could form in the mutant under both normal and high temperature. Under high temperature the number of lateral root of k209 was only 58.03% of the WT, and they could not outgrowth through the epidermis. Genetic analysis showed that the mutant phenotype was controlled by a single pair of recessive nuclear gene. Mapbased cloning analysis located the gene to a 4 002 kb region between InDel markers 7522K and 11524K on chromosome 4. This study will help the cloning of this mutant gene as well as further elucidation of the molecular genetic mechanism of lateral root development in rice.

Abstract:Based on the tea plant transcriptome database, we cloned the fulllength cDNA sequences of the key ratelimiting enzymeNacetylserotonin methyltransferase（CsASMT）in the melatonin synthesis pathway using SMART^TM RACE from the tea plant cultivars ‘Shuchazao’ . The full length cDNA was 1 282 bp, with an ORF of 1 065 bp, encoding 354 amino acids. The predict protein molecular and theoretic isoelectric point of CsASMT are 38.98 kD and 5.37, respectively. Phylogenetic tree analysis showed that CsASMT had the closest genetic relationship with Malus zumi ASMT9. The target gene was cloned into pET32a(+) and pMalc2X vector to construct a recombinant vector, respectively, and then transformed into E.coli BL21(DE3). After they are induced by 0.5 mg/mL IPTG at 28 ℃ for 6 h, pET32a（+）/CsASMT is expressed as inclusion body protein. But, pMalc2X/CsASMT is expressed as a large amount of soluble protein with molecular weight of about 79 kD in supernatant. Quantitative realtime PCR analysis showed that the expression of CsASMT was downregulated under the treatment of Ectropis oblique feeding. Exogenous application of melatonin, ABA, MeJA and SA could significantly upregulated the CsASMT. The obtained conclusion would provide a basis for elucidating further the function of CsASMT.

Abstract:In this study, based on the result of the genome survey sequencing of Brassica juncea, we cloned four WRKY71s genes by RTPCR technology, which named BjuWRKY7114. Bioinformatics analysis showed that BjuWRKY7114 contained 822, 840, 834 and 855 bp ORFs, encoding 273, 279, 277 and 284 amino acid residues, respectively. It is predicted that the molecular mass of BjuWRKY7114 proteins were 30.80, 27.11, 31.58, 32.18 kD, which isoelectric point were 7.75, 9.08, 8.35 and 7.76, respectively. Phylogenetic tree analysis showed that BjuWRKY7114 had the highest similarity with BrWRKY71 transcription factor. Subcellular localization prediction indicated that BjuWRKY71s were localized to the nucleus. BjuWRKY7114 genes were located on the chromosome A09, B04, A07 and scaffold144, respectively. Results of qRTPCR analysis showed that four BjuWRKY71s genes were responsive to high salt, abscisic acid（ABA） and low temperature stress. Under salt stress, the expression of BjuWRKY713 was increased continuously, while the expression of the other three genes was the highest at 6 h, and then decreased. Under the treatment with ABA, the expression of BjuWRKY71s gene was the highest at 6 h and then decreased gradually. After low temperature treatment, the expression level of the BjuWRKY71s was increased significantly. BjuWRKY714 was the most responsive to the abiotic stresses. These results could provide a foundation on further explore the function of BjuWRKY71s in B. juncea tolerance to abiotic stress.

Abstract:IiCYP79F1 gene was cloned from Isatis indigotica Fort. by RTPCR method, and its bioinformatics and expression analysis were performed. The results showed as follows: (1) the full length of gDNA for IiCYP79F1 was 2 109 bp, including two introns and three extrons; and the full length of ORF was 1 626 bp, encoding 541 amino acids (GenBank accession Number: KY774689.1). Bioinformatics analysis indicated that the secondary structure of IiCYP79F1 protein was mainly composed of αhelix (43.81%), random coil (35.49%), extended strand (13.68%) and βturn (7.02%); and its amino acid sequences had a high degree of identity with that of CYP79F1 in Brassica oleacea, Brassica napus, Brassica rapa and Eruca sativa. The phylogenetic analysis exhibited that IiCYP79F1 protein of I. indigotica Fort. had the closest relationship with Eruca sativa. (2) qRTPCR analysis demonstrated that IiCYP79F1 gene was expressed in spatiotemporal specificity and was highly expressed in stem and the seedling stage. MeJA, Ag⁺, glucose and mechanical injury promoted the expression of IiCYP79F1 gene, while SA and low temperature treatments had inhibiting actions. The results could lay the foundation for the further exploration of the function of IiCYP79F1 on the synthesis of glucosinolates, and provide a new idea for the new germplasm resources development.

Abstract:The NPR1, a diseaseresistant regulator, plays a key role in plant systemic acquired resistance. In our study, we cloned the gDNA and cDNA sequence of ZmNPR1 (GenBank accession number is MH619241) from a maize resistant inbred line D863F. It was found to contain a 1 866 bp open reading frame(ORF), which may encode a 621 amino acid polypeptide with a protein molecular weight of about 67.61 kD and a theoretical isoelectric point of 5.46. Phylogenetic analysis showed that ZmNPR1 was closely related to SbNPR1 of sorghum with 97% similarity. Real time quantitative PCR analysis showed that ZmNPR1 expression could be induced by rice blackstreaked dwarf virus (RBSDV) and significantly upregulated in leaves. Meanwhile, ZmNPR1 was expressed in leaves, stems, roots, tassels, ears and silks, and highly expressed in ears and leaves. The results indicated that ZmNPR1 may play an important role in the maize rough dwarf disease (MRDD) resistance.

Abstract:CDDP molecular marker was used to analysis genetic diversity of 47 Paeonia rockii DNA. The results showed that: (1) the orthogonal experimental design was used to optimize CDDP amplification system on P. rockii resources in primers and template DNA. A suitable CDDP reaction system was established: the CDDP reaction mixture, with a total volume of 20 μL, consisted of 10 μL of 2×Es Taq MasterMix, 1.5 μL of 1.0 pmol/μL primer, 4 μL of 15 ng/μL DNA and 4.5 μL of ddH2O. (2）19 of 21 primers yielded 112 bands, 97 were polymorphic which accounted for 86.61％ of all bands. (3) The results of UPGMA showed that: 47 P. rockii were grouped together with the same color in general. The similarity index value was 0.72~0.95 which showed the similarity degree among 47 P. rockii was high and the difference degree was low. In total, CDDP molecular marker was suitable for analyzing genetic diversity of P. rockii. The emergence of specific bands could provide theoretical basis for further study the identification of P. rockii.

Abstract:Pollen morphological characters of 22 species, 2 varieties and 2 forms from 15 genera of Malvaceae as well as Tilia chinensis of Tiliaceae were observed through light microscopy (LM) and scanning electron microscopy (SEM). Among these observed 26 taxa, pollen characters of 9 species, 2 varieties and 2 forms from 7 genera under LM were first reported, and pollen characters of 10 species, 1 variety and 2 forms from 8 genera under SEM were reported for the first time. The results indicate that：（1） the pollen grains of the observed 15 genera of the Chinese Malvaceae are usually large and spheroidal (dia. 54.4-211.5 μm) with spines, and aperture is colporate or pantoporate. The evolutionary trend of Malvaceae pollens is from a medium sized, 3zonocolporate pollen type with small, acute and bulbousbase spines to a larger polypantoporate pollen type with long, acute or blunt, flatbase and sometimes distinctly dimorphic spines. (2) The pollen morphological characters of Malvaceae have important taxonomic significance in the divisions of families, tribes, subtribes, and genera. Pollen characters support that Malvaceae can be divided into four tribes. Kydia and Hibisceae were ever placed in Bombacaceae, but their pollen morphological characters markedly differ from that of Bombacaceae. Instead, pollen characters support Kydia and Hibisceae as members of Malvacea and that Kydia can be placed in Hibisceae. (3) According to pollen morphology, we infer that Gossypieae and Malveae have a closer relationship and Abutilinae may be the most primitive group in the family, and Ureneae may be more advanced than Hibisceae. This study reports new pollen morphological characters and contributes to our knowledge on the taxonomy and phylogeny of Malvaceae.

Abstract:Relationship of external morphology, internal anatomical structure of flower bud, and meteorological factors during flower sex differentiation of Xanthoceras sorbifolium Bunge was studied by external morphological observation, paraffin section and meteorological data observation. Results showed that: (1) The difference of male and female flower distribution rates was extremely significant between apical and lateral inflorescences in X. sorbifolium Bunge. (2) There was no difference in the morphological structure between the two kinds of flowers at the early stage of sex differentiation. Stamen development included anther wall development and microsporocyte stage (20 d), and microsporogenesis stage (11 d), corresponding to morphological changes from buds expanding to buds exposing and inflorescence elongating rapidly. The pistil development included ovule development (30 d) and megasporogenesis (11 d). The change of external morphological characteristics appeared as inflorescence elongating and bud enlarging to sepal cracking. (3) The difference between male and female flowers appeared when male and female gametophytes were formed. Megaspore mother cell division stopped during the tetrad stage in male flowers. The corresponding external appearance of the buds was green, with a transverse diameter of 2.05-4.54 mm and a longitudinal diameter of 2.99-5.32 mm. The ≥K (biological zero point) effective accumulated temperature was 230.6 ℃. The abnormal development of female flowers stamen occurred 4 days later than male flowers pistil. Mononuclear pollen grains showed vacuolization decline during mitosis stage, with flower buds transverse diameter of 12.25-18.3 mm and longitudinal diameter of 8.3-10.98 mm. The ≥K (biological zero point) effective accumulated temperature was 264 ℃. The study indicated that external morphology of flower bud development, combining with meteorological factor data, could apparently reflect changes of internal structure, and could serve as indicator for sex differentiation stage. The present study showed that the two kinds of flowers of X. sorbifolium Bunge have both pistils and stamens, and the sex differentiation is caused by the different developmental degree of pistils and stamens in the late development period. Therefore, it is suggested that, functionally, it is more accurate to define the two kinds of flowers as “female functional flower” and “male functional flower”, respectively.

Abstract:Environmental factors are the main factors affecting the intraspecific variation of plants, and leaves are the organs most susceptible to the environment. In order to explore whether the leaf epidermal micromorphology has longitude variation and its influencing factors, we investigated the stomatal density, stomatal index, epidermal hair density, stomatal apparatus length and stomatal apparatus width of 8 populations of Caragana intermedia in the Inner Mongolia Plateau. The regression analysis is used to explore its degree of variation and impact factors. The results showed that: (1) the epidermis of the Caragana intermedia is covered by single cell nonglandular hair, the stratum corneum is rough, and the stomata are subsided which were the characteristics of drought resistance. The mean of stomatal density, stomatal index, epidermal hair density, stomatal apparatus length and stomatal apparatus width in the upper epidermis of C. intermedia were 302.81 pieces/mm², 9.94, 204.81 pieces/mm², 11.78 μm, 5.95 μm, and the lower surface of the leaves were 272.83 pieces/mm², 10.43, 187.45 pieces/mm², 12.49 μm and 6.18 μm, respectively. (2) The stomatal density and stomatal index increased with the increase of longitude, while the leaf epidermal hair density decreased with the increase of longitude. (3) The plasticity index of the epidermis is: epidermal hair > stomatal density > stomatal index > stomatal apparatus width > stomatal apparatus length. The leaf epidermis of C. intermedia responds to the changes of the environment mainly by adjusting the epidermal hair density and stomatal density. Sunlight hours, effective accumulated temperature, relative humidity, soil total carbon, total phosphorus and total nitrogen contents significantly affected the micromorphological characteristics of leaf epidermis.

Abstract:In order to provide the basis for evaluation on genetic diversity, germplasm breeding and so on, we selected 16 wild populations of Mirabilis himalaica from Tibet to investigate the fruit phenotypic trait variation in different provenances. We measured 8 fruit traits, and analyzed in diverse ways such as One way ANOVA, the principal component analysis, cluster analysis and the correlation analysis. The main results were as follows: （1） the average values of 8 traits varied among different populations, Nujiang mountain, Baxoi County （TNC2） had the lowest values of involucre tube length, involucre lobe length, involucre lobe width, fruit length, fruit shape and 100 fruits weight, and the other populations did not exhibit obvious regularity. Estimate of variation coefficient of fruit pattern was the highest in 9 populations, and fruit width or fruit length was the lowest in most populations. (2) Calculation basing on all the 351 individuals, the variation coefficients of 8 characteristics changed between 8.58%-25.57%, and the involucre lobe width had the higher value (25.57%) and the fruit width had the lower value (8.58%). One way ANOVA showed that the F value varied among 12.180-134.761 with extremely significant difference, which indicated that 8 morphological traits varied obviously among populations. (3) The principal component analysis indicated that the fruit length and the involucre lobe size were the major factors resulting in the morphological variations among populations. (4) Based on 8 fruit traits, 16 populations were clustered into 2 groups, which had no relations with their locations. (5) The correlation analysis showed that 3 environmental factors containing altitude, longitude, latitude had no significant influence on the 8 fruit traits, excluding the negative correlation between the involucre lobe width and longitude.

Abstract:The radial transport of nutrients in xylem ray tissues is very important for plant growth and development. At present, there are few studies on the radial transport rate of xylem ray tissues. With the dynamic changes of the age/seasonal growth and development of Haloxylon ammodendron, the characteristics of radial transport of xylem assimilation products are not clear. In this paper, H. ammodendron, a dominant species in the Gurbantunggut desert, was used as a test material to study the radial transport rate of nonstructural carbohydrates (NSC) in xylem of different ages and seasons. The relations between the NSC and anatomy of the xylem rays as well as vessels were analyzed. The results showed that: (1) the anatomical features of vessel and ray were increased with the tree age. The vessel length and vessel diameter of H. ammodendron were higher in May than that in July and October. The ray height, ray width and wall thickness of ray cell of H. ammodendron were higher in October than that in May and July. (2) The radial transport rate of NSC, soluble sugar and starch in H. ammodendron xylem increased significantly with the tree age (P < 0.05). There was no obvious difference between 13yearold and 18yearold trees in the radial transport rate of NSC, soluble sugar and starch (P > 0.05). (3) In different seasons, the radial transport rate of NSC was higher in May and October than that in July (P < 0.05). The radial transport rate of soluble sugar in H. ammodendron was the highest in May, followed in October, and then in July, and the difference between seasons was significant (P < 0.05). The starch radial transportation rate was decreased from May to October, and the seasonal difference was significant. (4) There was a significant positive correlation between vessel length and the radial transport rate of soluble sugar, vessel diameter and the radial transport rate of soluble sugar (P < 0.01), ray height and the radial transport rate of soluble sugar (P < 0.01), vessel diameter and the radial transport rate of NSC (P < 0.01) as well as ray height and the radial transport rate of NSC (P < 0.01). The radial transport function of H. ammodendron xylem was related to the anatomical structure of wood ray and vessel, and shows obvious seasonal dynamics.

Abstract:We used leaves of tree peony ‘Manyuan Chunguang’ as the materials to determine the contents of flavonol, anthocyanin, proanthocyanidin, chlorophyll, and carotenoid in different leaf color stages. RHSCC and Colorimeter were used to measure the leaf color phenotype; the expression level of flavonoid biosynthesis genes in different leaf color stages were detected by qRTPCR, and the relationships between pigments and flavonoid biosynthesis genes were analyzed. The potential causes of red faded in tree peony leaves were analyzed, and which provided genetic resources for further study on the molecular mechanism of this phenomenon. The results showed: (1) with the development of the tree peony leaves, the purplishred color was disappeared, the yellowgreen color was gradually appeared, and the adaxial (upper) and abaxial (lower) surface of leaves showed two different color changes. The RHSCC value, L^* and a^* values on the abaxial (lower) surface of leaves were higher than that of the adaxial (upper) surface, while the b^* and C^* values were lower than that of the adaxial (upper) surface.（2） The purplishred leaf was rich in anthocyanin and proanthocyanidin, while yellowgreen leaf was rich in chlorophyll, carotenoid and flavonol. (3) The expression levels of PsDFR and PsANS were consistent with the change trend of anthocyanin content, while the expression level of PsFLS and PsANR were consistent with the trend of flavonol content and proanthocyanidin content, respectively. (4) The expression pattern of PsMYB113 was significantly and positively correlated with the anthocyanin content, while the expression pattern of PsMYB4 was significantly and negatively correlated with the anthocyanin content；the expression pattern of PsMYBF1 was significantly and positively correlated with the flavonol content. The study found that leaf purplishred color faded was mainly caused by the decrease of anthocyanin content, and the decrease of anthocyanin content was the result of the coordinated expression of structure genes such as PsDFR, PsANS, PsFLS in the later developmental stages of tree peony leaves. In addition, PsMYB113, PsMYB4, PsMYBF1 may be the important transcription factors that regulated the above mentioned structure genes.

Abstract:The selfmade circulating nutrient solution system was used to set the circulating nutrient solution with a hanging root length of 0 cm (T₁), a static nutrient solution and an initial hanging root length of 0 cm (T₂), a circulating nutrient solution and a hanging root length of 2 cm (T₃). With these three treatments, we measured the dissolved oxygen, pH, EC value of nutrient solution, root and leaf morphological and physiological indicators, and root microstructure observation, to clarify the role of rhizosphere oxygen environment in hydroponic lettuce mechanism. The results showed that: (1) the rhizosphere oxygen environment of the lettuce was the best T₃ treatment, the T₂ treatment was the second, and the T₁ treatment was the worst. The pH of the nutrient solution and the total amount of ions were not much different. (2) The growth of roots and leaves of each treatment showed T₃>T₂>T₁; the root length, root surface area, root volume, average diameter, number of root tips, leaf surface area and leaf volume, and plant stem diameter and plant height, dry weight of the roots, the dry weight of the shoots, the seedling index and the rootshoot ratio were the highest in T₃ treatment, but there was no significant difference between T₃ and T₂, and both were significantly larger than those of T₁ treatment. The roottocrown ratio was significantly increased by 38.8% and 13.4%, respectively, compared to T₁. (3) The area of vascular bundles and xylem of root lettuce showed T₃>T₂>T₁. (4) The activities of SOD and POD activities in T₁ treatment were higher than those in T₂ and T₃ treatments. The CAT activity and MDA content were significantly higher than that of T₃ treatment. The chlorophyll and four organic acids in T₁ treatment were lower than that of T₂ and T₃. The content of acid and succinic acid is the largest with T₂, and the content of malic acid and malonic acid is the largest with T₃. It was found that rhizosphere hypoxia stress significantly inhibited the growth, physiology and quality of hydroponic lettuce, and the oxygen in the air was more effective than the oxygen in the nutrient solution. Setting the appropriate length of the roots of the lettuce can increase the contact area between the roots and the air, thereby increasing the supply of rhizosphere oxygen, solving the watergas contradiction, and improving the yield and quality of lettuce.

Abstract:In order to investigate whether orchid mycorrhizal (OM) fungi can improve Dendrobium officinale seedlings ability to cope with drought stress, we investigated the effect of inoculation with OM fungi on the growth of D. officinale seedlings under drought stress using a pot experiment. The relative water content, proline content, electrolyte leakage, reactive oxygen species, antioxidant enzyme activities in leaves were analyzed. The expression patterns of antioxidant enzyme genes in leaves were analyzed using quantitative PCR. The results were as follows: (1) the biomass of D. officinale seedlings and relative water content in leaves decreased and electrolyte leakage, proline content, malondialdehyde (MDA) content, the generation rate of O-·2 and H2O2 content in leaves increased in response to drought stress compared with control. (2) D. officinale seedlings inoculated with OM fungi maintained higher relative water content, lower electrolyte leakage, MDA content, the generation rate of O-·2 and H2O2 content in leaves under drought stress. OM fungi significantly improved the growth of D. officinale seedlings under different water conditions. The plant height, mass of roots, mass of shoots and biomass of D. officinale seedlings were higher than those of control. (3) OM fungi induced the expression of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) genes under drought stress. The activities of SOD, POD and CAT were found to increase significantly in cells resulting in alleviating oxidative damage of drought stress on plasma membrane. These findings suggested that the antioxidant enzyme activities and the expression levels of antioxidant enzyme genes in leaves of D.officinale seedlings could be improved by inoculation with OM fungi resulting in enhancing the antioxidant defense of D.officinale seedlings which reduced the inhibition of drought stress on D. officinale seedling growth.

Abstract:To clear the differences of alkaloid content and composition in natural Sophora moorcroftiana seeds among groups and within the group, the study chose S. moorcroftiana seeds from 10 groups lived at altitudes ranging from 2 900 meters to 4 100 meters in Tibet “one river and four streams” basin, adopted high performance liquid chromatography to measure important alkaloid content including oxymatrine, matrine, sophocarpine and sophoridine in 300 single plant seeds from 10 groups, used software SPSS for variance analysis, correlation analysis and cluster analysis, analyzed the relationship between geographic distribution and alkaloid content as well as heredity and variation among groups and screened out groups with higher alkaloid to provide S. moorcroftiana medicine exploitation and utilization with evidence. The result showed that: (1) oxymatrine, matrine and sophocarpine were all detected in S. moorcroftiana seeds of 10 groups and their contents were oxymatrine (46.18-64.08 mg/g)>matrine (1.14-9.82 mg/g)> sophocarpine (0.08-1.16 mg/g) in descending order, where oxymatrine content accounted for over 90% of total alkaloid, highest in group 4 (64.08±7.37 mg/g); others were little alkaloid, highest in group 3. There were significant differences of oxymatrine, matrine and sophocarpine among groups (P ＜0.01). (2) Oxymatrine had relevant less variation within the group and among groups; matrine and sophocarpine had relevant more variation within the group and among groups; moreover oxymatrine and sophocarpine had relevant more variation among groups than within the group; matrine had relevant less variation among groups than within the group. (3) Oxymatrine had significant positive correlation with altitude(r = 0.117^*). Matrine had extremely significant negative correlation with altitude, longitude and latitude (r ＜ -0.326^**). Others did not have obvious relationship. Oxymatrine had significant negative correlation with matrine as well as sophocarpine (r ＜ -0.162^**), while matrine had significant positive correlation with sophocarpine (r =0.789^**). (4) We could clarify 10 groups into 4 categories through cluster analysis. There were great differences among categories and most of differences were related to geography.

Abstract:Acer catalpifolium is a rare and endangered tree species endemic to China, and is the second important protected plant in the country. In order to clarify the structure of A. catalpifolium population and analyze its current survival situation, we selected the typical forest communities in karst forest of Maolan National Natural Reserve located at the junction of Guizhou and Guangxi. Using method of censusing every individual to analyze the population structure and population dynamics of A. catalpifolium we studied the aspects of height, diameter class, static life table, survival curve and life expectancy, providing theoretical basis for the population restoration, and reconstruction of forest ecosystems in degraded karst area. The results showed that: （1） the importance value of A. catalpifolium in the community is low ［valley (0.255), funnel (0.243), hillside (0.188) ］, which is a nondominant species in the Maolan karst forest. (2) A. catalpifolium population distributes in three community types of different topography sites: they are valley forest, funnel forest and hillside forest. A. catalpifolium grows the best with the most amount in valley forest, followed by funnel forest, but the worst and least in hillside forest. (3) A. catalpifolium in different habitats were serious shortage of Ⅰdiameter class (DBH < 2.5 cm，H < 33 cm) individuals, but Ⅱ diameter class (DBH < 2.5cm，H = 33 cm) individuals accounted for a large proportion, the number of middle and large trees were less, characterized by a stable population. (4) In different habitats, the survival numbers of A. catalpifolium population (exceptⅠdiameter class) decreased with the increase of diameter. The curves of mortality (q_x) and killing power (K_x) showed an increasing trend, life expectancy decreased monotonically, and the mortality ofⅠdiameter class in different habitats was negative, indicating a serious shortage of seedlings. The survival curve tended to be the type DeeveyⅡ. As a result, the seedlings of A. catalpifolium have higher mortality during the development process in Maolan karst forest, and the interspecific competition is fierce. In addition, the harshness of the Maolan karst habitat and the lack of soil nutrient space cause the growth of A. catalpifolium to be slow. Therefore, the decline of A. catalpifolium population is related to the harsh karst habitat and human interference.

Abstract:Dendrobium officinale Kimura et Migo homologous tetraploid was identified by means of stomata chloroplast chromosome counting and flow cytometry. On the basis of this, the multiplication efficiency was compared between the two schemes of stem segment propagation and protocorm induction, multiplication and differentiation, and the ploidy stability of protocorm was reidentified. The results showed that：（1） the strain ‘Huazi2’ in the laboratory was a pure contract tetraploid. （2）The best medium for propagation of stem segments was MS+2.0 mg/L 6BA+0.5 mg/L NAA+15% banana juice. For stem segment protocorm induction, the best culture medium for corm is MS+1.0 mg/L 6BA+0.5 mg/L NAA+0.2 mg/L KT, the inducing rate is 76.66%; The best medium for protocorm multiplication is MS+1.0 mg/L 6BA +0.5 mg/L NAA+15% potato extract. The best medium for protocorm differentiation is 1/2 MS+ 0.5 mg/L 6BA+20% potato extract， the protocorm differentiation rate was 85.70%; The best medium for rooting is 1/2 MS + 0.5 mg/L NAA+15% banana juice, the rooting rate was 92.77%.（3）The result of root tip identification of protocorm showed that the ploidy induced could be inherited stably.（4）The best time of transplanting was 5 days, and the survival rate of transplanting was 92.30%. A new rapid propagation technique system of autotetraploid lines of Dendrobium officinale Kimura et Migo was established in this experiment, which established the foundation for the industrial production and popularization of tetraploid plantlets.

Abstract:In order to provide references to the development and practical utilizations of the lichen symbiotic alga, we isolated two photobionts by using lichen species Peltigera rufescens and Peltigera elisabethae as the main research objects and studied the morphological characters, rDNAITS sequences as well as the capacities of the photobionts in the formation of the microbiotic soil crust under the laboratory artificial conditions in this research. (1) The I₁b and L₂ photobionts which were isolated from P. elisabethae and P. rufescens respectively belong to cyanobacteria. According to the analysis of phylogenetic tree which was constructed based on ITS sequences, I₁b was identified as Microcoleus vaginatus with 100% bootstrap value, while culture L₂ was identified as Nostoc sp. with 93% bootstrap value. (2) The most suited conditions for the microbiotic soil crust formation under laboratory artificial desert extreme situation were that 10% of water moisture content, 3∶1 (M. vaginatus: Nostoc sp.) ratio and 10 μg/cm² inoculation amount of photobionts.

Abstract:Two genera Siphonodon Griff. and Stichoneuron Hook. f., and two species Siphonodon celastrineus Griff., and Stichoneuron membranaceum Hook.f., were reported new records to China (Yunnan Province) in the present study. The voucher specimens are kept in Herbarium of Xishuangbanna Tropical Botanical Garden (HITBC).

Abstract:Several new records were found during our plant resources investigation in Centianhe National Wetland Park in Jianghua County of Hunan Province from 2017 to 2018. In this paper, we report a newly recorded family of monocotyledonCostaceae Nakai, including a newly recorded genus Hellenia Retzius and a newly recorded species Hellenia speciosa (J. Koenig) Govaerts in Hunan Province. Meanwhile, we make a brief overview on taxonomic study of Costaceae and a new accept name of Crape Ginger. The finding of Costaceae in Hunan provides basic and important data for studying biodiversity and floristic composition in this area.

Abstract:DELLA protein, a transcription factor that plays an inhibitory role in the GA signal transduction pathway, is a type of growth inhibitory protein that localized in the nucleus and can directly interact with proteins of key transcription factors in plants, thereby playing a central role in many plant signaling activities. This paper summarizes the identification, temporal and spatial expression patterns, molecular structure, regulatory mechanisms in GA signal transduction, interaction with PIF and Fbox protein of DELLA protein gene family and the role of DELLA protein in seed germination, morphogenesis, rhizobial symbiosis of legumes, stomatal closure, plant stress response and so forth of several fruit trees, vegetables, flowers, model plants, grain crops, and so forth at home and abroad in recent years, and the difference of DELLA protein gene family between these species are also compared. Finally, we prospected its future research hotspots and directions, to provide information for further exploration of the function of DELLA protein.