Abstract:The PCBER gene belongs to the PIP subfamily and is an important gene involved in the synthesis of lignans in the phenylpropane metabolic pathway. In this study, The GhPCBER plant overexpression vector pGWB17GhPCBRE was constructed and transformed into Arabidopsis thaliana, and gene silencing recombinant vector pTRV2GhPCBER was also constructed and transformed into cotton. Real time quantitative PCR was used to analyze the expression of GhPCBER gene under different tissues.The lignin and lignan contents in stem and leaf tissues from transgenic A. thaliana and cotton plants were extracted and determined. The results showed that: (1) GhPCBER plant overexpression vector pGWB17GhPCBRE and gene silencing recombinant vectors pTRV2GhPCBER were successfully constructed. Six transgenic A. thaliana lines with overexpression GhPCBER were obtained by genetic transformation, and GhPCBER gene silenced cotton plants were obtained(5 strains as a group). (2) PCR analysis showed that six transgenic Arabidopsis thaliana lines were overexpressing lines, among which the relative expression of lines 1, 2 and 3 was higher, and the expression in stem and leaf tissues was 7-14 and 6-16 times higher than that of wild type, indicating that the GhPCBER gene was successfully overexpressed in A. thaliana; The expression levels of GhPCBER gene silencing cotton plants in stems and leaves were 12% and 26% lower than those in wildtype cotton plants, respectively, indicating that the tobacco fragile virus (TRV) system (pTRV2GhPCBER) successfully inhibited the expression of GhPCBER gene. (3) The contents of lignin and lignan in stems and leaves of GhPCBER transgenic A. thaliana were significantly lower than that of wild type; the contents of lignin and lignan in stems and leaves of GhPCBER gene silencing cotton plants were significantly lower than that of wild type; Histochemical staining observation showed that the color of the stem of GhPCBER gene silencing cotton plants was significantly lighter than that of wild type, which also proved that the lignin content in the stems of silenced cotton plants decreased; (4) Realtime quantitative PCR analysis of eight related genes in the phenylpropanoid metabolic pathway revealed that overexpression or inhibition of the GhPCBRE gene resulted the reorientation of the phenylpropanoid metabolic pathway.

Abstract:In this study, Picea wilsonii was used as experimental material to clone a NAC transcription factor from cDNA library by PCR, which was named PwNAC30. Bioinformatics analysis showed that PwNAC30 open reading frame was 1 179 bp, encoding a total of 392 amino acids, a conserved NAM (no apical meristem) domain at its Nterminus and can be divided into five subdomains of AE. Multisequence comparison and phylogenetic tree analysis showed that PwNAC30 protein was clustered with North American spruce (P. sitchensis) of the Picea. Promoter cloning analysis showed that there were hormones and stress response elements such as gibberellin (GA), abscisic acid (ABA), methyl jasmonate (MeJA), TCrich repeats on the PwNAC30 promoter. Its promoter activity was significantly enhanced under ABA, GA, MeJA, low temperature, drought and salt treatments. Realtime PCR analysis showed that PwNAC30 had the highest expression in cones and the lowest in pollens and seeds. PwNAC30 responded to salt, drought, low temperature, ABA, MeJA, GA treatments, especially for salt, drought and MeJA. Subcellular localization experiments showed that PwNAC30 protein is localized in the nucleus and cytoplasm, mainly in the nucleus. Yeast one hybrid and two hybrid experiments showed that PwNAC30 protein had no transcriptional activation activity at its full length and Nterminus, whereas its Cterminus had transcriptional activation activity. PwNAC30 can form homodimers by itself. Studies have shown that PwNAC30 is a transcription factor with transcriptional activation activity at the Cterminus and is capable of forming a homodimeric structure by itself. It is widely involved in the signaling pathways of ABA, GA, MeJA and other hormones, and responds to salt, drought and low temperature.

Abstract:In this study, qRTPCR was applied to detect the temporal and spatial expression specificity of BjuA09DFR gene. In addition, the BjuA09DFR gene promoter was cloned, and the promoter GUS fusion expression vector of BjuA09DFR gene was constructed. We transferred the fusion expression vector into Arabidopsis thaliana by Agrobacteriummediated floral dip method. The expression pattern of BjuA09DFR gene promoter was analyzed by GUS histochemical staining in different tissues during the different development periods, which provided theoretical basis for further study of the function of BjuA09DFR gene promoter. The results showed that: (1) BjuA09DFR gene could express in multiple tissues of Brassica juncea, especially highly expressed in leaves, flowers, silicles and seeds of 15 days after pollination. (2) The fusion expression vector of GUS gene drived by BjuA09DFR gene promoter (pBjuA09DFR∷GUS) was successfully constructed，and transformed into wildtype A. thaliana by Agrobacteriummediated method. We successfully obtained positive transgenic plants by screening test of resistance to kanamycin and PCR detection. (3) Histochemical analysis of GUS showed that the GUS activity of transgenic A. thaliana displayed obviously temporal and spatial specificity, with the deeper staining in leaves, flowers, silicles and seeds of 15 days after pollination.

Abstract:In this study, geranylgeranyl diphosphate synthase 7 (CsGGDPS7) gene was identified from the tea genome. The fulllength cDNA of the CsGGDPS7 was cloned from the leaves of tea cultivar ‘Tieguanyin’ (GenBank accession number MH891780). The full length cDNA of CsGGDPS7 was 1 185 bp, with a 1 098 bp ORF, encoding 365 amino acids. Prediction results showed that CsGGDPS7 containing a Nterminal chloroplast targeting transit peptides, subcellular localization predicted that it could be located in chloroplast. Amino acid sequence analysis showed that the CsGGDPS7 had 5 conserved domains and 2 functional domains (DDXXXXD and DDXXD) of IsoprenoidBiosynC1 superfamily. Phylogenetic tree analysis showed that CsGGDPS7 and Olea europaea OeGGDPS7 had the closest genetic relationship. According to qPCR detection, expression of CsGGDPS7 in leaves was significantly higher than that of other tissues. There was no significant difference in the expression of CsGGDPS7 during the flower development. During the greenmaking procedure of oolong tea, the expression of CsGGDPS7 was significant upregulated rapidly from solar withering and reached its peak in the third tumbling. The expression of CsGGDPS1 and CsGGDPS2 were modulated by greenmaking procedure, but CsGGDPS4 did not.The result speculated that CsGGDPS7 might be related to the terpene aroma formation of oolong tea.

Abstract:In this study, we investigated the population genetic structure and evolutionary history of Pinus armandii and we aim to speculate the refugia of this species during Quaternary ice ages. The bipaternallyinherited nuclear gene AGP6 was utilized to study the genetic variations within and among 27 natural populations (129 individuals) of P. armandii in China. The results showed that：(1)P. armandii have a higher level of nucleotide diversity (π_t= 0.013 8, π_sil= 0.030 6) than the other Pinus species.(2) Bayesian clustering divided the total samples into two groups: one was from the middleeastern region and another was the southwestern group in China. Both the Network and phylogenetic analyses supported this conclusion. (3)Analysis of molecular variance (AMOVA) showed that the genetic variation mainly occurred within populations (65.65%) and among groups (30.18%), and only a little genetic variation occurred among populations (4.17%). A strongly multimodal mismatch distribution curve indicated that no recently population expansion took place for this endemic species.(4)Based on the geographic distributions and genetic diversity patterns of AGP6 haplotype, we speculated that P. armandii had several refugia in the Qinling Mountain and the Hengduan Mountain areas. The longtime geographic isolation between different refugium areas and heterogeneous habitats induced by large mountains and rivers may have resulted in the high level of population differentiation. In addition, the distinctly population genetic structure and evolutionary dynamics could be another contributing factor to the high level of nucleotide diversity of P. armandii.

Abstract:In order to understand the allelic variation and distribution of preharvest sprouting (PHS) genes in whet verieties of different regions, we genotyped 446 wheat cultivars from 7 wheat regions by the functional markers Vp1B3 and Dorm1 related to PHS resistance in China. The results indicated that: (1) Vp1 had three allelic variations detected by the marker Vp1B3: Vp1Bc (related to resistant PHS), Vp1Bb (related to resistant PHS) and Vp1Ba (related to susceptible PHS), and their frequencies were 62.8%, 4.3% and 32.9%, respectively. (2) DormB1 had two kinds of specific bands detected by the marker Dorm1:468 bp (genotype of DormB1a, correlated with susceptible PHS) and 606 bp (genotype of DormB1b, correlated with resistant PHS) accounted for 98.6% and 1.4%, respectively. (3) The detection by marker Dorm1 showed wheat germplasms with the genotype of DormB were distributed in Huanghuai winter wheat region (HHWWR) and Yangtze River middlelower reaches winter wheat region (YMWWR), with the ratios of 5.1% and 1.9%, respectively. The results of Vp1B3 indicated that wheat germplasms with (Vp1Bc+Vp1Bb) genotype (combination) were mostly distributed in YMWWR and Southwestern winter wheat region (SWWWR ) with the ratios of 75.0% and 74.1%, respectively. (4) Through the comprehensive identification of Vp1B3 and Dorm1 markers, 6 accessions of Vp1 and DormB1 loci related to resistant PHS were screened out, which were ‘Shanmai 611’, ‘Zhengnong 19’, ‘Yu 49198’, ‘Xinyang 0913’, ‘XianyangDasui’ and ‘Xuzhou 8066’, respectively. These accessions could be used as reference parents for PHS resistance breeding.

Abstract:In this study, 137 629 transcripts were assembled from 8.9 Gb of clean Illumina DNA sequencing read data, yielding 83 811 unigene sequences from Pueraria thomsonii ‘No. 1’. A phylogenetic analysis indicated that Pueraria lobata and Medicago sativa clustered together with Arachis hypogaea (peanut). We detected 25 452 SSR loci in the 83 811 assembled unigenes using MISA software. Trinucleotide repeats were the most abundant followed by dinucleotide repeats. Among the trinucleotide motifs, (AAG)_n (27.87%), was the most common repeat unit. A total of 229 SSR primer pairs were designed, and 28 markers that gave clear, polymorphic amplification products were used to analyze the genetic diversity within a panel of 44 Pueraria accessions. Ninety SSR fragments, consisting of 89 alleles, were amplified from genomic DNA of the 44 accessions. The average allele number is 3.178 6. Polymorphic information content (PIC) values ranged between 0.083 0 and 0.774 2 (mean = 0.455 7). Cluster analysis showed that the genetic similarity coefficients among the accessions ranged from 0.266 7 to 1.000 0. These results suggest that the detected P. lobata resources have abundant genetic diversity at DNA molecular level. The ingroup similarity coefficient (0.58) was observed in the 44 germplasm accessions, and all accessions could be clearly divided into two groups. The clustering results of tested P. lobata resource did not show clear correlation to their geographic origin. These markers are reliable genomic resource for genetic diversity analysis in Pueraria.

Abstract:To provide theoretical basis for effective use of melon germplasm resources, we studied the genetic relationship and diversity of melon with different degree of salt tolerance. In this study, the genetic diversity of melon germplasm resources was analyzed by SequenceRelated Amplified Polymorphism (SRAP) using 27 melon varieties with different salt tolerance levels. 24 primer pairs with clear amplification and rich polymorphism were selected from 364 pairs, and 415 clear sites were amplified totally, of which 241 were polymorphic sites and the polymorphic ratio was 58%. Average observed number of alleles (N_a) was 1.588 0, average effective number of alleles (N_e) was 1.347 0, average Neis gene diversity (H) was 0.201 3, average Shannons information index (I) was 0.301 0, and the results showed that melon germplasms had abundant genetic diversity. Unweighted pairgroup method with arithmetic means (UPGMA) clustering results showed that the genetic similarity coefficients were between 0.36 and 1.00. 27 melon varieties were divided into four classes at the genetic similarity coefficient of 0.72. Salt tolerant melon was distributed among three categories, medium salt tolerant melon was distributed through all the classes, and while salt sensitive melon was concentrated in the first group, the results demonstrated that genetic diversity of salt tolerant and medium salt tolerant melon were more abundant than that of salt sensitive melon. Cophenetic matrix correlation coefficient of genetic similarity coefficient and UPGMA clustering result was 0.749, which indicated that the cluster analysis was accurate. The study indicated that the genetic diversity of salt tolerant melon was rich, and in order to get salt tolerant heterosis varieties, more far genetic relationship germplasms need to be introduced.

Abstract:To construct a highdensity genetic linkage map of crested wheatgrass is the basis of fine mapping for important QTLs such as resistance, quality and yield, as well as the markerassisted breeding research. In this research, with 202 individuals from F₂ segregation population of tetraploid hybrid crested wheatgrass and their parents as materials, we constructed a genetic linkage map of crested wheatgrass based on SRAP molecular marker technique and Join map 4.0 mapping software. The results revealed that: (1) a total of 22 SRAP suitable primers with good polymorphism, clear and stable bands were screened to make a wide range of PCR amplification on the genomic DNA of F₂ individuals. A total of 510 SRAP polymorphic markers were obtained, accounting for 88.2%. (2) The analysis of segregation distortion showed that the ratio of distorted markers was only 14.12%, which met the requirements of genetic mapping. (3) The genetic linkage map of SRAP molecular markers of crested wheatgrass was successfully constructed. The map consisted of 14 linkage groups, including 510 SRAP markers, and covered the whole genome of 1 912.9 cM. The map length of linkage groups ranged from 86.4 cM to 179.0 cM, and the average distance between markers is 3.75 cM. It is a highdensity genetic map.

Abstract:Underground rhizomes of Fargesia yunnanensis from different ages were used as experimental materials in the study. They were observed under the light microscope byroutine section method, then their anatomical structure characteristics and dynamic changes in anatomical features with ages were analyzed, in order to provide new data information of anatomy for their structural study. The main results were as follows: (1) in an underground rhizome internode, there is only one layer of cells in the epidermis. The hypodermis is composed of 3-4 layers of fiber with thickened cell wall. The cortex generally has 20-25 layers of irregular parenchyma cells, which form air way cortexes when matured. The pith is solid without pith cavity. (2) The diameters of fiber cells wall increase as the increasing age of underground rhizomes, and inner phloem areas of underground rhizomes at the same age are larger than outer sides. The fiber lumens decrease with increasing age, while inner fiber lumens of underground rhizomes at the same age are larger than outer sides. The sizes of vascular bundles, phloem and vessels increase as the increasing age of underground rhizomes. (3) The protoxylem of vascular bundles generally has no vessel, and the metaxylem of outer vascular bundles generally has two larger vessels. However, in the middle and internal vascular bundles of the underground rhizome, there is usually only one vessel in the metaxylem, and the other metaxylem vessel is not developed or underdeveloped. (4) In the 0.5 to 2 year old underground rhizomes of F. yunnanensis, lignins dyed in purple are distributed in fiber cell wall, parenchyma cell wall and vessel cell wall, and the degree of staining increases with increasing age of underground rhizomes. This indicates that the content of lignin and the degree of lignification increase with increasing age of underground rhizomes.

Abstract:The phenotypic characters and leaf micromorphology of Acer stenolobum and its related species, A. stenolobum var. megalophyllum and A. pilosum, were studied in order to explore the position of A. stenolobum in plant taxonomy. The results showed that: (1) the variation of phenotypic traits of A. stenolobum from different habitats mainly came from within the population. (2) The phenotypic traits of A. stenolobum and its related species collected from the same origin are quite different. (3) The average coefficients of variation reflecting leaf size and shape of key fruit indicators were relatively large, and unable to accurately reflect interspecific relationships. Therefore, it does not support the main classification basis of “Flora of China”, Flora of China and various local floras with leaf size and doublewing angle as the main classification basis for A. stenolobum, A. stenolobum var. megalophyllum and A. pilosum. (4) The epidermis and the lower epidermis of the leaves of A. pilosum have surface fur, and it does not fall off during the life cycle. It is slightly different from the records of “Flora of China” and Flora of China to the A. pilosum. According to the relationship between the plant leaf veins relationship by Xu Bingqiang, the characteristics of the leaf vein of A. stenolobum, and A. stenolobum var. megalophyllum are basically the same, but the A. pilosum is more primitive than the A. stenolobum, and A. stenolobum var. megalophyllum. Our research provided evidence for treat A. stenolobum as a variety of the A. pilosum in Flora of China.

Abstract:In this study, 10 monocotyledons species were chosen in the hilly and gully region of the Loess Plateau. Conventional paraffin section method was used. The leaf anatomical structures of ten species in different vegetation zones (steppe zone, forest steppe zone and forest zone) and different erosion environments (south face slope, hilltop and north face slope) were observed. We measured upper cuticle thickness, upper epidermis thickness, lower epidermis thickness, lower cuticle thickness, leaf thickness, vessel diameter, and discussed anatomical structure characteristics and environmental adaptability of these species. The research results showed that: (1) there were different degrees of cuticle differentiation on the upper and lower epidermis in the ten monocotyledon plants. The leaves also had differentiation of bulliform cells in their upper epidermis. The locations and sizes of bulliform cells were different among different species. There were two or four big vessels in monocotyledon plants, which arranged in “V”shaped in the big vascular bundles. Monocotyledon plants could adapt to the special environment in this area through their own special anatomical structure characteristics. (2) In leaf anatomical structures, only vessels diameter had significant difference among different vegetation zones. With the decrease of soil moisture, plants adapted to poor water conditions mainly by increasing vessels diameter. (3) Protective tissues, such as epidermis thickness and upper cuticle thickness in leaf anatomical structures, were significant differences in different erosion environments. Plants adapted to poor water and strong light conditions mainly by increasing the thickness of epidermis and upper cuticle.

Abstract:The cultivar ‘Vladivostok’ which was easy to drop and cultivar ‘Berel’ which was not easy to drop were both used as test materials. Paraffin section technique was used to observe the anatomical structure of the carpopodium abscission zone. We determined the contents of endogenous hormones in the carpopodium abscission zone by high performance liquid chromatography, and also determined the active of cell wall related enzymes by enzyme linked immunosorbent assay (ELISA) technique. we analyzed changes of endogenous hormones and cell wallrelated enzyme activities in different Lonicera cearulea L. during the formation of the carpopodium abscission zone, and hope to reveal the relationship between endogenous hormones and cell wallrelated enzymes and their effects on fruit abscission. The results showed: (1) there were no obvious fracture in ‘Berel’ carpopodium abscission zone at the whole fruit growth period, but ‘Vladivostok’ carpopodium abscission zone was gradually disintegration when the fruit matured, ultimately. It relies on vascular bundle connected between fruit and carpopodium. (2) There was a significant difference in hormone levels and trends in carpopodium abscission zone between ‘Berel’ and ‘Vladivostok’. At maturity, the ABA and ETH contents of ‘Vladivostok’ were higher than that of ‘Berel’, while the IAA and ZT contents of ‘Vladivostok’ were lower than that of ‘Berel’; the ‘Vladivostok’ GA₃ content was lower than that of ‘Berel’ in veraison. (3) In ‘Vladivostok’, the activities of Cx and βglu increased during the fruit ripening period, and the activities of PG and PME reached the peak at lastveraison. In ‘Berel’, Cx activities did not change throughout the fruit growth period; By contrast the activities of PG, PME and βglu peaked in fruit early growth stage, then decreased when the fruit matured. (4) In ‘Vladivostok’ carpopodium abscission zone, there was significantly negative correlation between Cx and IAA/ABA (P<0.05). In ‘Berel’ carpopodium abscission zone, βglu activity was significantly negatively correlated with IAA/ABA (P<0.05); PME activity was extremely significantly positively correlated with ABA content (P<0.01). Studies indicate, during fruit ripening, the ‘Vladivostok’ fruit abscission was related with the increase of ABA content, the decrease of IAA content and change in Cx and PG enzyme activities. In addition, Cx activity is negatively regulated by the relative content ratio of IAA to ABA. Change in PME enzyme activity of ‘Berel’ cell walls can promote fruit abscission, and change in content of ABA positively regulate PME enzyme activity.

Abstract:In this study, physiologicalbiochemical and histochemical approaches were applied to investigate the role of H₂S in salicylic acid (SA) alleviated Al stress in the root of SB (aluminum (Al)sensitive black soybean). The results showed that: (1) Al accumulation in black soybean (SB) roots was increased by AlCl₃ treatment and the cotreatment of AlCl₃ and SA could significantly inhibit the accumulation of Al. But after adding H₂S scavenger (HT) or H₂S synthesis inhibitor (PAG), the accumulation of Al in SB roots was aggravated. (2) SA increased endogenous H₂S levels of black soybean (SB) root by 1.5fold under Al stress, and significantly alleviated root growth inhibition, reactive oxygen species (ROS) accumulation, oxidative damage and cell death induced by Al stress. Cotreatment of HT or PAG significantly reduced endogenous H₂S level, and it can reverse the alleviation effect of all SA under Al stress. (3) SA reduced the activities of black soybean (SB) apical antioxidant enzyme CAT, SOD and APX under Al stress, and inhibited the production of ROS in SB root cells. Inhibition of H₂S signal by HT or PAG enhances antioxidant enzyme activities. (4) Under the condition of Al stress, SA can further upregulate the expression of a series of Al tolerancerelated genes, such as exclusion mechanismrelated genes (Alresponsive transcription factor, GmART1; citric acid synthase, GmCS; citric acid transporter, GmMATE) as well as internal Al tolerance mechanismrelated genes (malic acid transporter, GmAlMT; Al³⁺related transporters, GmAlS1 and GmNIP1； 2). Reduction of endogenous H₂S level by HT or PAG can reverse the regulation of SA expression on these genes. (5) SA can increase the secretion of citric acid from black soybean (SB) root under Al stress, and this effect can also be inhibited by addition of HT or PAG. The study found that H₂S acted as a downstream signaling of SA and participate in the regulation of black soybean (SB) response to Al stress, which might provide some novel scientific basis for understanding Altolerance signaling network in plants.

Abstract:In this study, through the homemade nutrient solution circulation system, the system operation and stop time were set to 7.5 min (T₁), 15 min (T₂), 22.5 min (T₃), and 30 min (T₄) for 4 treatments. With the control (CK), the effects of different nutrient solution cycle intervals on nutrient solution environmental indicators and root morphology of hydroponic purple cabbage, proline, malondialdehyde content, endogenous hormones in roots and microscopic structure of root cells were studied. In order to explore the mechanism of the effect of nutrient solution circulation interval on the root growth of hydroponic purple cabbage. The results showed that: (1) during the 0th to 10th day, the dissolved oxygen content of the nutrient solution of CK decreased by 3.5 mg/L, and the dissolved oxygen of T₁-T₄ decreased by about 1.2 mg/L, and the nutrient solution of CK dissolved. The rate of oxygen decline is about 3 times that of T₁-T₄; the circulation interval of nutrient solution has no effect on the temperature of nutrient solution and the total amount of ions. (2) At the 10th day after treatment, the root morphological indexes such as total length, root surface area and root diameter of purple Chinese cabbage treated by T₁-T₄ were higher than that of CK treatment, and the roots of T₂ and T₃ grew more than that of T₁ and T₄, indicating that a certain range of nutrient solution circulation interval can promote root growth. (3) The contents of proline and malondialdehyde in the roots of purple cabbage of CK were the highest. Among T₁-T₄ treatments, the contents of proline and malondialdehyde in roots of T₂ were relatively high, and T₄ treatment was the lowest and both were significant below the control. (4) After 10 days of different treatments, there were significant differences in endogenous hormones in purple Chinese cabbage, and the contents of IAA and GA3 were consistent, both T₂>T₃>T₄>T₁>CK; the order of ABA content was CK>T₄>T₁ >T₃>T₂, and the ABA and ZR contents of T₂ are also at a minimum level. (5) Observation of cell microstructure revealed that the crosssection of the roots of CK, T₁-T₄ treatments from the inside to the outside of the third layer of cortical cells, the diameter of the new lateral roots at a distance of 1 cm from the root tip, the diameter of the vascular bundle and the xylem region accounted for the diameter of the root system. The proportions of T₁-T₄ were significantly higher than that of control, and the three indicators were the largest with T₂ (30, 450 μm, 42.22%), indicating that the root growth of T₂ is optimal. Studies have shown that the nutrient solution cycle time of 15 min (T₂) can significantly improve the dissolved oxygen content of nutrient solution, effectively increase the content of IAA and GA₃ in roots, promote the division of root cortical cells, increase the diameter of new lateral roots and the diameter of vascular bundles and xylem regions. The root system of hydroponic purple cabbage was optimally grown.

Abstract:Strain XD20 was an endophytic strain with nitrogen fixation activity isolated from sugarcane roots. In this experiment, 16S rDNA identification and nifH gene amplification were carried out, and its growth promoting characteristics, such as nitrogen fixation, phosphorus dissolving, ferritin production and indoleacetic acid (IAA) were analyzed. Meanwhile, the growth promoting effects on sugarcane after inoculating were also studied. The results showed that: (1) strain XD20 was identified as Pantoea agglomerans by 16S rDNA gene sequence. (2) About 360 bp was amplified by universal primer polyF/polyR of nifH gene, and the nitrogenase activity of the strain XD20 was 3 187.8 nmol·mL^-1·h^-1 by using acetylene reductase method. (3) Strain XD20 had an ability to produce IAA, which the concentration of IAA reached 36.71 μg·mL^-1, and also can dissolve organophosphorus and produce ferritin. (4) Inoculating the strain XD20 to different varieties of sugarcane (B8, ROC22 and GT40), increased the plant height, plant biomass, chlorophyll content in leaves, nitrate reductase activity, glutamine synthase activity and nitrate nitrogen content of three sugarcane cultivars at varying degrees, and the promoting effect of B8 was the most significant.

Abstract:We sprayed different concentrations of salicylic acid (0.5, 1, 2, 4, 8 mmol·L^-1) and 10 μmol·L^-1 1aminophentriazole (ABT), which was the inhibitor of salicylic acid on the seedling leaves of S. rebaudiana in the greenhouses and in the field, in order to explore the effects of salicylic acid on the main agronomic traits, glucoside and salicylic acid contents of S. rebaudiana leaves during harvest period. The results showed that: (1) the main agronomic characters of S. rebaudiana in the greenhouse and field increased first and then decreased with the increase of salicylic acid concentration in this experiment. Under the treatment of 2 mmol·L^-1 salicylic acid, the main agronomic characters of S. rebaudiana increased significantly in the greenhouse and field. And the dry weight per plant was 1.03 g and 16.76 g, respectively, which increased by 39.96% and 9.52% compared with 0.76 g and 12.34 g of the control. ABT treatment inhibited the agronomic traits of S. rebaudiana to some degree. (2) The contents of total glycoside and its composites of S. rebaudiana increased obviously under 1 mmol·L^-1 salicylic acid treatment, and reached the highest under 2 mmol·L^-1 salicylic acid treatment. The total glucoside contents of S. rebaudiana leaves in the greenhouse and field were 16.75% and 14.57%, respectively, which increased by 25.66% and 16.18% compared with 13.33% and 12.03% of the control, and RA glycosides also increased significantly to 10.59% and 9.77%, respectively. (3) The salicylic acid contents of S. rebaudiana leaves at the harvest time under 1 mmol·L^-1 and 2 mmol·L^-1 salicylic acid treatments had no significant difference with that of the control, but increased significantly after treatment with 4 and 8 mmol·L^-1 salicylic acid. The salicylic acid contents decreased a little under the treatments with ABT. It is suggested that spraying appropriate concentration of salicylic acid help to improve the yield and glycoside content of S. rebaudiana, especially the RA content. 2 mmol·L^-1 salicylic acid could be used to spray S. rebaudiana at the seedling stage in order to improve the yield and quality.

Abstract:Severe droughts have been associated with regionalscale forests mortality worldwide. Drought tolerance for tree species would be an important indicator for tree survival. Temperate forest in northeastern China plays a vital role in economic development and ecological environment construction of China. However, this forest is suffering project climate warming and drought. Therefore, it is urgent to assess the drought tolerance of trees in this forest. This study selected 8 tree species, which included Betula platyphylla, Phellodendron amurense, Juglans mandshurica, Fraxinus mandshurica, Quercus mongolica, Ulmus japonica, Larix gmelinii, and Pinus koraiensis trees in a natural environment at Maoershan Forest Research Station in the eastern mountain region of northeast China, and simultaneously measured the 7 water parameters derived from the PV curves and 5 actual water indices including transpiration rate, twig / leaf predawn and midday water potential, water content at incipient injury and waterretaining capability. The difference of drought tolerance was evaluated by single water index and comprehensive water index. The results showed that: (1) water parameters by PV curves ψ_tlp and ψ_sat measure drought tolerance of eight species, respectively, drought tolerance evaluation by single water index was different or even completely contradictory with each other, but by PV curve water parameters including |ψ_sat -ψ_tlp|, RWC_tlp, ROWC_tlp, ε_max and b values are basically identical. The order of drought tolerance was as follows: P. koraiensis > J. mandshurica> P. amurense> B. platyphylla> L. gmelinii> Q. mongolica> U. japonica> F. mandshurica. (2) According to the comprehensive evaluation results of 7 PV curve water parameters, the order of drought tolerance of 8 tree species was as following: P. koraiensis> J. mandshurica> P. amurense> L. gmelinii> Q. mongolica> B. platyphylla> U. japonica> F. mandshurica；according to the comprehensive evaluation results of 5 actual water indices, the order of drought tolerance of 8 tree species was as following: P. koraiensis> Q. mongolica> L. gmelinii> P. amurense> F. mandshurica> U. japonica> B. platyphylla> J. mandshurica；there were some differences between them, especially the positions of J. mandshurica, Q. mongolica and F. mandshurica changed greatly. (3) The order of comprehensive drought tolerance based on 12 water indices was as following: P. koraiensis>P. amurense>Q. mongolica>L. gmelinii>J. mandshurica>U. japonica>B. platyphylla>F. mandshurica. The study considers that the comprehensive evaluation results of 12 water indices have good agreement with the natural distribution of species in the eastern mountain region of northeast China.

Abstract:Shrub type plays an essential role in ecosystem recovery and affects soil quality, especially soil carbon (C), nitrogen (N) and phosphorus (P) contents. Studies on the effects of different shrub types on soil C, N and P stoichiometry are beneficial to understand the processes and functions of the ecological system. C, N and P stoichiometry are estimated in four typical shrubs: Caragana microphylla, Atraphaxis manshurica, Salix flavida and Artemisia halodendron. In order to elucidate the effect on ability of different shrub types on soil nutrient elements under the same environmental conditions and provide guidance for desertification control and ecological restoration, we measured soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP) contents in depth of 0-80 cm, compared ecological stoichiometry characteristics in different shrubs and soil depths and explored the correlation between indicators. Results showed that: (1)the mean contents of SOC，TN and TP were 0.90-2.18 g/kg, 0.19-0.32 g/kg and 0.27-0.32 g/kg. The average concentrations of SOC, TN and TP in 0-80 cm soil layer of A. manshurica is the highest in all of them. SOC and TN of C. microphylla and A. manshurica were significantly higher than that in others, but there were no significant differences between C. microphylla and A. manshurica. The average concentrations of TP in these four shrubs were no significant differences.(2)The contents of SOC, TN and TP in the surface layer (0-10 cm) of each shrub type were significantly affected by vegetation type. The surface layer (0-10 cm) of four shrubs was significantly higher than other layers. And they significantly declined with increasing soil depth.(3)The concentrations of SOC and TN decreased with the increase of soil depth in four shrubs, showed“inverted Pyramid”distribution pattern. However, the content of TP was no obviously change with the increase of soil depth, appeared“cylinder”distribution pattern.(4)The average ratios of C∶N, C∶P of A. manshurica were the highest, followed by A. manshurica and S. flavida, the lowest was found in A. halodendron. The ratios of C∶N, C∶P, N∶P and their differences decreased with the increase of soil depth. Both soil N∶P and C∶P ratios significantly declined with increasing soil depth, whereas the vertical pattern of soil C∶N ratio has high stability.(5)The correlations between SOC, TN and TP were significant, the ratios of C∶N, C∶P were mostly influenced by the content of SOC, the N∶P ratio was mostly influenced by the content of SOC, TN, and the ratios of C∶N, N∶P were significantly influenced by the ratio of C∶P. In summary, the difference of the adaptability of the 4 kinds of planting species was significant．A. manshurica and C. microphylla take effects in increasing soil nutrients obviously.

Abstract:The secondary vegetation is one of the typical and dominant vegetation type in Qiao Island, Zhuhai City, Guangdong Province. In this study, flora characteristics and family and genus areal types were investigated based on the recorded species of quadrat method. The quadrat method as well was applied to investigate the community characteristics and lifeform spectrum, and to analyze species diversity to reveal the typical characteristics of the secondary vegetation in Qiao Island. The result showed: (1) a total of 86 species of vascular plants belonging to 69 genera and 46 families were found in 15 quadrants. The geographical elements of the families and genera are both mainly composed of tropical and subtropical types. (2) The leaf characteristics presented as the dominant leaf type was single leaf whose percentage was 71.8%, the percentage of entire leaf (65.9%) was higher than that of nonentire leaf, and sclerophyll had a higher percentage (52.9%) among the leaf quality. The proportion of microphyll (45.3%) in research area of Qiao Island was significantly higher compared to that of its adjacent land regions, which tended to suggest the higher proportion of microphyll was one of the reasons to adapt to the dry habitats with the intensive lights in research area of Qiao Island. (3) Microphanerophytes (33.72%) and nanophanerophytes (23.26%) were predominant in life form, which was presumably influenced by both the manual intervention (introduced exotic plants for community construction) and the stage of vegetation succession. (4) Due to the sea wind and barren soil in Qiao Island, the species diversity of tree layer was lower than shrub layer and the ShannonWiener indexes in the study communities were low that was between 1.84 and 2.65, which indicate that the community was an immature one, and was in the intermediate phase of climax succession.

Abstract:Aspicilia is one of the important groups of lichenized fungi. The species of Aspicilia are widely distributed in arid and semiarid regions in the world, including Xinjiang, which had a richness of diversity. The Aspicilia specimens which were collected from Keketuohai Scenic Area in southern slope of Altai Mountains in Xinjiang were studied based on the morphologicalanatomical structures, chemical color reaction, thinlayer chromatography method and distribution ranges. As a result of our studies on this genus, the species Aspicilia boykinii, A. fumosa and A. sipeana are reported for the first time from China. Detailed taxonomic descriptions with photos of these three species were provided.