Abstract:In order to explore the molecular cytogenetic evidence of the relationship and phylogeny of genus Rosa, we located and analyzed the 45S and 5S rDNA of 17 species from 7 sections in China by using the technique of twocolor FISH (fluorescence in situ hybridization). The results suggested that: (1) one set of chromosomes corresponded to one 45S rDNA locus (except R. brunonii, which corresponded to two 45S rDNA), and one or two 5S rDNA loci. (2) At least one pair of 5S rDNA signals were colocated with 45S rDNA signals in diploid rose species, while 5S rDNA signals did not collocated with 45S rDNA signals in all of the tetraploid species; However, all tetraploid materials had at least one kind of rDNA signal homozygosity, indicating that they should be homologous tetraploid generated by direct doubling of diploid. (3) R. roxburghii f. roxburghii (sect. Microphyllae) was more distantly related to other species of Rosa, because it had a 5S rDNA signal on the short arm of the chromosome, unlike other species of _Rosa.(4) The karyotype as well as the numbers and locations of 45S and 5S rDNA were different in Aksu region and Yili region. The molecular cytogenetic evidence supported that R. laxa in Aksu region should be a new variety of the R. laxa. (5) To the best of our knowledge, the twocolor FISH analyses of tetraploid roses (6 taxa) and 8 diploid taxa has been reported for the first time in this study. The study provided that the heterologous chromosomes, differences of positions of rDNA signals on homologous chromosomes and the increase and loss of rDNA signals in both diploid and tetraploid plants in Rosa may be related to the structure variation and recombination of chromosomes. The structure variation and recombination of chromosomes were proved to played an important role in the evolution of Rosa at the level of molecular cytogenetics.

Abstract:Linalool is one of the most important volatile compounds in aromatic plants. The nerolidol/linalool synthase gene is an important regulatory gene for linalool biosynthesis. In this study, based on the transcriptome results of jasmine petals, we cloned the full length cDNA and promoter sequence of NEL/LINS using RTPCR and Genome Walking Technique, respectively. The content of linalool was detected by GCMS, and the expression level of JsNEL/LINS during the opening process and after treatments of IAA, GA, ABA and MeJA, which provided a theoretical basis for further study of the role of JsNES/LINS gene in the biosynthesis regulation of jasmine linalool. The results showed that： (1) the full length cDNA of JsNEL/LINS (GenBank accession number：MH513857) was 1 843 bp，contained 1 755 bp open reading frame (ORF)， encoding a protein of 584 amino acids, and belonged to hydrophilic and stable protein. The results of NCBIBLAST showed that JsNES/LINS had 56%，54%，54% and 50% similarities with Olea europaea OeNES， Antirrhinum majus AmNES/LINS1，AmNES/LINS 2 and Camellia saluenensis CsLINS, respectively. (2) The result of subcellular localization showed that JsNEL/LINS was located on the cytoplasm. 1 141 bp promoter sequence of the JsNES/LINS was isolated, and the result predicted that it contained several cisacting elements involved in plant hormones and light response，indicating that the expression of JsNEL/LINS was regulated by plant hormones and light. (3) The results of GCMS analysis showed that the relative content of linalool was the lowest when jasmine was not opened at 18:00, and reached the maximum when it was half open at 22:00, and then decreased. (4) The analysis of qRTPCR showed that the relative expression level of JsNES/LINS was consistent with the change of the relative content of linalool compounds during the flowering process. The expression of JsNES/LINS was induced by IAA, GA, ABA and MeJA, and the induction of MeJA was the most obvious, and the induction from high to low were MeJA>GA>ABA>IAA. It is speculated that JsNES/LINS plays an important role in the biosynthesis of linalool compounds and is regulated by plant hormones.

Abstract:In order to understand the regulation mechanism of NtLAR gene, we cloned the 5′terminal promoter sequence of NtLAR gene in this study using genome walking method from genomic DNA of Chinese narcissus (Narcissus tazetta var. chinensis cv. ‘Jinzhanyintai’). The sequencing result showed that the cloned fragment was 995 bp in length (GenBank number MH371155). Cisacting elements of the promoter were analyzed and predicted using plant care databases. Many cisacting elements were found, such as light response element ACE, Gbox, GATAmotif, GT1motif, hormone response element CGTCAmotif, ABRE, TGACGmotif, TGAelement, stress corresponding element and MYB binding site MBS. Two expression vectors pBI121pNtLAR∷GUS and pGreenII 0800pNtLARLuc were constructed successfully. Transient expression ofpBI121pNtLAR∷GUS in tobacco leaves showed that the cloned promoter fragment had activity. The transient expression results of pBI121pNtLAR∷GUS in Chinese narcissus showed that NtLAR promoter had different activities in different tissues of Chinese narcissus. The expression level of pNtLAR∷GUS is higher in basal plates and very low in petal and corona. When tobacco leaves were agroinfiltrated with pBI121pNtLAR∷GUS mixed with R2R3MYB genes NtMYB2 and NtMYB5 respectively, GUS staining and qRTPCR showed that the activity of NtLAR promoter could not be repressed by NtMYB2 or NtMYB5. Dural luciferase assay was also conducted in N. benthamiana leaves with pGreenII 0800pNtLARLuc mixed with NtMYB2 or NtMYB5. The results of dual luciferase assay were consistent with GUS staining and qRTPCR results.

Abstract:Membrane phospholipids are important sources of intracellular signal messengers and phosphatidic acid (PA) can be catalyzed by phospholipase Ds (PLDs) in response to different stress signals. In this study, we used Bioinformatics to identify and analyze the gene members of PLD gene family in Chinese cabbage; and the qRTPCR to analyze the expression of 18 BrPLD genes in nonheading Chinese cabbage, in order to explore the response mechanism of BrPLD gene family in nonheading Chinese cabbage to high temperature stress. The results showed that: (1) a total of 18 PLD gene family members were identified. Two of them (BrPLD03 and BrPLD09) were replaced by PH/PX domain. Another gene(BrPLD12)lacked its Nterminal conservative domain and was replaced by signal peptide. (2) Depending on the domain of the encoding protein，18 BrPLD genes were classified into three subgroups: 15 C2BrPLD, 2 PH/PXBrPLD and 1 SPBrPLD；analysis of physicochemical properties of amino acids revealed that most of the proteins encoded by the gene family were acidic proteins; 18 genes were distributed on another 8 chromosomes except chromosomes 4 and 7, and showed nonuniform distribution. The deletion of Ca²⁺ ligand base of BrPLDs protein was also found.(3) Quantitative RTPCR analysis of nonheading Chinese cabbage under high temperature showed that BrPLD gene could respond to high temperature stress, and the expression of BrPLD gene changed significantly. The expression of BrPLD gene was different in heattolerant and heatsensitive varieties. (4) Prediction of cisresponse elements with different functions in BrPLD gene family revealed that all family genes contained lightrelated action elements, 9 genes contained cisresponse elements related to low temperature, 10 genes contained droughtrelated elements, all 18 genes did not predict heatstressrelated cisresponse elements. The results of this study have important reference value for further studying the mechanism of BrPLD gene family responding to high temperature stress.

Abstract:Elongation factor 1β (EF1β) is one of the essential regulatory factors of peptide chain prolongation in the process of protein biosynthesis. This study cloned the EF1β gene sequence from Angelica sinensis using homologous cloning and RACE amplification techniques. We analyzed the sequence characterization, protein structure characteristics and expression profiling of EF1β gene under UVB radiation stress, to reveal the molecular mechanism of adaptation to UVB radiation stress in the process of cultivation habitat change of A. sinensis. The results showed that: (1) the fulllength sequence of EF1β gene (950 bp), encodes 225 amino acids, which was named AsEF1β gene (GenBank accession number: MG736314). The molecular weight of AsEF1β is 24.5 kD, theoretical isoelectric point of 4.48. AsEF1β belongs to hydrophilic amino acid, with the typical domain and conservative domain of family of EF1B super protein, and has a guanine nucleotide exchange domain at its Cterminal. The amino acid sequence of AsEF1β gene showed the highest similarity with that of Daucus carota L. var. sativa Hoffm., which belongs to the same family of Umbrella. (2) the qRTPCR analysis results indicated that AsEF1β gene in root of A. sinensis was significantly higher than that in stem and leaf (P<0.05). Under UVB radiation stress, the relative expression level of stem and leaf were upregulated, which was 2.43 times and 3.76 times that of natural light condition (P<0.05), respectively. Studies showed that AsEF1β gene may be involved in the adaptation process of A. sinensis to UVB radiation stress, which will be laid for further exploration on its ecological regulations in the growth and development, formation of stress resistance and biosynthesis of pharmacodynamic substances of medicinal plants.

Abstract:In order to further explore the genes related to terpenoid synthesis in the transcriptome of Narcissus tazetta var. chinensis, and to understand the metabolic pathways and molecular regulation mechanisms of N. tazetta, the study used the N. tazetta ‘Yunxiang’ as the material, screened the annotated terpenoid synthesis pathway genes and reannotated them with NCBI blastn based on the sequencing of the petal and corolla transcripts at the flowering stage. The representative gene was further screened by the expression of some candidate genes and the biosignal analysis. The isopentenyl pyrophosphate isomerase gene NaIDI was cloned by RTPCR, and analyzed for its protein sequence and specific expression. The results showed： (1) blast alignment screened 52 Unigenes associated with the upstream pathway of terpenoid synthesis, and secondary screening obtained 11 significant differentially expressed genes. (2) The open reading frame (ORF) of NaIDI gene is 858 bp in length and encodes 285 amino acids. The amino acid sequence was 97.19% similar to that of N. tazetta ‘Jinzhanyintai’. The subcellular localization is predicted in chloroplast. The phylogenetic analysis shows that it was closely related to asparagus. (3) The results of realtime fluorescence quantitative analysis showed that NaIDI was significantly expressed in different flowering periods and different tissues and organs of N. tazetta, and it had the highest expression in the corolla during the flowering stage, and it was consistent with the regularity of volatile steroids in different periods of flowering and different tissues and organs，indicating that NaIDI plays a certain role in the metabolism of terpenes.

Abstract:Miniature inverted repeat transposable elements (MITEs) are prevalent in eukaryotic genomes. Activities of MITEs induce abundant polymorphisms in species. They are known to critically influence genome evolution and gene regulation. In this research, 286 MITE family specific primers were developed for polymorphisms screening among 157 Brassica napus genotypes including 101 and 27 natural varieties collected from China and Canada, respectively and 29 synthesized lines. Polymorphisms produced from Insertion/deletion of MITEs were used to dissect genetic diversities and relationship between different B. napus lines. Results demonstrated that: (1) sixty pairs of primers displayed clear and repeatable polymorphism bands among genotypes, which occupied 21.0% of all developed primers； Polymorphic rate of primers developed from Stowawaylike and Touristlike families are 24.6% and 20.0%, respectively. (2) These 60 polymorphic primers were selected to screen MITE induced polymorphisms among Chinese, Canadian B. napus genotypes and 29 synthesized B. napus lines. There are 4 029, 1 044 and 1 087 distinguishable bands amplified, respectively. (3) UPGMA analysis showed that, the genetic similarities are 0.59-0.95, 0.73-0.95 and 0.64-0.93 in the populations of Chinese semiwinter, Canadian spring B. napus genotypes and synthesized B. napus lines, respectively. Our results indicate abundant interspecies polymorphisms are created by thousands of MITEs copies randomly insertion in genome. By using MITE family primers to detect the polymorphism of B. napus germplasm resources in different regions, we can find those polymorphisms provide resource for molecular marker assisted breeding of B. napus.

Abstract:Orchid mycorrhizal fungi (OrMF) play an important role in seed germination and growth of orchids. In this study, the operational taxonomic units (OTUs) of ITS sequences of mycorrhizal fungi in the roots of three Cypripedium species in the same habitat were obtained by culturedependent (peloton isolation) and cultureindependent (clone library) method, to study the phylogenetic relationship and diversity of OrMF. The results showed that: (1) the pelotons distributed in all of the root fragments; 64 OrMF were isolated, including 63 Tulasnellaceae strains and 1 Ceratobasidiacea strain; 7 OTUs were found, and the representative isolate of every OTU formed typical subglobose or ellipsoid monilioid mycelia in chain arrangement. All of the isolated fungi were asexual hyphae and did not produce asexual spores. (2) OrMF obtained from roots of three Cypripedium species by cultureindependent method were affiliated to Tulasnellaceae, Sebacinaceae, Ceratobasidiaceae and Thelephoraceae; The OTUs of Tulasnellaceae had an absolute predominance in type and quantity; It was Cypripedium tibeticum>C. flavum>C. bardolphianum in OTU type and quantity of OrMF acquired by both culturedependent and cultureindependent approach; And the types and quantity of mycorrhizal fungal OTUs obtained by the culturedependent method were less than the cultureindependent one. (3) The phylogenetic analysis of OTUs of Tulasnellaceae showed that the dominant and nondominant OTUs were distributed in three different clades of the phylogenetic tree; This phenomenon that orchids symbiose with many kinds of relatively distant relatives of OrMF may be related to the environmental adaptability of Cypripedium species; There was no significant difference in the OrMF species richness of different Cypripedium species, but there was a differentiation in the community structure.

Abstract:A morphology study is carried out on three freshwater species of Gyrosigma (Gyrosigma obtusatum, G. kuetzingii and G. sciotoense) using light and scanning electric microscopy to demonstrate their fine structural characters, and the regions of their geographical distribution in China are also summarized. The results show that: (1) all three species belong to the section Strigiles and all present two types of valve outline in valve view: Sshaped and reverse Sshaped (Sshaped); (2) G. obtusatum has weakly sigmoid valve outline, Tshaped external proximal raphe fissures, straight internal proximal raphe ending, and elliptic central area; G. kuetzingii bears distinctly sigmoid valve outline, external proximal raphe fissures which slightly deflect towards different sides, straight internal proximal raphe ending, and elliptic central area; and G. sciotoense possesses also weakly sigmoid valve outline, strongly hooked external proximal raphe fissures, Tshaped internal proximal raphe fissures, and oblique central area; (3) G. obtusatum is found in Guangdong, Guangxi, Hunan, Sichuan and Yunnan; G. kuetzingii is found in both Xinjiang and Hunan; and G. sciotoense is only discovered in Wuling Mountains, and this is its first report from the freshwater in China.

Abstract:In order to understand the effect of the pedicel development on the fruits quality of pear, we used 11 pear cultivars in this experiment. The main economic characters, soluble sugar, and mineral nutrients content of fruits were measured and analyzed. The pedicels were dissected and observed their tissue structures. The results showed that: (1) there were significant differences in morphology and microstructure of pedicels among different pear cultivars, with 10 vascular bundles in the pedicels in bigfruit cultivars, 9 vascular bundles in middlefruit cultivars and 5 vascular bundles in smallfruit cultivars. (2) In large P. pyrifolia system, the higher proportion of vascular bundle in the pedicel, the heavier the per fruit weight. (3) There was a very significantly positive correlation between pedicel diameter and fruit size in different pear cultivars, and the correlation was P. bretschneideri higher than P. pyrifolia. (4) The total soluble sugar content of fruit in the same cultivar was middle pedicel and thick pedicel significantly better than thin pedicel. (5) Ca and B contents of middle pedicel and thick pedicel fruit of ‘Akituki’ were significantly better than that of thin pedicel fruit. The results indicated that the structure of pedicels were different in different pear cultivars, and the development of pedicels were correlated with fruit quality. In particular, the pedicel diameter was one of the important factors that were limiting the fruit size and affecting the fruit quality. The fruit quality of middle pedicel in the same cultivar was better than that of thick pedicel and thin pedicel fruit.

Abstract:To investigate the effect of exogenous melatonin on heat tolerance in kiwifruit seedlings under high temperature stress, we used the potted seedlings of Actinidia deliciosa cv. Qinmei as materials pretreated with melatonin solution by root irrigating, then under 45 ℃ heat treatment to determine the physiological indexes of resistance. Results showed that： (1) melatonin pretreatment significantly reduced the relative electrical conductivity level and malondialdehyde content in the leaves of the kiwifruit seedling, and significantly increased the proline content, catalase activity and peroxidase activity when compared with high temperature control. And the best effect was observed when the concentration of melatonin solution was at 100~200 μmol·L^-1. (2) Melatonin pretreatment significantly increased the contents of total phenols, total flavonoids and total flavanols, and improved antioxidant capacity assayed by three methods (ABTS, FRAP, DPPH). In summary, melatonin can improve the antioxidant capacity of plants by increasing the contents of phenols and flavonoids, so as to effectively alleviate the damage of high temperature to kiwi seedlings and improve the heat resistance.

Abstract:Threeyear seedlings of four blueberry varieties, ‘Northland’, ‘Sierra’, ‘Berkeley’ and ‘Duke’, were used as test materials. In order to study their changes of growth potential, chlorophyll fluorescence parameters, osmotic adjustment substances and antioxidant enzyme activities under 3.4 (T1), 4.3 (T2), 4.8 (T3), 5.8 (T4) and 6.8 (T5) soil pH treatments by pot culture, we analyzed the relationship between various indicators, and hope to provide a theoretical basis for the production management of blueberry cultivated soil. The results showed that: (1) The growth potential of the aboveground parts of 4 blueberry varieties under T2 and T3 treatments was significantly higher than that of other treatments. (2) With the increasing of soil pH, the maximum photochemical efficiency (F_v/F_m), photochemical quenching coefficient (qP) and electron transfer efficiency (ETR) of four blueberry varieties showed a trend of first rising and then falling with increasing soil pH, and they rise to maximum under T3 treatment. At the same time, their Nonphotochemical quenching coefficient (NPQ) decreased firstly and then rise, it is lowered to the minimum under T3 treatment. (3) The contents of osmotic adjustment substances, soluble sugar (SS), soluble protein (SP) and proline (Pro) in blueberry leaves decreased firstly and then rise, it is lowered to the minimum under T3 treatment. (4) The activities of antioxidant, SOD and POD in blueberry leaves decreased firstly and then rise, it is lowered to the maximum under soil condition of T3 treatment, while POD activity showed a trend of “W” type, and it was higher under T3 treatment. (5) Correlation analysis and principal component analysis showed that there were different degrees of correlation between chlorophyll fluorescence parameters, osmotic adjustment substances and antioxidant enzyme activities, simultaneously. The plant height, leaf area and basal shoot length of blueberry were significantly correlated with soluble sugar, proline and chlorophyll fluorescence parameters. NPQ and F_v/F_m. It can be seen that the growth and physiological indexes of the four blueberry varieties can respond positively to different soil pH environments, and have suitable soil pH thresholds. Each indicator is at a good level under soil conditions of pH 4.8, which is most suitable for blueberry growth.

Abstract:The difference of ecophysiological and ecological response of community coexisting species to environmental is the important factor of community succession, of which, reactive oxygen scavenging is an important aspect of ecophysiology response. This paper takes on 10 kinds of common abandoned coexisting species in the Loess Plateau as study object, Ten coexisting species include Heteropappus hispidus, Artemisia scoparia, Artemisia sacrorum, Artemisia giraldii, Oxytropis glabra, Lespedeza dahurica, Bothriochloa ischaemum, Agropyron cristatum, Cleistogenes chinensis and Cleistogenes songorica. We determines the growth performance of individuals and populations, the main active oxygen removal indicators in the three months (August, September and October) of the growing season under different water treatment conditions (suitable water, moderate and severe stress). The measured growth performance indicators are individual plant height, biomass and population survival rate, active oxygen quenching indicators contain carotenoid content, superoxide dismutase (SOD) activity and glutathione (GSH) content. In this paper, the response differences and their interrelation of community coexisting species to water treatment on ecological suitability and reactive oxygen scavenger index are calculated and analyzed. The variation trend of the above indicators in succession ecological position is also demonstrated. The results show: (1) with the increase of water stress degree, the fitness of Artemisia scoparia in the succession early stage decreased, while the late growth of Bothriochloa ischaemum increased. (2) GSH and carotenoid enhanced with the water stress degree, both contents increased significantly. (3) There are prominent varietals diversities between carotenoids content, SOD activity and GSH content. Among them, the carotenoid content of Lespedeza dahurica, the SOD activity of Oxytropis glabra, the SOD activity and GSH content of Cleistogenes chinensis, and the carotenoid content and GSH content of Cleistogenes songorica were relatively high. Besides, the growth season variation of the above three indicators was also relatively obvious, the carotenoid and GSH contents in August were relatively high, while the GSH content and SOD activity in October were relatively high. (4) In the successional ecological position, ten coexisting species had relatively low levels of fitness and carotenoid content in the previous succession sequence, while the postsuccessive species were relatively higher, which indicates that the plants in the later stage of succession are more droughttolerant.

Abstract:In this study, taking the interface of moso bamboo (Phyllostachys edulis)Chinese fir (Cunninghamia lanceolata) forest as the research object, we compared and analyzed contents and correlations of soil organic carbon (SOC), total nitrogen (N), total phosphorus(P), alkalihydrolyzed nitrogen(HN) and available phosphorus(AP) at different expansive stages to reveal the effects of moso bamboo expansions on soil nutrients and stoichiometric characteristics, and to provide basis for rational regulation and ecological management of moso bamboo forest. The study shows: (1) for moso bamboo to Chinese fir, with the increase of moso bamboo proportion, the content of SOC increased first and then decreased, and the coefficient of variation of SOC increased gradually with the deepening of soil layer; the content of N increased first and then decreased, and the final stage of expansion is higher than the initial stage of expansion; The contents of P, HN and AP showed wavelike change trend with the expansion of moso bamboo. The contents of P, HN and AP in different expansion stages reached significant levels. The contents of P and AP in final expansion stage were lower than that in initial expansion stage, and the content of HN was higher than that in initial expansion stage. (2) During the expansion of moso bamboo to Chinese fir, C∶N showed an upward trend with the expansion of moso bamboo, and the difference between different expansion stages reached a significant level; N∶P showed an upward trend with the expansion of moso bamboo. The difference of N∶P in 0-20 cm soil layers reached a significant level, while that in 20-30 cm soil did not reach a significant level. HN∶AP increased first and then decreased with the expansion of moso bamboo, and the difference between different expansion stages reached a significant level, and the final expansion stage was smaller than the initial expansion stage. (3) SOC, N, P and C∶N, N∶P, HN∶AP are significantly correlated, and the correlation coefficient reaches a significant level. Among them, SOC and N are negatively correlated with HN∶AP, P is negatively correlated with N∶P and HN∶AP. This reflects that with the expansion of bamboo, soil N and P elements were more scarce. It is suggested that N and P elements be supplemented in time to promote the stable and healthy development of community.

Abstract:We investigated the understory species composition and diversity and determined the dominant stand factors affecting the understory species diversity using typical sampling method in five plantations (BF: Cupressus funebrisPterocarya stenoptera forest; YN: Ginkgo bilobaPhoebe zhennan forest; GZ: Swida wilsonianaCinnamomum camphora forest; FQ: Pterocarya stenopteraAlnus cremastogyne forest; CB: Cupressus funebris forest) in Yunding Mountain, Chengdu, to provide scientific basis for local plantation management. The results showed that: (1) a total of 168 understory plants were recorded, belonging to 62 families and 130 genera. The number of families, genera and species in the shrub layer and herb layer of five plantations was the greatest in the GZ. (2) The number of dominant species in five different plantation shrub layer was 7, 4, 7, 6, 4, and the number of herb layer was 5, 4, 9, 9, 10, all of which were small. (3) The ShannonWiener diversity index (H), Simpson dominance index (H′), Richness index (D), Pielou evenness index (J_sw) of five plantations were all expressed as: the herb layer > the shrub layer, the D of the BF and GZ was slightly higher in the shrub layer. The H, H′, and D of the shrub layer were the highest in the GZ, and there were no significant differences in the J_sw of the shrub layer among different plantations. The H, D and J_SW of the herb layer were sized as the CB, FQ, GZ, BF and YN, but the D of the GZ was slightly higher than FQ. (4) There were no significant differences in the effects of six stand factors on the four species diversity indexes in the shrub layer. The main stand factors affecting the D and H of the herb layer were average tree height, average branch height, average diameter at breast height, average crown and stand density. Stand factors had no effects on the H′ and J_SW in the herb layer. Research suggested that, the effects of stand structure on species diversity of the herb layer were more significant. Average tree height, average branch height, average diameter at breast height, average crown width and stand density had significant effects on the diversity of the herb layer.

Abstract:Anaphalis lactea and Saussurea hieracioides are the main species of alpine meadow in Gannan. The study uses a point pattern analysis method through field community surveys, analysis of spatial distribution and interspecific correlation of A. lactea and S. hieracioides populations with different altitude gradients (2 900 m, 3 500 m, 3 800 m) by using Riples K function. The aim is to understand the dynamics of the alpine meadow population and the development and succession trends. The results showed that： (1) there were significant differences in the distribution of the populations of A. lactea and S. hieracioides on three elevation gradients in the alpine meadow of Gannan. With the increase of altitude, the plant number, coverage and biomass of S. hieracioides population decreased gradually. However, the population of A. lactea increased at first and then decreased. (2) The population density of different elevation gradients is obviously different. The density of S. hieracioides population was 2 900 m > 3 500 m > 3 800 m, the density of A. lactea population was 3 500 m＞2 900 m＞3 800 m. (3) In the 2 900 m altitude meadow, A. lactea population aggregated and distributed in the range of 0-1.9 m, randomly distributed in the range of 1.9-3.9 m, and evenly distributed in the range of 3.9-5 m, S. hieracioides population aggregated and distributed in the range of 0-3.5 m, randomly distributed in the range of 3.5-5 m； In the 3500 m altitude meadow, the population of A. lactea was randomly distributed in the whole study range, while the population of S. hieracioides showed aggregated distribution; In the 3 800 m altitude meadow, the population of A. lactea was aggregated in the range of 0-4.1 m, and the population was randomly distributed in the range of 4.1-5 m with the increase of the research scale, and the population of S. hieracioides showed random distribution in the range of 0-0.6 m and 4.4-5 m, but in the range of 0.6-4.4 m, the population of S. hieracioides showed aggregated distribution. (4) In the 2 900 m altitude meadow, there was no correlation between A. lactea and S. hieracioides populations in the small scale of 0-1.9 m, but negatively correlated in the larger scale of 1.9-5 m; In the 3 500 m altitude meadow, the two populations showed no correlation; In the 3 800 m altitude meadow, there was a positive correlation between the two populations. The results showed that the distribution patterns of A. lactea and S. hieracioides populations were closely related to the change of elevation gradient, and the response strategies of different populations to the change of elevation gradient were different.

Abstract:To explore the differences of species functional groups and diversity of alpine meadow communities on different slopes in the eastern margin of Qilian, we investigated the characteristics of vegetation (height, coverage and frequency) on seven slopes (north slope, northwest slope, west slope, east slope, northeast slope, southwest slope, and south slope), determined soil factors, species evenness and diversity index and their correlation. The results showed that: (1) There were 21 families, 18 genera and 21 species in the study area, mainly Leguminosae (4 genera and 4 species), Compositae (3 genera and 3 species), Rosaceae (1 genus and 3 species), Cyperaceae (2 genera and 2 species), Gramineae (2 genera and 2 species) and Polygonaceae (1 genus and 2 species). The trend of plant families and genera are similar to species in different slopes, all of which are northeast, southwest and north slopes (76.19%) > south slope (66.67%) > east slope (61.90%) > west slope, northwest slope (19.05%). (2) The composition of grassland communities is different in different slopes, among which the east, south and northeast slopes are mainly herbaceous plants, the southwest and north slopes are herbaceous and shrub interlaced plant, and the west and northwest slopes are mainly shrubs plant. (3) The functional groups are different in different slopes. The important values of sedges on the east, south, north, south and southwest slopes are the highest, while the west and north slopes are only legumes and forbs, which has the highest value. (4) There are different dominant functional groups in different slopes. Important values of gramineous plants were as follows: shady slope (northeast slope) > sunny slope (south slope and southwest slope) > semisunny slope (east slope); for leguminous plants: sunny slope (south slope) > shady slope (north slope, northwest slope and northeast slope) > semisunny slope (east slope) > semishady slope (west slope); for forbs: semishady slope (west slope) > shady slope (north and northeast slope) > semisunny slope (east slope) > sunny slope (southwest slope and south slope). (5) With the change of slope gradient, the change of species richness and the ShannonWiener diversity index are consistent, which are represented as: shady slope > sunny slope > semisun slope > semishady slope. (6) Redundancy analysis showed that soil water content and C∶N are important factors affecting the important values of shrub plants (Daphne odora, Potentilla fruticosa and Rhododendron capitatum). These results suggest that changes in soil moisture, nutrients and light of different slope orientation have significantly affected the species functional groups and their diversity in alpine meadow vegetation communities.

Abstract:Relying on the 6hm² dynamic monitoring forest stand of research platform in Qizimei Mountains Nature Reserve, based on the sample area and species basic information data, by the method of multiple regression tree and redundancy analysis, we investigated the effect of terrain factors on habitat and species distribution of response to the environment and under different types of association analysis the change rule of species diversity. Researches show that: (1) according to the “1 SE” rules, four split in turn in altitude (1 453 m), slope (23.13°) and altitude (1 398 m), concave and convex degree (4.094) as the cutoff point 150 sample area can be divided into five clusters. (2) The redundancy analysis shows that the interpretation amount of terrain factor to species distribution is 0.077 6, and the interpretation rate is 16.36%. The explanatory power of each environmental factor to species distribution is in order: meanelve > slope > convexity. There was no significant correlation between slope direction and species distribution. (3) Cluster 5 had the highest stand density (527.4 plants/400 m²) and chest height sectional area (3.495 cm²/plant) in the five clusters. Cluster 4 was the lowest standing density (225.4 plants/400 m²) and average chest height sectional area (3.057 cm²/plant). (4) Among the five clusters, the ShannonWinener richness index and Simpson dominance index were highest in cluster 2, and lowest in cluster 5. The scale effect of species diversity was obvious. The highest Pielou evenness index was cluster 4, and the lowest was cluster 5. (5) The Jaccard similarity coefficient between two clusters was lowest in cluster 1cluster 2 (0.331) and highest in cluster 4cluster 5 (0.645). It was concluded that the 6 hm² sample topographic factor in the nature reserve of Qizimei Mountains had a certain effect on the shaping of the habitat in the region, and the “environmental sieve” composed of meanelve, slope and convexity affected the species distribution and diversity pattern in the region.

Abstract:Hoya lanceolata Wall. ex D.Don (Apocynaceae, Asclepiadoideae), a species previously known from Nepal, India, Myanmar, Thailand and Vietnam. It was found on a tree of dense moist forest in Yunnan Tongbiguan Provincial Nature Reserve, Dehong, Yunnan Province, China and its vouchers are kept in the Herbarium of Xishuangbanna Tropical Botanical Garden (HITBC).

Abstract:Tetracme pamirica Vassilcz. is reported as a newly recorded species of the genus Tetracme Bunge (Brassicaceae) from China, which was found in Diya County, Zhada, Tibet. The plants grow in dry valley slope land. This species differs from Tetracme quadricornis (Stephan ex Willd.) Bunge in the length of fruit 10-13 mm, and the length of seed 1-2 mm. Voucher specimens are deposited in HIMC.

Abstract:Saxifraga atuntsiensis W. W. Smith and Saxifraga aurantiaca Franchet belong to Saxifraga Linn. of Saxifragaceae, Corydalis dolichocentra Z. Y. Su & Lidén belongs to Corydalis DC. of Papaveraceae, Gentiana suborbisepala C. Marquand belongs to Gentiana Linn. of Gentianaceae, Androsace gmelinii (Linn.) Roemer & Schultes belongs to Androsace Linn. of Primulaceae, Lonicera oreodoxa H. Smith ex Rehder J. belongs to Lonicera Linn. of Caprifoliaceae, Ranunculus chuanchingensis L. Liou belongs to Ranunculus Linn. of Ranunculaceae, Pedicularis scolopax Maximowicz belongs to Pedicularis Linn. of Scrophulariaceae, eight newly recorded species of angiosperm from Tibet were reported. A brief morphological description and photos of these species were provided. The specimens were deposited in the herbarium of Research Institute of Xizang Plateau Ecology (XZE).

Abstract:As a major environment factor, low temperature affects the geographic distribution and diversity of plants, and threats the sustainable development of agriculture. ICE1 (INDUCER OF CBF EXPRESSION1)CBF (CREPEATBINDING FACTOR) signal pathway functions critical roles not only in plant cold tolerance, but also in plant growth and development. The insight into ICE1CBF pathway improves our understanding about how plants balance growth and cold tolerance. In this review, we summarized the latest advances in research of the sophisticated regulation of ICE1CBF pathway in cold tolerance, and mainly discussed the roles of ICE1CBF pathway in plant growth and development.