Abstract:In this study, the wildtype tomato (Solanum lycopersicum) was used as the experimental material. The 1 849 bp promoter fragment in the upstream of the start codon of the SlWRKY31 gene from tomato was isolated by PCR cloning method. This promoter was then used to drive the GUS gene expression in wildtype tomato, and the obtained transgenic tomato was analysed by GUS histochemical staining and quantitative assay of GUS activity after different stress treatments. These results showed that: (1) sequence analysis revealed that the length of this promoter was 1 849 bp, and contained a large number of abiotic stess and phytohormone responsive elements, such as heat stess responsive element (HSE), droughtinducibility element (MBS), defense and stess responsive element (TCrich repeats), woundresponsive element (WUNmotif), abscisic acid responsive element (AREB), and salicylic acid responsive element (TGAelement). (2) Quantitative realtime PCR (qRTPCR) showed that the SlWRKY31 gene was expressed ubiquitously in all tissues examined, but its expression level was significantly increased under Mannitol, NaCl, SA, ABA, and heat stress (42 ℃) treatments. (3) A plant expression vector was constructed using the SlWRKY31 promoter to drive the GUS reporter gene (SlWRKY31Pro::GUS), and was transformed into wildtype tomato by Agrobacteriummediated transformation. GUS histochemical staining analysis of the transgenic tomato plants showed that the GUS gene was expressed in all tissues of tomato, indicating that the SlWRKY31 promoter is a constitutive promoter. (4) The GUS histochemical staining and the quantitative assay of transgenic plants after different stress treatments showed that the SlWRKY31 promoter was significantly induced by NaCl, Mannitol, SA, ABA and heat stress (42 ℃), indicating that the SlWRKY31 promoter is an inducible promoter that can respond to multiple stresses.

Abstract:In order to investigate the pollen abortion characteristics of Oncidium Honey Angel and reveal the regulation relationship between pollen abortion and OnMYB106 gene，this study used Oncidium Honey Angel (male sterile) and Oncidium Sharry Baby (fertile) as experimental materials to observe the morphology and characteristics of pollen clusters and pollen grains. In addition, based on the transcriptome analysis, a MYB transcription factor gene (OnMYB106) was cloned from Oncidium Honey Angel by RTPCR technique, and the relative expression of the gene was analyzed by qRTPCR. The results showed that: (1) the anther chambers of Oncidium Honey Angel was obviously flattened, and the outer walls were sunken and shrunk. (2) The contents of Oncidium Honey Angel pollen cells were missing and the cytoplasm was vacuolated. Its pollen grains were abnormal, the pollen wall was not continuous, and there were many holes (not germination holes). (3) The OnMYB106 gene contains an open reading frame of 819 bp that encodes 272 amino acids. Comparison between the cDNA and genomic DNA sequences showed that OnMYB106 gene contains three exons and two introns. (4) Bioinformatical analysis revealed that OnMYB106 belongs to the SANT superfamily and has two consecutive MYB DNAbinding domains. It is a typical R2R3MYB transcription factor. Phylogenetic tree analysis showed that OnMYB106 had the highest consistency with the MYB106 protein sequence of Sorghum bicolor, Oryza sativa and Brachypodium distachyon, and the evolutionary distance was the closest. (5) Quantitative real time PCR results showed that OnMYB106 was downregulated in the Oncidium Honey Angel pollen cluster. OnMYB106 was expressed in different tissues of Oncidium Honey Angel, with the highest expression in flowers and the lowest expression in pseudobulbs. In the flowering stage, the expression level of OnMYB106 was the highest in the bud peroid, and only a small amount in the blooming period. This study showed that the abnormal pollen wall development of Oncidium Honey Angel may lead to pollen abortion. The OnMYB106 gene may play an important regulatory role in the growth and development of floral organs, and this gene may belong to the “early” expression genes of pollen development, which mainly affects the formation of pollen wall of Oncidium Honey Angel.

Abstract:Ephemeral plant Lepidium apetalum Willd. seedlings grow well at low temperatures in early spring in the north of Xinjiang, China, and have a perfect tolerance to low temperature stress. LaNHR2B (cold upregulated expression gene in L. apetalum), a gene found in L. apetalum, was previously reported as being upregulated in seedlings by cold stress. In this study, we obtained the fulllength cDNA sequence of LaNHR2B using homologybased cloning. We predicted and analyzed the nature and conformation of its encoding protein with bioinformatics software, the relationship between its expression and the growth stages of seedlings. We also studied its expression in response to cold induction and exogenous ABA treatment with quantitative RTPCR, and further explored the effects of LaNHR2B overexpression in Arabidopsis thaliana on cold tolerance. Results showed that: （1） the fulllength of LaNHR2B gene is 1 035 bp, encoding a protein consisting of 344 amino acid with a molecular weight of 85 791.16 kD, a theoretical PI of 5.06 and a formula of C₃₁₂₉H₅₂₂₅N₁₀₃₅O₁₃₀₇S₂₃₅. The protein contains alanine, threonine, glycine and cysteine, which has three transmembrane structures with unknown functions and strongly conserved in cruciferous plants. （2） Expression of LaNHR2B was upregulated by cold induction at 4 ℃, but this increase gradually decreased with the growth and development of seedlings, consistent with the decreasing trend of cold tolerance with growth. （3） Exogenous ABA induced LaNHR2B expression, and overexpression of LaNHR2B in A. thaliana enhanced cold tolerance. With these results we have proved that LaNHR2B expression has a close relationship with the cold tolerance of L. apetalum seedlings. Moreover, LaNHR2B may be a functional gene enhancing cold resistance after cold acclimatization, providing a certain theoretical basis and reference for further developing coldresistant breeding of crops with this gene.

Abstract:In this study, ‘Longjingchangye’ tea plant was used as tested material, and the cDNA sequence of the CsLEA5 gene in tea plant was cloned. The fulllength cDNA was 515 bp, including a 375 bp open reading frame that encodes 124 amino acids with a molecular weight of 13.5 kD and a theoretical pI of 5.92. Protein sequence analysis showed that CsLEA5 is a highly hydrophilic and stable protein, and contains a typical LEA_3 conserved domain, belonging to LEA_3 subfamily members of LEA protein. In addition, the promoter of CsLEA5 gene contains a variety of cisacting elements related to stress response, such as ethylene responsive element (ERE), stress responsive element (STRE), wound responsive element (wunmotif) and MYB, MYC transcription factor recognition sites, etc. The qRTPCR analysis showed that the expression of CsLEA5 gene had obvious tissue specificity, with the highest expression in leaves, followed by tender stem, and lower expression in other tissues and organs. Furthermore, the expression of CsLEA5 gene was induced by cold and drought stress, suggesting that it plays an important role in the response of tea plants to cold and drought stress. This study provides an important theoretical basis for understanding the resistance molecular mechanism of tea tree and screening the resistance candidate gene resources.

Abstract:An anthocyanin synthesis related gene named LrTTG1 (GenBank accession number MH633481) was cloned from Lycium ruthenicum using RTPCR and RACE methods. The sequence analysis showed that the length of LrTTG1 gene was 1 453 bp, which contained a 1 029 bp ORF encoding 342 amino acids with five WD40 repeats. Homology amino acid sequences comparison indicated that LrTTG1 had higher similarity with Solanum melongena TTG1 (83.73%). qRTPCR analysis revealed that LrTTG1 gene was expressed in stems, leaves, flowers, green fruits, purple fruits and black fruits, and the expression level (the highest) in green fruits was about 4 times that of black fruits (the lowest). LrTTG1 gene expression showed a trend on firstly falling and then rising with UV irradiation time. Anthocyanin content analysis showed that the content in black fruits was the highest (11.3 mg/g), which were about 9.4 times and 21.3 times of purple fruits (1.2 mg/g) and green fruits (0.53 mg/g), respectively. This study showed that the expression of LrTTG1 gene tended to decrease with the development of fruits, while the content of anthocyanin tended to increase, showing a negative correlation between them. It is speculated that LrTTG1 gene may play an important role in the anthocyanin synthesis of L. ruthenicum.

Abstract:The NtNHX13 gene was successfully isolated by homologous cloning from cultivated tobacco. The CDS length of NtNHX13 was 1 617 bp, and it was predicted to encode a 538amino acid protein. The theoretical isoelectric point of NtNHX13 protein was 8.67, and the molecular weight was 59.34 kD. The bioinformation analysis of NtNHX13 showed that it belonged to membrane protein containing 11 transmembrane regions，and had a conserved amiloride bindingsite specific to NHX protein. The phylogenetic tree analysis showed that NtNHX13 shared the same group with NHX from chicory and chrysanthemum. Tissuespecific expression analysis indicated that NtNHX13 was ubiquitously expressed in roots, stems, leaves and flowers, whereas had the highest level in leaves. The expression of NtNHX13 was upregulated after salt treatment, indicating that it was involved in salt stress response. The expression of NtNHX13 was upregulated in the early stage of topping, which was consistent with the increase of potassium content in this stage. Therefore, it was speculated that NtNHX13 could transport potassium ions from cytoplasm to vacuole.

Abstract:The fulllength cDNA sequence of metallothionein gene (BcMT2) was cloned from the leaves of nonheading Chinese cabbage disease resistant cultivar ‘Suzhouqing’ by race technique. qRTPCR was used to analyze the expression pattern of this gene in different tissues under biotic stress (P. parasitica) and abiotic stress (salt, drought, ABA) treatment conditions. SDSPAGE technology was used for analysis of prokaryotic expression characteristics for this gene. Sequence analysis showed that the fulllength cDNA of BcMT2 gene was 528 bp. The length of the open reading frame was 243 bp and encoded a total of 80 amino acids. The relative molecular mass was 8.02×10³ Da, and the theoretical isoelectric point was 4.61. The phylogenetic analysis of amino acid homology showed that the nonheading Chinese cabbage BcMT2 gene was belonged to the MT2 gene family of class Ⅱ plants and had similar evolutionary relationship with other plants of the same family. Among of them, the gene had the highest homology (100%), comparing with the gene (Bra029765) on A05 in Chinese cabbage. Quantitative realtime analysis showed that the expression of BcMT2 gene was the strongest in leaves of nonheading Chinese cabbage. The expression of BcMT2 gene was peaked at 48 h after infection by Pseudoperonospora cubensis in the diseaseresistant variety ‘Suzhouqing’, while the expression level was peaked at 72 h in the susceptible variety ‘Aijiaohuang’. Under salt treatment condition, the expression level of BcMT2 gene was peaked at 12 h in the resistant variety ‘Suzhouqing’, while the expression level was peaked at 24 h in the susceptible variety ‘Aijiaohuang’. Under ABA treatment, the expression level was peaked at 24 h in ‘Suzhouqing’, and the expression tendency of BcMT2 gene in ‘Aijiaohuang’ was similar to that of ‘Suzhouqing’. The expression of BcMT2 gene was inhibited in both materials under drought treatment conditions. Analysis of BcMT2 prokaryotic expression revealed that a specific molecular band of about 8×10³ Da was detected at 2, 4, and 6 h after induction at 37 ℃ and 1.0 mmol·L^-1 IPTG, which is related to the expected fusion protein. Results showed that nonheading cabbage BcMT2 gene plays an important role in the stress environment such as biotic stress and abiotic stress. In this study, BcMT2 has successfully achieved fused expression in Bacillus coli. The results established the foundation for the next step in the study of protein levels and the study of transgenic functions. Moreover, it will also provide important theoretical basis for breeding new nonheading cabbage varieties with high yield and good quality.

Abstract:In this test, SSR loci were searched for the mitochondrial and chloroplast genome sequences of Salvia miltiorrhiza by bioinformatics methods, and the SSR primers were designed by primer3.0 online software. 10 pairs of cpSSR primers and 13 pairs of mtSSR primers with high polymorphism were selected by PCR amplification. They were used to analyze the genetic diversity of 61 S. miltiorrhiza cultivars and the transferability of Salvia L. species.（1） Total 32 cpSSR and 24 mtSSR were identified from 2 genome sequences. There were 31 mononucleotide repeat sequences with 96.9% frequency, showing the dominant types in the cpSSR. Both A/T types were abundant among mononucleotide repeat sequences.（2） 46 alleles were detected in 23 pairs of SSR primers, the average number of alleles per SSR locus was 2, and the number of effective alleles was 1.566. The expected heterozygosities was 0.346, which was higher than the average level of dicotyledons (H_e=0.190); the polymorphism information content was 0.278, which was between 0.250 and 0.500; Shannons information index was 0.519. The results showed that S. miltiorrhiza had a moderate level of genetic diversity.（3） The cluster analysis on 61 S.miltiorrhiza showed that the genetic similarity coefficient was ranging from 0.54 to 0.96. It can be divided into 6 subgroups when the genetic similarity coefficient was 0.64: the S.miltiorrhiza in Sichuan, Shandong and Anhui provinces clustered in Ⅰ and Ⅱ subgroups, suggesting their close relationship. S.miltiorrhiza in Zhongjiang of Sichuan Province were distributed in all the subgroups, suggesting their rich polymorphism.（4） The results of transferability test showed that 11 pairs of mtSSR primers were successfully amplified in nine species belong to Salvia L., the transferability ratio was 64.63%, suggesting mtSSR markers showed a higher transferability. 9 pairs of cpSSR primers were successfully amplified in all samples of Salvia.L. species, and the transferability ratio was 44.66%, suggesting cpSSR markers showed a lower transferability. In addition, the primers cp5p, cp8p and cp10p had good generality among the genera of Lamioideae. These results indicated that 23 primers are suitable for SSR analysis of Salvia L. It would be useful for species relationship and study of genetic variation of Salvia L..

Abstract:We investigated and analyzed pollen morphologies of Ostericum Hoffm. (Apiaceae) of 8 species from 17 populations under light microscopy (LM) and scanning electron microscopy (SEM) in this research, in order to provide evidence for taxonomic identifications and studies of the relationship in this genus. The results showed that: (1) four types of the pollen grains from 17 populations were recognized including ellipse, subrectangular, superrectangular and equatorially constricted shapes. (2) Their shapes of equatorial view were ellipse, subrectangular, and superrectangular, and the shapes of polar view were mostly triangularrounded, while a few were triangular. (3) The polar axis length (P) is 24.7-35.6 μm, equatorial axis length (E) was 10.6-17.4 μm, P/E value and P×E^1/2 fell in 1.7-2.5 and 18.2-22.6, respectively. (4) Tricolporate apertures were observed in all the pollen grains with long and even colpus, in which most species were pleurotreme, yet a few were goniotreme. (5) Under SEM, the materials showed various exine ornamentations in equatorial regions which could be divided into three types, according to their different kinds of sculptures, as flaky cerebroid, long striate cerebroid and brevistriate baculate cerebroid. The surfaces of most grains had no appendage, except a few species contained granular or verrucous appendages. The study suggests that the pollen morphologies of Ostericum exhibited certain intraspecific stabilities both in pollen shapes and exine ornamentations, and also suggests interspecies diversities in aperture types, central protrudents and length, density and appendages of exine ornamentation. In conclusion, these morphological characteristics of pollen could probably present a potential information and significant evidence for a series of research on taxonomic revisions and genetic relationships of Ostericum.

Abstract:The objective of this work was to elucidate the effect of exogenous H₂S on cucumber protein expression under high salt stress. The saltsensitive cucumber cultivar ‘Chunxiaqiuwang’ was used as experimental material. The leaf proteins were separated by twodimensional electrophoresis (2DE), and the differential proteins were identified by matrixassisted laser desorption ionization tandem timeofflight/timeofflight mass spectrometry (MALDITOF/TOFMS). Functional annotation and metabolic pathway analysis of differentially expressed proteins were performed using NCBI and SwissProt database searches. The results showed: (1) about 2 490 protein spots were detected, of which 45 were differentially expressed at 1.5fold and P < 0.05 levels.The 24 proteins were upregulated, and 21 proteins were downregulated. (2) 26 proteins were successfully identified. These proteins are involved in photosynthesis (26.92%), protein metabolism (23.07%), energy and carbohydrate metabolism (11.54%), amino acid biosynthesis (11.54%), cell structure related protein (7.69%), antioxidant reaction (3.85%), signal transduction (3.85%) and unknown functional protein (11.54%). (3) The GO annotation showed that many differential expressed proteins is mainly composed of protein binding and hydrolase activity in molecular function, distributed in response to stimulus, organic substance metabolic process, response to stress and cell differentiation etc. in biological process, cell part and intracellular organelle in cellular component. KEGG metabolic pathway analysis showed that differential proteins are mainly involved in actin cytoskeleton regulation, apoptosis, carbon metabolism and light and regulation. The research indicated that exogenous H₂S induced differential expression of cucumber leaf protein under high salt stress, which provided a theoretical basis for the subsequent exploration of exogenous H₂S on the saltresistant molecular mechanism of cucumber.

Abstract:In the present study, the changes of DNA methylation in the barks of epicormic shoots which treated with mechanical wounding in rubber tree were analyzed by methylationsensitive amplification polymorphism (MSAP). The results showed that：（1） in comparison with the control, the levels of DNA methylation were slightly increased at the time point of 0.5 and 2 hours after mechanical wounding. And the larger decrease of DNA methylation levels were observed at 48 hours after mechanical wounding. （2）The main DNA methylation and demethylation events were occurred at 2 and 48 hours, respectively. （3）ATP synthase F1 subunit 1, phosphoribosylamineglycine ligaselike, cold shock domaincontaining protein 3, photosystem II 47 kD protein, E3 ubiquitinprotein ligase RING1, NADHubiquinone oxidoreductase and some hypothetical protein were identified from the differentially methylated sites induced by mechanical wounding. （4）Bisulfite sequencing showed that the both CCGG sites of ATP synthase F1 subunit 1 and NADHubiquinone oxidoreductase were hypomethylated inducing by mechanical wounding. Therefore, the results suggested the DNA methylation may involved in the response of mechanical wounding in epicormic shoots of rubber trees.

Abstract:In this experiment, the effects of different concentrations of cadmium (0, 5 and 10 mg·L^-1) on the growth of 10 kinds of rootstock seedlings squash, the content of malondialdehyde (MDA), the content of Cd in shoots and the transfer coefficient (TF) were studied by means of nutrient solution culture. We used membership function method to comprehensively evaluate its ability and absorption and accumulation ability of Cd in order to screen excellent rootstocks The results showed that: (1) the whole plant biomass of ‘Duomei 109’, ‘Xinli 3’, ‘Qiangli No. 1’, ‘Heizi Nangua’ and ‘Yunnanheizi Nangua’ were significantly lower than that of control under 5 mg·L^-1 and 10 mg·L^-1 Cd treatments, and the biggest decreased were ‘Heizi Nangua’ and ‘Yunnanheizi Nangua’, which were the worst resistance. However, the biomass of ‘Yemu Yixiong’, ‘Qingjia Zhenjia’, ‘Jinyou 108’ and ‘Kangxian No. 1’ had no difference with the control, and the tolerance was the strongest. (2) Under the two concentrations of Cd treatments, the antioxidase activities in seedlings of ‘Jinyou 108’ was higher, and the MDA contents in roots and leaves were not significantly different from the control, indicating that it was not subjected to membrane lipid peroxidation injury. The antioxidase activity in ‘Yemu Yixiong’ seedlings was higher, and the increase of MDA content was smaller, which was 1.01~1.56 times of the control, indicating that the membrane lipid peroxidation injury was relatively small. The antioxidase activity of ‘Domei 109’, ‘Qiangli 1’ and ‘Yunnan Yunnanheizi pumpkin’ seedlings were decreased significantly under the 5 mg·L^-1 and 10 mg·L^-1 Cd treatments, and the MDA content increased greatly, which was 1.30-2.46, 1.33-3.11, 1.45-3.24 times higher than that of the control, respectively, and the most severely affected. (3) The Cd content and TF of ‘Jinyou 108’ and ‘Qingjia Zhenjia’ were lower, and the Cd absorption capacity was the weakest under Cd treatment, followed by ‘Yemu Yixiong’. However, ‘Lianglijia’, ‘Heizi Nangua’ and ‘Yunnanheizi Nangua’ were the highest, and the Cd absorption capacity was the strongest. (4) The comprehensive evaluation results of the membership function values showed that the tolerance of 10 variety pumpkin seedlings for rootstocks to Cd was as follows: ‘Jinyou 108’ >‘Yemu Yixiong’ >‘Xinli 3’ >‘Qingjia Zhenjia’> ‘Kangxian No. 1’> ‘Duomei 109’ >‘Heizi Nangua’ > ‘Lianglijia’> ‘Qiangli No. 1’ > ‘Yunnanheizi Nangua’. The studies showed that the tolerance of rootstock pumpkin varieties to cadmium stress was significantly different, and ‘Jinyou 108’ was the best, which has good growth potential, strong tolerance, and the capacity of cadmium absorption and transport was the weakest under cadmium stress.

Abstract:In order to explore the physiological mechanism of nitrogen metabolism in wheat roots after anthesis under field management models that integrated by differnet water controls and fertilizer managements, provide theoretical basis and technical support for improving nitrogen use efficiency and realizing high yield and good quality in production, we determined the activities of glutamine synthetase (GS), glutamate synthetase (GOGAT), glutamicpyruvic transaminase (GPT) and nitrate reductase (NR) in roots of different soil layers (0-20 cm and 20-40 cm) after anthesis (0, 7, 14, 21, 28 d) under three management models at different yield levels ［highyield and highefficiency model (HH), highefficiency model (HE), super highyield model (SH)］ by using Aikang58 that planted in rootbox. The results showed that: (1) the activities of nitrogen metabolism enzymes in roots of 20-40 cm soil layer were higher than those of 0-20 cm in late stage of wheat growth; the activities of four nitrogen metabolism enzymes in roots of two soil layers under HH model were significantly higher than those of SH and HE models, but there was no significant difference between SH and HE model in most periods. (2) GS activity in roots of two soil layers under three models showed a tendency of “downrisedown”, and reached a peak at 14 days after anthesis, then decreased. (3) Compared with SH and HE models, the GOGAT activity intensity and maintenance time in roots under HH model were higher than those under SH and HE models; GPT activity in roots of two soil layers under HH and SH model had no obvious change from anthesis to 7 days after anthesis, but decreased rapidly from 7 days to 14 days and remained at a certain level from 14 days to 28 days. (4) NR activity in roots of two soil layers under three models decreased more slowly from anthesis to 21 days after anthesis and decreased rapidly from 21 days after anthesis to 28 days after anthesis. (5) There were significant differences in grain yield and its components among three models, and grain yield of HH model was significantly higher than that of SH and HE model. The study showed the reasonable cultivation model could better coordinate the physiological activities of the upper and underground parts of wheat, and then guarantee the high yield. Furthermore, the root nitrogen assimilation ability of HH model was the strongest and its yield was the highest.

Abstract:In order to find out the impact and mechanism of orchid mycorrhizal (OM) fungi on photosynthesis of Dendrobium officinale, we investigated the effect of OM fungi on the growth of D. officinale seedlings using a pot experiment. The chlorophyll content, photosynthetic characteristics, chlorophyll fluorescence parameters, and the expression of pepc gene were analyzed. The results were as follows: (1) OM fungi could improve the growth of D. officinale seedlings. The height of plants, mass of roots, mass of shoots and total biomass of D. officinale seedlings were of 1.21, 1.54, 1.71 and 1.68fold, respectively, compared to control. Chlorophyll content, net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) of D. officinale seedlings increased too. (2) The potential photochemical efficiency (F_v/F₀), photochemical maximum efficiency (F_v/F_m), the photochemical quenching coefficient (q_P), nonphotochemical quenching coefficient (q_N), quantum yield of electron transport (Yield) and apparent photosynthetic electron transport rate (ETR) in leaves of _{D. officinale} seedlings inoculated with OM fungi were higher than that of control. (3) OM fungi could enhance the expression level of pepc gene, PEPC activity, and promote photosynthetic carbon assimilation of D. officinale. Therefore, the development of D. officinale mycorrhiza could improve photosynthesis, the expression level of pepc gene and the growth of D. officinale seedlings.

Abstract:Pleurocarpous mosses, a group of bryophytes with large size, have complex morphological structure and play important roles in soil and water conservation. In this study, vegetative propagation of six species of pleurocarpous mosses that collected from the typical Hilly Loess Plateau region were investigated by artificial cultivation experiment, so as to determine their characteristics and interspecific differences. The results showed that: (1) the six species of moss exhibited strong regenerative capacities. The germination times of the new gametophyte and protonema averaged out to 10^th and 17^th day of cultivation, respectively. Furthermore, the germination time of gametophyte of the six mosses was earlier than that of proteome. Among the six mosses, Brachyhecyum albicans was the first one that germinated gametophyte and Hypnum bambergeri was the last one. (2) During cultivation period, the branch length, branch number and coverage of the six mosses showed an increasing trend along with the increasing of cultivation time, and stabilized, thereafter. The branch length and number of the six mosses tended to be stable in the 21st and 28th day after germination, respectively. Coverage of the six mosses, except Amblystegium serpens, whose coverage continued to increase, began to stabilize after 42day cultivation. B. albicans showed the largest increase of branch length, branch number and coverage, which were 4.73 mm, 1.53 and 46.22%, respectively. (3) The average rate of coverage, branch length and branch number showed significant differences between moss species. The three indices of B. albicans are 0.97%·d^-1, 0.24 mm·d^-1 and 0.101 shoot·d^-1, respectively. They are significantly higher than those of other species (P<0.05). The slowest rate of branch length, branch number and coverage were observed in Taxiphyllum taxirameums (0.17 mm·d^-1), Hypnum bambergeri (0.041 shoot·d^-1) and Entodon caliginosus (0.46%·d^-1). The results showed a strong reproductive and artificial cultivation capacity of the six species of common pleurocarpous moss from Hilly Loess Plateau region. Further, B. albicans showed an advantage over other species. This is as earlier report on the reproductive and cultivation capacity on the pleurocarpous mosses in the region, which may provide support for the application of such moss species in soil and water conservation and ecological restoration.

Abstract:In this paper, 50 subtropical evergreen deciduous broadleaved mixed forest plots in the Xingdoushan National Nature Reserve of Hubei Province were studied. The leaf function of different life forms (shrubs, trees and lianas) and soil nutrients were determined by sample analysis. The determination was carried out, and the effects of soil nutrients on leaf functional traits of different lifetype woody plants were analyzed by redundancy analysis (RDA) and stepwise regression. The results show that: (1) the mean value of specific leaf area (SLA) of shrubs was the highest (319.87 cm·g^-1), and the average leaf dry matter content (LDMC) of trees was the highest (0.40 g·g^-1), leaf area (LA) of lianas, leaf thickness (LT), leaf total nitrogen content (LTN) and leaf total phosphorus content (LTP) mean value are the highest, They are: 105.07 cm², 0.24 mm, 20.10 mg·kg^-1, 1.19 mg·kg^-1; The LDMC and LTN distribution of the three life forms are concentrated, while the distribution of LA, SLA and LTN is right partial, but the distribution of LT and LTP are left partial, while that of shrubs and lianas are right partial distributed. (2) The pH value of soil in the study area is 3.81~4.95, all of which are acidic soil, and the content of soil organic matter is between 4.57% and 12.05%, with an average value of 7.79%; Soil rapidly available potassium and Soil availablenitrogen were as follows: 64.52~339.29 and 82.83~678.15 mg·kg^-1, Soil total N content, Soil total phosphorus content and Soil rapidly available phosphorus were as follows: 5.48 mg·kg^-1、0.46 mg·kg^-1 and 0.39 mg·kg^-1. (3) Among variation of leaf traits in three different life forms, soil nutrientshad the highest impacton liana variation, explaining 24% of them, next is shrubs (15%), and the lowestweretrees (13%). (4) Trees and liana are greatly affected by soil organic matter, and shrubs are greatly affected by rapidly available potassium. Although the main factors affecting functional traits of different life types are different, the main influencing factors are soil organic matter, soil total phosphorus, and rapidly available potassium. Research suggests: The soil of Xingdoushan National Nature Reserve can explain the variation of leaf functional traits of different life types of plants to some extent, and the influence degree is different. This difference is beneficial to species coexistence and biodiversity maintenance in this area. At the same time, the study on the relationship between leaf function and soil nutrients of different life type plants in subtropical region was made up.

Abstract:In order to explicate the current state of natural Armeniaca sibirica population and predict the population dynamics in the future, were investigated three populations along altitude gradients in mountain areas of northern Hebei Province. According to the diameter at breast height (DBH) class of the tree, the age class structures of three A. sibirica populations were analyzed, static life tables were constructed by smoothing out technique, and comparative fluctuations cycles of the populations were carried out by spectral analysis. In addition, more analysis were performed to reveal the effects of altitude factors on population dynamics of natural A. sibirica and the mechanism of population renewal and maintenance. Furthermore, we provide the scientific basis for the protection and management of A. sibirica populations. The results showed as follows: (1) DBH decreased gradually with the increasing altitude. There were 15 age classes with the maximum DBH of 12.47 cm in the lowaltitude habitat of 872 m (H1), 17 age classes with the maximum DBH of 14.10 cm in the middlealtitude habitat of 1 131 m(H2), and 11 age classes with the maximum DBH of 8.76 cm in the highaltitude habitat of 1 328 m (H3). The individuals of each population showed H1(2 158) > H2(1 262) > H3(133). (2) The population structure dynamics of A. sibirica at different altitudes all belonged to the increasing type. V′_pi of each population was greater than 0, with the dynamic change of H2(57.51%, 3.38%)＞H1(47.42%,3.16%)＞H3(27.57%, 2.51%). (3) Life expectancies of A. sibirica populations were fluctuant for the same age class in different altitudes and for different age classes in the same altitude. In the three altitudes, the survival curves of the populations trended toward DeeveyⅡ type, and the mortality rate of each diameter stage had little change and tended to be stable. (4) The mortality rate of A. sibirica population showed 7 (H1), 6 (H2) and 3 (H3) peaks along altitude gradients, indicating that the number of death fluctuations in the life cycle of the A. sibirica population decreased gradually with the increase of altitude. (5) Population dynamic spectrum analysis showed that, there were obvious small periodic fluctuations in the population harmonics of A. sibirica as well as the effect of fundamental wave at different altitudes, the harmonics of A. sibirica population in H1, H2 and H3 altitude fluctuated at A2 and A8, A7, A5, respectively. The natural regeneration of its current populations is good. If not strong anthropogenic disturbances or severe natural disasters, A. sibirica would maintain the dominant position in the community．

Abstract:In order to understand the structure of the population and analyze its current survival situation, we conducted this investigation in the field survey data with a total area of 5.25 hm₂ in the east end of Tianshan wild fruit forest in Yili of Crataegus songarica K.Koch populations, and static the life table of population by smoothing out technique, drawing the survival curve, mortality and disappearance rate curve parameters, and the survival analysis of 4 survival functions, using the population dynamic quantization and time series prediction analysis of population dynamics. The results showed that: (1) in the east end of Tianshan wild fruit forest, the middle and old age individuals in C.songarica population were less, namely the class Ⅰ of individuals accounted for 65.5% and the class Ⅱ droped quickly to 6.5%. Therefore, the population structure belongs to the growth type and the survival curve of C.songarica populations tended to be DeeveyⅡ type in the research area; (2)The changes in the mortality and disappearance rate curves are basically the same in the research area, with a total of 4 death peaks at the class Ⅰ, class Ⅵ, class Ⅸ and class Ⅻ, respectively. And the highest peak occurred at the class Ⅰ, being 89.9%; (3)The results of the 4 survival function curves showed that the population of C. songarica had the characteristics of early decline, mediumterm stability, post recession early, and the time series analysis showed that the old class population would increase in the future. Research shows that the growth of C. songarica urgently needed to supplement seedlings or young individuals and to prohibit felling adult individuals so as to provide guarantee for the conservation and recovery of C. songarica population．

Abstract:In order to explore the diversity characteristics of bryophytes in the underground forest , we use gradient method to study the diversity of bryophytes in underground forest of Monkeyear Tiankeng, which is about280 meters apart from the earths surface and its diameter is about 300 metres. Research results show that: (1) there are 71 species of bryophytes in underground forest,there are five growth matrices of bryophytes, and the trunk is the most abundant growth matrix of bryophytes (41 species). The number of the other four growth matrix species presents adecreasing trend of forest land >stone surface >carrion> leaf surface. (2) There are 10 species of lifeforms in underground forest, a total of 88% of the lifeform types enjoy the dark and humid environment, while only 12 percent are adapted to the bright and dry environment. (3) Studying on the Margalef of bryophytes, shows that middle (8.461 7)> bottom (7.502 0) > top (6.978 5), and Pielou of bryophytes shows that top (0.945 4) > bottom(0.907 2) >middle (0.844 5). (4) Analysis of the Bata diversity of bryophytes, which shows that the difference of bryophyte community is between (0.75-1.00) in different gradient of underground forest, and the difference between bottom and top is as high as 0.960 8. (5) Analysis shows that the underground forest has high dissimilarity not only in different gradient but also in whole forest, its structure differentiation is obvious and its habitat is complex, all of that is because of its unique topography and hydrothermal conditions. (6) RDA analysis showed that light, humidity and temperature were the main factors influencing the bryophytes species distribution of underground forest of Tiankeng,among which light had the greatest influence. (7) The comparison of species diversity in and out of Tiankeng shows that underground forest of Tiankeng has higher species diversity of bryophytes and it is a natural refuge for the species in karst rocky desertification area.

Abstract:Halenia elliptica D. Don. f. alboflavida J. L. Wang, a form of Halenia (Gentianaceae) from Daofu County, Sichuan Province, China, is described. It differs from the typical form, H. elliptica D. Don., by having white petals and partially yellowish spurs.

Abstract:Receptorlike kinases (RLKs) are a class of singletransmembrane receptors with kinase activity. They modulate plant growth and development by perceiving and transmitting extracellular signals to regulate cellular physiological responses. Plant roots are suffered by a large amount of external stimuli and endogenous developmental signals during growth and development. Plants must integrate these signals and transform into cellular responses to adapt to changeable environmental conditions. RLKs regulate plant root growth and development by communicating with exogenous and endogenous signals as information monitors on plasma membrane. In this paper, we summarized recent studies on the structure, classification and mechanism of RLKs, and highlighted their function and roles in signal transduction in root development, which provides important information for further revealing the function and mechanism of RLKs in plant root growth and development.