The NAC (NAM, ATAF1/2 and CUC2) gene family is one of the largest plant-specific transcription factor families, functioning as crucial regulators in diverse biological processes such as plant growth and development as well as biotic and abiotic stress responses. Although it has been widely characterized in many plants, the significance of the NAC family in Dendrobium officinale remained elusive up to now. In this study, a genome-wide search method was conducted to identify NAC genes in Dendrobium officinale (DoNACs) and a total of 110 putative DoNACs were obtained. Phylogenetic analysis classified them into 15 subfamilies according to the nomenclature in Arabidopsis and rice. The members in the subfamilies shared more similar gene structures and conversed protein domain compositions. Furthermore, the expression profiles of these DoNACs were investigated in diverse tissues and under cold stress by RNA-seq data. Then, a total of five up-regulated and five down-regulated, cold-responsive DoNACs were validated through QRT-PCR analysis, demonstrating they were involved in regulating cold stress response. Additionally, the subcellular localization of two down-regulated candidates (DoNAC39 and DoNAC58) was demonstrated to be localized in the nuclei. This study reported the genomic organization, protein domain compositions and expression patterns of the NAC family in Dendrobium officinale, which provided targets for further functional studies of DoNACs and also contributed to the dissection of the role of NAC in regulating cold tolerance in Dendrobium officinale.

The homeodomain-leucine zipper (HD-ZIP) gene family, as one of the plant-specific transcription factor families, plays an important role in regulating plant growth and development as well as in response to diverse stresses. Although it has been extensively characterized in many plants, the HD-ZIP family is not well-studied in Dendrobium officinale, a valuable ornamental and traditional Chinese medicinal herb. In this study, 37 HD-ZIP genes were identified in Dendrobium officinale (Dohdzs) through the in silico genome search method, and they were classified into four subfamilies based on phylogenetic analysis. Exon-intron structure and conserved protein domain analyses further supported the prediction with the same group sharing similar gene and protein structures. Furthermore, their expression patterns were investigated in nine various tissues and under cold stress based on RNA-seq datasets to obtain the tissue-specific and cold-responsive candidates. Finally, Dohdz5, Dohdz9, and Dohdz12 were selected to validate their expression through qRT-PCR analysis, and they displayed significantly differential expression under sudden chilling stress, suggesting they might be the key candidates underlying cold stress response. These findings will contribute to better understanding of the regulatory roles of the HD-ZIP family playing in cold stress and also will provide the vital targets for further functional studies of HD-ZIP genes in D. officinale.

以3种竹柳品系3号、5号、7号为试验材料，以垂柳为参照，通过不同人工模拟－20、－25、－30、－33、－35、－38、－40℃等低温处理，测定各枝条的相对电导率、可溶性蛋白、SOD、POD、游离脯氨酸及丙二醛含量等抗寒性相关指标，运用Logistic方程计算半致死温度，通过主成分分析法和隶属函数法综合评价各竹柳品系与垂柳的抗寒性。结果表明，不同温度梯度下，各抗寒指标与竹柳品系和垂柳的抗寒性显著相关（P＜0．05）；各竹柳品系抗寒性均高于垂柳，相对电导率与抗寒综合指数大小为竹柳5号＞竹柳7号＞竹柳3号＞垂柳；半致死温度与抗寒综合指数极显著负相关（P＜0．01）。

以3年生银杏幼苗为材料，设置轻度、中度、重度3种干旱处理，测定叶片光合参数变化。结果表明，干旱胁迫条件下银杏叶片相对含水量保持在75．31％～87．19％；随着干旱胁迫的加重，光合速率及气孔导度加速下降，而胞间CO2浓度先下降后上升；PSⅡ反应中心电子受体侧、供体侧结构变化，叶绿素荧光初始荧光逐渐上升，最大荧光、电子传递活性下降，热耗散增大；50％～65％的田间持水量条件下，光量子效率最高。这表明在轻度干旱时，银杏叶片光合作用下降主要是气孔因素引起的，光合机构没有受到严重的损伤，而在中度、重度干旱胁迫下，叶片光合作用下降是由非气孔因素引起的，伴随着PSⅡ反应中心电子供体侧和受体侧的结构损伤。

The degree of harm to the development of Coreopsis that is caused by different density of the chlorine-salt and non-chlorine-salt plant-based snowmelt were studied. The result shows that the contents of soluble sugar and malondialdehyde (MDA) in the leaves of Coreopsis which is used certain density of non-chlorine-salt plant-based snowmelt agent are lower than that of leaves of Coreopsis which is used the chlorine-salt snowmelt agent. The contents of chlorophyll and relative water content of are significantly higher than that of the latter. As compared with the control group, malondialdehyde(MDA), soluble sugar content have no obvious change with the augment of the amount of non-chlorine-salt plant based snowmelt agent. Chlorophyll content and relative water content increase first and then decrease. With the augment of the amount of chlorine-salt snowmelt agent, the contents of malondialdehyde (MDA) and soluble sugar increase obviously, and the chlorophyll content and relative water content show obvious decrease. When the density reaches 8g/L, as threatened by chlorine-salt snowmelt agent, the leaves of Coreopsis become obviously brown, but the Coreopsis under non-chlorine-salt plant based snowmelt agent has no obvious suffering.

The effects of deicing salts on seed germination and growth of shoots and roots of four kinds of ground covers (Poa pratensts, Bromus inermis Layss,Coreopsis basalis,Cosmos bipinnatus Cav. ) were studied. The length of roots and shoots of ground covers were also determined in this paper. The results showed that the inhibition effect on seed germination and growth response in the four kinds of ground covers was increased with increasing concentration of deicing salts. Cosmos bipinnatus Cav.showed the highest tolerance to deicing salts, followed by Bromus inermis Layss, Coreopsis basalis and Poa pratensis. The critical value of tolerance to deicing salts were 14.69 g/L, 10.04 g/L, 7.38 g/L and 7.31 g/L forCosmos bipinnatus Cav, Bromus inermis Layss, Coreopsis basalis and Poa pratensis,respectively and the maximum value were 21.08 g/L, 16.51 g/L, 14.67 g/L and 13.50 g/L, respectively.

Using Kentucky bluegrass (Poa pratensis l.) as the main test object, we studied its relative water content, water saturation deficit, leaf water potential, ratio of free water to bond water, relative growth rate, total nitrogen content and total phosphorus content. The results showed that the concentrations of 15 g/L make Kentucky bluegrass hurt after 7 days. All water indexes appeared declining tendency. The treatments of 25 g/Land 30 g/L concentrations restrain plant growth severely after 21 days. The content of total nitrogen, total phosphorus of leaf decreased after experiment, while the root changed not obviously. Considering the changing of indexes with neighbor concentrations processing, we found that the differences of 20 g/Land 25 g/L treatments appeared obviously and smoothly in seven indexes after 21 days.

Taking non-chlorine plant-based snow melting agent as experimental subjects, Shenyang Airport Expressway and Shenben highway greenbelt green belt as monitoring sample plot, the paper researched the dynamic residual of non-chlorine plant-based snow melting agent in the soil and the changes of soil fertility. Liquid chromatograph was applied to determine, and the data were analyzed by SPSS and Excel. The results showed that soil depth, distance, time is the main factors affecting the dynamic residues of non-chloride snow melting agent, the impact order is time>soil depth>distance. With the increase of time, highway edge distance and soil depth, the content of non-chloride snow melting agent in soil decreased until the complete degradation.

为大连以及气候类型相近城市的绿地规划和植物多样性建设提供科学依据.本研究对105个不同类型和不同规模的大连城市绿地样方内植物群落的树种组成、群落特征和物种多样性进行分析,结果表明:调查样方共有植物种类262种,其中乔木类115种,灌木类50种,草本类97种.乔木与灌木树种的比例约为1.0∶0.43;常绿植物与落叶植物的种类比例约为1.0∶4.3.在五种绿地类型中,总体物种多样性表现为公共设施绿地、居住绿地和公园绿地较高,道路绿地次之,其他绿地最差.

The species of arbors and the number for each species in 7 parks in DaLin were investigated. The tree species composition was analyzed by means of four indexes of number of tree species, Simposon, Shannon-Wiener and Peilou species evenness. We draw a conclusion that there are 75 species subjected to 31 families and 40 genera in 7 parks. For Simposon index, the order (from the highest to the lowest) is Ganjingzi Park, Xinghai Park, Fumin Park, Mingzhu Park, Laodong Park, Zhongshan Park, Zelonghu Park. For the Shannon-Wiener index the order is Ganjingzi Park, Fumin Park, Xinghai Park, Laodong Park, Mingzhu Park, Zhongshan Park and Zelonghu Park. For Peilou species evenness index, the order is Xinghai Park, Laodong Park, Ganjingzi Park, Fumin Park, Mingzhu Park, Zhongshan Park and Zelonghu Park.

Plant specimen,as a basic means to preserve the plant resources and plant information,provide important scientific evidence for the administration and use of plant resources and cannot be replaced by written records.Plant specimen are classified into material objects and digitized specimen according to their existence pattern and appearance.Compared with the material objects,the digitized specimen collected and processed by digital technology have more advantages,which have become a heated topic in this field.The digitized landscape plant specimen can not only provide important contents for the landscape plant teaching practice,but also important references for the landscape plant design and arrangements.Though building database is an important way to normalize the collection and administration of landscape plant speimen,the process ranging from using the tools with different parameters to sorting out a good tool to use(or a computer software) and from the collecting and classifying all kinds of information to processing and building database has to be normalized.What's more,the scheme of collection and the way of procession have to be normalized and integrated.This research centers on the scientific study of exsiccata and immersion specimens in the Plant Specimen House of Collection in Shenyang Agricultural University.By means of the computer-assisted digital technology and means,the digitized technology of the rosaceae plants exsiccata is explored in contrast to the color of living specimens,aiming at providing technical supports for digitizing type specimens and identifying plants in a taxonomic way.This paper makes a systematical research of the digitized restoration technology of the original color of plant exsiccata,the construction of the digitized classification system of plant morphology of rosaceae plants,and the design of the plant morphological classification database of rosaceae plants.

Taking Prunus wilsonii as experimental material,by spraying 0,0.5,1.0,1.5,2.0 mmol/L SA solution respectively to the tested plants leaves,under artificial low-temperature stress,five physiological indexes anthocyanin content,free proline content,relative electrical conductivity,SOD content and MDA content were determined and the effects of exogenous salicylic acid on freezing resistance of Prunus wilsonii were studied.The results showed that the application of exogenous salicylic acid could inhibit the destructive effect of low temperature on anthocyanin,improve the activity of SOD enzyme,increase the content of free proline and reduce the content of MDA and the relative conductivity,thus weakening the damage of low temperature on Prunus wilsonii,improving freezing resistance of the Prunus wilsonii 1.0 mmol/L SA treatment was optimum.

Plant landscape for the green space of parks in Huludao city was investigated and analyzed.According to the plant information in Huludao city and the plant disposition materials at home and abroad,this paper discussed the characteristics of plant landscape for the green space of parks.The existing problems were summarized.The article draw meaningful conclusions as follows: tree species selection,community structure and plant disposition mode of green space are related to the park site conditions,ecology and landscape function.The green space of parks have the maximum of plant species and the most complicated ecological community.

The adaptability of Sedum lineare Thunb on the stone slope was studied in this article. Sedum lineare Thunb was planted on bare stone slope of the Qingyuan part of the Shen ji highway. The physiological indicators under drought stress, above-ground and underground biomass were determined, and the plant communities were investigated. The results showed that Sedum lineare Thunb expressed strong drought resistance through the three basic adversity physiological indicators. In aspects of ecological adaptability, the proportion of above-ground and underground biomass reached 12.15, and the value of SDR reached 50.32. So it is able to adapt to harsh conditions. Sedum lineare Thunb could be applied on the stone slope.

The 14 species introduction and acclimatization plants with high ornamental value including 8 species of arbor and 6 species of shrubs in Shenyang Landscape Plant Specimens Park were chosen as study objects to track and survey.The characteristics of cold resistance and drought tolerance were explored through investigating the trees height,blossom period,fruit maturity and the growth status in high and low temperature in order to discuss the feasibility of introduction and acclimatization.Finally,according to the geographical environment of Shenyang city,there are several suggestions for the introduction and acclimatization of the landscape plants.

By results and indicators of the two experiments, this paper evaluated the effect of reinforcing embankment of Portulaca grandiflora, and compared the difference of effectiveness between the Portulaca grandiflora with seed propagation at this year and the Portulaca grandiflora with self-propagating at the following year.

Taking aquatic plants Monochoria korsakowii as materials,under the conditions of the nutrient solution containing,different concentrations of phenol and ammonia nitrogen on the growth of Monochoria korsakowii of the ground part and the underground part,and Monochoria korsakowii resistance uptake and accumulation of organic pollutants in water phenol and ammonia nitrogen were studied.The results showed that Monochoria korsakowii could grow in the sewage contains a certain concentration of phenol and ammonia nitrogen,and removal force of phenol and ammonia nitrogen was more considerable,the average removal rates respectively was 85.2% and 73.1%;while the enrichment coefficient for phenol of Monochoria korsakowii of the ground parts of the underground part respectively reached 9.58and 4.64,the largest accumulation of its nitrogen were 712.682mg and 498.815mg per plant.It showed Monochoria korsakowii could remove the phenol and ammonia nitrogen in the waste water and played a good role for purifying water.

Taking Selaginella tamariscina and Selaginella sanguinolenta as experimental materials,the photosynthetic characteristics of the leaves under different light intensity(no shading(control CK:light transmittance 100%),single shading(light transmittance 70%),double shading(light transmittance 50%),three layer of shading(light transmittance 20%)) were studied.The results showed that the 2 species of Selaginella in no shading and single shading conditions,net photosynthetic rate was higher than the other two treatment of Selaginella;Selaginella tamariscina diurnal variation of net photosynthetic rate curve for Shuangfeng,had obvious midday depression,but Selaginella sanguinolenta midday depression was not obvious.The degree of recovery from midday depression,Selaginella tamariscina illumination adaptability was wider than Selaginella sanguinolenta.Chlorophyll content and specific leaf weight changed further proved the point.

In order to further understand and improve the plants disposition patterns in green space of public gardens in Dalian city,by using typical sample sampling method,the plants disposition patterns in 5 parks have been researched.What's more,the plants composition,growth form,community density,the ratio of arbores and bushes and coverage in the given thirty quadrats were surveyed.The results showed that:(1)The arbor-shrub-grass disposition pattern took up 70 percent,the arbor-shrub disposition pattern took up 10 percent and the arbor-grass disposition pattern took up 20 percent.The arbor-shrub-grass disposition pattern was mainly used.(2)The coverage of arbor was 62.94 percent,the coverage of shrub was 6.95 percent and the coverage of grass was 66.51 percent.The overall coverage was high and the middle structure was simple.(3)The average density of arbors was 14 plant per 300 m2,the average density of shrubs was 17 plant per 300 m2 and the latter was slightly bigger than the former.(4)The most used arbors were Metasequoia glyptostroboides,Ginkgo biloba,etc.7 plants;the most used shrubs were Ilex purpurea,Buxus sinica,etc.8 plants;Hosta planta ginea 'Fairy variegata' and Petunia hybrid,etc.12 herbal plants were used as cover plant;The Poa was used as the only type turfgrass.

Taking Selaginella tamariscina as experimental materials,from five physiological indexes of Selaginella tamariscina starting,the net photosynthetic rate(Pn),stomatal conductance(Gs),the ratio of intercellular CO2 concentration and atmospheric CO2 concentration(Ci/Ca),transpiration rate(Tr) and water use efficiency(WUE),diurnal photosynthetic changes of Selaginella tamariscina under different drought stress conditions were studied.The results showed that the net photosynthetic rate of the normal watering plants(CK) showed a bimodal curve of diurnal variation and had a character of photosynthetic depression at midday;The net photosynthetic rate,stomatal conductance and transpiration rate of Selaginella tamariscina decreased under drought stress;Diurnal photosynthetic changes of Selaginella tamariscina under mild drought stress condition were the same as CK;Diurnal photosynthetic changes of Selaginella tamariscina under moderate drought stress condition also showed a bimodal curve,but the net photosynthetic rate all day significantly decreased;The midday depression phenomenon and bimodal curve of Selaginella tamariscina under severe drought stress condition disappear,the change of stomatal conductance and transpiration rate was close to zero range all day.