Table of Content

05 July 2020, Volume 40 Issue 4

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Research Report

Peristome Submicro Structure of Hypopterygium in Karst Tiankeng

WU Jin, ZHANG Zhao-Hui, WANG Zhi-Hui

2020, 40(4):  481-489.  doi:10.7525/j.issn.1673-5102.2020.04.001

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The microenvironment of Karst Tiankeng has a significant effect on the characteristicsof plant structure.In order to provide reference for the structural adaptation of the peristome of moss in the microenvironment, the submicrostructure of the peristome of the Hypopterygium in the karst Tiankeng was studied by scanning electron microscope (SEM).From the submicroscopic morphology of peristome, two species of Hypopterygium, named H.flavo-limbatum C.Muell and H.japonicum Mitt, have obvious differences in the shapeof their dentium, tropism of dentium, dorsal ridges of the exstomium, ventral lateral stripes of the processus and whether they have ganglioma or not.It belongs to the characteristic of stability and can be used as the basis of system classification. On the other hand, the length and width of dentium, number of plates, transverse raphe and middle raphe are variable characteristics, which should be screened when the peristome of mosses are used as the basis of systematic classification.Illuminance, air temperature, air humidity and altitude are the main environmental factors affecting the development and growth of peristome morphological and structural of H.flavo-limbatum in Tiankeng. Air humidity, illuminance and artificial interference are the main environmental factors affecting the development and growth of peristome morphological and structural of H.japonicum in Tiankeng. Both of the peristome structures of two species of Hypopterygium are most affected by humidity, andtheir habitats are mostly humid and rich in soil moisture.

Effects of Primary Dormancy-released Status and Drying Treatment on Germination of Fraxinus mandshurica Seeds

LU Yan, YAN Yue, CUI Cheng-Cheng, ZHANG Peng

2020, 40(4):  490-495.  doi:10.7525/j.issn.1673-5102.2020.04.002

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In order to explore the effects of different primary dormancy-released status and drying treatment on the germination of Fraxinus mandshurica seeds, we used mature F.mandshurica seeds with primary dormancy to study different naked stratification(warm stratification for 10 weeks and cold stratification for 8 weeks, warm stratification for 12 weeks and cold stratification for 8 weeks, warm stratification for 10 weeks and cold stratification for 10 weeks, warm stratification for 12 weeks and cold stratification for 10 weeks) and drying treatment(drying or not drying) of F.mandshurica seed germination performance under suitable temperature and higher temperature conditions. The results showed that the germination of F.mandshurica seeds with different primary dormancy-released status was similar at different temperatures, and the germination of the seeds was affected by drying treatment. The more fully the seeds without drying breaking the primary dormancy were, the stronger their germination ability was. However, if the dormancy-released seeds were subjected to the drying treatment, the more dormancy was released(especially the longer low temperature time), the more the seed germination ability decreased. The induction of secondary dormancy(hot dormancy) of F.mandshurica seeds was less affected by the state of seed primary dormancy breaking, but was more affected by the drying treatment. Drying treatment can reduce the germination ability of F.mandshurica seeds, especially under higher temperature conditions, and the more fully breaking the primary dormancy, the greater the impact of drying treatment on seed germination. In the production, if the dormancy-released seeds need to be re-dried, the best method of stratification is warm stratification for 10 weeks and cold stratification for 8 weeks.

Physiological Responses of Two Astragalus membranacus Seedlings to Sulfur Deficiency

ZHANG Ye, YANG Nan, LIU Yang, TANG Zhong-Hua, GUO Xiao-Rui, WANG Hong-Zheng

2020, 40(4):  496-504.  doi:10.7525/j.issn.1673-5102.2020.04.003

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The responses of biomass accumulation, photosynthesis capacity and secondary metabolites accumulation to sulfur deficiency were investigated in the herbs of Astragalus membranaceus(Fisch.) Bge. (A.membranaceus) and its variety of mongholicus(A.membranaceus var. mongholicus) using a hydroponics culture system. Compared with the application of whole Hoagland solutions, the decreasing of sulfur concentration inhibited the elongation growth and biomass accumulation in the both plants, and led to the appearances of leaf chlorosis and root browning. Additionally, sulfur deficiency reduced the contents of chlorophylls and the photosynthesis capacity in leaves, as well as elevated the degree of membrane lipid peroxide in the whole plant. However, we found that the effect of sulfur deficiency on A.membranaceus var. mongholicus was lower than that on A.membranaceus. Under the condition of no sulfur application, the non-photochemical quenching in A.membranaceus var. mongholicus was significantly increased. More than that, more isoflavonoids(calycosin, formononetin, calycosin-7-O-β-flucoside and ononin) were induced by sulfur deficiency in var. monholicus than A.membranaceus. We concluded that sulfur deficiency affected the chlorophyll synthesis and photosynthesis, led to the membrane peroxide, and finally caused the inhibition of growth and development of A.membranaceus and its variety. However, the variety showed stronger adjustability to sulfur deficiency through the increasing of the light protection capability and synthesis of more isoflavones.

Physiological Characteristics of Davidia involucrata Bracts and Leaves with Different Colors

LIANG Ling, JIANG Jie-Bei, ZHANG Teng-Ju, Lü Jia-Yao, CHEN Xiao-Hong

2020, 40(4):  505-513.  doi:10.7525/j.issn.1673-5102.2020.04.004

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To explain the coloration mechanism of pink Davidia involucrata Baill., D.involucrata bracts and leaves with two different colors were selected to study the physiological indexes including pigment, basal metabolite content and enzyme activity. The flavonoid content(FC) of pink leaves was 1.52 times that of green leaves. Flavonoid contents in two colors of bracts were low, and the difference was not obvious(P>0.05). The anthocyanin contents(AC) in the bracts and leaves of pink plants were 1.68 times and 3.67 times that of common ones, and the difference was extremely obvious(P<0.01). The photosynthetic pigment contents of pink leaves were slightly lower than that of green leaves(P>0.05). Compared to common plants, pink ones accumulated more soluble sugar(SS) and proline(Pro) but less soluble protein(SP)(P<0.05). Compared to the leaves, the bracts accumulated less soluble sugar(SS) but much more proline(Pro) and soluble protein(SP)(P<0.01). The activities of phenylalanine ammonia-lyase(PAL) and chalcone isomerase(CHI) of pink ones were significantly higher(P<0.01), while peroxidase(POD) and superoxide dismutase(SOD) activities in two colors of plants were not much different(P>0.05). The enzyme activities of the bracts were mostly higher than that of the leaves(P<0.05), especially the CHI activity. The contents of flavonoid and anthocyanin were significantly positively correlated with soluble sugar, proline contents, PAL and CHI activities, but negatively correlated with soluble protein content. In conclusion, anthocyanin directly caused the bracts to turn pink, and flavonoid and anthocyanin caused the leaves to be pink. Soluble sugar, soluble protein, proline, PAL and CHI affected the anabolism of anthocyanin.

Callus Induction and Differentiation from the Filaments of Paeonia ostii ‘Feng Dan’

DU Yi-Ming, ZHONG Yuan, SHANG Hong-Qin, CHENG Fang-Yun

2020, 40(4):  514-522.  doi:10.7525/j.issn.1673-5102.2020.04.005

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With the filaments of Paeonia ostii as explants, the effect of developmental stage of explant, basal media and PGRs on callus induction, proliferation and differentiation were investigated, and the morph-histological observation of different types of callus was performed. The translucent and white filaments from flower bud of 13-19 mm in diameter is optimal for callus induction. The optimal callus induction medium was SH containing 1 mg·L^-1 2,4-D, 2 mg·L^-1 NAA and 0.2 mg·L^-1 BA. The optimal proliferation medium was SH containing 0.5 mg·L^-1 2,4-D, 0.5 mg·L^-1 NAA and 0.25 mg·L^-1 BA, and the proliferation rate was 3.86. The filaments callus can be divided into three types according to their morphological and microstructural characteristic, the type Ⅰ callus presented typical embryogenic callus characteristics, and somatic embryogenesis was observed from this kind of callus; there were plenty of vascular tissues formed in the type Ⅱ and type Ⅲ callus, and shoot organogenesis was observed from the type Ⅱ callus, but no morphogenesis from the type Ⅲ callus. These results suggested that the filaments have important regeneration potential as a good novel explant source, which have important value in establishing in vitro regeneration system of tree peony.

Effect of Warm Water Soaking on Protective Enzyme Activity and Endogenous Hormones Content of Eucommia ulmoides Seed During Different Stages of Germination

WANG Ning, DONG Ying-Ying, YUAN Mei-Li, WANG Ya-Nan, ZENG Sheng-Yun

2020, 40(4):  523-529.  doi:10.7525/j.issn.1673-5102.2020.04.006

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The experiment was conducted to investigate the regulation mechanism of enzymes and endogenous hormones of different stages of Eucommia ulmoides Oliver seed germination, aiming to provide scientific basis for taking effective treatment measures during the different stages of seed dormancy and germination to increase seedling emergence rate. The effects of warm water soaking on the germination of E.ulmoides seeds were studied with room temperature(CK), 40℃, 50℃, 60℃ and 70℃. And the activities of superoxide dismutase(SOD), peroxidase(POD), and malondialdehyde(MDA) content were determined by routine physiological and biochemical methods. Levels of 4 endogenous hormones, such as gibberellin(GA₃), indole acetic acid(IAA), zeatin riboside(ZR) and abscisic acid(ABA) were quantitatively determined by enzyme-linked immunosorbent assay. The result showed that:①The seed germination rate could be increased by soaking seeds with different temperature water, and the germination rate reached its maximum under 50℃ warm water treatment. ②Compared with room temperature water treatment, the activity of SOD and POD in the seeds were increased under 50℃ warm water, and reduced the degree of cytoplasm membrane was oxidized, and the content of MDA was decreased continuously, thus promoted the development of seeds in a direction favorable for germination. In addition, treatment with 50℃ warm water promoted the growth of endogenous GA₃, IAA and ZR in seeds, and decreased the content of endogenous ABA, and the values of GA₃/ABA, IAA/ABA and ZR/ABA were significantly higher than those of room temperature water, which ultimately promoted the germination of E.ulmoides.

Nutrient Stoichiometry of Current-year Stems of Wild Apple Trees (Malus sieversii) in Mountainous Area of West Junggar Basin,Xinjiang,China

LIU Xiao-Yan, ZHOU Xiao-Bing, ZHANG Jing, TAO Ye

2020, 40(4):  530-542.  doi:10.7525/j.issn.1673-5102.2020.04.007

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Malus sieversii is a relic and rare wild fruit tree species from tertiary, and is the ancestor of cultivated apple trees in the world. In order to understand the nutrient stoichiometric characteristics of differentiation of M.sieversii, a total of 20 plots were investigated in 2016 and 2017 in mountainous area of west Junggar Basin, Xinjiang, China. The current-year stems of M.sieversii were collected, and the stoichiometric characteristics of nitrogen(N), phosphorus(P) and potassium(K) in stems, the differences in environmental gradients and the influencing factors were systematically analyzed. The N, P, K contents and N:P(7.03, 1.24, 5.96 mg·g^-1 and 5.71, respectively) in stems in 2016 were higher than those in 2017(5.49, 1.08, 4.46 mg·g^-1 and 5.13, respectively). Stem P had the lowest variability(CV=21.0% and 23.3%) while stem N had the strongest variability(CV=37.5% and 34.9%). There were significant correlations among stem N, P and K. Stem N:P, N:K were mainly influenced by N, while stem P:K were affected by K. ANOVA showed that significant differences in stem nutrient stoichiometry were detected among different years, sampling sites, degrees of altitude, grazing gradients, degrees of disease and insect pest, deadwood rates and fruit amounts. At the sampling plot level, longitude and latitude, slope position, grazing intensity and soil N content were the main factors affecting stem stoichiometry; at the individual plant level, the degree of diseases and insect pests and fruit amount were the key factors. When the in situ rejuvenation of M.sieversii is carried out, the moderate grazing, increasing soil N content and management of diseases and insect pests should be well considered.

Effects of Exogenous Salicylic Acid on Physiological and Electrical Impedance Parameters of Trollius chinensis Seedlings under High Temperature Stress

LIU Jin-Yu, GAO Yue-Hao, HUANG Jin-Shuo, ZHANG Qin

2020, 40(4):  543-551.  doi:10.7525/j.issn.1673-5102.2020.04.008

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In order to solve the problem of poor growth of Trollius chinensis seedlings during summer in low altitude areas of North China, the effects of salicylic acid spraying on physiological and electrical impedance parameters of T.chinensis seedlings under high temperature stress were studied for improving the heat resistance of T.chinensis. With T.chinensis seedlings as experimental materials, exogenous salicylic acid(SA) was sprayed with four concentration gradients(0.5, 1.0, 1.5 and 2.0 mmol·L^-1) and placed in an artificial climate chamber for high temperature stress test at 38℃ on day and 30℃ at night. The results showed that spraying 0.5-1.0 mmol·L^-1 salicylic acid could effectively reduce the heat injury index, relative conductivity and malondialdehyde(MDA) content of T.chinensis seedlings, alleviating chlorophyll degradation, significantly increase soluble sugar content, free proline content and superoxide dismutase(SOD) activity, among which 1.0 mmol·L^-1 salicylic acid(SA) had the best treatment effect, indicating that spraying SA with appropriate concentration could improve the heat resistance of T.chinensis seedlings, so as to alleviate the high temperature damage. The correlation analysis of each index showed that the heat injury index was positively extremely correlated with relative conductivity, negatively significantly correlated with total chlorophyll content, soluble sugar content and extracellular resistivity(r_e)(P<0.05), positively significantly correlated with intracellular resistivity(r_i) and Pro content, and positively significantly correlated with relaxation time(τ) and Pro content and SOD activity. Therefore, the resistance parameters such as extracellular resistivity, intracellular resistivity and relaxation time that can be used as an evaluation index of response of T.chinensis to high temperature stress.

Intraspecific and Interspecific Competition of Quercus mongolica Forest

LIU Wan-Sheng, LI Xiang, CHEN Fu-Yuan, ZHU Meng-Ting, MU Li-Qiang

2020, 40(4):  552-558.  doi:10.7525/j.issn.1673-5102.2020.04.009

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Quercus mongolica forest is one of the typical forest types in Northeast China. The Hegyi competition index was used to analyze the intraspecific and interspecific competition status of Q.mongolica using fixed sample circle method in a 1 hm² permanent plot of Q.mongolica forest in Heilongjiang Zhongyangzhan Black-Billed Capercaillie National Nature Reserve. The intraspecific and interspecific competition intensity of Q.mongolica accounted for 28.08% and 71.92% of the total competition intensity, respectively. Some species, includingBetula platyphylla,B.dahurica and Larix gmelinii,with big size and large quantity, gave a high competition pressure to Q.mongolica. The order of the intraspecific and interspecific competition intensity of Q.mongolica was:Betula platyphylla > Quercus mongolica > Betula dahurica > Larix gmelini > Populus davidiana > Tilia amurensis > Salix raddeana. The DBH of Q.mongolica has a power function relationship with the competition intensity of the whole stand, intraspecific and interspecific competition intensity. With the increase of the DBH of the objective trees, the three types of competition decreased. When the DBH Q.mongolica is less than 20 cm, the competition intensity is greater. When the DBH is greater than 20 cm, the competitive pressure on Q.mongolica is less and tends to stabilize. The obtained model can well predict the intraspecific and interspecific competition intensity of Q.mongolica.

Dynamics Change of Soil Moisture in Mountain Jujube Forest after Rainy Season in Loess Area of Northern Shaanxi Province

AI Ning, ZONG Qiao-Yu, GAO Jin-Xu, QIANG Da-Hong, LIU Chang-Hai

2020, 40(4):  559-567.  doi:10.7525/j.issn.1673-5102.2020.04.010

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With the jujube forest, apple forest and abandoned grassland in the Qijiashan jujube test base of Yanchuan, northern Shaanxi as the research objects, we studied the dynamic change of soil moisture. There were significant differences in soil moisture among jujube forests at different slope positions, slope directions and land preparation methods. Among them, the highest soil moisture of all slope positions was in the lower slope, being 14.19%; the highest soil moisture of all slope directions was in the shady slope, being 14.19%; the soil moisture of the horizontal terrace was significantly higher than that of the original slope. The vertical trends of soil moisture among different vegetation types in the study area were basically same. The soil moisture of jujube forest was the highest, 11.49%; the soil water storage in 0 to 100 cm of different vegetation types was jujube forest land(144.76 mm) > apple land(124.19 mm) > the smallest(72.20 mm). There were differences in soil water storage deficits of different vegetation types. Before the rainy season, the 0 to 20 cm soil layer had the smallest deficit, and the sequence of the average deficit degree from high to low was grassland, jujube forest and apple forest; after the rainy season, the descending sequence of the soil water deficit was grassland, apple forest and jujube forest. Soil water deficit after the rainy season was higher than that before the rainy season, except jujube forest. After the rainy season, the soil water deficit in the 0 to 20 cm soil layer of the three vegetation types in the study area increased; in the 20 to 100 cm soil layer, the soil water storage compensation degree of the jujube forest was positive, and the soil moisture was compensated, but the highest compensation degree was only 22.95%, and the soil moisture of jujube forest was still in a state of deficit and had not fully recovered. The soil water storage compensation degree of apple forest was negative, indicating that the soil water deficit was further aggravated. The grassland soil water compensation degree maintained around 0, and the soil water deficit did not continue to deteriorate.

Urban Street Tree Species Composition in 35 Cities of China

WANG Ke, XIAO Lu, TIAN Pan-Li, ZHANG Xi-Ting, WANG Hong-Yuan, WANG Wen-Jie

2020, 40(4):  568-574.  doi:10.7525/j.issn.1673-5102.2020.04.011

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Clarifying the composition of the urban forest tree is the base of urban forest construction and management.Previous studies were mostly located in a singlecity or region, and it was difficult to reveal its general rule.We selected China's 35 majorcities, with a total of 88 632 plots by using Baidu Street View(BSV).These cities were divided into Northern, Southern, Qinghai-Tibet and Northwestern cities, according to their geographical region location. We compared the differences in street tree composition between cities and between regions. Results showed that:①There were 99street trees commonly used in the 35 cities based on the street BSV survey.The most common tree species were Populus spp., Salix spp., Cinnamomum camphora, Cedrus deodara and Sophora japonica. ②Most of the street trees in Southern cities are broad-leaved trees e.g.,Cinnamomum camphora, while in Northern and Northwestern cities, Populus spp., Salix spp. and S.japonicawere dominant, and in the Qinghai-Tibet area, Populus spp. and conifer were dominant. ③Only Kunming and Guilin street species configuration were reasonable at species levelaccording tothe 10/20/30 "rule of thumb". In particular, the relative abundance of Populus spp. was as high as 61.2%, in Karamay. The proportion of Cinnamomum camphora trees exceeds 50% of the total number of tree species in Changsha and Hangzhou.The primary reason was that single-species occupy absolute predominance which made the relative abundance ratio of other tree species less or even no. In the four areas,street tree configuration was unreasonable at the species level. To solve this problem, we should reduce the use of Populus spp., Salix spp., Cedrus deodara, S.japonica in the North, and other trees suitable for native growth should be added in Northwest, Qinghai-Tibet, and Southern. Our study provides important parameters for the nationalplanning of urban forest, scientific evaluation and construction, systematic comparison of multiple cities, support of urban forest management and comprehensive improvement of ecological service functions.

Gene Cloning and Stress Response Analysis of Natural Disorder Protein in Populus trichocarpa

DONG Shi-Wei, YANG Yu-Ning, WANG Nai-Rui, ZHANG Han-Guo, LI Shu-Juan

2020, 40(4):  575-582.  doi:10.7525/j.issn.1673-5102.2020.04.012

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In order to know the related information of PtrIDP1(Potri.010G161200.1) gene in Populus trichocarpa and to explore the expression characteristics of the gene in different tissues and under different stress, primers were designed according to the full-length sequence of the gene obtained from Phytozome database, and the target fragment of the gene was cloned. The complete CDs region of the gene is 423 bp long and encodes 140 amino acids. The expression vector of subcellular localization was constructed, and the epidermal cells of the onion were transiently transformed. The result showed that the PtrIDP1 was located in the cell nucleus under the laser confocal microscope. The expression specificity of PtrIDP1 gene in different tissues of P.trichocarpa and its response to abiotic stress were analyzed by real-time quantitative RT-PCR. The results showed that PtrIDP1 gene was expressed in the roots, stems and leaves of P.trichocarpa, but the lowest expression was in the roots, whereas the relative expression was higher in the stems and leaves. The expression patterns of PtrIDP1 gene were different under the induction of high salt and drought stress, and the preliminary analysis suggested that PtrIDP1 gene was involved in the process of responding to abiotic stress in P.trichocarpa.

Isolation of the BpbHLH112 Gene and Expression Analysis of Its Promoter in Betula platyphylla

JIANG Cheng, ZHANG Xi, TIAN Qing, LI Li

2020, 40(4):  583-592.  doi:10.7525/j.issn.1673-5102.2020.04.013

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The Open Reading Frame sequence of the BpbHLH112 was cloned from Betula platyphylla, and its expression patterns under diverse abiotic stresses were explored. Furthermore, the 1 446 bp promoter region of BpbHLH112 was cloned, and bioinformatics analysis revealed that it harbors numerous cis-regulatory elements associated with signaling molecules and abiotic stress as well as signal transduction. The BpbHLH112 promoter was then analyzed for its ability to control the expression of the GUS reporter gene in transgenic tobacco plants. BpbHLH112-GUS expression was strongly induced by the plant stress regulators in the transformed tobacco plants. These results might provide an important contribution for elucidating the regulation mechanisms of BpbHLH112 expression in responding to the plant stress regulators.

Genetic Transformation and Function Analysis of PsnHB13 Gene Isolated from Populu ssimonii×P.nigra in Nicotiana tabacum

XIAO Di, LIU Yi, LI Kai-Long, ZHENG Mi, QU Guan-Zheng

2020, 40(4):  593-601.  doi:10.7525/j.issn.1673-5102.2020.04.014

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Cloning of the gene PsnHB13 of the HD-ZIP family, bioinformatics analysis, the construction of overexpression vector and performing of tobacco genetic transformation. The result shows that the cDNA of PsnHB13 was 870 bp and encode 289 amino acids. In our study, PsnHB13 was amplified from Populu ssimonii×P.nigra cDNA by PCR. Plant overexpression vector(pROKII-PsnHB13) was constructed and transformed into wild-type tobacco by agrobacterium-mediated leaf disc transformation. The transgenic plants were confirmed by PCR, and the result showed PsnHB13 gene was integrated into tobacco genome. The result of qRT-PCR detection of T2 generation plants showed the mRNA of PsnHB13 was transcribed in transgenic tobaccos. By observation, PsnHB13 overexpressed leads the differences of leaf, flower and root in tobacco. Thus, PsnHB13 plays a negative role in the growth of tobacco leaves, roots and flowers, and provides a theoretical basis for poplar growth and development.

Cloning and Bioinformatics Analysis of LoERF017 Gene from Larix kaempferi

MA Miao-Miao, LI Cheng-Hao, LIU Xiao, ZHANG Xin, YANG Jing-Li

2020, 40(4):  602-612.  doi:10.7525/j.issn.1673-5102.2020.04.015

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The LoERF017 gene cloned from Larix kaempferi was sequenced and found to be 624 bp in length, encoding a total of 207 amino acids. The protein encoded by LoERF017 is predicted to include only one AP2 domain, and its secondary structure includes α-helix (30.43%), random coil (54.11%), extended strand 12.56%), and β-sheet (2.9%). Subcellular localization of the gene showed that LoERF017 was located in the nucleus. The results of qRT-PCR showed that the expression level of LoERF017 gene in L.kaempferi had certain tissue specificity. The expression of this gene in root was the highest, the expression in stem was the lowest, and the expression in leaves was middle. Under drought stress, the expression of LoERF017 gene increased in the root, but decreased after rehydration. It was preliminarily predicted that this gene is mainly expressed and functions in root of L.kaempferi, and it was speculated that LoERF017 might be related to drought resistance.

Transcriptome Analysis and Gene Functional Annotation in Phoebe bournei

LIU Dan, ZENG Qin-Meng, LIU Bin, LI Yu, CHEN Shi-Pin

2020, 40(4):  613-622.  doi:10.7525/j.issn.1673-5102.2020.04.016

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The second generation Illumina HiSeq sequencing technology was used to sequence the xylem, phloem and leaves of Phoebe bournei, and 41 383 707, 43 343 922, 44 191 586 clean reads fragments were obtained, respectively. After transcript splicing, the total length of the sequence was 120 535 288 bp, including 383 331 contings. The contings were further assembled to obtain 151 729 Unigenes with an average length of 542 bp. The gene function of the transcriptome unigenes was annotated with the NR database. It was found to have the most similar sequence with grape(34%) and low homology with cucumber, wild strawberry and soybean(3% each). The GO function annotation showed that it can be divided into 52 branches of biological process, cell component and molecular function. Using eggNOG, it can be divided into 25 categories. The KEGG function annotation indicates that the genes involved in the transcriptome are involved. There are 176 metabolic pathways, most of the notes on ribosome and carbon metabolism are obtained. In addition, through the MISA software analysis, a total of 35 972 SSR sites were obtained. Among them, single nucleotide, dinucleotide and trinucleotide were dominant repeat types, and the number of SSR sites was 21 762(60.50%), 8 931(24.83%) and 4 924(13.69%), respectively. It laid a foundation for further research on genetics, breeding and molecular biology.

Scientific Notes

Preparation of Resveratrol-Nanostructured Lipid Carrier and Evaluation of in vitro Antioxidant Activity

WANG Xin-Yu, LI Hong-Kun, YU Liang, ZHAO Xue-Lian, YU Xue-Ying, FU Yu-Jie

2020, 40(4):  623-628.  doi:10.7525/j.issn.1673-5102.2020.04.017

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Resveratrol is a natural functional component, with whitening, antioxidant and other effects, can be used to improve skin lesions and cell aging. Resveratrol has low solubility and poor stability in water, which impedes its application in medicine and cosmetics. The nanostructured lipid carrier loaded with resveratrol was prepared to improve the stability and functional activity of resveratrol. The resveratrol nanostructured lipid carrier(NLC) was prepared by thermal high pressure homogenization method, and the homogenization pressure was determined to be 600 bar with GMS as the solid lipid, oleic acid as the liquid lipid, with their ratio of 1:1, 4% Tween 80 as the emulsifier, and the smallest particle size of resveratrol lipid carrier was 179 nm after three cycles.The results of MTT experiment and ROS scavenging experiment also showed that resveratrol did not produce obvious toxicity to cells when the lipid carrier concentration of resveratrol was less than 100 μmol·L^-1, and had better antioxidant activity than resveratrol API.

Development of Microsatellite Primers of Quercus championii with RAD-seq Data

NING Xin, JIANG Xiao-Long, DENG Min, XU Gang-Biao

2020, 40(4):  629-634.  doi:10.7525/j.issn.1673-5102.2020.04.018

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Microsatellite(simple sequence repeat, SSR) is a co-dominant molecular marker commonly found in plant genome with high polymorphism. This genotyping method is widely used in the study of spatial genetic structure of populations. With the blooming of the new sequencing technologies, the development method of SSR is also more diverse. Quercus championii is a precious wood species in the evergreen broad-leaved forest of South China. The development of its molecular markers can promote the species breeding and germplasm conservation. We used the reads obtained from RAD-seq(restriction-site associated DNA sequence) of four individuals of Q.championii to developed SSR primers. The pyRAD analysis showed that:(1)the reads containings 46 000-84 000 repeats sequence in each individual; (2)within the individual ranged clustering, 5 500-24 000 loci were detected; (3)1 158 concordance loci were obtained after clustering between individuals. Finally, 186 loci with flanking sequences were not mutated and repeating base was in the middle were obtained. A total of 25 primers pairs were designed using premier 5.0 and validated in 36 individuals from 3 populations. The results showed that 17 primer sets were successfully amplified and 106 alleleswere obtained. The number of alleles per primer between 2-12, and the average number is 6.2. The expected heterozygosity and observed heterozygosity of the primers were 0.19-0.88 and 0.11-0.76, respectively. The rapid, effective, and low cost in this method can be applied to the development of molecular markers of population genetics.

Response Surface Optimized Enzymatic Hydrolysis-microwave Assisted Extraction Process of Mulberry Leaf Polysaccharide

ZHU Ya-Wei, WANG Li-Tao, AN Juan-Yan, Lü Mu-Jie, SUN Jian-Hang, GUO Na, FU Yu-Jie

2020, 40(4):  635-640.  doi:10.7525/j.issn.1673-5102.2020.04.019

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The response surface analysis was used to optimize the process of extracting polysaccharide from mulberry leaves by enzymatic hydrolysis-microwave assisted method.Based on the single factor test, the Box-Behnken method was used to study the effects of liquid-solid ratio, extraction time and extraction temperature on the extraction rate of mulberry leaf polysaccharides. The fitting equation was significant, and the optimal extraction conditions of mulberry leaf polysaccharides were finally determined as follows:enzyme content 2%, enzymolysis pH6, enzymolysis temperature 50℃, enzymolysis time 20 min, liquid-solid ratio 15 mL·g^-1, extraction time 13 min, and extraction temperature 76℃.Under these conditions, the actual extraction rate of mulberry leaf polysaccharide was 15.23%, which was closed to the theoretical simulation value of 15.12%. Therefore, the established model was true and reliable. The method can be used for extracting polysaccharide components in mulberry leaves with the advantages of simple process, low cost and high application value.