Picea mongolica, known for its remarkable tolerance to cold, drought, and salinity, is a key species for ecological restoration and urban greening in the "Three Norths" region of China. MYB transcription factors are involved in plant responses to abiotic stress and synthesis of secondary metabolites. However, studies are limited regarding the MYB transcription factors in P. mongolica and their roles in salt stress tolerance. In this study, 196 MYBs were identified based on the genome of Picea abies and the transcriptome of P. mongolica. Phylogenetic analysis classified the MYB transcription factors into seven subclasses. The R2R3-MYB subclass contained the maximum number of genes (84.77%), while the R-R and R1R2R3 subclasses each represented the smallest proportion, at about 0.51%. The MYB transcription factors within the same subclass were highly conserved, exhibiting similar motifs and gene structures. Experiments with varying salt stress gradients revealed that P. mongolica could tolerate the salt concentration up to 1 000 mmol/L. From the transcriptome data of P. mongolica exposed to salt stress (1 000 mmol/L) for 0, 3, 6, 12, and 24 h, a total of 34 differentially expressed MYBs were identified, which suggested that these MYBs played a key role in regulating the response to salt stress. The proteins encoded by these differentially expressed genes varied in length from 89 aa to 731 aa, with molecular weights ranging from 10.19 kDa to 79.73 kDa, isoelectric points between 4.80 and 9.91, and instability coefficients from 41.20 to 70.99. Subcellular localization analysis indicated that most proteins were localized in the nucleus, while three were found in the chloroplasts. Twelve MYBs were selected for quantitative real-time PCR (qRT-PCR), which showed that their expression patterns were consistent with the RNA-seq data. This study provides valuable data for further investigation into the functions and mechanisms of MYB family members in response to salt stress in P. mongolica.

Prunus mira Koehne, is an economically and ecologically important woody oilseed tree species in China, but currently, it is facing great challenges from climate change and human activities, impacting its distribution area and, consequently, its growth and seed quality. Therefore, it is important to investigate the spatial distribution of P. mira and changes in seed kernel oil quality with respect to climate change for the conservation and utilization of this species. This study explored the influence of climate change on the geographical distribution, ecological niches, and seed oil quality of P. mira. Based on the Biomod2 platform and ensemble modeling, 10 species distribution model groups were incorporated to simulate potential distribution areas. High-performance liquid chromatography was used to analyze the oil composition of P. mira seeds. The results revealed that the current potential distribution area in China primarily comprises high-altitude regions of the Tibetan and Yunnan-Guizhou Plateaus. Future climate projections suggest limited migration of suitable areas for P. mira, which initially decrease before experiencing an increase in the distribution area. Furthermore, variations in P. mira seed oil characteristics were aligned with climate-induced changes, with seeds from more habitable regions producing improved oil qualities.

Studying the evolutionary history of plants in the Qinghai-Tibetan Plateau region provides a theoretical basis for the conservation and use of plant genetic resources. In this study, we analyzed five chloroplast gene fragments to examine the genetic diversity and phylogeography of Prunus mira in 577 individuals from 32 populations. The results indicated that P. mira populations exhibit high genetic diversity and significant phylogeographic structure (NST > GST). High genetic differentiation (FST = 0.979) and limited gene flow were detected among populations, likely due to geographic isolation. Neutrality tests and mismatch analysis indicated that the P. mira population has not experienced significant expansion during the historical period and remains relatively stable. Additionally, based on haplotype distribution and genetic diversity levels, we propose that P. mira had three refugia during the glacial period. Considering the genetic diversity of P. mira populations, we propose dividing all populations into two conservation units and prioritizing in situ conservation of populations with high genetic diversity within each unit. Furthermore, ex situ conservation of specific populations could prevent the loss of unique genes, such as those in populations with low genetic diversity but distinct haplotypes.

Exploring the phenotypic trait variation and diversity of Lycium ruthenicum germplasm resources can support selection, breeding, and genetic improvement, enhancing agricultural production. This study collected 213 wild Lycium ruthenicum seedlings from a resource nursery in Alxa League, Inner Mongolia. These seedlings originated from eight sources across four provinces. Using 11 pseudo-qualitative traits and 20 quantitative traits, the phenotypic variation of the germplasm was analyzed. The analysis involved the coefficient of variation, Shannon–Wiener index (H), Simpson’s genetic diversity index (D), principal component analysis, correlation analysis, and Q-type cluster analysis. The results showed that the variation range of 31 phenotypic traits across the 213 Lycium ruthenicum germplasm resources was 17.26% to 105.41%, with an average coefficient of variation of 39.85%. The H and D indexes ranged from 0.18 to 1.58 and 0.20 to 0.75, respectively. For the 11 pseudo-qualitative traits, the H and D ranges were 0.18 to 1.58 and 0.07 to 0.74, with average values of 0.77 and 0.42. For the quantitative traits, the H and D ranges were 0.54 to 1.49 and 0.25 to 0.75, with average values of 1.21 and 0.63. This indicates that Lycium ruthenicum germplasm resources exhibit significant phenotypic diversity, with quantitative traits showing higher diversity than pseudo-qualitative traits. Principal component analysis revealed that the cumulative variance contribution rate of the first 10 principal components was 74.03%, comprehensively reflecting the information of the 31 traits. Q-type cluster analysis grouped the 213 Lycium ruthenicum germplasm resources into six clusters, each with distinct phenotypic characteristics. This analysis also identified the trait characteristics and breeding value of each cluster. The results of this study provide valuable information on the genetic improvement, conservation, and evaluation of Lycium ruthenicum germplasm resources.

Ulmus pumila 'Zhonghua Jinye' is an important landscape tree species because of its golden leaves. Leaf coloration is the main factor that determines the ornamental and economic value of U. pumila. Gene expression and metabolite accumulation patterns were studied by transcriptome and metabolome to explore the physiological and molecular mechanisms of leaf color changes in U. pumila. The results showed that the leaf color change of U. pumila was regulated by the metabolism of chlorophyll, flavonoids, and carotenoids. The content of total chlorophyll and chlorophyll a decreased gradually with seasonal changes, which was mainly caused by the obstruction of chlorophyll synthesis and the activation of the chlorophyll degradation pathway. Among them, the expression level of chlorophyll synthesis-related genes (GluTR, UROD, PPO, and POR) were down-regulated, while certain genes (CHLG, CAO, HCAR, PPH, and PAO) in the chlorophyll degradation pathway were significantly up-regulated. In addition, flavonoids gradually accumulated with seasonal changes. Among them, twentysix key genes (PAL, 4CL, CHS, F3H, FLS, 3GT, DFR, and ANS) in flavonoid biosynthesis were involved in regulation of flavonol and anthocyanin biosynthesis. Furthermore, carotenoids (lutein, zeaxanthin, and beta-carotene) were also mainly accumulated in July and August. Finally, the candidate gene, UpCrtR-b, in carotenoid biosynthesis was identified in the present study and was found to be expressed in plastids by functional verification. In tobacco, overexpression of UpCrtR-b could increase carotenoid accumulation and make tobacco leaves yellowish. This study revealed the molecular mechanism of leaf color regulation in U. pumila, and provided a theoretical basis for better utilization of this species as a landscape tree, which also provides the possibility for further enriching the variation mechanism and cultivating colored leaf plants.

In the present study, we identified the members of the small auxin-up RNA (SAUR) gene family in Prunus sibirica and analyzed their localization, phylogeny, duplication, cis-elements in the promoter, and expression patterns. In total, 57 PsSAURs were identified, which were randomly distributed along eight chromosomes. Among them, eight and ten pairs of segmentally duplicated genes and tandem duplication genes were found in 13 and 21 PsSAURs, respectively. Phylogenetic analysis indicated that the PsSAURs were divided into five groups (Group A–E). Light-responsive, methyl jasmonate, abscisic acid, salicylic acid, and gibberellin, as well as low-temperature responsiveness, and defense and stress responsiveness were identified by analyzing PsSAURs promoter sequences. The collinearity analysis of P. sibirica SAURs and Prunus mume and Prunus persica SAURs family genes detected 35 and 59 pairs of gene pairs, respectively, and the Ks values of all collinearity gene pairs were almost less than 1. Expression pattern analysis showed that PsSAURs had different tissue and stage expression patterns. However, research on SAURs in non-model plants remains limited, and studies on the expression and function of SAURs are lacking. This study pro­vides a foundation for further investigations into the functional analyses of SAURs in P. sibirica.

Ammopiptanthus mongolicus is an ancient remnant species from the Mediterranean displaying characteristics such as high-temperature tolerance, drought resistance, cold resistance, and adaptability to impoverished soil. In the case of high-temperature tolerance, heat shock transcription factors (HSFs) are integral transcriptional regulatory proteins exerting a critical role in cellular processes. Despite extensive research on the HSF family across various species, there has been no analysis specifically focused on A. mongolicus. In this study, we identified 24 members of the AmHSF gene family based on the genome database of A. mongolicus, which were unevenly distributed over 9 chromosomes. Phylogenetic analysis showed that these 24 members can be categorized into 5 primary classes consisting of a total of 13 subgroups. Analysis of the physical and chemical properties revealed significant diversity among these proteins. With the exception of the AmHSFB3 protein, which is localized in the cytoplasm, all other AmHSF proteins were found to be situated in the nucleus. Comparison of amino acid sequences revealed that all AmHSF proteins contain a conserved DNA-binding domains structure, and the DNA-binding domains and oligomerization domains of the AmHSF gene exhibit conservation with counterparts across diverse species; we investigated the collinearity of AmHSF genes in relation to those of three other representative species. Through GO enrichment analysis, evidence emerged that AmHSF genes are involved in heat stress responses and may be involved in multiple transcriptional regulatory pathways that coordinate plant growth and stress responses. Finally, through a comprehensive analysis using transcriptome data, we examined the expression levels of 24 AmHSFs under 45 °C. The results revealed significant differences in the expression profiles of AmHSFs at different time intervals during exposure to high temperatures, highlighting their crucial role in responding to heat stress. In summary, these results provide a better understanding of the role and regulatory mechanisms of HSF in the heat stress response of A. mongolicus, meanwhile also establishing a foundation for further exploration of the biological functions of AmHSF in the adversity response of A. mongolicus.

Picea mongolica is a rare and valuable tree species in China, having high tolerance for drought, cold, and sand burial. The late embryogenesis abundant protein (LEA protein) is a crucial transcription factor that plays a key role in both plant embryonic development and stress response. LEA genes have, however, not yet been reported in P. mongolica. In this study, through the analysis of genome data from Picea abies and transcriptome data from P. mongolica, a total of 49 PmLEAs were discovered and categorized into eight subfamilies based on their Pfam domain and phylogenetic relationship. RNA-Seq research revealed that 37 PmLEAs were differentially expressed at various stages of embryonic development. Using qRT-PCR, we found that most PmLEAs responded strongly to drought stress, with genes in the same subfamily exhibiting identical expression patterns. In particular, PmLEA25 is the most highly induced by drought treatment. Furthermore, we heterologously transformed PmLEA25 into Arabidopsis. The overexpression of PmLEA25 remarkably increased the germination rate, root length, and antioxidant capacity in Arabidopsis under drought treatment, compared with WT. The results serve as a point of reference for gaining a deeper comprehension of the function of PmLEA25 in the molecular process of stress resistance in P. mongolica. Additionally, they offer significant genetic materials for the purpose of breeding stress-resistant spruce species.

为预测我国欧李适生区分布及气候变化对其的影响.利用R语言和ArcGis筛选出欧李(Cerasus hu-milis(Bunge)Sok)134个分布数据和25个环境因子;调用ENMeval程序包,优化最大熵生态位模型参数;根据Pearson相关分析和方差膨胀因子(VIF)分析,筛选出建模所需的环境因子,利用刀切法评估影响欧李适生区的主导环境因子.利用优化后的模型,构建欧李适生区的地理分布,推测末次间冰期、末次冰盛期和全新世中期的潜在适生区,分析其历史时期适生区分布变化,预测不同气候情景欧李未来分布区的变化趋势.模型预测结果表明:在默认参数设置时,调控倍率为1,特征组合为LQHPT,delta.AICc值为297.65.将模型参数优化后,在特征组合为LQH,调控倍率为2.5时,delta.AICc值为0,最大熵模型的拟合度最佳.据刀切法评估结果,降水量变异系数、最冷月极端低温、海拔、最湿月降水量、气温变异系数是影响欧李分布的主导环境因子.当前我国欧李的适生区主要分布于天津、北京、山东、河北地区;气候变化对欧李的影响较为明显;未来气候变暖将会引起欧李适生区的向北迁移,尤其在温室气体高排放浓度下更敏感,迁移距离更大.

The production and quality of apricots in China is currently limited by the availability of germplasm resource characterizations, including identification at the species and cultivar level. To help address this issue, the complete chloroplast genomes of Prunus armeniaca L., P. sibirica L. and kernel consumption apricot were sequenced, characterized, and phylogenetically analyzed. The three chloroplast (cp) genomes ranged from 157,951 to 158,224 bp, and 131 genes were identified, including 86 protein-coding genes, 37 rRNAs, and 8 tRNAs. The GC content ranged from 36.70% to 36.75%. Of the 170 repetitive sequences detected, 42 were shared by all three species, and 53–57 simple sequence repeats were detected with AT base preferences. Comparative genomic analysis revealed high similarity in overall structure and gene content as well as seven variation hotspot regions, including psbA-trnK-UUU, rpoC1-rpoB, rpl32-trnL-UAG, trnK-rps16, ndhG-ndhI, ccsA-ndhD, and ndhF-trnL. Phylogenetic analysis showed that the three apricot species clustered into one group, and the genetic relationship between P. armeniaca and kernel consumption apricot was the closest. The results of this study provide a theoretical basis for further research on the genetic diversity of apricots and the development and utilization of molecular markers for the genetic engineering and breeding of apricots.

Picea mongolica is a rare tree species in China, which is of great significance in combating desertification and improving the harsh ecological environment. Due to the low rate of natural regeneration, high mortality, and susceptibility to pests and cold springs, Picea mongolica has gradually become extinct. At present, somatic embryogenesis (SE) is the most effective method of micro-proliferation in conifers, but the induction rate of embryogenic callus (EC) is low, and EC is difficult to differentiate from non-embryonic callus (NEC). Therefore, the EC and NEC of Picea mongolica were compared from the morphology, histological, physiological, and transcriptional levels, respectively. Morphological observation showed that the EC was white and transparent filamentous, while the NEC was compact and brownish-brown lumpy. Histological analyses showed that the NEC cells were large and loosely arranged; the nuclei attached to the edge of the cells were small; the cytoplasm was low; and the cell gap was large and irregular. In the EC, small cells, closely arranged cells, and a large nucleus and nucleolus were observed. Physiological studies showed significant differences in ROS-scavenging enzymes between the EC and NEC. Transcriptome profiling revealed that 13,267 differentially expressed genes (DEGs) were identified, 3682 were up-regulated, and 9585 were down-regulated. In total, 63 GO terms had significant enrichment, 32 DEGs in plant hormone signal transduction pathway were identified, and 502 different transcription factors (TFs) were characterized into 38 TF families. Meanwhile, we identified significant gene expression trends associated with somatic embryo development in plant hormones (AUX/IAA, YUCCA, LEA, etc.), stress (GST, HSP, GLP, etc.), phenylpropanoid metabolism (4CL, HCT, PAL, etc.), and transcription factors (AP2/ERF, MYB, WOX, etc.). In addition, nine genes were chosen for RT-qPCR, and the results were consistent with RNA-Seq data. This study revealed the changes in morphology, histology, physiology, and gene expression in the differentiation of NEC into EC and laid the foundation for finding the key genes to promote EC formation.

为筛选高亲和的柿杂交亲本组合,以4个优良甜柿品种为母本、8个柿特异雄性种质(品种)为父本,设计19个杂交组合,开展人工控制杂交授粉,对各杂交组合花后8周的座果率和得种数等进行统计,分析其杂交亲本的亲和性,并对未成熟种子的幼胚进行胚挽救组织培养,获得杂交F1代幼苗后,对其雌/雄和甜/涩性状进行分子标记早期鉴定.结果表明:1)8个父本材料的花粉活力存在显著差异,其中携带中国甜柿基因的野生雄株(雄株8号)的花粉活力最强,可达90.38％,离体萌发率为45.89％;而雌雄同株的'西村早生'花粉活力最差,仅35.29％.2)雄株8号和'太秋'花粉均可在'阳丰,'富有,'罗田甜柿'柱头上正常萌发.3)不同杂交组合亲本间的亲和性差异明显,'阳丰'×雄株8号杂交组合坐果率和亲和指数最高,分别为48.39％和1.56;'富有'×'西村早生'的杂交组合坐果率和亲和指数最低,分别为5.53％和0.05.4)未成熟种子经胚挽救组织培养,获得了705株杂交子代,经过雌/雄和甜/涩分子标记早期鉴定,共鉴定出359份雌株和346份雄株,363份完全甜柿和342份非完全甜柿,其中符合育种目标的完全甜柿雌株有181份.本研究为甜柿杂交育种和新种质创新提供了理论指导和材料基础.

沙地云杉(Picea mongolica)是我国稀有珍贵树种,具有耐旱、耐寒、耐沙埋的优良抗性.LBD(lateral organ boundaries domain)是植物侧生器官中重要的转录因子,在植物生长发育和胁迫应答进程中起关键作用,但目前尚未报道有关沙地云杉中LBD基因家族的研究.本研究参考挪威云杉全基因组数据及沙地云杉转录组数据鉴定沙地云杉LBD基因,进行生物信息学分析并利用qRT-PCR检测LBD基因在不同组织(茎尖、主根、侧根、茎和叶)及盐胁迫胁迫条件下的表达水平.结果表明,在沙地云杉转录组中共鉴定出30个LBD基因(PmLBD1-30),蛋白序列长度在119～309 aa之间,分子量为10.5～33.4 kD,等电点介于5.15～9.26之间,Cell-PLoc亚细胞定位显示均位于细胞核中;所有的LBD蛋白结构域、基因结构高度保守,并由相似的基序组成;根据系统发育树可将其分为5个亚家族(Class Ⅰ a～e),沙地云杉在各类中的成员依次为4,11,5,1,9个;qRT-PCR试验结果显示,PmLBDs在不同组织中均有表达,如PmLBD2/5/18/19在茎中高表达,Class Ⅰb中的PmLBD9/20/23基因在侧根中强烈表达;大多数PmLBDs的表达强烈响应盐胁迫,17个PmLBD基因在盐处理后上调表达,而6个PmLBD基因在盐处理后下调表达,且同一亚族基因表达情况呈现相似趋势.

柿是中国重要的经济林树种之一,绝大部分栽培品种为六倍体,极少数日本品种为九倍体.通过自然选育或人工创制培育的柿九倍体品种,凭其优良的综合性状表现,展现出极大的利用价值和发展潜力,同时表明多倍体育种是柿创新优异种质、选育突破性良种的重要途径.通过对国内外利用2n配子、体细胞染色体加倍、胚乳培养、原生质体融合等途径诱导柿多倍体的育种研究进展,以及形态学、染色体计数、流式细胞仪法等倍性鉴定方法的应用情况进行综述,总结了近年来柿多倍体育种成果.就目前柿多倍体育种技术中存在的问题进行了讨论,并对未来研究方向进行了展望,以期为其他经济林树种多倍体育种提供有益的启示.

Population genetic diversity contributes to the protection and utilization of germplasm resources, especially via genetic breeding. In the present study, start codon targeted polymorphism (SCoT) molecular markers were used to study the genetic diversity of 278 individuals from 10 Prunus sibirica L. populations in Inner Mongolia. A total of 289 polymorphic bands were amplified with 23 SCoT primers, showing a polymorphism percentage of 98.87% and an average of 12.6 polymorphic bands per primer. The SCoT21, SCoT32, and SCoT53 primers amplified up to 17 bands, and the polymorphism percentage was 100%. The minimum number of bands amplified by SCoT25 was 9, and the polymorphism percentage was 90%. Therefore, SCoT molecular markers were shown to be highly polymorphic and suitable for genetic diversity studies of P. sibirica in Inner Mongolia. The analysis of molecular variance showed that 39% of the observed genetic differentiation occurred among populations and 61% occurred within populations, indicating that the genetic differentiation within populations was greater than that among populations. The results of the unweighted pair-group method with an arithmetic cluster analysis, principal coordinate analysis and STRUCTURE analysis were basically the same and divided the 278 individuals from the 10 populations into 2 groups. The results indicated that the efficient SCoT molecular marker-based genetic diversity analysis of P. sibirica in Inner Mongolia can provide a reference for P. sibirica variety breeding and resource development.

Picea mongolica, a native species with excellent industrial wood quality and strong sand-fixing capacity, may be utilized in construction of urban green spaces in arid areas in China. However, now the sustainability of the ecosystems where this species grows is at serious risk due to a lack of natural regeneration. In this study, we developed an efficient regeneration system and comprehensively analyzed various factors affecting somatic embryogenesis (SE) using zygotic embryos as explants. We identified the optimal plant growth regulators (PGRs) performance and the best donor trees (k81) for the generation of somatic embryos (SEMs). Additionally, we confirmed that the positive developmental window of SEMs initiation was at the end of July to early August, which is when zygotic embryos was at the late embryogeny. In this time period, specific transcripts associated with the regulation of epigenetic modifications, plant hormone-related genes, and embryonic development-related transcription factors play important roles for early SEMs initiation. These results may provide a valuable resource for vegetative propagation of Picea mongolica. Our results may help to establish a reliable protocol for plantlet regeneration, which may facilitate urban greening applications and industrialization in arid areas.

Hydrangea bretschneideri Dipp is a highly popular ornamental plant for garden decoration. Genetic engineering technology has been successfully used in many plant species, but it is limited in Hydrangea. Here we established an efficient regeneration system by using stem segments as explants for the first time. In our study, the plant growth regulators (PGRs) were evaluated at the different regeneration processes, including axillary shoots regeneration and root induction. We found that the optimal concentration for axillary buds' induction was 2.0 mgL(-1) 6-BA and 0.5 mgL(-1) 1 IAA, its highest induction rate was 70%. Moreover, the highest axillary shoots proliferation coefficient was 10.7 on the Murashige and Skoog (MS) medium with 2.0 mgL(-1) 6-benzyladenine (BA), 0.2 mgL(-1) indole-3-butyric acid (IBA), and 1.0 mgL(-1) gibberellin A3 (GA3). The highest frequency of root induction was 80.0 +/- 0.06% by culturing the elongated shoots in 1/2 MS medium containing 0.1 mgL(-1) IBA. In summary, our study will provide an effective technology for large-scale propagation and important pathway for promoting the popularization and application of Hydrangea bretschneideri Dipp.

Zygotic embryogenesis is a critical process during seed development in gymnosperms. However, knowledge on the genome-wide transcriptional activation that guides this process in conifers is limited, especially in Picea mongolica. This tree species is endemic to semiarid habitats of Inner Mongolia in China. To extend what is known about the molecular events underpinning its zygotic embryogenesis, comparative transcriptomic analyses of gene expression in zygotic embryos were performed by RNA sequencing in P. mongolica. Our results showed that most changes in transcript levels occurred in the early embryonic pattering determination and formation of mature embryos. Transcripts related to embryogenic competence, cell division pattern, hormones, and stress response genes were identified during embryogenesis. Auxin is essential for early embryo patterning and pre-cotyledon embryonic formation. However, ABA is a major regulator of embryo maturation. Moreover, we found that methylation-related gene expression is associated with activation of early-stage embryos, late embryogenesis abundant proteins, and storage/energy-related genes with late and mature embryos. Furthermore, network analysis revealed stage-specific and multistage gene expression clusters during embryogenesis. WOX, MYB, AP2, and HLH transcription factors seem more relevant to embryogenesis in different stages. Our results provide large-scale and comprehensive transcriptome data for embryo development in P. mongolica. These data will lay a foundation for the protection and utilization of P. mongolica resources.

Prunus mira, an important economic fruit crop and ancestral peach species, is widely distributed along the Yarlung Zangbo Grand Canyon and tributary basins in the Tibetan plateau. Due to infrastructure construction and deforestation, natural habitat of P. mira has been severely damaged, leading to reduction in its distribution range and population size and it is listed as a critically endangered species in China’s list of National Key Protected Wild Plants. In this study, 85 novel single nucleotide polymorphism (SNP) markers were developed based on restriction-site associated DNA sequencing. The minor allele frequency, observed heterozygosity, and expected heterozygosity ranged from 0.064 to 0.748, 0.086 to 0.846, and 0.126 to 0.562, respectively. The PIC ranged from 0.117 to 0.423. Ten loci showed significant deviations from the Hardy–Weinberg equilibrium after Bonferroni correction (p < 0.05). These novel SNPs can be useful for future population and conservation genetics studies on this species.

PiceaMill. species are important components of boreal and subalpine forests. They have a wide geographical range in the Northern Hemisphere, extending from the Eurasian continent to North America. In this study, publications onPiceaspecies from 2002 to 2016 were identified via the Web of Science (WoS) and the China National Knowledge Infrastructure (CNKI) databases, and subjected to relationship network visualization using CiteSpace software. This study represents the first such analysis ofPiceaand provides a reference for bibliometrics in forest tree species research. The results show that the total number of publications onPiceaarchived in WoS was 20,958 and that the number of papers published annually has increased over time, peaking at 1725 in 2013. The studies were mainly conducted in North America, Europe and Asia; among them, Canada published the most papers and showed the strongest betweenness centrality (0.11). Among research institutions, the Swedish University of Agricultural Sciences in Uppsala had the highest publication record. The research contributions of the Chinese Academy of Sciences, the Chinese Academy of Forestry, and Beijing Forestry University have improved rapidly in recent years, greatly enhancing the international impact of Chinese research in this field. The research contents were grouped into five categories: forest ecosystems, pest resistance, extraction and functional analyses of active ingredients from various plant organs, nursery and afforestation techniques, and timber quality research. In China, the number of papers from the CNKI database was 4532, increasing at an even pace. The research topics onPiceaincluded forest ecosystems, seedling and afforestation techniques, basic studies on individual species and populations, and pests and diseases. Within and outside China, hotspots inPicearesearch included the relationships betweenPiceaand environmental factors, and the genomic sequences ofPicea.