Explore the vast range of titles available.

Populus tomentosa, of section Populus, is distributed mainly in northern China. This species has high resistance to many diseases and insects, and it plays key roles in shelterbelts and urban afforestation in northern China. It has long been suspected to be a hybrid, but its parents remain unknown. In the present study, we report four newly sequenced complete cp genomes from section Populus and comparative genomic analyses of these new sequences and three published cp genome sequences. The seven cp genomes ranged from 155,853 bp (P. tremula var. davidiana) to 156,746 bp (P. adenopoda) in length, and their gene orders, gene numbers and GC contents were similar. We analyzed SNPs, indels, SSRs and repeats among the seven cp genomes, and eight small inversions were detected in the ndhC-trnV, rbcL-accD, petA-psbJ, trnW-trnP, rpl16-rps3, trnL-ycf15, ycf15-trnL, and ndhF-trnL intergenic regions. Furthermore, seven divergent regions (trnH-psbA, matK, psbM-psbD, ndhC-trnV, ycf1, ndhF-ccsA and ccsA-ndhD) were found in more highly variable regions. The phylogenetic tree reveals that P. tomentosa is closely related to P. alba and P. alba var. pyramidalis. Hence, P. alba was involved in the formation of P. tomentosa.

As a critical raw material, tungsten plays a broad role in machining, electronics, aerospace, and other high-tech industries. The extraction of tungsten from tungsten concentrates is a prerequisite for the production of high-purity products. Approximately 70% of China’s tungsten resources are in the form of scheelite. The extraction method of low-quality scheelite is crucial for the production application of the tungsten process as resources of high-quality wolframite are gradually being depleted. This article systematically reviews the processes and challenges faced in the hydrometallurgical process of scheelite concentrates and provides useful insights. Typical leaching processes for scheelite concentrate have shown excellent leaching efficiencies, with tungsten trioxide (WO3) recoveries exceeding 90%. Alkaline leaching processes are promising, but temperature and pressure are crucial for this method. The sintering–leaching process is energy-consuming and costly. Meanwhile, leaching with hydrochloric acid (HCl) or sulfuric acid (H2SO4) often results in the formation of tungstic acid (H2WO4) on the mineral surface, which inhibits further leaching and leads to a low extraction rate. In contrast, the mixed-acid leaching method is more promising, with recovery close to 100%, a short process, and low-cost, and the acid leaching solution is recyclable.

, a core genus of Salicaceae, plays a significant ecological role as a source of pioneer species in boreal forests. However, interspecific hybridization and high levels of morphological variation among poplars have resulted in great difficulty in classifying species for systematic and comparative evolutionary studies. Here, we present phylogenetic analyses of 24 newly sequenced plastomes and 36 plastomes from GenBank, which represent seven genera of Salicaceae, in combination with a matrix of eighteen morphological characters of 40 taxa to reconstruct highly supported relationships of genus . Relationships among the 60 taxa of Salicaceae strongly supported two monophyletic genera: and . was nested within the genus , and five clades within were divided. Clade I included the three taxa , and . Clade II contained thirteen taxa [ var. , and (NC)]. Clade III included the ten taxa var. , and . Clade IV included , and . The last clade comprised , and . This phylogeny is also supported by morphological traits, including bark smoothness, bud size, petiole shape, leaf inflorescence, male anther length and male anther tip.

Background Simao pine is one of the primary economic tree species for resin and timber production in southwest China. The exploitation and utilization of Simao pine are constrained by the relatively lacking of genetic information. Construction a fine genetic linkage map and detecting quantitative trait locis (QTLs) for growth-related traits is a prerequisite section of Simao Pine's molecular breeding program. Results In our study, a high-resolution Simao pine genetic map employed specific locus amplified fragment sequencing (SLAF-seq) technology and based on an F 1 pseudo-testcross population has been constructed. There were 11,544 SNPs assigned to 12 linkage groups (LGs), and the total length of the map was 2,062.85 cM with a mean distance of 0.37 cM between markers. According to the phenotypic variation analysis for three consecutive years, a total of seventeen QTLs for four traits were detected. Among 17 QTLs, there were six for plant height (Dh.16.1, Dh16.2, Dh17.1, Dh18.1–3), five for basal diameter (Dbd.17.1–5), four for needle length (Dnl17.1–3, Dnl18.1) and two for needle diameter (Dnd17.1 and Dnd18.1) respectively. These QTLs individually explained phenotypic variance from 11.0–16.3%, and the logarithm of odds (LOD) value ranged from 2.52 to 3.87. Conclusions In our study, a fine genetic map of Simao pine applied the technology of SLAF-seq has been constructed for the first time. Based on the map, a total of 17 QTLs for four growth-related traits were identified. It provides helpful information for genomic studies and marker-assisted selection (MAS) in Simao pine.

Docynia delavayi (Franch.) Schneid is a plant used both as food and traditional folk medicine. The leaves of D. delavayi are rich in polyphenols, plants with phenolic content are known to be extremely beneficial in terms of human nutrition. In the present study, we used metabolome technology (UPLC-ESI-MS/MS) to examine the young and mature D. delavayi leaves on metabolites changes, which were then analyzed and compared. As a result, 477 metabolites (including 111 flavonoids, 47 others (consisted of nine vitamin, 18 saccharides and alcohols, and 20 unassigned metabolites), 71 phenolic acids, 52 amino acids and derivatives, 18 alkaloids, 61 lipids, 24 terpenoids, 33 nucleotides and derivatives, 18 lignans and coumarins, 12 tannins, 30 organic acids) were identified, of which 281 differentially accumulated metabolites, including 146 up-regulated metabolites and 135 down-regulated metabolites. The result of clustering and PCA analyses showed that young and mature leaves were separated, which indicated that there was a great difference in metabolites between young and mature leaves. Meanwhile, we also found that both young and mature leaves displayed unique metabolites with important biological functions. KEGG enrichment analysis showed that 90 of the differential metabolites were mainly concentrated in 68 KEGG pathways. The result will greatly complement the existing knowledge on the D. delavayi leaves for lays a foundation for subsequent development and utilization.

Species of the genus Populus , which is widely distributed in the northern hemisphere from subtropical to boreal forests, are among the most commercially exploited groups of forest trees. In this study, the complete chloroplast genomes of five Populus species ( Populus cathayana , P. kangdingensis , P. pseudoglauca , P. schneideri , and P. xiangchengensis ) were compared. The chloroplast genomes of the five Populus species are very similar. The total chloroplast genome sequence lengths for the five plastomes were 156,789, 156,523, 156,512, 156,513, and 156,465 bp, respectively. A total of 130 genes were identified in each genome, including 85 protein-coding genes, 37 tRNA genes and eight rRNA genes. Seven genes were duplicated in the protein-coding genes, whereas 11 genes were duplicated in the RNA genes. The GC content was 36.7% for all plastomes. We analyzed nucleotide substitutions, small inversions, simple sequence repeats and long repeats in the chloroplast genomes and found nine divergence hotspots ( ccsA + ccsA-ndhD, ndhC-trnV , psbZ-trnfM , trnG-atpA , trnL-ndhJ , trnR-trnN , ycf4-cemA , ycf1 , and trnR-trnN ), which could be useful molecular genetic markers for future population genetic and phylogenetic studies. We also observed that two genes ( rpoC2 and rbcL ) were subject to positive selection. Phylogenetic analysis based on whole cp genomes showed that P. schneideri had a close relationship with P. kangdingensis and P. pseudoglauca , while P. xiangchengensis was a sister to P. cathayana.

The genus Ficus is an evergreen plant, the most numerous species in the family Moraceae, and is often used as a food and pharmacy source. The phylogenetic relationships of the genus Ficus have been debated for many years due to the overlapping phenotypic characters and morphological similarities between the genera. In this study, the eight Ficus species (Ficus altissima, Ficus auriculata, Ficus benjamina, Ficus curtipes, Ficus heteromorpha, Ficus lyrata, Ficus microcarpa, and Ficus virens) complete chloroplast (cp) genomes were successfully sequenced and phylogenetic analyses were made with other Ficus species. The result showed that the eight Ficus cp genomes ranged from 160,333 bp (F. heteromorpha) to 160,772 bp (F. curtipes), with a typical quadripartite structure. It was found that the eight Ficus cp genomes had similar genome structures, containing 127 unique genes. The cp genomes of the eight Ficus species contained 89–104 SSR loci, which were dominated by mono-nucleotides repeats. Moreover, we identified eight hypervariable regions (trnS-GCU_trnG-UCC, trnT-GGU_psbD, trnV-UAC_trnM-CAU, clpP_psbB, ndhF_trnL-UAG, trnL-UAG_ccsA, ndhD_psaC, and ycf1). Phylogenetic analyses have shown that the subgenus Ficus and subgenus Synoecia exhibit close affinities and based on the results, we prefer to merge the subgenus Synoecia into the subgenus Ficus. At the same time, new insights into the subgeneric classification of the Ficus macrophylla were provided. Overall, these results provide useful data for further studies on the molecular identification, phylogeny, species identification and population genetics of speciation in the Ficus genus.

Pinus yunnanensis Franch. is a major component of coniferous forests in southwestern China. Little is known about its intraspecific variation. Morphological variations in needle and cone traits of P. yunnanensis were analyzed to quantify variability among and within natural populations. Seven traits were measured on 10 needles collected from 30 trees in each of the 18 sampled populations of P. yunna- nensis. Four cone traits were measured in 221 individual trees from nine populations. The results showed that there were significant differences （p 〈 0.01） both among popu- lations and within populations in each needle and cone trait. The proportion of phenotypic variation of nearly all needle and cone traits was over 50 % within populations, which showed trees within populations accounted for a majority of the total variation. The needle traits showed higher vari- ability within population than cone traits. Variability in theneedle traits was correlated with geo-climatic parameters （longitude, latitude, altitude, temperature, and precipitation）. Needle length and the ratio of needle length to fascicle sheath length showed clinal variation in response to latitudinal and altitudinal gradients. A hierarchical classification of all populations based on needle traits led to the formation of four major groups. The findings provide important genetic information for the evaluation of variation. Moreover, it will assist in management of genetic diversity of P. yunnanensis.

Castanopsis mekongensis is highly valued in the furniture industry for its good wood texture, an endemic species in Yunnan province, southwest China. In our study, the chloroplast genome of C. mekongensis was assembled and characterized based on Illumina pair-end sequencing data. The total genome size of C. mekongensis was 160,699 bp, displayed a typical quadripartite structure including a pair of inverted repeat (IRs, 25,714 bp) regions separated by a large single-copy (LSC, 90,278 bp) region and a small single-copy (SSC, 18,963 bp) region. The overall guanine-cytosine (GC) content was 36.8%. We annotated 130 genes in the genome, containing 85 protein-coding genes, 37 tRNA genes, and eight rRNA genes, 12 genes contain a single intron, and two genes have two introns. The result of phylogenetic analysis based on maximum-likelihood (ML) phylogenetic tree indicated that C. mekongensis was most closely related to C. hainanensis.

Pinus yunnanensis Franch. is an particular conifer tree species in Yunnan-Guizhou plateau in south- west China. The morphological and anatomical traits of needles are important to evaluate geographic variation and population dynamics of conifer species. Seedlings from seven populations of P. yunnanensis were analyzed, look- ing at 22 morphological and anatomical needle traits. The results showed that variations among and within popula- tions were significantly different for all traits and the variance components within populations were generally higher than that among populations in the most tested needle traits. The proportions of three-needle fascicle were significantly different among populations. The traits related to needle size in both morphology and anatomy were positive with latitude and negative with annual temperature and precipitation. Ratio indices, including mesophyllarea/vascular bundle area, mesophyll area/resin canals area, vascular bundle area/resin canals area and mesophyU area/（resin canals area and vascular bundle area）, were negatively correlated with elevation and positively corre- lated with the annual mean temperature, showing some fitness feature for the populations. Needle traits were more significantly correlated with longitude than with other four environmental factors. Needle length was significantly correlated with almost all environmental factors. First four principal components accounted for 81.596 % of the variation with eigenvalues 〉1; the differences among populations were mainly dependent on needle width, stomatal density, section areas of vascular bundle, total resin canals, and mesophyll, as well as area ratio traits. Seven populations were divided into three categories by Euclidean distance. Variations in needle traits among the populations have shown systematic microevolution in terms of geographic impact on P. yunnanensis. This study would provide empirical data to characterize adaptation and genetic variation of P. yunnanensis, which would be helpful for management of genetic resources and reason- able utilization of them in future.