Japonica Var Research Articles

Dynamic Characteristics of Soil Respiration in Park Green Spaces in Qingdao City

Urban green spaces play an essential role in maintaining the carbon cycle and mitigating climate change in urban ecosystems. In order to gain more carbon sinks from urban green ecosystems, it is essential to determine the carbon sequestration statuses and soil respiration rates of dominant green spaces, especially park green spaces. However, in comparison to natural ecosystems, the dynamic characteristics of soil respiration in artificial park green spaces remain unclear. This study investigated the soil respiration rates for three forest communities (dominated by Prunus serrulata var. lannesiana, Cedrus deodara, Ginkgo biloba, respectively), a shrub community (dominated by Aucuba japonica var. variegata) and a lawn community (dominated by Poa pratensis) in the Qingdao Olympic Sculpture and Culture Park. We used the CRIAS-3 portable photosynthesis system in combination with the SRC-1 soil respiration chamber to measure the soil respiration rate from July 2022 to June 2023 and analyzed the dynamic variations in the soil respiration rate for these specific plant communities. Our results showed that the diurnal variation in soil respiration presented a unimodal curve for the five plant communities, and it peaked at midday or in the early afternoon. They also exhibited a significant seasonal difference in the soil respiration rate, which was characterized by higher rates in summer and lower rates in winter. The lawn community exhibited significantly higher soil respiration rates compared to the woody plant community. The mean annual soil respiration rate (RS) was, respectively, 2.88 ± 0.49 µmol·m−2·s−1, 1.94 ± 0.31 µmol·m−2·s−1, 1.43 ± 0.21 µmol·m−2·s−1, 1.24 ± 0.14 µmol·m−2·s−1 and 1.05 ± 0.11 µmol·m−2·s−1 for the lawn community, Ginkgo biloba community, Prunus serrulata var. lannesiana community, shrub community and Cedrus deodara community. The soil temperature at a 10 cm depth (T10) accounted for 67.39–86.76% of the variation in the soil respiration rate, while the soil volumetric water content at a 5 cm depth (W5) accounted for 9.29–44.01% of the variation for the five plant communities. The explained variance for both T10 and W5 ranged from 67.8% to 87.6% for the five plant communities. The Q10 values for the five different communities ranged from 1.97 to 2.75. Based on these findings, this paper concludes that the factors influencing the soil respiration process in urban green spaces are more complicated in comparison to natural ecosystems, and it is essential to comprehensively analyze these driving factors and key controlling factors of soil respiration across urban green spaces in future studies.

Thioredoxin reductase inhibition and glutathione depletion mediated by glaucocalyxin A promote intracellular disulfide stress in gastric cancer cells.

Thioredoxin reductase 1 (TXNRD1) has been identified as one of the promising chemotherapeutic targets in cancer cells. Therefore, a novel TXNRD1 inhibitor could accelerate chemotherapy in clinical anticancer research. In this study, glaucocalyxin A (GlauA), a natural diterpene extracted from Rabdosia japonica var. glaucocalyx, was identified as a novel inhibitor of TXNRD1. We found that GlauA effectively inhibited recombinant TXNRD1 and reduced its activity in gastric cancer cells without affecting the enzyme's expression level. Mechanistically, the selenocysteine residue (U498) of TXNRD1 was irreversibly modified by GlauA through a Michael addition. Additionally, GlauA formed a covalent adduct with glutathione (GSH) and disrupted cellular redox balance by depleting cellular GSH. The inhibition of TXNRD1 and depletion of GSH by GlauA conferred its cytotoxic effects in spheroid culture and Transwell assays in AGS cells. The disulfide stress induced cytotoxicity of GlauA could be mitigated by adding reducing agents, such as DTT and β-ME. Furthermore, the FDA-approval drug auranofin, a TXNRD1 inhibitor, triggered oligomerization of the cytoskeletal protein Talin-1 in AGS cells, indicating that inhibiting TXNRD1 triggered disulfide stress. In conclusion, this study uncovered GlauA as an efficient inhibitor of TXNRD1 and demonstrated the potential of TXNRD1 inhibition as an effective anticancer strategy by disrupting redox homeostasis and inducing disulfide stress.

Changes in soil microbial community and function across stand age of Cryptomeria japonica var. sinensis plantations in subtropical China

Microbial communities are important influencing factors in soil biogeochemical cycling. Differences in stand age can affect microbial communities and functions by altering soil biochemical characteristics. Studying the changes in soil microbial communities and functions at different ages of Cryptomeria japonica var. sinensis can provide a theoretical basis for the scientific management of plantations. Therefore, we collected soil samples from different soil depths from 7- (7a), 13- (13a), 24- (24a), 33- (33a), and 53-year (53a) C. japonica var. sinensis plantations, to assess the differences in soil biochemical characteristics, soil bacterial and fungal communities, soil enzyme activity, and soil respiration rate. Results showed that as the stand age increases, the ACE and Shannon indices of fungal communities showed an initial increase followed by a decrease, whereas the Chao 1 index showed an increasing trend. The ACE and Shannon indices of bacterial communities did not change with stand age, but the Chao1 index decreased with an increase in stand age. In addition, the fungal ACE and Chao1 indices and bacterial Shannon index were higher at the 0–15 cm depth than at the 15–30 cm depth. Soil microbial community composition varied with stand age and soil depth, including Proteobacteria and Unclassified_k_Fungi relative abundances, and their functional groups' (nitrogen cycling-related bacteria, saprophytic fungi, pathogens, and ectomycorrhizal fungi) relative abundances. In addition, stand age will indirectly affect soil microbial function by influencing soil biochemical characteristics and microbial communities at the 0–15 cm depth, whereas at the 15–30 cm depth, there is no direct or indirect impact on the above indicators. In summary, significant variations exist in soil microbial communities and their functions across stand ages, and these differences will further vary between soil depths. Our research contributes to a better understanding of the impact of different ages of afforestation on soil biogeochemical cycling, providing valuable microbial information for the sustainable management of C. japonica var. sinensis forests in the future.

Comparative study on metabolites, nutrients, and antioxidant capacity of endosperm in Gymnocladus chinensis, Gleditsia sinensis, and Gleditsia japonica var. delavayi

‘Zaojiaomi’ is a traditional food derived from Gleditsia sinensis or Gleditsia japonica var. delavayi endosperm. However, metabolite profile of Gymnocladus chinensis endosperm and its comparison to the aforementioned species remains understudied. This research employed a UPLC-MS based metabolomics approach to investigate and compare metabolite composition of G. chinensis endosperm with that of G. sinensis and G. japonica endosperm. A total of 1177 metabolites were identified, with 579 and 577 differentially abundant metabolites found between G. chinensis vs. G. japonica and G. chinensis vs. G. sinensis, respectively. They were mainly enriched in pathways related to flavonoid biosynthesis, suggesting potential for enhanced antioxidant activity, compared to G. japonica and G. sinensis. Additionally, G. chinensis endosperm was found to be rich in L-arginine, L-aspartic acid, and zinc elements, which have various health benefits. These findings provide valuable insights into metabolic composition of G. chinensis endosperm and its potential as a functional food source.

Occurrence of biennial sporophytes of the kelp Saccharina japonica in Hokkaido, Japan

Recent studies suggest that relict communities of Saccharina japonica var. ochotensis are rarely observed in southwestern Hokkaido, where S. japonica. var. religiosa is generally distributed. Previous research has mainly focused on the morphology of these species, and field survey data is very limited. In the present study, relict S. japonica var. ochotensis communities were observed only near the estuaries of larger rivers, specifically in estuarine areas where bedrock is present and the seashore has a gentle gradient slope. The biomass and size (length, width, and weight) of annual and biennial relict S. japonica. var. ochotensis were recorded. The carbon/nitrogen ratio of the kelp sporophytes was analyzed, and relatively lower values were observed in the relict community of this species. This information may help in the maintenance of kelp beds in southwestern Hokkaido and the wise utilization of relict S. japonica var. ochotensis in the estuarine areas of southwestern Hokkaido, Sea of Japan.

Attenuated total reflection Fourier-transform infrared spectroscopy reveals environment specific phenotypes in clonal Japanese knotweed

BackgroundJapanese knotweed (Reynoutria japonica var. japonica), a problematic invasive species, has a wide geographical distribution. We have previously shown the potential for attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy and chemometrics to segregate regional differentiation between Japanese knotweed plants. However, the contribution of environment to spectral differences remains unclear. Herein, the response of Japanese knotweed to varied environmental habitats has been studied. Eight unique growth environments were created by manipulation of the red: far-red light ratio (R: FR), water availability, nitrogen, and micronutrients. Their impacts on plant growth, photosynthetic parameters, and ATR-FTIR spectral profiles, were explored using chemometric techniques, including principal component analysis (PCA), linear discriminant analysis, support vector machines (SVM) and partial least squares regression. Key wavenumbers responsible for spectral differences were identified with PCA loadings, and molecular biomarkers were assigned. Partial least squared regression (PLSR) of spectral absorbance and root water potential (RWP) data was used to create a predictive model for RWP.ResultsSpectra from plants grown in different environments were differentiated using ATR-FTIR spectroscopy coupled with SVM. Biomarkers highlighted through PCA loadings corresponded to several molecules, most commonly cell wall carbohydrates, suggesting that these wavenumbers could be consistent indicators of plant stress across species. R: FR most affected the ATR-FTIR spectra of intact dried leaf material. PLSR prediction of root water potential achieved an R2 of 0.8, supporting the potential use of ATR-FTIR spectrometers as sensors for prediction of plant physiological parameters.ConclusionsJapanese knotweed exhibits environmentally induced phenotypes, indicated by measurable differences in their ATR-FTIR spectra. This high environmental plasticity reflected by key biomolecular changes may contribute to its success as an invasive species. Light quality (R: FR) appears critical in defining the growth and spectral response to environment. Cross-species conservation of biomarkers suggest that they could function as indicators of plant-environment interactions including abiotic stress responses and plant health.

Characterization and Phylogenetic Analysis of the Chloroplast Genomes of Stephania japonica var. timoriensis and Stephania japonica var. discolor.

This study sequenced the complete chloroplast genomes of Stephania japonica var. timoriensis and Stephania japonica var. discolor using the Illumina NovaSeq and PacBio RSII platforms. Following sequencing, the genomes were assembled, annotated, comparatively analyzed, and used to construct a phylogenetic tree to explore their phylogenetic positions. Results indicated that the chloroplast genomes of S. japonica var. timoriensis and S. japonica var. discolor both displayed a typical double-stranded circular tetrameric structure, measuring 157,609 and 157,748 bp in length, respectively. Each genome contained 130 annotated genes, with similar total GC content and relative codon usage patterns, showing a distinct preference for A/U at the third codon position. Simple sequence repeat analysis identified 207 and 211 repeats in S. japonica var. timoriensis and S. japonica var. discolor, respectively, primarily the A/T type. Boundary condition analysis indicated no significant expansion or contraction in the inverted repeat regions with consistent gene types and locations across both varieties. Nucleotide polymorphism analysis highlighted greater variation in the intergenic regions than in the coding sequences of Stephania chloroplast genomes. Phylogenetic analyses demonstrated that the species Stephania clustered into a distinct, well-supported clade. Notably, Stephania japonica, along with S. japonica var. discolor and S. japonica var. timoriensis, established a monophyletic lineage. Within this lineage, S. japonica and S. japonica var. discolor were closely related, with S. japonica var. timoriensis serving as their sister taxon.

A knot of hybrids: Differentiating Asian knotweeds in North‐Eastern France using genetic, cytological, and morphological data

AbstractThe two invasive Reynoutria species, Reynoutria japonica var. japonica and Reynoutria sachalinensis, and their hybrid Reynoutria x bohemica are often misidentified by managers and nonspecialists. The taxonomic confusions are all the more exacerbated by the infraspecific variability of introduced populations in terms of morphology, genetic diversity, and ploidy level. We resolved the identity of North‐Eastern French invasive populations using 4582 single‐nucleotide polymorphisms (SNPs) from a RADseq analysis, DNA contents estimated by flow cytometry, and 12 vegetative morphometric variables. The SNPs supported only one single genotype for R. japonica over 11 localities, while the nine localities of Reynoutria x bohemica were represented by one genotype each. Estimation of genome size using DAPI staining and flow cytometry revealed only octoploid cytotypes for R. japonica and hexaploid cytotypes for R. x bohemica, whereas R. sachalinensis was represented by tetraploid and hexaploid cytotypes. Among morphometric variables, no single one allows for a clear differentiation of the three taxa. We propose a combination of characters to easily and quickly identify these three invasive taxa based on six vegetative criteria including leaf and apex length, as well as leaf shape, leaf base, and apex shape, and the extrafloral nectaries on the node.

First Report of Leaf Blight Caused by Botryosphaeria dothidea on Aucuba japonica in Zhejiang Province, China.

Aucuba japonica var. variegata Dombrain is a common evergreen cultivated ornamental in China (Li et al. 2016). In December 2022, severe leaf blight on A. japonica was observed next to the Meishiyuan of Zhejiang Normal University (29°8'4″N, 119°37'54″E) in Jinhua City, Zhejiang Province, China. There were seven plants in the surveyed area, and over 50% of leaves were affected. The early symptoms were small gray spot parts with brown borders on the tip of the leaves. Then the grey parts gradually expanded and became brownish black. In severe cases, the whole leaves became black and blighted. To identify the pathogen, 5 symptomatic leaves were randomly collected from 5 plants and cut into small pieces (5 mm × 5 mm), surface disinfected in 1% sodium hypochlorite solution for 3 min, followed by 75% alcohol for 30 s, then rinsed in sterile distilled water thrice. Tissues were cultured on potato dextrose agar (PDA) and incubated at 28°C for 7 days. Pure cultures were obtained by the single-spore method. Thirteen strains were isolates from the tissues, and nine of them showed similar morphological characteristics. Colonies were white initially, then became gray. The undersides of the colonies became black gradually. Hyaline, fusiform conidia (n = 30) were 17.1 to 24.76 µm (average 20.39 ± 1.906 µm) in length and 5.4 to 6.61 µm (average 6.19 ± 0.434 µm) in width. The DNA of nine isolates were extracted by Ezup Column Bacteria Genomic DNA Purification Kit, and their sequences were identical, so they were named QM1. The internal transcribed spacer (ITS) region, translation elongation factor 1-α (TEF1), and β-tubulin (TUB2) genes were amplified with primer pairs ITS1/ITS4, TEF1-728F/TEF1-986R and βt2a/βt2b (Slippers et al. 2004), respectively. The BLAST analysis indicated that ITS (OR215464), TEF1 (OR243689), and TUB2 (OR243688) of the isolate QM1 were 99 to 100% identical to those of Botryosphaeria dothidea (GenBank accession nos. MH329646 for ITS sequences; OL891702 for TEF1 sequences; MK511445 for TUB2 sequences). In addition, the phylogenetic tree based on sequences from ITS, TEF1 and TUB2 was constructed with MEGA 11 by use of the maximum likelihood method with 1,000 bootstrapping iterations. Based on the multi-locus phylogeny and morphological features, the isolate QM1 was identified as B. dothidea. To test the Koch's postulates, ten leaves from three healthy two- to three-year-old A. japonica plants were surface disinfested with 75% ethanol for 30 s, rinsed with ddH2O three times. The leaves were wounded with a sterile needle and inoculated with 2ml drop of the isolate QM1 conidial suspension (106 spores/mL), with sterile distilled water as a control. All plants were placed in a greenhouse at 28°C, >70% relative humidity and 12 h light/day. The experiment was repeated three times. After 7 days, leaves of the inoculated group showed symptoms similar to those observed on the naturally infected leaves, while leaves of the control group remained asymptomatic. The pathogen was reisolated from inoculated leaves and was confirmed as B. dothidea based on morphological and molecular analyses. It has been reported B. dothidea cause leaf disease in a wide range of hosts in China, such as Camellia oleifera (Hao et al. 2023), Kadsura coccinea (Su et al. 2021). To our knowledge, this is the first report of Botryosphaeria dothidea causing leaf blight on Aucuba japonica in Zhejiang Province of China. B. dothidea are usually secondary invaders and are known to cause diseases in stressed plants. The results further expand the host-range of B. dothidea, and would help to establish control strategy against the disease.

Pharmacological and phytochemical insights on the pancreatic β-cell modulation by Angelica L. roots

Ethnopharmacological relevanceAngelica roots are a significant source of traditional medicines for various cultures around the northern hemisphere, from indigenous communities in North America to Japan. Among its many applications, the roots are used to treat type 2 diabetes mellitus; however, this application is not mentioned often. Ethnopharmacological studies have reported the use of A. japonica var. hirsutiflora, A. furcijuga, A. shikokiana, and A. keiskei to treat diabetes symptoms, and further reports have demonstrated the three angelica roots, i.e., A. japonica var. hirsutiflora, A. reflexa, and A. dahurica, exhibit insulin secretagogue activity. Aim of the studyThis study aimed to phytochemically characterize and compare angelica roots monographed in the European Pharmacopeia 11th, isolate major plant metabolites, and assess extracts and isolates' capability to modulate pancreatic β-cell function. Materials and methodsRoot extracts of Angelica archangelica, Angelica dahurica, Angelica biserrata, and Angelica sinensis were phytochemically profiled using liquid chromatography method coupled with mass spectrometry. Based on this analysis, simple and furanocoumarins were isolated using chromatography techniques. Extracts (1.6–50 μg/mL) and isolated compounds (5–40 μmol/L) were studied for their ability to modulate insulin secretion in the rat insulinoma INS-1 pancreatic β-cell model. Insulin was quantified by the homogeneous time-resolved fluorescence method. ResultsForty-one secondary metabolites, mostly coumarins, were identified in angelica root extracts. A. archangelica, A. dahurica, and A. biserrata root extracts at concentration of 12.5–50 μg/mL potentiated glucose-induced insulin secretion, which correlated with their high coumarin content. Subsequently, 23 coumarins were isolated from these roots and screened using the same protocol. Coumarins substituted with the isoprenyl group were found to be responsible for the extracts' insulinotropic effect. ConclusionsInsulinotropic effects of three pharmacopeial angelica roots were found, the metabolite profiles and pharmacological activities of the roots were correlated, and key structures responsible for the modulation of pancreatic β-cell function were identified. These findings may have implications for the traditional use of angelica roots in treating diabetes. Active plant metabolites may also become lead structures in the search for new antidiabetic treatments.

Optimizing the biomass balance of macroalgae and sea urchins in kelp beds by removing the urchins

ABSTRACT In this study, we conducted sea urchin removal (SUR) experiments at two sites along Hokkaido’s southwestern and northwestern coasts in the Sea of Japan and one site along the northeast coast in the Sea of Okhotsk, to elucidate the biomass balance between macroalgae and sea urchins at different urchin barren sites. The experiments resulted in the restoration of macroalgal biomass at all sites and an increase in macroalgal diversity, indicating that it was the impact of high grazing pressure reducing the macroalgae, regardless of the particular experimental site. Notably, the recovery of the macroalgal biomass was characterized by increased kelp biomass, including Saccharina japonica var. religiosa and S. japonica var. ochotensis. In addition, negative correlations were observed between macroalgal biomass and sea urchin density. The lowest sea urchin density inducing an increase of macroalgal biomass was approximately the same in the reproductive growth phase (0.1 kg m−2) and in the vegetative growth phase (0.15 kg m−2) of Saccharina spp., the dominant kelps, regardless of the experimental site. These values can be helpful indicators for managing sea urchin density in order to restore macroalgae. In contrast, the maximum sea urchin density inducing the lowest macroalgal biomass varied markedly depending on the study site, indicating that different levels of kelp productivity are influenced by oceanographic conditions. Moreover, a strong positive correlation was observed between macroalgal biomass and sea urchins’ gonadosomatic index (GSI). Based on this correlation, macroalgal biomass supporting sea urchins with commercial value (GSI ≥ 15%) was estimated to be 1.6 kg m−2. This sea urchin density value is also a helpful indicator for managing macroalgal biomass and commercially valuable sea urchins. Moreover, this value will depend on the influence of the oceanographic environment of the site, particularly the nutrient conditions, on macroalgal productivity. In addition, we have also discussed how macroalgae and sea urchins can best coexist at the experimental sites.

New linkage maps for the Cupressaceae species Chamaecyparis obtusa and Thujopsis dolabrata var. hondae and comparison with the linkage map of Cryptomeria japonica

ABSTRACT Comparative mapping studies, which can determine whether the genome structure differs among genera, have yet to be conducted in Cupressaceae. This study analyzed three important forestry species in Japan: Cryptomeria japonica, Chamaecyparis obtusa, and Thujopsis dolabrata var. hondae. To date, linkage maps have only been constructed for C. japonica. We constructed the first linkage maps for C. obtusa and T. dolabrata var. hondae using double digest restriction-site associated DNA sequencing (ddRAD-Seq) data, expressed sequence tag-derived simple sequence repeat (EST-SSR) markers, and single-nucleotide polymorphism (SNP) markers designed from homologous unigenes obtained from RNA-seq data. The lengths of the linkage maps were 1,835 cM (1,981 markers) for C. obtusa and 1,833 cM (1,295 markers) for T. dolabrata var. hondae. A total of 11 distinct linkage groups were identified in these maps, corresponding to the haploid number of Cupressaceae. Using four published linkage maps for C. japonica, we then constructed a composite linkage map with 7,784 markers. Finally, the three linkage maps were compared using 207 SNP markers designed from homologous unigenes. Although most markers were mapped to the same LG despite representing different species, indicating strong synteny. The high level of interspecific and intergeneric synteny and macro-collinearity detected in Cupressaceae were similar to those of other trees. We also detected three major chromosomal rearrangements between but not within subfamilies, which may have been caused by the taxonomic distance. This is the first example of comparative mapping for Cupressaceae species.

Characterization of the chloroplast genome of Gleditsia species and comparative analysis

The genus Gleditsia has significant medicinal and economic value, but information about the chloroplast genomic characteristics of Gleditsia species has been limited. Using the Illumina sequencing, we assembled and annotated the whole chloroplast genomes of seven Gleditsia species (Gleditsia sinensis, Gleditsia japonica var. delavayi (G. delavayi), G. fera, G. japonica, G. microphylla, Fructus Gleditsiae Abnormalis (Zhū Yá Zào), G. microphylla mutant). The assembled genomes revealed that Gleditsia species have a typical circular tetrad structure, with genome sizes ranging from 162,746 to 170,907 bp. Comparative genomic analysis showed that most (65.8–75.8%) of the abundant simple sequence repeats in Gleditsia and Gymnocladus species were located in the large single copy region. The Gleditsia chloroplast genome prefer T/A-ending codons and avoid C/G-ending codons, positive selection was acting on the rpoA, rpl20, atpB, ndhA and ycf4 genes, most of the chloroplast genes of Gleditsia species underwent purifying selection. Expansion and contraction of the inverted repeat (IR)/single copy (SC) region showed similar patterns within the Gleditsia genus. Polymorphism analysis revealed that coding regions were more conserved than non-coding regions, and the IR region was more conserved than the SC region. Mutational hotspots were mostly found in intergenic regions such as “rps16-trnQ”, “trnT-trnL”, “ndhG-ndhI”, and "rpl32-trnL” in Gleditsia. Phylogenetic analysis showed that G. fera is most closely related to G. sinensis,G. japonica and G. delavayi are relatively closely related. Zhū Yá Zào can be considered a bud mutation of the G. sinensis. The albino phenotype of G. microphylla mutant is not caused by variations in the chloroplast genome, and that the occurrence of the albino phenotype may be due to mutations in chloroplast-related genes involved in splicing or localization functions. This study will help us enhance our exploration of the genetic evolution and geographical origins of the Gleditsia genus.

Dimeric ent-kauranoids isolated from Isodon japonica var. Glaucocalyx and their anti-inflammatory activities

The phytochemical investigation of the aerial parts of Isodon japonica var. glaucocalyx afforded four undescribed (glaucocalyxin O-R, 1–4) and six known ent-kauranoids (5–10). Their structures were established using NMR and MS measurements. Compounds 1 and 2 are dimeric ent-kaurane-type diterpenoids. Moreover, the plausible biogenetic pathways for compounds 1 and 2 were proposed as Michael addition between two monomers. Eight compounds were assayed for their anti-inflammatory activity by evaluating NO production in LPS-induced RAW 267.4 cells, and compounds 7, 8 and 9 exhibited relatively remarkable anti-inflammatory activities at 10 μM.

Transcriptome analysis of Iris japonica var. variegata for chlorophyll and photosynthesis-related pathways involved in white–green striped leaves

Transcriptome analysis of Iris japonica var. variegata for chlorophyll and photosynthesis-related pathways involved in white–green striped leaves

A polysaccharide from the seed of Gleditsia japonica var. delavayi: Extraction, purification, characterization and functional properties

Gleditsia japonica var. delavayi is widely distributed in Yunnan and Guizhou, China, and the perisperm of its seeds is frequently used as a traditional banquet sweet food with transparent color, smooth-tasting, low-fat, and high-carbohydrate. Herein, a cellulase-assisted extraction method was applied using response surface methodology to optimize the extraction of polysaccharides from the seeds of G. japonica var. delavayi. The highest extraction yield (82.23 ± 0.50%) was obtained under 5% cellulase, 176 mL/g liquid-to-material ratio, and enzymolysis parameters of 55 °C for 90 min at pH 4.5. The purified seed polysaccharide (PS) primarily contained galactomannan (weight average molecular weight, 42.74 kDa), which was linked by the monosaccharide residues 1,6-α-Galp, 1,4,6-α-D-Galp, 1,2,4,6-β-D-Manp, and 1,3,6-α-D-Galp. The PS obtained has a single-crystal structure, is thermodynamically stable, and its molecules aggregate in water. Furthermore, PS possesses high cholate binding capacity and a substantial inhibitory effect on α-glucosidase and α-amylase. Taken together, the findings of this report offer a theoretical foundation for developing and utilizing G. japonica var. delavayi.

Geographical Variation Reveals Strong Genetic Differentiation in Cryptomeria japonica var. sinensis

The adaptive capacity of tree species is crucial for their survival under environmental change. Liushan (Cryptomeria japonica var. sinensis), an allogamous conifer species, is widely distributed across southern China. However, despite its broad distribution, there have been few investigations on the geographical variation and environmental adaptability of this species. Here, we combined the phenotypic (eight needle traits) and genetic data (14 nSSR loci) to fill this gap by assessing the genetic variation of geographical populations and exploring environmental adaptations of this species. Both phenotypic and molecular genetic analyses indicated a strong genetic differentiation among geographic populations. All populations could be clustered into three groups that were consistent with their geography. Most of the needle traits showed significantly correlated with geography and environmental factors. Geographical isolation and environmental differences are the main factors that have shaped current morphological traits and patterns of genetic variation. We suggest conservation measures to be implemented on a population level with existing populations, especially those with rare phenotypes as the main goal. Our findings shed light on the geographic variation in Liushan and expanded the knowledge of its putative adaptive mechanisms, ultimately benefiting the conservation of this species.

Flora of six Lower Mississippi River islands (U.S.A.)

Lower Mississippi River islands are part of the last remaining floodplain habitat of the river, and studying their biodiversity is important to understand the river ecosystem. We conducted a floristic survey of six Lower Mississippi River islands between river miles 668 and 526 in southern Arkansas and northern Mississippi. These islands contain a variety of habitats and span a range of sizes, from 106 to 697 vegetated hectares. We identified 491 taxa (485 species plus six infraspecific taxa) from 2,310 specimens collected from June 2020 to December 2021. These taxa are within 89 families and 282 genera, and 100 (20.6%) species are not native to the Mississippi River drainage basin. Nine taxa found on Arkansas islands are tracked by the Arkansas Natural Heritage Commission for conservation. Five taxa found in Mississippi are tracked by the Mississippi Natural Heritage Program. We found five taxa that had not previously been reported in Arkansas (Equisetum variegatum, Achyranthes japonica var. hachijoensis, Stellaria aquatica, Potentilla paradoxa, Cyperus diandrus) and seven previously unreported in Mississippi (Euploca convolvulacea, Sisymbrium loeselii, Chaiturus marrubiastrum, Mentha canadensis, Potentilla norvegica, P. paradoxa, Physalis mollis). Additionally, we collected 266 Arkansas county records, including 132 in Phillips, 64 in Desha, and 28 in Chicot counties, respectively, and 42 in Washington County, Mississippi. The high number of new encounters and tracked species found emphasizes the need for more botanical study on Lower Mississippi River islands. Of the 485 species in the flora, we found 110 species on all six islands (22.7%), 43 on five of the six islands, 47 on four islands, 75 on three islands, 72 on two islands, and 138 on only one island (28.5%). The number of unique species found on only one island illustrates how variable and dynamic these islands are in this riparian zone.

Morphology and molecular phylogeny of Erysiphe japonica var. japonica found on Quercus aliena in Korea

AbstractIn October 2022, Erysiphe powdery mildew from the section Typhulochaeta was found on Quercus aliena for the first time in Korea. Based on morphological characteristics and molecular‐phylogenetic analysis of the internal transcribed spacer region (ITS) and large subunit (LSU) gene sequences of the rDNA, the fungus was identified as Erysiphe japonica var. japonica. This is the first report of E. japonica var. japonica in Korea and the third report of this mildew on Q. aliena, with this current fungus‐host association spreading to China and Japan. Based on Korean samples, this study provides detailed morphology and molecular phylogeny of E. japonica var. japonica.

Optimizing species selection for the structural timbers of traditional farmhouses in a snowy rural area of northeastern Japan

AbstractVernacular houses constructed using local woods contain information about forest‐resource use. To clarify how timber was used to construct wooden farmhouses, we identified the timber species composition of 11 houses built between 1845 and about 1940 in Tadami, a snowy rural area in northeastern Japan, and interviewed 70 residents. We recorded 2004 timber parts (99–308 parts per house) and 171.2 m3(1828 parts) of known species (14 taxa).Cryptomeria japonica(cedar) andPinus parvifloravar.pentaphylla(white pine) were used for all essential structural parts and accounted for 44% and 39% of the total timber volume, respectively.Fagus crenata(beech) was the third most commonly used species (7%), for roof supports, beams, and girders. The interviews revealed that the timber was typically sourced from local private or common woodlands within 1 km and that local craftsmen selected and hauled the trees. Considering the region's unique and complex vegetation, as land‐cover distribution is strongly influenced by frequent avalanches, the timber was likely managed within local stands of tall trees, and the most available species would have been cedar (although whether native or planted is unknown), followed by native white pine on mountain ridges around settlements. In comparison, beech stands that could supply sufficient amounts of timber might have been limited. Based on the characteristics of the trees used as house timber in Tadami, we conclude that despite the surrounding harsh, snowy conditions, locally available species of tall trees were historically selected for timbers.