Cryptomeria Research Articles

Localization of TWISTED NEEDLES Locus on Linkage Map of Japanese Cedar (Cryptomeria japonica D. Don)

Sugi (Cryptomeria japonica D. Don) is an important forestry species in Japan. C. japonica ‘Spiralis’ is a mutant with twisted needles. The mutant is called Yore-sugi in Japan and is known as ‘Rasen’ in other countries. The twisted trait is regulated by a dominant gene called TWISTED NEEDLES, and it can be identified by observing the needles within 1 to 2 months after germination. The TWISTED NEEDLES gene may be useful for improving the efficiency of genome editing technology in C. japonica. In this study, we attempted to identify the linkage group of the TWISTED NEEDLES locus and investigate markers that sandwich this locus using the mapping family. First, we identified the linkage group containing the TWISTED NEEDLES locus based on the distortion from the expected segregation ratio using 32 mutant individuals of the mapping family. The segregation distortion showed that the TWISTED NEEDLES locus was located on the 11th linkage group (LG11). Next, a linkage map of LG11 was constructed based on genotype data from the single-nucleotide polymorphism (SNP) markers and double digested restriction site-associated DNA sequencing (ddRAD-seq) using 123 individuals of the MMY-1 family. On this map, six markers were located at the same position as the TWISTED NEEDLES locus. To investigate markers sandwiching the TWISTED NEEDLES locus, a partial linkage map around the TWISTED NEEDLES locus was constructed using 643 individuals of the MMY-1 family. The TWISTED NEEDLES locus was located in the 0.6 cM region between gSNP01822 and the other five markers (Contig_4705-179, Contig_4518-93, Contig_4398-118, gSNP04056, and Contig_4970-113).

Review: Vegetation history of Cryptomeria japonica in Japan since the last interglacial period

AbstractThe natural distribution of Japanese cedar (Cryptomeria japonica) has been disturbed by human activities, owing mainly to its value as timber; thus, its position in the vegetation zone of Japan is not clear. Therefore, it is important to determine the history of C. japonica forests before human influence. We reviewed the transitions in distribution and abundance of C. japonica in the Japanese Archipelago since the last interglacial period by using published pollen data. During the last interglacial, temperate deciduous broadleaf forests developed on northeastern Honshu Island, whereas on southwestern Honshu Island C. japonica populations increased, accompanied by warm‐temperate evergreen broadleaf trees. During the first half of the last glacial period, C. japonica forests developed throughout the Japanese Archipelago except on Hokkaido. Thereafter, 60,000–30,000 years ago, C. japonica covered the area around Lake Biwa and the Izu Peninsula. During the Last Glacial Maximum, C. japonica was most abundant on the Izu Peninsula, and small refugial populations were located along the coast of the Sea of Japan from southwestern to northeastern Honshu, and along the Pacific coast of Shikoku Island. During the Middle Holocene, C. japonica populations increased rapidly in southwestern Honshu. Two thousand years ago, before the intensification of human activities, C. japonica was widespread in warm‐ to cool‐temperate zones on the Sea of Japan side of Honshu, the Izu Peninsula, the Pacific coast of Shikoku Island, and Yakushima Island. This evidence indicates that C. japonica is one of the major tree species in the Japanese vegetation zone.

Cedars of the North Mountains: Historical forest culture and practices in modern day nature policies

The region north of Kyoto is referred to as Kitayama, which literally translates as North Mountains. The region is the location of Cryptomeria japonica, Japanese cedar or sugi, production in Japan. Cedar logs grown there are used as pillars in the construction of buildings in a typical Japanese minimalist style, but also traditional rooms included in modern houses. Cedar was planted widely in Japan following World War II not only to rebuild the economy but also to grow raw materials to contribute to post-war housing reconstruction. In Kitayama, cedar has been grown for over 600 years and using specific silvicultural techniques by a community that has a unique cultural legacy which developed around cedar cultivation. The Kitayama sugi economic-socio-cultural-ecological complex thrived following World War II but is currently under stress. Demand for its highly priced products is declining. It is recognized in Japan and by the city of Kyoto as a valuable cultural historical heritage and efforts are being made to preserve it as such. The success of these efforts has been mixed so far. This paper reviews the Kitayama sugi economic-socio-cultural-ecological complex in order to understand how historical indigenous forestry practices change over time and how they might be dealt with in advanced societies such as Japan.

Effects of the growth and the root ball formation of the containerized Sugi (<i>Cryptomeria japonica</i> (L.f.)D.Don) seedlings on the irrigation method

スギコンテナ苗の育苗技術の構築を目的に，育苗時の潅水方法（底面給水と頭上潅水（常法））が苗木の成長，物質生産および根鉢形成に及ぼす影響について検討した。1 成長期間，両潅水法で育苗したコンテナ苗の苗高，根元径，形状比および苗木乾重（地上部，粗根，細根）には有意な差異は認められなかった。コンテナ苗の地下部は，根系が培地をしっかり包み込んだ根鉢が形成され，培地の崩落や根腐れは認められず，根鉢硬度（山中式硬度計による指標硬度）および細根率には有意な差異は認められなかった。スギコンテナ苗の育苗において，底面給水は頭上潅水と同等な育苗成績を示したことから，有効な潅水法と考えられる。

High-throughput sequencing covers greater nematode diversity than conventional morphotyping on natural cedar forests in Yakushima Island, Japan

Massive sequence reads obtained via high-throughput sequencing (HTS) methods have provided opportunities to extensively identify nematodes in certain habitats, thereby enabling the generation of assemblage patterns depicting nematode communities in natural ecosystems. However, we do not know whether HTS analysis yields assemblage patterns for nematode communities that are similar to those generated by conventional morphological analyses. We compared the community structures of soil nematodes determined by HTS and morphological analyses in natural Japanese cedar (Cryptomeria japonica) forests more than 1,000 years old on Yakushima Island, South Japan. Soil nematodes were collected at two sites, namely, Shiratani (SR) and Arakawa (AR), and identified to the genus level under a compound light microscope. Nematodes were also subjected to DNA sequence analysis, focusing on partial small subunit rRNA. Morphological analysis divided the nematodes into 9 orders, 34 families, and 42 genera. The 509 amplicon sequence variants were assigned to 11 orders, 45 families, and 76 genera. Based on the phylogenetic analysis of Aphelenchoides, our sequences were divided into 12 independent clades with bootstrap values greater than 70%. From both morphological and HTS analyses, 77 and 72 genera were identified for SR and AR, respectively, and HTS analysis covered 88% and 85% of the total nematode genera in samples from SR and AR, respectively. The nematode abundance obtained via HTS analysis was significantly correlated with the morphological abundance of Acrobeloides, Aphelenchoides, Helicotylenchus, Rhabdolaimus, and Wilsonema. The non-metric multidimensional scaling scatter plot indices showed that nematode community structures were significantly different between SR and AR, regardless of the methodology. Thus, HTS analysis is more useful than morphological analysis for identifying the nematode communities of natural ecosystems to uncover hidden diversity.

The effects of functional differences in cultivar of Cryptomeria japonica on nutrient dynamics and soil invertebrates in a common garden

AbstractRecently, some studies have established the ecological effects of intraspecific variation in phytochemical traits on soil ecosystems. Because plantations comprise a major proportion of forest area in some regions, intraspecific functional variation in plantation tree species is of great importance to forest ecosystems. Intraspecific variation in plantation tree species can result from natural geographical and cultivated variation. A previous study estimated the effects of geographical variation of Cryptomeria japonica, the most dominant plantation tree in Japan. The results showed that the significant consequences for ecosystem processes, such as calcium (Ca) dynamics and community composition of soil invertebrates, vary among the geographical variation of C. japonica. However, no studies have shown the effect of cultivar variation of tree species on the soil invertebrate community through alteration of the availability of nutrients. In this study, we used a common garden where four cultivars of C. japonica (Kumotoshi, Aya, Obi, and Satsumameasa) were planted in separate plots. In these plots, we measured the concentration of nutrients in leaves, litter and roots, strontium isotope ratio (87Sr/86Sr) of leaves. Root activities, exchangeable nutrients in soil, and soil parameters such as soil pH and abundance and composition of soil invertebrates. Our results show that cultivating different varieties of C. japonica may alter the accumulation of Ca in soil and soil pH. Furthermore, the effects of the cultivated varieties of C. japonica shape the abundance and composition of soil invertebrates by altering the soil properties, such as Ca concentration and pH in the soil.

Preparation of Formed Coke from Biomass by Sequence of Torrefaction, Binderless Hot Briquetting and Carbonization

This paper proposes a method of preparing high-strength formed coke from woody biomass without binder. Chipped and pre-dried Japanese cedar was heat-treated in an inert atmosphere (i.e., torrefied) at 225–325°C (Tt), pulverized to sizes in three different ranges, molded into briquettes (in the form of thick disk with diameter/thickness ≈ 2.5) at temperature up to 200°C by applying mechanical pressure of 128 MPa. The torrefied/briquetted cedar (TBC) was then converted into coke by heating to 1000°C in an inert atmosphere at normal pressure. This process sequence enabled to prepare coke having indirect tensile strength (St) of 8–32 MPa, which was much higher than that without torrefaction, below 5 MPa. The torrefaction greatly improved pulverizability of the cedar, which was further promoted by increasing Tt. St of TBC and that of coke both increased as the particle sizes of TBC decreased, but this explained only a minor part of significant effect of Tt on St of the coke. St was maximized at Tt = 275°C regardless of the degree of pulverization. The Tt effects on physicochemical properties of TBC and coke were investigated in detail. The difference in St of coke by Tt was mainly due to that in the increment of St along the carbonization at 500–1000°C. Fracture surfaces of the coke had particular morphologies that had been inherited from the original honeycomb structure of the cedar.

Archaeal community structures associated with fine root systems of Cryptomeria japonica (Cupressaceae) in central Japan

ABSTRACT Archaea live in extreme environments and have been found in non-extreme environments in recent years. Although most studies have focused on the nitrification function of archaea in forest soils, few studies have focused on how archaea in rhizospheres are involved in nutrient absorption. To elucidate the archaeal community pattern inhabiting the fine roots of trees, we examined the taxonomic identity and community structure of archaea in Japanese cedars (Cryptomeria japonica). Root samples were collected from six C. japonica plantations in central Japan. DNA was separately extracted from the first- and third-order roots, and archaeal taxa were determined by the cloning method focusing on 16S rDNA. As a result, 90% of the sequences were classified as in the phylum Thaumarchaeota, with 1.1b and 1.1c groups in the phylum accounting for 65% and 25%, respectively. Archaeal community structures were significantly correlated with soil pH, but neither the root orders nor the plantation sites showed significant clustering. These results suggest that Thaumarchaeota is the dominant archaeal group in the fine roots of C. japonica, and community structures are affected by a proximate chemical factor of soil acidity.

Combustion characteristics of densified solid biofuel with different aspect ratios

Bio-coke is a solid biofuel with a high density and high compressive strength. Demonstration tests have shown that bio-coke can be used as an alternative to coal and coal coke. The effects of biomass type and production conditions on combustion characteristics have been studied for small diameter bio-coke (φ50 mm or less). In this study, we focused on fuel size and investigated the combustion characteristics of φ12 to 100 mm samples. Experiments were conducted in a preheated, forced convection atmosphere using a batch-type vertical combustion apparatus to simulate rapid temperature increase and combustion under isothermal conditions in a gasification and melting furnace or blast furnace. Two biomass species (Japanese cedar and green tea) were selected as materials to study the effect of biomass species. We developed experimental correlations to predict the combustion time of bio-coke, considering the effects of scale and aspect ratio. The flaming and char combustion times of bio-coke can be approximated using the shape factor (V/S)n even when the aspect ratios are different. We obtained that the characteristic length is (V/S) to the power of 0.52–0.64. Furthermore, we found that Japanese cedar bio-coke has 2.5 times faster in flaming combustion than green tea bio-coke.

Torrefaction of woody biomass and in-situ pyrolytic reforming of volatile matter: Analyses of products and process heat demand

Torrefaction of Japanese cedar (TR) and in-situ vapor-phase pyrolytic reforming of volatile matter from TR (PYR) were investigated with three main objectives; quantification of the heats required for TR and PYR (QTR and QPYR, respectively), demonstration of high conversion of bio-oil into syngas by PYR without either catalyst or oxidizing agent, and clarification of effects of water washing of the cedar prior to TR on QTR and QPYR as well as the product distribution. The cedar was subjected to TR and PYR at temperatures of TTR = 250–350 °C and TPYR = 500–800 °C, respectively. QTR was defined as the difference in enthalpy between the TR products at TTR and dry cedar at 25 °C, and determined from compound or elemental composition of char, bio-oil, water, and non-condensable gases. QTR increased with TTR in a range of 1.0–4.0% of the cedar HHV, which could be covered by burning the gas and a small portion (0.5–13.0%) of bio-oil from TR at TTR ≥ 280 °C. The water washing removed substantial portions of the inherent alkali and alkaline earth metallic species. This resulted in slight increase in QTR, 0.2–0.8%-HHV and decrease in the gas yield, in particular, those of CO and CO2. PYR converted substantial portions of the bio-oil from TR at TTR = 300 °C. The bio-oil conversion into CO/H2–rich gas was 85–90% at TPYR = 800 °C. QPYR, which was defined as the enthalpy difference between the volatile matter from TR at 300 °C and that from PYR at TPYR, increased with TPYR but as small as 1.4–5.8% of the cedar HHV. The water washing slightly decreased QPYR, and this was quantitatively explained by slightly smaller bio-oil yield from TR of the water-washed cedar at TTR = 300 °C than that of the cedar. QPYR was a function of decrease in the bio-oil yield by PYR, which was not influenced by the water washing.

Preface: Functional biogeography in Japanese cedar

Preface: Functional biogeography in Japanese cedar

Intraspecific variation in growth‐related traits—from leaf to whole‐tree—in three provenances of Cryptomeria japonica canopy trees grown in a common garden

AbstractTo elucidate the physiological and morphological factors underlying intraspecific variation in growth rate, we examined the variation in leaf and whole‐tree traits for three geographical variations of ca. 45‐year‐old Japanese cedar (Cryptomeria japonica D. Don) with contrasting heights and radial growth in a common garden. Traits that reflect leaf‐level photosynthesis, water relations, and whole‐tree level crown structure in relation to light use and hydraulic architecture were measured. Overall, intraspecific variation in growth characteristics in field‐grown adult trees was regulated by whole‐tree properties rather than leaf properties. Most leaf traits were similar among provenances. Nevertheless, the leaf traits exhibited highest maximum net photosynthetic rate, dark respiration rate, and light compensation point in provenances whose native habitats are most similar to the common garden in the present study. Together with previous reports that this provenance has higher root nutrient acquisition capacity than the other two provenances, it can be said that organ‐level resource use strategies are coupled in a tandem manner. At the whole‐tree level, hydraulic architecture—as explained by axial variation in the hydraulically weighted tracheid diameter—can be linked to leaf distribution with respect to light use strategies as well as water transport capacity, leading to differences in growth characteristics among provenances. The study of intraspecific variation in growth characteristics in trees with a wide range of native habitats is expected to be a useful indicator for predicting changes in growth potential and forest dynamics in response to climate change in each habitat.

Provisioning Flexibility and Nestling Growth of Green-Backed Tit Parus monticolus in a Mosaic of Mixed-Oak Forest and Cedar Plantation in Taiwan

In heterogeneous landscapes, birds may mistime their breeding attempts relative to local food abundance. How birds cope with this challenge has been little studied. In this study, we compared the provisioning behavior and nestling condition of the Green-backed Tit Parus monticolus nesting in a landscape mosaic comprised of native mixed-oak forests and exotic Japanese Cedar Cryptomeria japonica plantations. Parent birds in the larvae-poor plantations time their breeding as they do in the larvae-rich forests and have clutches of similar size. We found that parent birds were flexible in adjusting their criteria for prey choice on the basis of larval abundance. In early spring, in cedar plantations where larval abundance was low, male parents maintained constant nearby feeding trips to the early broods, just as they did in the mixed-oak forests, but reduced their dietary specialization on larvae, while female birds increased their provisioning frequency. Combining both parents' efforts, the early brood nestlings raised in the cedar plantations received food deliveries more frequently and with a higher proportion of non-larval prey than their counterparts did in the mixed-oak forests. In contrast, during late brood rearing, when larvae were abundant, both parents in the plantations foraged heavily on larvae at the expense of other prey, just as they did in the mixed-oak forests. We found that parent birds reared heavier nestlings as the contribution of large larvae to the diet increased. Moreover, the nestlings during early broods in the plantations had lower body weights than their counterparts in the mixed-oak forests. We suggest that the provisioning flexibility of Green-backed Tits helps them gather food for raising nestlings when their breeding attempts are less synchronized with the larval food supply in their habitat. As a result, they can breed successfully in the exotic cedar plantations.

Genotype-by-environment interaction and genetic dissection of heartwood color in Cryptomeria japonica based on multiple common gardens and quantitative trait loci mapping.

The heartwood color of a major plantation tree Cryptomeria japonica shows high variability among clones and cultivars, and brighter heartwood has higher value in the usage of non-laminated wood such as in traditional construction, which makes heartwood color an important trait in breeding of this species. However, the genetic basis of the interactions between genetics and the environment on heartwood color has been understudied while these are necessary for effective breeding programs in multiple environmental condition. The objectives of the present study were to evaluate the effects of genetics and environments on heartwood color and how they interact in contrasting environments, and to identify genomic regions controlling heartwood color in C. japonica across multiple environments. Heartwood color in terms of L*a*b* color space and spectral reflectance was measured in common gardens established in three contrasting sites. Quantitative trait loci (QTL) that affect heartwood color were identified using previously constructed highly saturated linkage maps. Results found that heartwood color was largely genetically controlled, and genotype-by-environment interaction explained one-third of the total genetic variance of heartwood color. The effect of the environment was small compared to the effect of genetics, whereas environmental effects largely varied among heartwood color traits. QTL analysis identified a large number of QTLs with small to moderate effects (phenotypic variation explained of 6.6% on average). Some of these QTLs were stably expressed in multiple environments or had pleiotropic effects on heartwood color and moisture content. These results indicated that genetic variation in phenotypic plasticity plays an important role in regulating heartwood color and that the identified QTLs would maximize the breeding efficiency of heartwood color in C. japonica in heterogeneous environments.

Decadal trends in 137Cs concentrations in the bark and wood of trees contaminated by the Fukushima nuclear accident

Understanding the actual situation of radiocesium (137Cs) contamination of trees caused by the Fukushima nuclear accident is essential for predicting the future contamination of wood. Particularly important is determining whether the 137Cs dynamics within forests and trees have reached apparent steady state. We conducted a monitoring survey of four major tree species (Japanese cedar, Japanese cypress, konara oak, and Japanese red pine) at multiple sites. Using a dynamic linear model, we analyzed the temporal trends in 137Cs activity concentrations in the bark (whole), outer bark, inner bark, wood (whole), sapwood, and heartwood during the 2011–2020 period. The activity concentrations were decay-corrected to September 1, 2020, to exclude the decrease due to the radioactive decay. The 137Cs concentrations in the whole and outer bark samples showed an exponential decrease in most plots but a flat trend in one plot, where 137Cs root uptake is considered to be high. The 137Cs concentration ratio (CR) of inner bark/sapwood showed a flat trend but the CR of heartwood/sapwood increased in many plots, indicating that the 137Cs dynamics reached apparent steady state within one year in the biologically active parts (inner bark and sapwood) and after several to more than 10 years in the inactive part (heartwood). The 137Cs concentration in the whole wood showed an increasing trend in six plots. In four of these plots, the increasing trend shifted to a flat or decreasing trend. Overall, the results show that the 137Cs dynamics within forests and trees have reached apparent steady state in many plots, although the amount of 137Cs root uptake in some plots is possibly still increasing 10 years after the accident. Clarifying the mechanisms and key factors determining the amount of 137Cs root uptake will be crucial for predicting wood contamination.

Regional Differences in Carbon-14 Data of the 993 CE Cosmic Ray Event

Cosmogenic nuclides such as 14C from tree rings and 10Be and 36Cl from ice cores are excellent proxies for the past extremely large solar energetic particle (SEP) events, which are dozens of times larger than the largest SEP event in the history of observation. So far, several rapid 14C increases have been discovered, which are considered to have originated from extreme SEP events (or set of successive SEP events) from verifications using multiple cosmogenic nuclide analyses in natural archives. Although these events are characterized by a rapid increase in cosmogenic nuclide concentrations, 14C data recorded worldwide do not always show similar variations, especially during the 993 CE event, where a rapid increase was recorded in either 992–993 CE or 993–994 CE in several records. We present new 14C data of the Japanese cedar sample for the 993 CE event. Although the latest data show no significant increase in 1 year, an overall increase pattern is consistent with the previously reported 14C data of the Japanese cedar, which supports that a significant 14C increase occurred from 993 to 994 CE in the Japanese sample. Given the dominant 14C production in high latitudes by SEPs, the difference in timing of increase may be a transport effect in the atmosphere. Moreover, the difference in the timing of the 14C increase can cause a 1-year age-determination error using the 993 CE radiocarbon spike. Compared with the 14C data between tree samples from high latitude and midlatitude, including Japan, high-latitude data can capture 14C changes originating from SEP events more quickly and clearly and may be more suitable for a SEP event exploration in the past.

Cones of Coniferous Taxa as a Potential Source of Bioactive Polyphenols

Background: Coniferous cones are a by-product of forestry and wood logging, used for many possible purposes, e.g., the extraction of polyphenols. Objective: The aim of the present article was the comparison of the antioxidant polyphenol content of the differently matured cones of 17 selected conifers, either common in Hungary or yet uninvestigated. Methods: Total polyphenol content, ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl assays were used to determine the antioxidant contents. A scoring system was implemented using the three assay results to evaluate and compare the overall antioxidant power of the samples. Result and Conclusion: Highest antioxidant contents were found in green cones, followed by mature and opened cones. Taxa with the highest scores were Tsuga canadensis, Cryptomeria japonica, Chamaecyparis lawsoniana, Thuja orientalis, Metasequoia glyptostroboides and Picea abies. For the samples with the highest overall antioxidant power the high-performance liquid chromatographic/ tandem mass spectrometric polyphenol profiling was carried out (green cones of T. canadensis and P. abies) and 83 compounds have been tentatively identified and described. Results contribute to the future bioactivity testing and evaluation of the cone extracts of T. canadensis and P. abies.

Which Is the Best Substrate to Regenerate? A Comparative Pot Experiment for Tree Seedling Growth on Decayed Wood and in Soil

Dead wood is an important microsite for seedling regeneration in forest ecosystems. Although recent studies have found important associations between fungal wood decay type (white rot and brown rot) and both density and species composition of regenerating seedlings, its abiotic and biotic mechanisms are unknown. In the present study, pot experiments were conducted with the seedlings of two ectomycorrhizal tree species (Abies veitchii and Betula ermanii) and two arbuscular mycorrhizal tree species (Chamaecyparis obtusa and Cryptomeria japonica) to evaluate their growth using three substrates: brown rot wood, white rot wood, and soil. Results showed that the shoot growth of B. ermanii grown in white rot wood was greater than in other substrates, but this effect disappeared in sterilized substrates, suggesting some biotic positive effects occur in white rot wood. The seedling weights of Cr. japonica and Ch. obtusa were found to be greater in soil than in wood, and this may be partly attributable to the high mycorrhizal rate of their roots in soil. Colonization of arbuscular and ectomycorrhizal fungi was restricted to the seedlings in unsterilized soil. These results demonstrate the importance of the biological mechanisms affecting seedlings’ preferences for a variety of regeneration microsites and illustrate the need for future experiments to include larger sets of seedling species.

Eczema phenotypes and IgE component sensitization in adolescents: A population-based birth cohort

BackgroundEczema patients are commonly immunoglobulin (Ig)E polysensitized. Although atopic dermatitis (AD) phenotypes have been recognized, IgE sensitization patterns based on AD phenotypes have not been well illustrated. We aimed to investigate how eczema phenotypes impact IgE component sensitization patterns. MethodsThis birth cohort study investigated a general population in the Tokyo Children's Health, Illness, and Development Study (T-Child Study) until children reached the age of 13 years. Eczema was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Allergen component specific IgE antibody titers were measured using a multiplex array ImmunoCAP ISAC. ResultsPersistent eczema phenotype until adolescence was strongly associated with allergic march symptoms, such as wheezing and hay fever, and oral allergy symptoms, and IgE component sensitizations of airborne (Japanese cedar, house dust mite, Timothy, cat, and dog) and cross-reactive allergens (Bet v 1 family) compared to early-remission and late-onset eczema. On the other hand, late-onset eczema did not show any strong associations with allergic symptoms and IgE sensitization. Adolescents with persistent eczema have high comorbidity of symptoms of pollen-food allergy syndrome. ConclusionsEarly-onset eczema is deeply connected with the later allergic march, and late-onset eczema differs from the phenotype of allergic march. Early-onset eczema characterizing IgE sensitization was likely to be an extrinsic type, and late-onset eczema, which was not related to IgE sensitization, was likely an intrinsic type. Pollen-Food Allergy Syndrome is one of the allergic features in allergic march.

Impact of Preventive Measures on Subjective Symptoms and Antigen Sensitization against Japanese Cedar, Cypress Pollen and House Dust Mites in Patients with Allergic Rhinitis: A Retrospective Analysis in the COVID-19 Era

For >2 years, Japan’s government has been urging the populace to take countermeasures to prevent COVID-19, including mask wearing. We examined whether these preventive behaviors have affected the rate and degree of sensitization against pollen and house dust antigens in patients with allergic rhinitis. We retrospectively surveyed 2565 patients who had undergone allergy blood testing during the period 2015–2021. We subdivided this period into eras based on the COVID-19 pandemic: the pre-COVID (2015–2019, n = 1879) and COVID (2020–2021, n = 686) eras. The positive rates for Japanese cedar and cypress in the 40–59-year-olds and those for house dust in the 20–39-year-olds were significantly reduced in the COVID era versus those in the pre-COVID era. Each group’s mean antigen-specific CAP scores decreased significantly from the 1st to 2nd era: from 1.98 to 1.57 for cedar (p < 0.01), 1.42 to 0.95 for cypress (p < 0.05), and 2.86 to 2.07 for house dust (p < 0.01). Our survey of the patients’ clinical records indicates that 47.5% of the pollinosis patients reported improvement in nasal symptoms after the three seasons of pollen dispersion in the COVID era. Japan’s quarantine policies designed to combat the spread of COVID-19 thus coincide with pivotal measures to alleviate allergic reactions.