真司 原, 修 松田, 幸仁 落合, 博順 飛田, and 木玄 宇都, “Effects of Near-Infrared Light Screening and Fungicide Treatment on the Germination Rate of Cedar and Cypress Seeds,” 日本森林学会誌, vol. 98, no. 5, pp. 247–251, 2016.
doi: 10.4005/jjfs.98.247.
優 市原, 栄 藤井, 裕萌 安藤, and 勇人 升屋, “Seed Rot That Inhibits Germination of Cedar Seeds Sown in Containers,” 日本森林学会誌, vol. 101, no. 3, pp. 134–137, 2019.
doi: 10.4005/jjfs.101.134.
C.-H. Choi, K.-J. Cho, and W.-S. Tak, “Effect of Immersion Temperatures and Times on Moisture Absorption and Germination of Cryptomeria japonica Seeds,” Korean Journal of Plant Resources, vol. 20, no. 5, pp. 398–403, 2007.https://www.koreascience.or.kr/article/JAKO200704503654744.page.
본 연구는 우리나라 남부지역 주요 조림수종인 삼나무 종자의 침지시 온도 및 시간 조절을 통해 발아율을 향상시키고자 실시되었는바 다음과 같은 결과를 얻었다. 삼나무 종자의 발아적온은 }20\^{∘}C{ 및 }25\^{∘}C{이었으며, 고온인 }35\^{∘}C{에서 가장 발아율이 낮았다. 또한 15, 20, 25, 30, }35\^{∘}C{의 온도조건에서 시간에 따른 수분흡수율은 }30\^{∘}C{ 및 }35\^{∘}C{에서 높게 나타났다. 초기수분흡수속도는 }30\^{∘}C{에서 가장 빨랐으며 본 실험 중 가장 저온인 }15\^{∘}C{에서 가장 늦었다. 수분흡수속도상수 역시 고온인 }30\^{∘}C{와 }35\^{∘}C{에서 높게 나타났으며 }15\^{∘}C{와 }20\^{∘}C{에서는 대체적으로 낮게 나타났다. 한편, 삼나무 종자는 }35\^{∘}C{를 제외하고는 모두 30시간 이상이 경과한 후에 평형에 도달하여 많은 차이를 나타내었다. 온도별 침지시간에 따른 삼나무 종자는 발아율에 있어 일정한 경향을 나타내지는 않았다. }30\^{∘}C{에서 48시간 침지한 종자에서 가장 높은 발아율(45.3%)을 보였으며, 나머지는 모두 무처리구와 유사하거나 낮은 경향을 보였다. 종자의 평균발아일수는 침지온도 및 침지시간에 따라 뚜렷한 경향을 보이지는 않았는데 침지 48시간까지는 대체적으로 균일한 수준이었으나 }35\^{∘}C{를 제외한 나머지 온도조건들에서는 60시간에서 급격한 증가를 보였다. }30\^{∘}C{ 48시간 침지처리의 경우는 무처리구와 같은 경향을 보였으나 이외 대부분 처리구들은 무처리구 보다 평균발아일수가 길었다. 결과적으로 침지온도 및 침지시간의 조절은 삼나무 종자의 발아일수를 단축시킬 수는 없으나 기존상태로 유지하면서 발아율은 향상시킬 수 있다. This study was carried out to enhance germination of the seed by different immersion temperatures(15, 20, 25, 30 and }35\^{∘}C{) and times(1, 6, 12, 18, 24, 36 and 48 hours) in Cryptomeria japonica that is a major plantation species in the southern Korea. Optimum germination temperature was between }20\^{∘}C{ and }25\^{∘}C{, and the lowest germination was observed at }35\^{∘}C{ Moisture absorption increased with increasing immersion time as a whole and was high at }30\^{∘}C{ and }35\^{∘}C{. Initial moisture absorption rate was highest at }30\^{∘}C{ whereas was lowest at }15\^{∘}C{ Moisture absorption rate constant was also high at }30\^{∘}C{ and }35\^{∘}C{, however, it was relatively low at }15\^{∘}C{ and }20\^{∘}C{ Germination was the highest when the seeds were immersed for 48 hours at }30\^{∘}C{. In mean germination time(MGT) the seeds immersed for 48 hours at }30\^{∘}C{ did not differ from non-treatment, while the others showed higher values than non-treatment. Consequently, germination could be enhanced and MGT was kept by optimum immersion temperature and time.
T. Enoki, M. Takagi, S. Ugawa, E. Nabeshima, and H. Ishii, “Regional and Topographic Growth Variation among 45-Year-Old Clonal Plantations of Cryptomeria Japonica: Effects of Genotype and Phenotypic Plasticity,” Journal of Forest Research, vol. 25, no. 5, pp. 329–338, Sep. 2020.
doi: 10.1080/13416979.2020.1767267.
Success of clonal tree plantations depends on genotype as well as phenotypic plasticity, which determines acclimation potential of individual trees to different environmental conditions. Short-term acclimation of genotypes to local growing conditions can be tested using clonal trials, but stand productivity and yield depends on the ability of the genotype to acclimate to long-term environmental variation. In Japan, clonal plantations of Cryptomeria japonica (Thunb. ex L. f.) D. Don are common and many elite clones have been developed. We evaluated growth of clonal C. japonica plantations in 45-year-old clonal trials taking into account effects of both genotype, environment and their interaction (i.e., phenotypic plasticity). In all five sites, tree sizes were larger for clonal cultivars evaluated initially as “early-growth type” than for the “late-growth type” cultivars. All cultivars showed decrease in tree height from lower to upper slope. The differences in tree growth among cultivars were more marked in sites where trees grew well, suggesting poor site conditions prevented the early-growth cultivars from fully exploiting their growth potential. Phenotypic plasticity of each cultivar was evaluated as growth variation among sites (regional variation) and along slope within sites (topographic variation). Plasticity was observed at both regional and topographic scales and cultivars with higher plasticity generally grew larger. The result of our study suggested that genotypes with greater phenotypic plasticity may possess greater acclimation potential, enabling them to grow well under a wide range of environmental conditions.
K. Fukumoto, T. Nishizono, F. Kitahara, and K. Hosoda, “Evaluation of Individual Distance-Independent Diameter Growth Models for Japanese Cedar (Cryptomeria Japonica) Trees under Multiple Thinning Treatments,” Forests, vol. 11, no. 3, p. 344, Mar. 2020.
doi: 10.3390/f11030344.
Understanding the tree growth process is essential for sustainable forest management. Future yields are affected by various forest management regimes such as thinning; therefore, accurate predictions of tree growth are needed under various thinning intensities. This study compared the accuracy of individual-level distance-independent diameter growth models constructed for different thinning intensities (thinning intensity-dependent multiple models: TDM model) against the model designed to include all thinning intensities (thinning intensity-independent single model: TIS model) to understand how model accuracy is affected by thinning intensity. We used long-term permanent plot data of Japanese cedar (Cryptomeria japonica) stands in Japan, which was gathered from four plots where thinning was conducted at different thinning intensities: (1) intensive (41% and 38% of trees removed at 25 and 37 years old, respectively), (2) moderate (38% and 34%), (3) light (32% and 34%), and (4) no thinning. First, we specified high interpretability distance-independent competition indices, and we compared the model accuracy both in TDM and TIS models. The results show that the relative spacing index was the best competition index both in TDM and TIS models across all thinning intensities, and the differences in the RMSE (Root mean square error) and rRMSE (relative RMSE) in both TDM and TIS models were 0.001–0.01 cm and 0.2–2%, respectively. In the TIS model, rRMSE varied with thinning intensity; the rRMSE was the lowest for moderate thinning intensity (45.8%) and the highest for no thinning (59.4%). In addition, bias values were negative for the TIS model for all thinning intensities. These results suggest that the TIS model could express diameter growth regardless of thinning intensities. However, the rRMSE had varied with thinning intensity and bias had negative values in the TIS model. Therefore, more model improvements are required for accurate predictions of long-term growth of actual Japanese cedar stands.
Y. Hiraoka et al., “Potential of Genome-Wide Studies in Unrelated Plus Trees of a Coniferous Species, Cryptomeria Japonica (Japanese Cedar),” Frontiers in Plant Science, vol. 9, p. 1322, 2018.
doi: 10.3389/fpls.2018.01322.
A genome-wide association study (GWAS) was conducted on more than 30,000 single nucleotide polymorphisms (SNPs) in unrelated first-generation plus tree genotypes from three populations of Japanese cedar Cryptomeria japonica D. Don with genomic prediction for traits of growth, wood properties and male fecundity. Among the assessed populations, genetic characteristics including the extent of linkage disequilibrium (LD) and genetic structure differed and these differences are considered to be due to differences in genetic background. Through population-independent GWAS, several significant SNPs found close to the regions associated with each of these traits and shared in common across the populations were identified. The accuracies of genomic predictions were dependent on the traits and populations and reflected the genetic architecture of traits and genetic characteristics. Prediction accuracies using SNPs selected based on GWAS results were similar to those using all SNPs for several combinations of traits and populations. We discussed the application of genome-wide studies for C. japonica improvement.
K. Hirayama and M. Sakimoto, “Seedling Demography and Establishment of Cryptomeria Japonica in a Cool-Temperate, Old-Growth, Conifer Hardwood Forest in the Snowy Region of Japan,” Journal of Forest Research, vol. 10, no. 1, pp. 67–71, Feb. 2005.
doi: 10.1007/s10310-004-0104-0.
To clarify the establishment pattern of Cryptomeria japonica seedlings, the demography of current-year seedlings was studied under various micro-environmental conditions for 2 years in a cool-temperate old-growth forest in the snowy region of Japan. In both years, more than 70% of seedlings that emerged died within a year, and differences in the survival rate of seedlings with respect to micro-environmental conditions were similar. While a number of seedlings survived at the sites on fallen logs and in mineral soil, almost no seedlings survived at the sites with either broad-leaved or coniferous litters at the end of the first growing season. The negative litter effect may kill most small seedlings of C. japonica. In addition, we found that survival rates of the seedlings were greater as the distance from the nearest adult and canopy openness increased. An analysis using Quantification Theory I showed that, of the possible micro-environmental factors, substrate conditions had the strongest effect on the survival of seedlings. The analysis also indicated that distance from the nearest adult and canopy openness also affected seedling survival significantly and to almost the same extent, although the effects were weaker than those for the substrate condition. Given the limited establishment sites for C. japonica seedlings, layering is suggested to be the main mode of regeneration in this forest.
T. Igasaki et al., “Somatic Embryogenesis and Plant Regeneration from Immature Zygotic Embryos of Cryptomeria Japonica D. Don,” Plant Cell Reports, vol. 22, no. 4, pp. 239–243, Nov. 2003.
doi: 10.1007/s00299-003-0687-5.
This report describes the successful plant regeneration via somatic embryogenesis from immature zygotic embryos of Cryptomeria japonica D. Don. For the induction of embryogenic tissue, we determined that the optimal medium contained N6-benzyladenine and 2,4-dichlorophenoxyacetic acid. Immature zygotic embryos that were collected at the end of June yielded embryogenic tissue at the highest frequency. Embryogenic tissues that had proliferated in liquid medium included small and loosely packed cells and elongating or elongated cells. We used ten cell lines to determine the optimal medium for the development of somatic embryos. Induced somatic embryos germinated with synchronous sprouting of cotyledons, hypocotyls and roots. Gibberellin A3 in the germination medium had a positive effect on both the elongation of hypocotyls and the survival of seedlings. The frequencies of induction and germination of somatic embryos differed among the cell lines examined. Most of the seedlings grew normally. This system of somatic embryogenesis required 4–5 months for the regeneration of C. japonica plantlets from immature zygotic embryos.
T. Igasaki, N. Akashi, and K. Shinohara, “Somatic Embryogenesis in Cryptomeria Japonica D. Don: Gene for Phytosulfokine(PSK) Precursor,” in Somatic Embryogenesis, A. Mujib and J. Šamaj, Eds. Berlin, Heidelberg: Springer, 2006, pp. 201–213.
doi: 10.1007/7089_033.
Genetic transformation requires a reproducible system for the regeneration of plants via somatic embryogenesis or organogenesis. We established a reproducible system of plant regeneration based on somatic embryogenesis in Cryptomeria japonica D. Don. The developmental stage of the zygotic embryos was critical in the induction of embryogenic tissue. Embryogenic tissues that proliferated in liquid medium included small and loosely packed cells and elongating or elongated cells. Phytosulfokine, which has been identified as a plant growth factor, had a dramatic stimulatory effect on the formation of somatic embryos of C. japonica in the presence of polyethylene glycol. Induced somatic embryos germinated with synchronous sprouting of cotyledons, hypocotyls and roots, and most of the seedlings grew normally. This system of somatic embryogenesis in C. japonica should allow the genetic engineering of transgenic C. japonica with allergen-free pollen grains.
H. Iwasaki, K. Uchiyama, M. Kimura, Y. Saito, T. Hakamata, and Y. Ide, “Impact of a Tree Improvement Program on the Genetic Diversity of Sugi (Cryptomeria Japonica D Don) Plantations,” Forest Ecology and Management, vol. 448, pp. 466–473, Sep. 2019.
doi: 10.1016/j.foreco.2019.06.023.
The main purpose of this study was to investigate how a shift in seed sources owing to the implementation of a tree improvement program affected the genetic diversity of plantation forests. We investigated the genetic diversity and pairwise relatedness between individuals in sugi (Cryptomeria japonica D Don) plantations established before (“Pre-B”) and after (“Post-B”) the start of the Japanese tree improvement program. Based on SSR and SNP markers, most genetic diversity indices and the degree of relatedness within plantations were comparable between “Pre-B” and “Post-B”. However, there were large variations in the proportion of closely related pairs within plantations in both groups. Additionally, in “Post-B” plantations, parental contributions greatly diverged among plus-tree clones. The results of this study indicated that the shift in the seed sources, caused by the implementation of a tree improvement program, did not have a significant effect on the genetic diversity of plantations. However, the results also indicated that the degree of relatedness within plantations varied significantly according to how seeds are collected regardless of the type of seed sources. Furthermore, it was also revealed that genetic diversity in “Post-B” plantations could have decreased because of a deviation from equal parental contributions in seed orchards. Our results indicated that effective management of seed orchards is important to secure the genetic diversity of plantation forests.
A. Izuno, T. E. Maruyama, S. Ueno, T. Ujino-Ihara, and Y. Moriguchi, “Genotype and Transcriptome Effects on Somatic Embryogenesis in Cryptomeria Japonica,” PLOS ONE, vol. 15, no. 12, p. e0244634, Dec. 2020.
doi: 10.1371/journal.pone.0244634.
Somatic embryogenesis (SE), which is in vitro regeneration of plant bodies from somatic cells, represents a useful means of clonal propagation and genetic engineering of forest trees. While protocols to obtain calluses and induce regeneration in somatic embryos have been reported for many tree species, the knowledge of molecular mechanisms of SE development is still insufficient to achieve an efficient supply of somatic embryos required for the industrial application. Cryptomeria japonica, a conifer species widely used for plantation forestry in Japan, is one of the tree species waiting for a secure SE protocol; the probability of normal embryo development appears to depend on genotype. To discriminate the embryogenic potential of embryonal masses (EMs) and efficiently obtain normal somatic embryos of C. japonica, we investigated the effects of genotype and transcriptome on the variation in embryogenic potential. Using an induction experiment with 12 EMs each from six genotypes, we showed that embryogenic potential differs between/within genotypes. Comparisons of gene expression profiles among EMs with different embryogenic potentials revealed that 742 differently expressed genes were mainly associated with pattern forming and metabolism. Thus, we suggest that not only genotype but also gene expression profiles can determine success in SE development. Consistent with previous findings for other conifer species, genes encoding leafy cotyledon, wuschel, germin-like proteins, and glutathione-S-transferases are likely to be involved in SE development in C. japonica and indeed highly expressed in EMs with high-embryogenic potential; therefore, these proteins represent candidate markers for distinguishing embryogenic potential.
L. G. Jull, S. L. Warren, and F. A. Blazich, “Nitrogen Nutrition of Containerized Cryptomeria Japonica ‘Elegans Aurea,’” Journal of Environmental Horticulture, vol. 12, no. 4, pp. 212–215, Dec. 1994.
doi: 10.24266/0738-2898-12.4.212.
Containerized, rooted stem cuttings of ‘Elegans Aurea’ Japanese cedar [Cryptomeria japonica (L.f.) D. Don ‘Elegans Aurea’] grown in calcined clay, were fertilized three times weekly for 14 weeks with a complete nutrient solution containing 0, 25, 50, 100, or 200 mg N/liter supplied as ammonium nitrate. Top and root dry weights were not affected by N rate suggesting that 25 mg N/liter was adequate for maximizing growth. Nitrogen fertilization increased top and root dry weights by 149% and 20%, respectively, compared to the nontreated controls (0 mg N/liter). As N concentrations increased, root area and total root length decreased linearly. Nitrogen fertilization decreased root:top ratio by 50% compared to the nontreated controls. However, the root:top ratio was not affected by N rate. Percent top N concentration was increased by N compared to the nontreated control. Percent top K, Ca, and Mg decreased linearly with increasing N rates. There was a quadratic response in percent top P with a maximum at 50 mg N/liter.
L. G. Jull, S. L. Warren, and F. A. Blazich, “Rooting ‘Yoshino’ Cryptomeria Stem Cuttings as Influenced by Growth Stage, Branch Order, and IBA Treatment,” HortScience, vol. 29, no. 12, pp. 1532–1535, Dec. 1994.
doi: 10.21273/HORTSCI.29.12.1532.
Stem cuttings of ‘Yoshino’ Japanese cedar [Cryptomeria japonica (L.f.) D. Don ‘Yoshino’], consisting of tips (terminal 20 cm) of first-order laterals, distal halves (terminal 10 cm) of tips of first-order laterals, and proximal halves (basal 10 cm) of tips of first-order laterals, or tips (terminal 10 cm) of second-order laterals, were taken on four dates that represented four growth stages (softwood, semi-hardwood, hardwood, and pre-budbreak). The cuttings were treated with 0, 3000, 6000, or 9000 mg IBA/liter. Branch order affected all rooting measurements at each growth stage. Regardless of growth stage, tips of and proximal halves of first-order laterals containing lignified wood had the highest percent rooting, root count, total root length, root area, and root dry weight. Hardwood tips of and semi-hardwood proximal halves of first-order laterals exhibited the highest overall rooting (87%), followed by softwood proximal halves of first-order laterals (78%). Rooting of distal halves of first-order laterals and tips of second-order laterals never exceeded 55% and 34%, respectively, at any growth stage. IBA treatment influenced percent rooting, root count, total root length, root area, and root dry weight of semi-hardwood, hardwood, and pre-budbreak cuttings, except for root dry weight of semi-hardwood cuttings. IBA had no affect on softwood cuttings. Chemical name used: 1H-indole-3-butyric acid (IBA).
N. Junko, O. Mayumi, Y. Tsuyoshi, and H. Keizo, “Effect of woody ash mixing to growing media on the growth and nutrient condition of containerized Sugi (Cryptomeria japonica) and Hinoki (Chamaecyparis obtusa) seedlings,” 森林総合研究所研究報告, vol. 17, no. 1, pp. 75–84, 2018.https://jglobal.jst.go.jp/en/detail?JGLOBAL_ID=201802270192781191.
Most of the combustion ash produced from woody biomass power plants (hereinafter abbreviated as combustion ash) is industrial waste. Although it is treated as a substance, combustion ash is effective as a soil material because it contains fertilizer elements such as Ca and K. May be available. In this study, in order to explore the possibility of using combustion ash as a container seedling raising medium, Sugi and cypress in a medium (0% (control) group, 5% group, 10% group, 25% group) in which the mixing ratio (volume ratio) of combustion ash was changed. Was cultivated for 8-9 months, and the growth and nutrient status of the seedlings were examined. Mixing of combustion ash for both Sugi and Hinoki is an individual Did not promote the chief. The effect of the mixing ratio of combustion ash on growth depends on the tree species, and in Sugi In the 25% group and in the 10% and 25% groups of Japanese cypress, the growth of seedling height, diameter and dry weight was significantly suppressed as compared with the control group. The commutative Mg and Na contents at the time of digging were lower in the medium with a higher mixing ratio of combustion ash. High mixing ratio of combustion ash The Ca content of sugi leaves was higher in the treatment plots, but the Mg and K contents of sugi and cypress leaves and Ca of cypress leaves There was no significant difference in content between treatments. From the above results, Sugi and Hino by mixing combustion ash with the medium. As a container seedling medium material without showing any effect of promoting the growth of seedlings and without significantly impairing the growth of seedlings. It was clarified that the upper limit of the ratio of combustion ash that can be mixed with the medium is 10% for Sugi and 5% for Hinoki. rice field. In the future, it is necessary to study the soundness of container seedlings mixed with combustion ash in the medium after planting them in the forest.
D. H. Kim, S. H. Han, J. J. Ku, and K. Y. Lee, “Effects of Cryoprotectants and Post-Storage Priming on Seed Germination of Sugi (Cryptomeria Japonica,” Silvae Genetica, vol. 58, no. 1-6, pp. 162–168, Nov. 2009.
doi: 10.1515/sg-2009-0021.
Among the ex situ methods for the preservation of forest tree germplasm, conventional seed banking is considered the most efficient method for the majority of species whilst cryopreservation has an important role in long-term conservation. The influence of cryoprotectants prior to liquid nitrogen (LN) storage and osmoconditioning priming treatments with polyethylene glycol (PEG) after LN storage were evaluated for germination (%), germination value (GV) and mean germination time (MGT) in seeds of Cryptomeria japonica. Sugi seeds were treated with two cryoprotectants (DMSO and PVS2) before immersion into LN and stored for three days. Although the C. japonica seeds survived liquid nitrogen treatment, their viability was reduced from 25% of intact seeds to 17% in LN. The seeds treated with 35% DMSO showed higher germination (28%) as compared with seeds directly-immersed in LN without cryoprotectant treatment. In contrast, PVS2 pretreated seeds decreased germination (13%). Two concentrations of PEG priming treatments were carried out. Osmoconditioning treatment in -0.4 MPa PEG solution after removal from LN enhanced the subsequent germination percentage and decreased MGT. PEG treatments at both -0.4 and -1.2MPa to PVS2 pretreated seeds before cryopreservation partially alleviated the negative effect of PVS2. DMSO pretreated seeds immersed into LN and treated
Cryptomeria japonica is a conifer of great load that detaches for the fast growth and good lumber potential. In spite of could being propagated by seeds, the vegetative propagation of Cryptomeria japonica is justified for the maintenance of the desirable characteristics of selected plus trees. In function of this and the lack of information about vegetative propagation out of Japan, this work had as objective to verify the effect of indolbutiric acid (IBA) and alcohol on rooting of cuttings of three adult clones of Cryptomeria japonica. The cuttings from three trees with nine years old, after prepared, received phytosanitary treatment for the clear, followed by the treatment with different concentrations of iba (T1 = 0 mg L-1; T2 = water + alcohol (1:1 v/v); T3 = 2,000 mg.L-1 IBA; T4 = 4,000 mg.L-1 IBA; T5 = 8,000 mg.L-1 IBA). The best results showed that the studied clones presents variation in clones in terms of the evaluated characteristics and has low level of rooting independent of the tested concentrations of IBA. the concentration with maximum technical efficiency is around 4,000 mg.L-1 IBA, with 22.9% of rooting for clone 2.
M. Kurita et al., “Transcriptome Analysis in Male Strobilus Induction by Gibberellin Treatment in Cryptomeria Japonica D. Don,” Forests, vol. 11, no. 6, p. 633, Jun. 2020.
doi: 10.3390/f11060633.
The plant hormone gibberellin (GA) is known to regulate elongating growth, seed germination, and the initiation of flower bud formation, and it has been postulated that GAs originally had functions in reproductive processes. Studies on the mechanism of induction of flowering by GA have been performed in Arabidopsis and other model plants. In coniferous trees, reproductive organ induction by GAs is known to occur, but there are few reports on the molecular mechanism in this system. To clarify the gene expression dynamics of the GA induction of the male strobilus in Cryptomeria japonica, we performed comprehensive gene expression analysis using a microarray. A GA-treated group and a nontreated group were allowed to set, and individual trees were sampled over a 6-week time course. A total of 881 genes exhibiting changed expression was identified. In the GA-treated group, genes related to ‘stress response’ and to ‘cell wall’ were initially enriched, and genes related to ‘transcription’ and ‘transcription factor activity’ were enriched at later stages. This analysis also clarified the dynamics of the expression of genes related to GA signaling transduction following GA treatment, permitting us to compare and contrast with the expression dynamics of genes implicated in signal transduction responses to other plant hormones. These results suggested that various plant hormones have complex influences on the male strobilus induction. Additionally, principal component analysis (PCA) using expression patterns of the genes that exhibited sequence similarity with flower bud or floral organ formation-related genes of Arabidopsis was performed. PCA suggested that gene expression leading to male strobilus formation in C. japonica became conspicuous within one week of GA treatment. Together, these findings help to clarify the evolution of the mechanism of induction of reproductive organs by GA.
E. Maruyama, T. Tanaka, Y. Hosoi, K. Ishii, and N. Morohoshi, “Embryogenic Cell Culture, Protoplast Regeneration, Cryopreservation, Biolistic Gene Transfer and Plant Regeneration in Japanese Cedar (Cryptomeria Japonica D. Don),” Plant Biotechnology, vol. 17, no. 4, pp. 281–296, 2000.
doi: 10.5511/plantbiotechnology.17.281.
Somatic embryogenesis in Cryptomeria japonica was initiated at a relatively high frequency from immature seeds collected from the end of June to mid-July. Induction of embryogenic cultures was possible on media with or without plant growth regulators, and the initiation frequency varied from 5 to 16%. Embryogenic cell lines have been maintained and proliferated for more than 2 years in solid and liquid media. For long-term storage embryogenic cells were cryopreserved using a simple freezing method. Cotyledonary embryos were obtained mostly on maturation media containing abscisic acid (ABA) and polyethylene glycol (PEG) as osmotic agent, however, the plant conversion rate was still low. Plants regenerated from somatic embryos continued growing in a greenhouse. Furthermore, a procedure for the individual culture of protoplasts isolates from embryonal masses, and an approach for microprojectile bombardment-mediated transformation using pIPT and pMAT vectors was also described.
T. E. Maruyama, S. Ueno, H. Mori, T. Kaneeda, and Y. Moriguchi, “Factors Influencing Somatic Embryo Maturation in Sugi (Japanese Cedar, Cryptomeria Japonica (Thunb. Ex L.f.) D. Don),” Plants, vol. 10, no. 5, p. 874, May 2021.
doi: 10.3390/plants10050874.
This paper presents the results of several experiments identifying basal salts (BS) contained in maturation medium, polyethylene glycol (PEG) concentration, abscisic acid (ABA) concentration, additional supplementation with potassium chloride (KCl), amino acid (AA) concentration, and proliferation culture medium (PCM) as the main culture factors affecting somatic embryo maturation in sugi (Japanese cedar, Cryptomeria japonica, Cupressaceae). Highly efficient embryo maturation was achieved when embryogenic cell lines (ECLs) were cultured on media supplemented with a combination of PEG, ABA, and AAs. More than 1000 embryos per gram of fresh weight (FW) can be produced on EM maturation medium supplemented with 175 g L−1 PEG, 100 µM ABA, 2 g L−1 glutamine, 1 g L−1 asparagine, and 0.5 g L−1 arginine.
T. E. Maruyama, S. Ueno, S. Hirayama, T. Kaneeda, and Y. Moriguchi, “Somatic Embryogenesis and Plant Regeneration from Sugi (Japanese Cedar, Cryptomeria Japonica D. Don, Cupressaceae) Seed Families by Marker Assisted Selection for the Male Sterility Allele Ms1,” Plants, vol. 9, no. 8, p. 1029, Aug. 2020.
doi: 10.3390/plants9081029.
One of the possible countermeasures for pollinosis caused by sugi (Cryptomeria japonica), a serious public health problem in Japan, is the use of male sterile plants (MSPs; pollen-free plants). However, the production efficiencies of MSPs raised by conventional methods are extremely poor, time consuming, and resulting in a high seedling cost. Here, we report the development of a novel technique for efficient production of MSPs, which combines marker-assisted selection (MAS) and somatic embryogenesis (SE). SE from four full sib seed families of sugi, carrying the male sterility gene MS1, was initiated using megagametophyte explants that originated from four seed collections taken at one-week intervals during the month of July 2017. Embryogenic cell lines (ECLs) were achieved in all families, with initiation rates varying from 0.6% to 59%. Somatic embryos were produced from genetic marker-selected male sterile ECLs on medium containing maltose, abscisic acid (ABA), polyethylene glycol (PEG), and activated charcoal (AC). Subsequently, high frequencies of germination and plant conversion (≥76%) were obtained on plant growth regulator-free medium. Regenerated plantlets were acclimatized successfully, and the initial growth of male sterile somatic plants was monitored in the field.
T. E. Maruyama et al., “Somatic Embryogenesis Initiation in Sugi (Japanese Cedar, Cryptomeria Japonica D. Don): Responses from Male-Fertile, Male-Sterile, and Polycross-Pollinated-Derived Seed Explants,” Plants, vol. 10, no. 2, p. 398, Feb. 2021.
doi: 10.3390/plants10020398.
This study aimed to obtain information from several embryogenic cell (EC) genotypes analyzing the factors that affect somatic embryogenesis (SE) initiation in sugi (Cryptomeria japonica, Cupressaceae) to apply them in the improvement of protocols for efficient induction of embryogenic cell lines (ECLs). The results of several years of experiments including studies on the influence of initial explant, seed collection time, and explant genotype as the main factors affecting SE initiation from male-fertile, male-sterile, and polycross-pollinated-derived seeds are described. Initiation frequencies depending on the plant genotype varied from 1.35 to 57.06%. The best induction efficiency was achieved when seeds were collected on mid-July using the entire megagametophyte as initial explants. The extrusion of ECs started approximately after 2 weeks of culture, and the establishment of ECLs was observed mostly 4 weeks after extrusion on media with or without plant growth regulators (PGRs). Subsequently, induced ECLs were maintained and proliferated on media with PGRs by 2–3-week-interval subculture routines. Although, the initial explant, collection time, and culture condition played important roles in ECL induction, the genotype of the plant material of sugi was the most influential factor in SE initiation.
O. Matsuda et al., “Determination of Seed Soundness in Conifers Cryptomeria Japonica and Chamaecyparis Obtusa Using Narrow-Multiband Spectral Imaging in the Short-Wavelength Infrared Range,” PloS one, 2015.
doi: 10.1371/journal.pone.0128358.
Enrichment of sound seeds was accompanied by an increase in germination rate of the seed lot, and SQI calculated from seed area-averaged reflectance spectra and spatial distribution patterns of pixelwise SQI within each seed area were both proven as reliable criteria for sound seed selection. Regeneration of planted forests of Cryptomeria japonica (sugi) and Chamaecyparis obtuse (hinoki) is the pressing importance to the forest administration in Japan. Low seed germination rate of these species, however, has hampered low-cost production of their seedlings for reforestation. The primary cause of the low germinability has been attributed to highly frequent formation of anatomically unsound seeds, which are indistinguishable from sound germinable seeds by visible observation and other common criteria such as size and weight. To establish a method for sound seed selection in these species, hyperspectral imaging technique was used to identify a wavelength range where reflectance spectra differ clearly between sound and unsound seeds. In sound seeds of both species, reflectance in a narrow waveband centered at 1,730 nm, corresponding to a lipid absorption band in the short-wavelength infrared (SWIR) range, was greatly depressed relative to that in adjacent wavebands on either side. Such depression was absent or less prominent in unsound seeds. Based on these observations, a reflectance index SQI, abbreviated for seed quality index, was formulated using reflectance at three narrow SWIR wavebands so that it represents the extent of the depression. SQI calculated from seed area-averaged reflectance spectra and spatial distribution patterns of pixelwise SQI within each seed area were both proven as reliable criteria for sound seed selection. Enrichment of sound seeds was accompanied by an increase in germination rate of the seed lot. Thus, the methods described are readily applicable toward low-cost seedling production in combination with single seed sowing technology.
H. Mori, K. Yamashita, S.-T. Saiki, A. Matsumoto, and T. Ujino-Ihara, “Climate Sensitivity of Cryptomeria Japonica in Two Contrasting Environments: Perspectives from QTL Mapping,” PLOS ONE, vol. 15, no. 1, p. e0228278, Jan. 2020.
doi: 10.1371/journal.pone.0228278.
Long-lived forest tree species experience a wide range of environmental conditions throughout their lifespan. Evaluation of the underlying growth and development mechanisms of these species is essential to predict tree growth under climate change. This study investigated climate sensitivity to temperature, precipitation, dry periods, and the associated genomic regions in Cryptomeria japonica, Japan’s most commercially important tree. We used tree rings and common garden experiments with three clonal replicates planted in two contrasting environments in Kyushu (Kumamoto site) and Honshu (Chiba site), Japan. Tree growth showed a significant negative correlation with the dry period (>4 days) in March of the year of tree-ring formation at the Chiba site. In contrast, temperature and precipitation had little influence on tree growth. Quantitative trait locus (QTL) analysis was performed to investigate climate sensitivity to dry periods at the Chiba site, revealing 13 significant QTLs. One QTL showed a substantially large contribution to the overall climate sensitivity, accounting for 12.4% of the total phenotypic variation. The phenotypic variance explained (PVE) by other QTLs ranged from 0.9% to 2.9%, and the total PVE by all QTLs was 35.6%. These findings indicate that the tree population at the Chiba site could be vulnerable to drought in early spring and that the QTL showing the greatest impact on climate sensitivity may be closely related to genes associated with tolerance or adaptation to drought stress. The QTLs identified in this study could be useful for molecular breeding, forest management, and predicting the growth of C. japonica under a changing climate.
Y. Moriguchi et al., “Factors Influencing Male Reproductive Success in a Cryptomeria Japonica Seed Orchard Revealed by Microsatellite Marker Analysis,” Silvae Genetica, vol. 56, no. 1-6, pp. 207–214, Nov. 2007.
doi: 10.1515/sg-2007-0031.
We investigated the influence of male flower production, floral synchrony and inter-tree distances on male reproductive success in a miniature seed orchard of Cryptomeria japonica. We used six microsatellite markers to determine the paternity of each seed. In the seed orchard, the average pollen contamination and clonal self-fertilization rates were 38.7% and 1.7%, respectively. The level of male reproductive success of constituent clones varied from 0.0 to 15.7%. Five clones showing the highest male reproductive success contributed ca. 30% of all analyzed seeds as a pollen donor after excluding contamination by external sources of pollen. The statistical analyses showed that male reproductive success was strongly influenced by male flower production of each clone and, possibly, by their distance to the mother trees. The linear regression which included male flower production and floral synchrony as independent variables, however, accounted for only 14.7% of variation of male reproductive success, suggesting that other factors such as pollen competition might also influence male reproductive success. Since we found no significant correlation between male reproductive and female reproductive successes, it may be better to equalize male and female reproductive successes independently
Y. Moriguchi, Y. Yamazaki, H. Taira, and Y. Tsumura, “Mating Patterns in an Indoor Miniature Cryptomeria Japonica Seed Orchard as Revealed by Microsatellite Markers,” New Forests, vol. 39, no. 3, pp. 261–273, May 2010.
doi: 10.1007/s11056-009-9169-0.
To evaluate the practical application of an indoor seed orchard, we compared the seed production, final germination rates and mating patterns of potted Cryptomeria japonica D. Don clones in two miniature seed orchards: one in a glasshouse and the other outdoors. There was no statistically significant difference in total seed production between the orchards (P = 0.275, ANOVA). However, the final germination rate of seeds produced in the indoor orchard was significantly lower than that of seeds produced in the outdoor orchard (P < 0.01, Wilcoxon test). The average self-fertilization rate was higher in the indoor orchard (27.2%) than in the outdoor orchard (5.6%), and this parameter was strongly associated with the reduced final germination rates of the seeds harvested in the glasshouse. Pollen contamination was considerably lower in the indoor seed orchard (48.9% in the outdoor seed orchard and 4.4% in the indoor seed orchard). χ2 tests indicated that the paternal contributions of each constituent clone differed significantly in both orchards (P < 0.001 in both cases). The strong variations in paternal contributions among indoor orchard clones was significantly correlated with their respective pollen production capacities (Spearman ρ = 0.693, P < 0.001). To reduce the high self-fertilization rates, we recommend the use of orchard clones with similar pollen production capacity in indoor seed orchards.
Y. Moriguchi, H. Yomogida, H. Iwata, M. Takahashi, H. Taira, and Y. Tsumura, “Paternity Analysis in a Progeny Test of Cryptomeria Japonica Revealed Adverse Effects of Pollen Contamination from Outside Seed Orchards on Morphological Traits,” Tree Genetics & Genomes, vol. 7, no. 5, p. 1089, May 2011.
doi: 10.1007/s11295-011-0397-z.
To evaluate the effects of pollen contamination from outside of Cryptomeria japonica seed orchard on the growth performance (height and diameter at breast height, DBH) and morphological traits (stem straightness and basal stem straightness), paternity testing using seven microsatellite markers was performed in a progeny test. In the studied progeny test, high rates of inconsistency were found between the observed and expected genotypes. The average rates of pollen contamination from outside the orchard and self-fertilization were 58.47% and 0.65%, respectively. We divided the individuals of the studied progeny test into two groups based on their genotype data, for which: (1) both parents were elite trees and (2) only the mother trees were elite trees, and then compared them with respect to the growth performance and morphological traits of progenies using data at 20 and 30 years old. Significant adverse effects of contaminating pollen were detected in relation to straightness, but not tree height and DBH. The results suggest that the genetic gains for straightness generally show higher narrow-sense heritability than growth traits, which should be increased by reduction of pollen contamination. Breeding with paternal analysis (BWPA) is an effective approach for evaluating breeding materials based on maternal and paternal information revealed by DNA markers. The use of BWPA in progeny test allows effective forward- and backward selection without laborious and time-consuming tasks. In this study, we also suggest that the significant pollen contamination and paternal deviation found in the open-pollinated progeny test are serious impediments for BWPA.
Semantic Scholar extracted view of "Effect of stratification and gibberellic acid on seed germination and seedling growth of Cryptomeria japonica (Linn. f.) D. Don." by J. Mugloo et al.
R. Nakada, Y. Fujisawa, and Y. Hirakawa, “Effects of Clonal Selection by Microfibril Angle on the Genetic Improvement of Stiffness in Cryptomeria Japonica D. Don,” vol. 57, no. 5, pp. 553–560, Aug. 2003.
doi: 10.1515/HF.2003.082.
The microfibril angle (MFA) of latewood tracheids and its radial variation at breast height in Cryptomeria japonica D. Don (sugi) were investigated with twelve clones collected from three sites in the Kyushu region, Japan. Large variations both between clones and between sites were observed. The MFAs were well correlated to the stiffness of the logs collected from the sample trees. A simulation of clonal selection according to the ranking of the clones in MFA demonstrated that the log stiffness of the selected population was much improved even when the selection relied on MFAs in the second ring from the pith. The improvement in log stiffness by MFA selection was not different from the selection by log stiffness itself. The results indicate that early selection by MFA is very effective in improving log stiffness in this species.
K. Ohba, “Clonal Forestry with Sugi (Cryptomeria Japonica),” in Clonal Forestry II: Conservation and Application, M.-R. Ahuja and W. J. Libby, Eds. Berlin, Heidelberg: Springer, 1993, pp. 66–90.
doi: 10.1007/978-3-642-84813-1_4.
Since ancient times, sugi (Cryptomeria japonica D. Don) has been one of the most important conifer species in Japan. In the People’s Republic of China, descriptions of Cryptomeria foriunei Hooibrenk ex Otto et Dietr, are also found, however, it is not so popular in Chinese forestry (cf. Hashimoto 1983). In Taiwan, in 1896, the seeds of C. japonica were firstly introduced from Japan, and at present about 45 000 ha of plantations have been established in the mountainous region at an elevation of 800-2000 m above sea level (cf. Sakaguchi 1983). In Korea, as it is cold and dry in winter, the C. japonica plantations introduced in ca. 1915 are limited to the southern area of the country. There are now about 74000 ha of plantation (cf. Hyun 1983). According to the description of the above authors, C. japonica seems to have very limited uses in Taiwan and Korea.
The study indicates that temperature optima of 22°C, darkness and GA 3 (25 mg 1 - 1 ) are factors promoting germination of this species. The present study investigates the germination requirements of the seeds of Cryptomeria japonica with respect to temperature, light and gibberellic acid. The study indicates that temperature optima of 22°C, darkness and GA 3 (25 mg 1 - 1 ) are factors promoting germination of this species. Poor germination at high temperature under both light and dark conditions may be an indication of thermo sensitive nature of this species.
S. Ray and N. D. Paria, “Seed and Seedling Morphology of Two near Threatened Indian Species: Cryptomeria Japonica and Cupressus Cashmeriana (Cupressaceae Sensu Lato),” Annals of Plant Sciences, vol. 7, no. 4, pp. 2179–2186, Mar. 2018.
doi: 10.21746/aps.2018.7.4.3.
Seed and Seedling morphology of two species of Cupressaceae – Cupressus cashmeriana Royle ex Carriéreand Cryptomeria japonica (Thunb. Ex L.f.) D. Don have been studied using light microscope (LM) and scanning electron microscope (SEM). Both the species are categorized as Near Threatened (NT) in IUCN Red List Category (2013). For characterization of seed, different parameters like shape, size, base, apex, surface were considered. For the study of seedlings, the parameters like germination pattern, root, hypocotyl, number of paracotyledons, number and nature of first leaf and subsequent leaves have been characterized. The seed and seedling characters as studied in this investigation are important as taxonomic markers for identification purpose.
M. Saito, H. Taira, and Y. Furuta, “Cytological and Genetical Studies on Male Sterility inCryptomeria Japonica D. Don,” Journal of Forest Research, vol. 3, no. 3, pp. 167–173, Aug. 1998.
doi: 10.1007/BF02762139.
Genetic male sterility is a useful trait in plant breeding, especially in angiosperm crops such as corn, onion and carrot. We found a male sterile sugi (Cryptomeria japonica D. Don) tree in Toyama, Japan. Pollen of sugi is one of the major causes of pollinosis in Japan. We carried out this research in an attempt to make clear the characteristics and inheritance of this male sterility. Microsporogenesis of the male sterile tree proceeded meiosis, however, the microspores collapsed after they were separated from pollen tetrads in locules, resulting in complete male sterility. Most likely, ethylene evolution was responsible for male sterility expression. Full seed setting in the male sterile tree indicated normal macrosporogenesis. Seeds obtained from crossing between male sterile and normal lines showed relatively high level of germination and their seedlings grew vigorously. The somatic chromosome numbers of 241 germinated seeds, derived from the male sterile tree, were mostly 22, euploid. These results indicated that male sterile tree was different from other similar previously reported trees with low pollen fertility, resulting from triploid or trisomics. Probably, male sterility in sugi is either nuclear genetic male sterility or cytoplasmic male sterility.
M. Saito, H. Taira, and Y. Tsumura, “Study of Sugi (Cryptomeria Japonica D. Don) with Male-Sterility Gene Using CAPS Markers,” Journal of Forest Research, vol. 10, no. 1, pp. 61–66, Feb. 2005.
doi: 10.1007/s10310-004-0103-1.
The frequency of open-pollinated male-sterile seedlings from a male-sterile mother tree in Cryptomeria japonica D. Don was determined in 765 open-pollinated seedlings. Pollen was not formed by 29 out of the 765 seedlings. To find pollen donor candidates for 29 male-sterile seedlings, a male-sterile tree was crossed with five individuals in the neighborhood of the mother tree. Analysis of microspores in male flowers of F1 seedlings revealed that one of the five individuals had a heterozygous male-sterility gene. Paternity tests were conducted on the 29 male-sterile seedlings using eight kinds of CAPS markers in C. japonica. The pollen parents of 29 male-sterile seedlings were not only a tree in the neighborhood of the mother tree, but also other trees. Since it was found that the pollen parents of four of the male-sterile seedlings were not in the study plot, it was inferred that C. japonica trees that possess the male-sterility gene grow in other places and may be widely distributed.
K. Seiwa, M. Ando, A. Imaji, M. Tomita, and K. Kanou, “Spatio-Temporal Variation of Environmental Signals Inducing Seed Germination in Temperate Conifer Plantations and Natural Hardwood Forests in Northern Japan,” Forest Ecology and Management, vol. 257, no. 1, pp. 361–369, Jan. 2009.
doi: 10.1016/j.foreco.2008.09.002.
To document the spatial and temporal variation of environmental signals inducing seed germination in temperate forests, we measured temporal patterns of environmental signals and seed germination of six pioneer tree species in unthinned and thinned stands of conifer forests (Cryptomeria japonica plantations) and in the understory and gaps of hardwood forests in Japan. We also conducted germination experiment in laboratory for the six pioneer species to test the effects of red:far-red (R:FR) light ratio and temperature fluctuations on the seed germination. In conifer forests, the photosynthetic photon flux density (PPFD), the R:FR ratio, and the amplitude of temperature fluctuations in thinned stands were 2, 1.5, and 3 times higher, respectively, than those of unthinned stands. The PPFD and R:FR ratios just above forest floor also increased after the removal of thick litter accumulation. As a result, higher seed germination was observed in thinned compared to unthinned stands for three photoblastic species, whereas little differences were observed for three non-photoblastic species. These findings suggest that thinning, which frequently reduces litter accumulation, can substantially affect the regeneration of pioneer species and the resultant species diversity in conifer plantations. None of the measured environmental signals changed seasonally in unthinned stands of conifer forests, but they all changed remarkably in the understory of the hardwood forests. In this system, all signals were high and nearly identical to those in the gaps in early spring prior to canopy closure. Thus, the percent germination of the three photoblastic species was enhanced by high R:FR ratios and/or large temperature fluctuations even beneath the canopy and was nearly equal to that in the thinned conifer stands where the environmental conditions were nearly identical to those in the gaps. However, all of the environmental signals decreased with the expansion of canopy leaves and reached minimums at canopy closure. Even in the thinned stands and the gaps, the PPFD and magnitude of temperature fluctuations decreased over time due to shading by growing herbs and/or emerging canopy leaves. In these temporally changing environments, the germination of all photoblastic species ceased simultaneously. This study clearly demonstrated that the environmental signals inducing seed germination of photoblastic pioneer species spatially and temporally change in temperate forests, particularly in deciduous hardwood forests. Furthermore, these signals, PPFD, R:FR ratio, and the amplitude of temperature fluctuations, appear to play a very important role in tree regeneration and subsequent species diversity.
T. Shibuya, T. Taniguchi, S. Tsukuda, S. Shiozaki, and K. Itagaki, “Adventitious Root Formation of Japanese Cedar (Cryptomeria Japonica D. Don) Cuttings Is Stimulated by Soaking Basal Portion of Cuttings in Warmed Water While Cooling Their Apical Portion,” New Forests, vol. 45, no. 4, pp. 589–602, Jul. 2014.
doi: 10.1007/s11056-014-9414-z.
To improve the propagation of Japanese cedar (Cryptomeria japonica D. Don), we investigated the effects of apical and basal temperatures during a water soaking treatment on the adventitious root formation of 70-mm long shoot tip cuttings which have an apical bud. The basal portion of the cuttings was soaked for 28 days in water with temperatures ranging from 10 to 35 °C, at an air temperature of 5 or 10 °C. Control cuttings were soaked in water at 25 °C, with an air temperature of 25 °C. Treated cuttings were then planted in vermiculite rooting medium and grown at an air temperature of 25 °C for 35 days. Adventitious roots initiated earlier and developed more in the cuttings treated with apical temperatures of 5 or 10 °C and basal temperatures of 20–30 °C than in the control cuttings. The rooting percentage was greatest (93 %) in the cuttings treated with a 10/25 °C apical/basal temperature, whereas few control cuttings rooted (13 %). This suggests that the temperature gradient created by warming the basal portion of the cuttings while cooling their apical end stimulates adventitious root formation. When we tested seasonal variation of rootability at 10/25 °C, the rooting percentage increased from early autumn to winter, and decreased from winter to summer. The soluble sugar contents did not directly affect the formation of adventitious roots in the present study.
Y. Shimizu, M. Ando, and F. Sakai, “Clonal Structure of Natural Populations of Cryptomeria Japonica Growing at Different Positions on Slopes, Detected Using RAPD Markers,” Biochemical Systematics and Ecology, vol. 30, no. 8, pp. 733–748, Aug. 2002.
doi: 10.1016/S0305-1978(01)00109-0.
Cryptomeria japonica D. Don (Japanese cedar), an economically important timber species endemic to Japan, is dominant on ridges and upper slopes in cool-temperate natural forests of Kyoto Prefecture. Recruitment of sexual progeny in the area near the Japan Sea is extremely rare, and propagation occurs predominantly through clonal growth by layering. The development pattern that occurs with layering and the resulting complexity of the population structure make it difficult to identify distinct clones, even by excavation. Therefore, we used the randomly amplified polymorphic DNA (RAPD) technique to examine the clonal structure of upper- and lower-slope plots established in two C. japonica populations in Kyoto Prefecture. A total of 263 plants sampled from four plots were analyzed using 10 arbitrarily chosen decamer primers, which produced 50 highly reproducible RAPD bands. There was a different clonal structure in upper- and lower-slope plots. Lower-slope plots were made up of a small number of genets with many ramets, while upper-slope plots were made up of a large number of genets with a few ramets. Clonal diversity measured using PD, Simpson’s D, and Fager’s E was higher in the upper-slope plots. These results show that natural C. japonica populations maintain relatively high clonal variation, compared with other clonal plant species, and that repeated seedling recruitment occurred more frequently in upper-slope plots than in lower-slope plots.
Y. Shimizu, M. Ando, and F. Sakai, “RAPD Marker Diversity Within and Among Natural Populations of the Clonal Tree Cryptomeria Japonica D. Don.,” Journal of Sustainable Forestry, vol. 15, no. 3, pp. 75–90, May 2002.
doi: 10.1300/J091v15n03_04.
The Japanese cedar, Cryptomeria japonica D. Don., is one of the most important endemic species in Japan. A long history of heavy logging has resulted in natural populations being discontinuously distributed and scattered among small, restricted areas. An understanding of the patterns of genetic variability among and within populations of C. japonica is important for conserving the genetic resources of this economically important species. We studied genetic variation by random amplified polymorphic DNA (RAPD) markers in C. japonica of Kyoto prefecture, western Japan. A total of 398 plants sampled from six natural populations were analyzed by ten arbitrarily chosen decamer primers, resulting in 50 highly reproducible RAPD bands. Analysis of molecular variance partitionated the RAPD variation into the among- and within population components. The within-population component accounted for 93.75% of the variation. The among-population component accounted for only 6.25%. Indirect estimates of gene flow indicated that the average number of migrants exchanged among six populations per generation was 3.72. A Mantel test for each population did not yield significant correlations between geographic and genetic distances. The extent and distribution of C. japonica diversity in the Kyoto prefecture is in agreement with the conclusion that long-lived, wind-pollinated, out-crossing species with wide ranges retain a considerable amount of genetic diversity within populations and exhibit little genetic differentiation among populations.
S.-G. Son, H.-J. Kim, C.-S. Kim, Y.-J. Kang, C.-S. Kim, and K.-O. Byun, “The Time for Collecting of Cryptomeria Japonica Seeds,” Korean Journal of Plant Resources, vol. 22, Jan. 2009.
The time of seed collection is regarded as one of major concerns to obtain sound seeds. The physical and germinal aspects of Cryptomeria japonica D. Don (Taxodiaceae) seeds were analyzed to determine the optimum harvesting time in Korea. Cones were picked every 10 days from the of July to the of October in both 2005 and 2006. Seeds were collected from picked cones. Seed size and weight were not significant in two consecutive years. The 1,000-seed weight was 3.3 g for cones picked at the of August and 5.3 g for cones picked at the of September. The size of seeds was increased as the time of collection from the of August to the of September: from 19.3 mm to 21.3 mm in length and from 15.8 mm to 18.5 mm in width. Average germination rates in 2005 was 18.3% and 19.6% in 2006. The highest germination rate was 34.3% from seeds collected at the of September in 2005. In 2006, the highest germination rate was 31.7% for seeds collected at the same date as the 2005 seeds. After the end of September, germination rate was decreased in both years. The results implied that the best cone picking time for Korean C. japonica seeds is around the end of September.
H. Taira, M. Saito, and Y. Furuta, “Inheritance of the Trait of Male Sterility in Cryptomeria Japonica,” Journal of Forest Research, vol. 4, no. 4, pp. 271–273, Nov. 1999.
doi: 10.1007/BF02762782.
Matings of male-sterile C. japonica and fertile elite C. japonica, as well as backcross seedlings of male-sterile trees, were carried out to clarify the genetic trait of male sterility of the C. japonica. The seeds from male-sterile C. japonica were germinated in an incubator and grown them in the greenhouse between 1994 and 1997. The seedlings were treated with 100 ppm gibberellin at early July 1994 and early July 1995 to promote the formation of male flowers. In the middle of January 1995, the male flowers of all seedlings were examined under the microscope to confirm the production of pollen. In January 1996, pollen did not developed in to the male flowers from the seedlings between the fertiled elite and backcross C. japonica. In January 1997, all seedlings of elite C. japonica produced pollen in their male flowers; however, pollen did not developed in 55 out of 120 backcrossed seedlings. This evidence suggests that the heredity pattern of male sterility in C. japonica is nuclear male sterility controlled by a pair of recessive genes.
H. Taira, Y. Tsumura, Y. Tomaru, and K. Ohba, “Regeneration System and Genetic Diversity of Cryptomeria Japonica Growing at Different Altitudes,” Canadian Journal of Forest Research, vol. 27, no. 4, pp. 447–452, Apr. 1997.
doi: 10.1139/x97-001.
T. Taniguchi and T. Kondo, “Difference in the Ability of Initiation and Maintenance of Embryogenic Cultures among Sugi (Cryptomeria Japonica D. Don) Seed Families,” Plant Biotechnology, vol. 17, no. 2, pp. 159–162, 2000.
doi: 10.5511/plantbiotechnology.17.159.
Zygotic embryos of Cryptomeria japonica were collected from 20 clones and cultured on half-concentration of Murashige and Skoog medium containing 10μM2, 4-dichlorophenoxyacetic acid to examine the differences in embryogenic tissue (ET) initiation among seed families. ETs were obtained in all the seed families tested, with an overall initiation rate of 45.6% (689 from 1512 explants). However, initiation rates and maintenance rates differed considerably among seed families. They varied from 7.5% to 78.5% and from 1.2% to 27.8%, respectively.
M. Tsuruta, T. E. Maruyama, S. Ueno, T. Kaneeda, and Y. Moriguchi, “Plant Regeneration and In Vitro Growth Performance of Male-Sterile Somatic Plantlets of Sugi (Japanese Cedar, Cryptomeria Japonica) Derived from Different Embryogenic Cell Lines,” Forests, vol. 12, no. 11, p. 1592, Nov. 2021.
doi: 10.3390/f12111592.
With the spread of pollinosis caused by sugi (Japanese cedar, Cryptomeria japonica) pollen, the use of pollen-free somatic seedlings of sugi is expected in Japan. However, there is a lack of knowledge on the relationship between the abilities during somatic embryogenesis, initial in vitro growth traits, and subsequent growth of somatic seedlings. In the present study, we provide the first basic information on somatic embryo maturation efficiency, somatic embryo germination, and plantlet conversion frequencies, as well as on in vitro growth performance of pollen-free somatic plantlets derived from different embryogenic cell lines (ECLs). Somatic embryo maturation efficiency varied from 34 to 514 cotyledonary embryos per plate and the average for the 19 ECLs tested was 244 embryos per plate. Subsequently, the overall average rates of somatic embryo germination and conversion among ECLs were 87.8% and 85.3%, respectively. The results of in vitro growth performance of pollen-free somatic plantlets showed significant differences in growth rate among ECLs.
T. Ujino-Ihara, “Transcriptome Analysis of Heat Stressed Seedlings with or without Pre-Heat Treatment in Cryptomeria Japonica,” Molecular Genetics and Genomics, vol. 295, no. 5, pp. 1163–1172, Sep. 2020.
doi: 10.1007/s00438-020-01689-3.
With global warming as a major environment concern over the coming years, heat tolerance is an important trait for forest tree survival during the predicted future warmer weather conditions. Cryptomeria japonica is a coniferous species widely distributed throughout Japan, and thus, can adapt to a wide range of air temperatures. To elucidate genes involved in heat response in Cryptomeria japonica, transcriptome analysis was conducted for seedlings under heat shock conditions. To test whether heat acclimation affects levels of gene expression, half of the seedlings were pretreated with moderately high temperatures prior to heat shock. De novo assembly of the transcriptome generated 107,924 unigenes and the analysis of differentially expressed genes was conducted using these unigenes. A total of 5217 differentially expressed genes were identified. Most genes upregulated by heat shock, regardless of pre-heat treatment, were conserved to heat response genes of angiosperm species, such as heat shock factors (Hsf) and heat shock proteins (Hsp). Pre-heating of seedlings affected expression levels of several Hsfs and their induction was lower in pre-heated seedlings than in seedlings without pre-heat treatment. This suggests a conserved role of Hsfs in heat response and heat acclimation in seed plants. On the other hand, many unknown genes were upregulated in only seedlings without pre-heat treatment after heat exposure. Notably, expression of gypsy/Ty3 type retrotransposons was dramatically induced. These findings provide valuable information to develop a better understanding of the molecular mechanisms of heat response and acclimation in C. japonica.
K. Wada and M. Kawasaki, “On the root development of Sugi (Cryptomeria japonica) and Hinoki (Chamaecyparis obtusa) seedlings transplanted in early spring.,” On the root development of Sugi (Cryptomeria japonica) and Hinoki (Chamaecyparis obtusa) seedlings transplanted in early spring., no. No. 96, 1970.https://www.cabdirect.org/cabdirect/abstract/19740613820.
Periodic observations from Feb. to April showed that the roots of C. japonica and C. obtusa began to grow at a soil temperature of 3 deg C, and grew fast at 7-8 deg . Measurements in May showed that in central Honshu, with both species, transplanting in early spring gave the best root growth.
K. Watanabe, S. Shida, and M. Ohta, “Evaluation of End-Check Propagation Based on Mode I Fracture Toughness of Sugi (Cryptomeria Japonica),” Journal of Wood Science, vol. 57, no. 5, pp. 371–376, Oct. 2011.
doi: 10.1007/s10086-011-1187-9.
The relation between crack propagation based on fracture mechanics and end-check propagation during drying was evaluated in this study. Corresponding to the direction of end-check propagation, the mode I fracture toughness of air-dried sugi specimens in TR, TL, and intermediate systems was examined by single-edge-notched bending tests. The occurrence and propagation of end checks on sugi (Cryptomeria japonica D. Don) blocks during drying were observed at the scale of the annual rings. It was found that the critical stress intensity factor (KIC) decreased as the crack propagation changed from TL to TR. The value of KIC in the TR system was significantly lower than that in the TL system. As a measure of fracture energy, the area under the load-crack opening displacement curve in the TR system was more than twice that in the TL and intermediate systems. These results indicate that cracks perpendicular to the tangential direction initiate radially with ease, and then crack arrest occurs to prevent growing. This finding provides a consistent interpretation of the end-check propagation observed during drying as follows: tiny end checks, as an analog of TR cracks, occur easily and selectively in latewood or transition wood and propagate toward the pith during drying. When there is no corresponding secondary check in the forward latewood, the checks are arrested and do not propagate further.
Y. Yoshino and S. Taniguchi, “Seed Damage by Stink Bugs in Cryptomeria Japonica Seed Orchards,” Journal of the Japanese Forestry Society, vol. 73, no. 6, pp. 460–465, 1991.
doi: 10.11519/jjfs1953.73.6_460.
Seed damage by stink bugs was investigated in five Cryptomeria japonica D. DON seed orchards in Hyogo Prefecture. The dominant stink bug species was Elasmucha putoni SCOTT in Yamasaki and Haga seed orchards and Plautia stali SCOTT in Santo, Hidaka and Muraoka seed orchards. The population density of these species increased in July or August. Germination rates of seeds bagged and protected from stink bugs was 1. 9_??_ 2.6 (1989) and 1.3_??_1.9 (1990) times that of unbagged seeds.