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Taiwania (Taiwania cryptomerioides Hayata) has long been regarded as a living fossil from the Tertiary period of Mesozoic Era for its distinguished yellowish-red color with purplish-pink streaks presented in its heartwood. With this elegant appearance that matches the color “red” for good fortune in the Taiwanese culture, Taiwania is supposed to be a popular wood in Taiwan where it is a native species of. Extractives contribute to the properties of wood. It is a fascinating subject to investigate extractives biosynthesis in the process of heartwood formation. Up to date, there is no phytochemistry study of Taiwania sapwood. In this study, three new sesquiterpenoids, Taiwania A (1), Taiwania B (2), and Taiwania C (3), together with 75 known compounds in the Taiwania sapwood. The structures of extractives were determined by analysis of spectroscopic data and comparison with the literatures. This study supported secondary reaction lignans could be found in sapwood that confirmed our previous research on the Taiwania-type of heartwood formation.

The heartwood of Taiwania (Taiwania cryptomerioides Hayata) has the excellent decay resistance and fascinating color qualities due to the accumulation of bioactive compounds. However, limited infor...

Taiwania cryptomerioides is a monotypic species, and its terpenoid-rich property has been reported in recent years. To uncover monoterpene biosynthesis in T. cryptomerioides, this study used transcriptome mining to identify candidates with tentative monoterpene synthase activity. Along with the phylogenetic analysis and in vitro assay, two geraniol synthases (TcTPS13 and TcTPS14), a linalool synthase (TcTPS15), and a β-pinene synthase (TcTPS16), were functionally characterized. Via the comparison of catalytic residues, the Cys/Ser at region 1 might be crucial in determining the formation of α-pinene or β-pinene. In addition, the Cupressaceae monoterpene synthases were phylogenetically clustered together, they are unique and different from those of published conifer species. In summary, this study aimed to uncover the ambiguous monoterpenoid network in T. cryptomerioide, which would expand the landscape of monoterpene biosynthesis in Cupressaceae species.

Taiwania (Taiwania cryptomerioides Hayata) is one of the economically important tree species indigenous to Taiwan. Hundreds of secondary metabolites have been identified from its wood, bark, root, and needles with lignans as the dominant ones. This substance group contributes a lot to the color, durability, and bioactivities of Taiwaniana. The present paper is dedicated to the quantification of radial and longitudinal lignan distribution. The extractives begin to accumulate largely in the transition zone (TZ), and reach a maximum after finishing the heartwood (hW) formation. Both dibenzyl-γ-butyrolactone type and arylnaphthalide type lignans were found in sapwood (sW) except for the compound taiwanin A. Clearly, the heartwood formation of Taiwania differs from the hitherto known hW formation types and it is suggested to be denominated as Taiwania-type hW formation, where the biosynthesis of extractives begins in the sW and where their accumulation is clearly elevated in the TZ. A generalized biosynthesis scheme of Taiwanin is presented showing the putative relationships among the most important dimeric lignans that lead to the formation of taiwanin type lignans.

The genetic variation in wood property and growth of Taiwania (Taiwania cryptomerioides) was investigated at two test sites in the same general location, but one at 1200 m (LK20) and another at 1900 m (LK24). A rangewide sample of 48 open-pollinated families in Taiwan was involved. The test plantations were 16 years old when the wood property data were collected. Traits studied include wood specific gravity, tracheid length, ring width. DBH at ages13, 16, and 22 and height at age 13 were also analyzed. Site environment had a dominant effect on growth and wood density, but showed little interaction with family. The site effect was evident in large between-site differences in means, range of family means, and size of family variance components and heritability estimates. These differences are attributable to the site characteristics of LK24 (high elevation, upper slope near a mountain crest) and an unfavourable local climate. Taiwania is fast growing and produces quality wood, and is also an interesting species from the perspective of evolutionary biology. Protection of its genetic variability should be a priority to be managed. We propose that the existing five progeny tests be protected since these tests well-represent the genetic variability of the species in Taiwan.

The genetic diversity and differentiation of five populations of Taiwania cryptomerioides Hayata in mainland China were investigated using inter-simple sequence repeats (ISSR). In comparison with other coniferous species, T. cryptomerioides from mainland China possesses little genetic variation, particularly at the level of individual populations (the percentage of polymorphic loci, Nei’s gene diversity and Shannon’s indices of diversity at the species and population levels are 38.02%, 0.1326, 0.1986 and 9.27%, 0.035, 0.0518 respectively). In contrast, the level of population differentiation is much higher (GST: 0.7269; Shannon’s genetic differentiation: 0.7392; Hickory è B: 0.668; AMOVA genetic differentiation: 72.37%). The genetic divergence of pairs of populations was not significantly correlated with the geographical distance separating them. Current patterns of genetic variation were related to biogeographic history and the small population size. On the basis of these findings, we discuss the development of conservation strategies for this endangered species.

Taiwania (Taiwania cryptomerioides Hay) is an important timber species in Taiwan. Growth in generally improved trees under intense silvicultural practice is so rapid that rotations or the practice of thinning trees may be as short as 20–30 years. Thus, the wood properties of young plantation trees need to be characterized to effectively use this resource. The effects of different thinning and pruning methods on the compressive strength parallel to grain of young Taiwania trees were explored. Average compressive strengths with various thinning treatments revealed the trend of no thinning > medium thinning > heavy thinning and in the pruning treatments showed the trend of medium pruning > no pruning > heavy pruning. However, most results showed no statistically significant differences among thinning and pruning treatments.

Four new diterpenes, 3-oxosaprorthoquinone (1), 3-oxomicrostegiol (2), 3-oxoisotaxodione (3), and taiwaninal (4), together with two known compounds, 3-oxosapriparaquinone (5) and 6-dehydrohinokiol (6), were isolated from the roots of Taiwania cryptomerioides. The structures of 1-4 were principle elucidated based on spectral evidence.

This study investigated the effects of various thinning and pruning methods on the knots (number and size) and lumber recovery from Taiwania (Taiwania cryptomerioides Hay.) plantation trees. The results showed that heavy thinning caused more knots and larger-diameter knots than medium or no thinning; moreover, pruning caused fewer numbers of knots and smaller-diameter knots than no pruning. Better-quality Taiwania trees occurred with the no-thinning/no-pruning treatments, as shown by analyzing the knots, although the results also showed that the healing process seemed to have produced not completely clear wood during the 9 years after the pruning treatment. The thinning intensity slightly enhanced the lumber recovery of logs. Pruning did not affect lumber recovery from taiwania trees and logs. Thinning increased the lumber recovery per tree due to an increase in the diameter at breast height.

The effects of various thinning and pruning methods on the density profile and annual ring characteristics of Taiwania (Taiwania cryptomerioides Hay.) using the drilling resistance technique were investigated. The results showed that thinning caused wider annual rings than medium thinning or no thinning, and pruning caused narrower annual rings than no pruning. Moreover, the thinning treatment affected annual rings more effectively than the pruning treatment. The average ring density after the thinning treatments showed a trend as follows: no thinning > medium > heavy. This indicates that thinning reduces the average ring density. The average ring density after the pruning treatments showed a trend as follows: medium > no pruning > heavy. However, the differences between thinning and no thinning were not statistically significant. The percentage of latewood in Taiwania after these three thinning and pruning treatments are shown. The results with silvicultural treatments have the order: medium > not treated > heavy, but there are no statistically significant differences among thinning, pruning, and thinning where pruning interactions were observed. Moreover, there were highly significant negative relations between the average ring width and the various ring densities for Taiwania, but the determination coefficients were small. In addition, there was a highly positively significant relation between the latewood percentage and latewood width.

Taiwania (Taiwania cryptomerioides Hayata), native to Taiwan, is one of the most economically important tree species grown there. In this article we summarize the current results of phytochemistry and bioactivity of Taiwania extracts, including antifungal, antitermite, antibacterial, and antimite activities as well as cytotoxicity against three tumor cells. The resources of Taiwania are also addressed.

Antitermitic activity of Taiwania (Taiwania cryptomerioides Hayata) against Coptotermes formosanus Shiraki was demonstrated in laboratory tests. Blocks of sapwood and heartwood from T. cryptomerioides exhibited antitermitic activity. Bioassays revealed that heartwood essential oil exhibited the highest antitermitic activity, followed by sapwood essential oil and then the n-C6H14soluble fraction when tested at 10 mg/g. The order of termite mortality of three compounds purified from n-C6H14soluble extracts of heartwood was cedrol > α-cadinol > ferruginol. The termite resistance of T. cryptomerioides wood can be attributed to the termiticidal activity of cedrol and α-cadinol.

The proportions of sapwood and heartwood of trees have significant impacts on various uses. Electric resistivity tomography (ERT) and corresponding electrical resistance (ER) value maps were examined in Japanese cedar (Cryptomeria japonica D. Don), Taiwania (Taiwania cryptomerioides Hayata), and Luanta fir (Cunninghamia konishii Hayata) trees. The position of the sapwood-heartwood demarcation was measured on incremental cores from living trees and the corresponding ER of the sapwood-heartwood boundary was acquired from the ER map. A positive significant relationship was found between the maximum ER plus minimum ER values (ERmax + ERmin) and ER of the sapwood-heartwood demarcation from the tomographic data. The position of the sapwood-heartwood demarcation was determined by corresponding ER, and the critical ER can be established by the ERmax + ERmin value of the tomographic data. The results from this study indicate that ERT technique can be used to determine the position of the sapwood-heartwood boundary and can serve as a methodology in undamaged living trees of Gymnosperm species.

Five new cadinane-type sesquiterpenes, 15-acetoxy-T-muurolol (1), isokhusinodiol (2), cadin-10(14)-ene-4beta,5alpha-diol (3), cadinane-4beta,5alpha,10beta-triol (4), and muurolane-4beta,5beta,10beta-triol (5), together with five known compounds, T-cadinol (6), T-muurolol (7), alpha-cadinol (8), delta-cadinol (9), and khusinodiol (10), were isolated from the roots of Taiwania cryptomerioides. The structure of the new constituents were elucidated through chemical and spectral studies.

Five new podocarpane-type trinorditerpenes were isolated from the bark of Taiwania cryptomerioides. Structures of 1beta, 14-dihydroxy-13-methoxy-6,8,11,13-podocarpatetraene (1), 1beta, 14-dihydroxy-13-methoxy-8,11,13-podocarpatriene (2), 13-hydroxy-12-methoxy-8,11,13-podocarpatrien-3-one (3), 14-hydroxy-13-methoxy-1,8,11,13-podocarpatetraen-3-one (4), and 13-methoxy-8,12-podocarpatriene-11,14-dione (5) were determined by NMR, MS, and other spectral and chemical evidence.

Karyotype analyses were conducted onCunninghamia konishii, Cunninghamia lanceolata, andTaiwania cryptomerioides, all members ofTaxodiaceae. The somatic chromosome number was found to be 2n = 2x = 22 in all species which concurrs with previous reports. The karyotypes are generally asymmetrical with the smaller chromosomes being more submedian than the larger ones. Chromosomes with unusual or specific structures, thought to be associated with the nucleolar organizing region, were found in each species.Cunninghamia species have a marker chromosome pair with an unusually long secondary constriction.Taiwania has an unusually long kinetochore region present in a submedian chromosome pair.