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This report presents 1 new orchid from Taiwan, viz., Goodyera maculata T.P. Lin. New insights revealed a progenitor and progeny relationship between Cheirostylis chinensis and Che. takeoi. I also present trimorphic flowers of Calanthe lyroglossum and dimorphic Gastrodia flexistyla.

This report presents 2 new orchids from Taiwan, viz., Goodyera similis var. similoides T.P. Lin, and Platanthera quadricalcarata T.P. Lin, and 1 natural hybrid Crepidium ×cordilabium T.P. Lin. Bulbophyllum maxi W.M. Lin ex. T.P. Lin is emended with a new definition. Nervilia taiwaniana S.S. Ying was found to be synonymous with N. taitoensis Hayata.

This report presents 3 new orchids from Taiwan, i.e., Oreorchis wumanae T.P. Lin, Cymbidium × oblancifolium Z.J. Liu & S.C. Chen, and Cheirostylis tortilacinia var. wutaiensis T.P. Lin. A color variant of the flower of Oberonia formosana is also presented.

This report presents one new hybrid orchid of Taiwan, i.e., Gastrochilus × hsuehshanensis which resulted from hybridization between G. formosanus and G. rantabunensis. Also, the existence of both Cyrtosia javanica and Cypripedium macranthos in Taiwan is questionable, and these were excluded from the Taiwanese orchid flora.

This report presents two new orchids of Taiwan, i.e., Cheirostylis octodactyla f. cymbiformes and Gastrodia rubinea. Lecanorchis bihuensis is revised and emended with new information.

This report presents two new mycoheterotrophic orchids of Taiwan, i.e., Cyrtosia septentrionalis (Rchb.f.) Garay and Gastrodia kaohsiungensis T.P. Lin. The genus Cyrtosia in Taiwan is also reviewed. The pollinia of Galeola lindleyia and G. falconeri share the same morphology as two species of Cyrtosia found in Taiwan. The pollinia may provide new evidence to merge Galeola with Cyrtosia.

This report presents three new orchids of Taiwan, i.e., Epipogium meridianus T.P. Lin, Liparis monoceros T.P. Lin, and Nervilia septemtrionarius T.P. Lin. Epipogium meridianus could be a hybrid between E. roseum and E. kentingensis.

This report presents three new orchids of Taiwan, i.e., Habenaria alishanensis T.P. Lin & D.M. Huang, Neottia cinsbuensis T.P. Lin & D.M. Huang, and Nephelaphyllum tenuiflorum Blume.

This report presents three new orchids of Taiwan, i.e., Aphyllorchis montana Reichb. f. forma pingtungensis T.P. Lin, Cheirostylis pusilla Lindl. var. simplex T.P. Lin, and Cheirostylis nantouensis T.P. Lin.

Summary Ethylene Response Factor 1 (ERF1) plays a crucial role in biotic and abiotic stress responses. Previous studies have shown that ERF1 regulates stress-responsive gene expression by binding to different cis-acting elements in response to various stress signals. ERF1 was also reported to be unstable in the dark, and it regulates hypocotyl elongation. Here, we elucidated the mechanism underlying degradation of ERF1. Yeast two-hybrid screening showed that UBIQUITIN-CONJUGATING ENZYME 18 (UBC18) interacted with ERF1. The interaction between ERF1 and UBC18 was verified using pull-down assays and coimmunoprecipitation analyses. We then compared the ERF1 protein abundance in the UBC18 mutant and overexpression plants. Based on the results of protein degradation and in vivo ubiquitination assays, we proposed that UBC18 mediates ERF1 ubiquitination and degradation. ERF1 was more stable in UBC18 mutants and less stable in UBC18 overexpression lines compared with that in wild-type plants. ERF1 was degraded by the 26S proteasome system via regulation of UBC18 and promotes dark-repression of downstream genes and proline accumulation. UBC18 negatively regulated drought and salt stress responses by altering the abundance of ERF1 and the expression of genes downstream of ERF1.

This is a comprehensive name list of native orchids of Taiwan identified since the publication of Flora of Taiwan Vol. 5, second edition (2000). The 330 species, subspecies, varieties and natural hybrids of native orchids reported in that publication increases to 454 in the current list. Type information and selected references, diagnostic notices for each species are reported herein for reference.

ORA47 (octadecanoid-responsive AP2/ERF-domain transcription factor 47) of Arabidopsis thaliana is an AP2/ERF domain transcription factor that regulates jasmonate (JA) biosynthesis and is induced by methyl JA treatment. The regulatory mechanism of ORA47 remains unclear. ORA47 is shown to bind to the cis-element (NC/GT)CGNCCA, which is referred to as the O-box, in the promoter of ABI2. We proposed that ORA47 acts as a connection between ABA INSENSITIVE1 (ABI1) and ABI2 and mediates an ABI1-ORA47-ABI2 positive feedback loop. PORA47:ORA47-GFP transgenic plants were used in a chromatin immunoprecipitation (ChIP) assay to show that ORA47 participates in the biosynthesis and/or signaling pathways of nine phytohormones. Specifically, many abscisic acid (ABA) and JA biosynthesis and signaling genes were direct targets of ORA47 under stress conditions. The JA content of the P35S:ORA47-GR lines was highly induced under wounding and moderately induced under water stress relative to that of the wild-type plants. The wounding treatment moderately increased ABA accumulation in the transgenic lines, whereas the water stress treatment repressed the ABA content. ORA47 is proposed to play a role in the biosynthesis of JA and ABA and in regulating the biosynthesis and/or signaling of a suite of phytohormone genes when plants are subjected to wounding and water stress.

This report presents three new orchids in Taiwan, i.e., Epipactis fascicularis T.P. Lin, Neottia piluchiensis T.P. Lin, and Platanthera nantousylvatica T.P. Lin.

SUMMARY Although glutathione is well known for its reactive oxygen species (ROS) scavenging function and plays a protective role in biotic stress, its regulatory function in abiotic stress still remains to be elucidated. Our previous study showed that exogenously applied reduced glutathione (GSH) could improve abiotic stress tolerance in Arabidopsis. Here, we report that endogenously increased GSH also conferred tolerance to drought and salt stress in Arabidopsis. Moreover, both exogenous and endogenous GSH delayed senescence and flowering time. Polysomal profiling results showed that global translation was enhanced after GSH treatment and by the induced increase of GSH level by salt stress. By performing transcriptomic analyses of steady-state and polysome-bound mRNAs in GSH-treated plants, we reveal that GSH has a substantial impact on translation. Translational changes induced by GSH treatment target numerous hormones and stress signaling molecules, which might contribute to the enhanced stress tolerance in GSH-treated plants. Our translatome analysis also revealed that abscisic acid (ABA), auxin and jasmonic acid (JA) biosynthesis, as well as signaling genes, were activated during GSH treatment, which has not been reported in previously published transcriptomic data. Together, our data suggest that the increased glutathione level results in stress tolerance and global translational changes.

In this report three new orchids to Taiwan, i.e., Cephalantheropsis longipes, Habenaria tsaiana and Nervilia linearilabia are presented. Cephalantheropsis dolichopoda (Fukuy.) Lin is a new combination from Calanthe dolichopoda Fukuy. Liparis sp. is an unknown species also included for reference.

In this report six new orchids to Taiwan, i.e., Bulbophyllum confragosum, Bulbophyllum hirundinis var. puniceum, Bulbophyllum albociliatum var. shanlinshiense, Nervilia ratis, Oberonia linguae and Goodyera velutina var. albo-nervosa are presented.

ETHYLENE RESPONSE FACTOR1 (ERF1) is an upstream component in both jasmonate (JA) and ethylene (ET) signaling and is involved in pathogen resistance. Accumulating evidence suggests that ERF1 might be related to the salt stress response through ethylene signaling. However, the specific role of ERF1 in abiotic stress and the molecular mechanism underlying the signaling cross talk still need to be elucidated. Here, we report that ERF1 was highly induced by high salinity and drought stress in Arabidopsis (Arabidopsis thaliana). The salt stress induction required both JA and ET signaling but was inhibited by abscisic acid. ERF1-overexpressing lines (35S:ERF1) were more tolerant to drought and salt stress. They also displayed constitutively smaller stomatal aperture and less transpirational water loss. Surprisingly, 35S:ERF1 also showed enhanced heat tolerance and up-regulation of heat tolerance genes compared with the wild type. Several suites of genes activated by JA, drought, salt, and heat were found in microarray analysis of 35S:ERF1. Chromatin immunoprecipitation assays found that ERF1 up-regulates specific suites of genes in response to different abiotic stresses by stress-specific binding to GCC or DRE/CRT. In response to biotic stress, ERF1 bound to GCC boxes but not DRE elements; conversely, under abiotic stress, we observed specific binding of ERF1 to DRE elements. Furthermore, ERF1 bound preferentially to only one among several GCC box or DRE/CRT elements in the promoter region of its target genes. ERF1 plays a positive role in salt, drought, and heat stress tolerance by stress-specific gene regulation, which integrates JA, ET, and abscisic acid signals.

In this report, three new native orchids (Bulbophyllum tenuislinguae, Epipogum kentingensis, and Neottia hohuanshanensis) are reported. Another species previously reported under the name Lecanorchis nigricans was renamed Lecanorchis bihuensis. Bulbophyllum hymenanthum indeed occurs in Taiwan, but a detailed description requires further research.

Transcriptional activities of plants play important roles in responses to environmental stresses. ETHYLENE RESPONSE FACTOR53 (AtERF53) is a drought-induced transcription factor that belongs to the AP2/ERF superfamily and has a highly conserved AP2 domain. It can regulate drought-responsive gene expression by binding to the GCC box and/or the dehydration-responsive element in the promoter of downstream genes. Overexpression of AtERF53 driven by the cauliflower mosaic virus 35S promoter resulted in an unstable drought-tolerant phenotype in T2 transgenic Arabidopsis (Arabidopsis thaliana) plants. Using a yeast two-hybrid screen, we identified a RING domain ubiquitin E3 ligase, RGLG2, which interacts with AtERF53 in the nucleus. The copine domain of RGLG2 exhibited the strongest interacting activity. We also demonstrated that RGLG2 could move from the plasma membrane to the nucleus under stress treatment. Using an in vitro ubiquitination assay, RGLG2 and its closest sequelog, RGLG1, were shown to have E3 ligase activity and mediated AtERF53 ubiquitination for proteasome degradation. The rglg1rglg2 double mutant but not the rglg2 or rglg1 single mutant exhibited a drought-tolerant phenotype when compared with wild-type plants. AtERF53-green fluorescent proteins expressed in the rglg1rglg2 double mutants were stable. The 35S:AtERF53-green fluorescent protein/rglg1rglg2 showed enhanced AtERF53-regulated gene expression and had greater tolerance to drought stress than the rglg1rglg2 double mutant. In conclusion, RGLG2 negatively regulates the drought stress response by mediating AtERF53 transcriptional activity in Arabidopsis.

In this report, four new species (Lecanorchis latens sp. nov., Liparis liangzuensis sp. nov., Malaxis shampoae sp. nov., and Spiranthes nivea sp. nov.), and one new record (Hancockia uniflora) are presented. Descriptions and figures are also provided.

The membrane protein AtTLP18.3 of Arabidopsis (Arabidopsis thaliana) contains a domain of unknown function, DUF477; it forms a polysome with photosynthetic apparatuses in the thylakoid lumen. To explore the molecular function of AtTLP18.3, we resolved its crystal structures with residues 83 to 260, the DUF477 only, and performed a series of biochemical analyses to discover its function. The gene expression of AtTLP18.3 followed a circadian rhythm. X-ray crystallography revealed the folding of AtTLP18.3 as a three-layer sandwich with three α-helices in the upper layer, four β-sheets in the middle layer, and two α-helices in the lower layer, which resembles a Rossmann fold. Structural comparison suggested that AtTLP18.3 might be a phosphatase. The enzymatic activity of AtTLP18.3 was further confirmed by phosphatase assay with various substrates (e.g. p-nitrophenyl phosphate, 6,8-difluoro-4-methylumbelliferyl phosphate, O-phospho-l-serine, and several synthetic phosphopeptides). Furthermore, we obtained the structure of AtTLP18.3 in complex with O-phospho-l-serine to identify the binding site of AtTLP18.3. Our structural and biochemical studies revealed that AtTLP18.3 has the molecular function of a novel acid phosphatase in the thylakoid lumen. DUF477 is accordingly renamed the thylakoid acid phosphatase domain.

In this report, 10 new native orchids (Brachycorythis peitawuensis, Bulbophyllum electrinum var. calvum, Bulbophyllum kuanwuensis var. luchuensis, Bulbophyllum kuanwuensis var. rutilum, Cheirostylis rubrifolius, Corybas puniceus, Erythrodes blumei var. aggregatus, Nervilia tahanshanensis, Oberonia pumilum var. rotundum, and Tainia caterva), two newly recorded species (Vexillabium nakaianum and Chiloschista parishii) and three new names (Bulbophyllum electrnum var. sui, Corybas taliensis and Flickingeria parietiformis) are presented. Description and figures are also provided.

Cinnamomum kanehirae Hayata (Lauraceae), the most valuable subtropical and temperate broadleaf timber tree in Taiwan, is rapidly disappearing from the wild. Taking advantage of a scion garden established by the Taiwan Forestry Research Institute, we examined patterns of chloroplast DNA (cpDNA) variations in 19 populations including 94 individuals. By sequencing two cpDNA fragments using universal primers (the trnL-trnF and petG-trnP intergenic spacers), we found eight polymorphic sites, six haplotypes, and extremely low nucleotide diversity (π = 0.00016) from 792 bp aligned sequences. The ancestral haplotype is widely distributed. Among the populations studied, three separated populations, at Yungfeng, Fuli, and Tahu have high nucleotide diversity. No phylogeographical structures of haplotypes were revealed because the tests of NST−GST for populations did not differ from zero in any situations; a ‘star-like’ genealogy is characteristic when all haplotypes rapidly coalesce and is a general outcome of population expansion. The neutrality test also suggested demographic expansion. The genetic divergence and diversity analyses suggested that two potential refugia existed during the last glaciation with a major one located in southeastern Taiwan and a minor one located in Tahu in north-central Taiwan in the Hsuehshan Range, west of the Central Mountain Range.

This study examined the spatial pattern of chloroplast DNA (cpDNA) variation in Cyclobalanopsis glauca (Thunb. ex Murray) Oerst. (Fagaceae) in 140 trees from Taiwan (25 populations), Japan (three), Ryukyus (two), Hong Kong (one) and Mainland China (one). By sequencing three cpDNA intergenic spacer fragments using universal primers (trnT-trnL, trnV-trnM, including the trnV intron, and petG-trnP), we found a total of 1,980 bp and 15 polymorphic sites. Among them, 12 sites were caused by point mutation, and three resulted from insertion. This gives rise to a total of 13 cpDNA haplotypes. The level of differentiation among the populations studied is relatively high (GST = 0.612). Two ancestral haplotypes (A and B) are distributed widely in East Asia. Interestingly, all the derived cpDNA variations are found only in Taiwan but not in other areas. The Central Mountain Ridge (CMR) of Taiwan creates an unsurpassed barrier to the east-west gene flow of C. glauca. Among the populations on the west of CMR, only three separated populations, Yangmingshan, Wushe and Chinshuiying, have high haplotype diversity, each consisting of sister haplotypes all mutated from the same ancestral haplotype. Thus, they have probably originated from de novo mutation after the last glaciation. This inference agrees with the observation that no spatial autocorrelation existed on the west side. Two unrelated dominant lineages on the east of the CMR (haplotypes D and F) showed significant spatial genetic structure. Estimate of NST - GST was -0.090 and differed significantly from zero. Thus at the local scale, the phylogeographical component of the genetic structure is significant on the east of the CMR. Accompanied by published palynological records of the last glaciation, this study suggests the possibility that these two types were colonized northward from the southeastern part of Taiwan. 'Star-like' genealogy is characterized, with all the haplotypes coalescing rapidly and as a general outcome of population expansion (Page & Holmes 1998). A neutrality test also suggested a demographic expansion recovered from a bottleneck. We therefore inferred that the southeastern part of Taiwan might be a potential refugium for C. glauca.

Rice blast disease resistance to the fungal pathogen Magnaporthe grisea is triggered by a physical interaction between the protein products of the host R (resistance) gene, Pi-ta, and the pathogen Avr (avirulence) gene, AVR-pita. The genotype variation and resistant/susceptible phenotype at the Pi-ta locus of wild rice (Oryza rufipogon), the ancestor of cultivated rice (O. sativa), was surveyed in 36 locations worldwide to study the molecular evolution and functional adaptation of the Pi-ta gene. The low nucleotide polymorphism of the Pi-ta gene of O. rufipogon was similar to that of O. sativa, but greatly differed from what has been reported for other O. rufipogon genes. The haplotypes can be subdivided into two divergent haplogroups named H1 and H2. H1 is derived from H2, with nearly no variation and at a low frequency. H2 is common and is the ancestral form. The leucine-rich repeat (LRR) domain has a high πnon/πsyn ratio, and the low polymorphism of the Pi-ta gene might have primarily been caused by recurrent selective sweep and constraint by other putative physiological functions. Meanwhile, we provide data to show that the amino acid Ala-918 of H1 in the LRR domain has a close relationship with the resistant phenotype. H1 might have recently arisen during rice domestication and may be associated with the scenario of a blast pathogen–host shift from Italian millet to rice.

In this report, two newly discovered native orchids, Corybas shanlinshiensis and Nervilia crociformis, are presented. Also description and figures of Dendrobium luzonense were provided.

† Background and Aims Evolutionary and ecological roles of the chloroplast small heat shock protein (CPsHSP) have been emphasized based on variations in protein contents; however, DNA sequence variations related to the evolutionary and ecological roles of this gene have not been investigated. In the present study, a basal angiosperm, Machilus, together with the eudicot Rhododendron were used to illustrate the evolutionary dynamics of gene divergence in CPsHSPs. † Methods Degenerate primers were used to amplify CPsHSP-related sequences from 16 Rhododendron and eight Machilus species that occur in Taiwan. Manual DNA sequence alignment was carried out according to the deduced amino acid sequence alignment performed by CLUSTAL X. A neighbour-joining tree was generated in MEGA using conceptual translated amino acid sequences from consensus sequences of cloned CPsHSP genes from eight Machilus and 16 Rhododendron species as well as amino acid sequences of CPsHSPs from five monocots and seven other eudicots acquired from GenBank. CPsHSP amino acid sequences of Funaria hygrometrica were used as the outgroups. The aligned DNA and amino acid sequences were used to estimate several parameters of sequence divergence using the MEGA program. Separate Bayesian inference of DNA sequences of Rhododendron and Machilus species was analysed and the resulting gene trees were used for detection of putative positively selected amino acid sites by the Codeml program implemented in the PAML package. Mean hydrophobicity profile analysis was performed with representative amino acid sequences for both Rhododendron and Machilus species by the Bioedit program. The computer program SplitTester was used to examine whether CPsHSPs of Rhododendron lineages and duplicate copies of the Machilus CPsHSPs have evolved functional divergence based on the hydrophobicity distance matrix. † Key Results Only one copy of the CPsHSP was found in Rhododendron. However, a higher evolutionary rate of amino acid substitutions in the Hymenanthes lineage of Rhododendron was inferred. Two positively selected amino acid sites may have resulted in higher hydrophobicity in the region of the a-crystallin domain (ACD) of the CPsHSP. By contrast, the basal angiosperm, Machilus, possessed duplicate copies of the CPsHSP, which also differed in their evolutionary rates of amino acid substitutions. However, no apparent relationship of ecological relevance toward the positively selected amino acid sites was found in Machilus. † Conclusions Divergent evolution was found for both Rhododendron lineages and the paralogues of CPsHSP in Machilus that were directed to the shift in hydrophobicity in the ACD and/or methionine-rich region, which might have played important roles in molecular chaperone activity.

In this report, four newly discovered native orchids: Bulbophyllum fimbriperianthium, Eulophia pulchra var. actinomorpha, Saccolabiopsis wulaokenensis, and Tropidia nanhuae, including a new record of the genus, Saccolabiopsis, are presented.

Quercus glauca (Thunb. ex Murray) Oerst (Fagaceae) has a wide distributional range in Taiwan. In this study, the evolutionary history and the most genetically divergent sites of Q. glauca were studied using a nuclear gene marker, glyceraldehyde‐3‐phosphate dehydrogenase. Also, the consistency of the results obtained from nuclear gene and cytoplasmic loci was investigated. Using a genealogical approach (TCS software), we determined haplotypes and their relationships to one another. We used the level of divergence for each population from the remaining populations (calculated as mean values of pairwise population differentiation, FST, for each population) to locate the most genetically divergent areas in Taiwan. According to the average FST of each population in comparison with the remaining ones, a peak was found in the northern part of central Taiwan, and another was found in the southeastern region. The peak profiles of the mean FST values for all three DNA data sets (nDNA, cpDNA, and mtDNA) showed simil...

Background and Aims The genetic variation and divergence estimated by allozyme analysis were used to reveal the evolutionary history of Castanopsis carlesii in Taiwan. Two major questions were discussed concerning evolutionary issues: where are the diversity centres, and where are the most genetically divergent sites in Taiwan? Methods Twenty-two populations of C. carlesii were sampled throughout Taiwan. Starch gel electrophoresis was used to assay allozyme variation. Genetic parameters and mean FST values of each population were analysed using the BIOSYS-2 program. Mean FST values of each population against the remaining populations, considered as genetic divergence, were estimated using the FSTAT program. Key Results Average values of genetic parameters describing the within-population variation, the average number of alleles per locus (A = 25), the effective number of alleles per locus (Ae = 138), the allelic richness (Ar = 238), the percentage of polymorphic loci (P = 69%), and the expected heterozygosity (He = 0270) were estimated. High levels of genetic diversity were found for C. carlesii compared with other local plant species. Genetic differentiation between populations was generally low. Conclusions From the data of expected heterozygosity, one major diversity centre was situated in central Taiwan corroborating previous reports for other plant species. According to the mean FST value of each population, the most divergent populations were situated in two places. One includes populations located in north central Taiwan between 2480N and 2420N. The other is located in south-eastern Taiwan between 2240N and 2310N. These two regions are approximately convergent with the most divergent locations determined for several other plant species using chloroplast DNA markers published previously. An important finding obtained from this study is that unordered markers like allozymes can be used to infer past population histories as well as chloroplast DNA markers do.

Nested clade phylogeographical analysis (NCPA), developed by A. R. Templeton and his colleague, was used to infer the evolutionary events that shaped the spatial genetic structure of Trochodendron aralioides in Taiwan. Genetic variation of two intergenic spacers of chloroplast DNA (petG-trnP and trnA-psbJ) among 24 populations, in which two from Japan, two from the Ryukyus and 20 from Taiwan, was examined. The NCPA suggests that the populations in Taiwan were first isolated from those of Japan proper. Since then, the spatial genetic structure in Taiwan was attributable to restricted gene flow.

In this report, two newly discovered native orchids, Bulbophyllum albociliatum (Liu & Su) Nakejima var. weiminianum and Flickingeria shihfuana, are presented.

Aims To unravel isolation and differentiation of the genetic structure of the Euphrasia transmorrisonensis complex, a showy herb, among alpine regions of mountain peaks in subtropical Taiwan and to infer its evolutionary history. Location Alpine ecosystems of high-montane regions of Taiwan. Methods Phylogenetic analyses of the trnL intron and the trnL–trnF intergenic spacer of chloroplast (cp) DNA, and the intertranscribed spacer (ITS) of nuclear ribosomal (nr) DNA between 18S and 26S were carried out on 18 populations of the E. transmorrisonensis complex in Taiwan. Results In total, 10 haplotypes for cpDNA and 14 haplotypes for nrDNA were detected. Three population groups located in the northern, north-eastern, and south-central regions of the Central Mountain Range (CMR) were revealed according to the frequencies of haplotypes and haplotype lineages of nrDNA. Balancing selection might have played a role in the evolution of Euphrasia in Taiwan. Main conclusions By integrating the spatial-genetic patterns of cpDNA and nrDNA, two possible evolutionary histories of Euphrasia in Taiwan were inferred. The favourable hypotheses for interpreting the data suggest at least three origins of the E. transmorrisonensis complex in Taiwan, corresponding to each nuclear lineage in the northern (II), northern/north-eastern (I), and central/southern regions (III) with subsequent hybridization between lineages I and II and lineages II and III. These lineage boundaries are strengthened by the finding that haplotypes of C derived from cpDNA were found in the geographical region of lineage II of nrDNA, while haplotypes of A derived from cpDNA were found in the region of lineage III of nrDNA. Thus, the origin of chloroplasts exclusive to lineages II and III supports their long-term isolation from one another.

A non-destructive continuous monitoring technology was developed for documenting diurnal changes in branch weight using resistance strain gauges. The capacity of rainfall interception by the canopy can be directly measured by attaching strain gauges to the branch. The amount of water loaded in tree reaches a maximum in the early morning, and a minimum in the afternoon. Thus, the branch is the heaviest in the early morning, and the lightest in the afternoon. Differences between the weight in the morning and in the afternoon can represent as the daily change in water loading of the branch. The branch can be considered as an elastic cantilever in response to the changes in weight of water carried by the branchlets and leaves, and the changes in strain are caused by the change in the bending stress of branch. Thus, the branch increases its weight when rainfall interception occurs, that also changes the stress of branch. The technique reported in this paper will provide an effective approach to investigating biological biometrics.

In this study, we examined spatial patterns of chloroplast DNA (cpDNA) variation in a total of 30 populations of Castanopsis carlesii Hayata (Fagaceae), a subtropical and temperate tree species, including 201 individuals sampled throughout Taiwan. By sequencing two cpDNA fragments using universal primers (the trnL intron and the trnV-trnM intergenic spacer), we found a total of 1663 bp and 21 polymorphic sites. These gave rise to a total of 28 cpDNA haplotypes. The level of differentiation among the populations studied was relatively high (GST = 0.723). Two ancestral haplotypes are widely distributed. The Central Mountain Ridge (CMR) of Taiwan represents an insurmountable barrier to the east-west gene flow of C. carlesii. Among the populations studied, three separated populations, at Lienhuachih, Fushan and Lichia, have high nucleotide diversity. Estimates of NST-GST for populations on both sides of the CMR indicate that no phylogeographical structure exists. According to the genealogical tree, number of rare haplotype and population genetic divergence, this study suggests that two potential refugia existed during the last glaciation: the first refugium was located in a region to the north of Hsuehshan Range (HR) and west of the CMR; the second refugium was located in south, especially southeastern Taiwan. In fact, the second refugium happens to be the same as that reported for Quercus glauca. A 'star-like' genealogy is characteristic when all haplotypes rapidly coalesce and is a general outcome of population expansion. The neutrality test and mismatch distribution also suggest demographic expansion recovering from a bottleneck.

Luanta-fir (Cunninghamia konishii), an endemic to Taiwan, is an outcrossing, long-lived conifer. Populations of C. konishii are generally fragmented due to a once high intensity of timber exploitation. C. konishii and Cunninghamia lanceolata are two sibling taxa constituting derivative-progenitor species relationship. The amount of genetic variations within and between 11 and 10 populations of C. konishii and C. lanceolata, respectively, were assessed using amplified fragment length polymorphism (AFLP) markers in this report. Three AFLP primer pairs generated a total of 357 and 226 markers for C. konishii and C. lanceolata samples, of which 56.1 and 65.3% are polymorphic, respectively. Analysis of molecular variance indicates a 4.78% variation between C. konishii and C. lanceolata. A relatively high value of genetic variation (24.60%) was apportioned between the populations of C. konishii. In contrast, a lower divergence value (12.21%) between populations was found for C. lanceolata. The population with the highest genetic diversity was found in Nantou County, which concurred with the results of many other tree species investigated in Taiwan. The estimates of the number of migrants between populations (Nm), obtained from population pair-wise ΦST, suggest that gene flow in C. konishii is efficient in some adjacent populations but is restricted in the rest. Individual UPGMA tree, generated based on AFLP markers, suggests six evolutionary lineages for C. konishii. All evolutionary lineages of C. konishii were derived from C. lanceolata. In conclusion, the migration patterns of Cunninghamia from mainland China may have been established following multiple sources, migrant-pools, long-distance dispersal events, and via different directions.

Aim This paper described current phylogeographical patterns of chloroplastic DNA variation of Trochodendron aralioides, a temperate tree species, and inferred its possible refugium in Taiwan. This information was compared with the known phylogeographical pattern of subtropical tree species. Location A total of 24 populations were sampled including 20 from Taiwan, two each from the Ryukyus and Japan. Methods A haplotype network was constructed by computer program TCS, various parameters of genetic diversity were calculated and neutrality was tested by computer program DnaSP. To examine the similarity of genetic structure among populations, a maximum parsimony tree was reconstructed by computer program PAUP*. The results of isozyme of T. aralioides from a previous publication were incorporated into this study to infer the phylogeographical history. Results Nine haplotypes according to six substitutions, two indels and one inversion of the two cpDNA intergenic spacer fragments (petG-trnP and petA-psbJ) of T. aralioides were recognized. Genetic structure of the population of Japan is totally different from those of Taiwan and the Ryukyus. In Taiwan, the genetic structure was differentiated among populations revealed by Gst = 0.700 and Nst = 0.542, and the population genetics was clearly spatially structured. Two population groups were recognized. The first group was distributed islandwide and extended to the Ryukyus. The second group contained five of the seven known haplotypes, and was restricted to the area between latitude 24°46′ and 24°06′ N. Conclusions In Taiwan, north-central area between latitude 24°46′ and 24°06′ N is potentially a refugium during the last glaciations. This finding is contradicted to subtropical species as Cyclobalanopsis glauca.

The genus Chamaecyparis comprises five species and one variety native to Taiwan, Japan, Canada, and USA, which demonstrates a classical eastern Asian, western North American, and eastern North American disjunct distributional pattern. The phylogenetic relationships of the species of Chamaecyparis were inferred by comparing 1130 bp of the combined data set of chloroplast trnV intron and petG-trnP intergenic spacer. The phylogenetic tree shows that Chamaecyparis nootkatensis (Cupressus nootkatensis or Xanthocyparis nootkatensis) is clearly diverged from other Chamaecyparis species. For Chamaecyparis species, C. thyoides is sister to C. formosensis and C. pisifera and these together form a monophyletic group. C. lawsoniana is sister to C. obtusa and C. taiwanensis; and these form another monophyletic group. Homogeneity in evolutionary rates was found among species in these two monophyletic groups. Results indicate the divergent evolution of C. taiwanensis and C. formosensis and molecular evidence in this investigation supports C. taiwanensis as a variety of C. obtusa. Utility of cpDNA intergenic spacer petG-trnP in Chamaecyparis is also discussed. Several biogeographical implications were inferred: (1) at least two divergence events have produced the eastern Asian, and both western and eastern North American disjunct distribution in Chamaecyparis; (2) intercontinental sister species pairs are found in Chamaecyparis; (3) cpDNA divergence between two intercontinental sister pairs of C. thyoides and C. pisifera, and C. lawsoniana and C. obtusa is 2.8% and 1.1%, which suggest an estimated divergence time of 14 and 5.5 million years ago during middle and late Miocene, respectively; (4) cpDNA divergence of two Asian Chamaecyparis groups between C. obtusa and C. taiwanensis, and between C. pisifera and C. formosensis is 0.25% and 0.57%, which suggest an estimated divergence time of 1.3 and 2.9 million years ago during Pleistocene and late Pliocene, respectively; these estimated divergence times suggest a relatively recent migration of Chamaecyparis to Taiwan from the Japanese Archipelago; (5) that climatic deterioration caused the disappearance of Chamaecyparis in continental Asia is probable.

The recalcitrant (desiccation sensitive) seeds of Machilus thunbergii were histochemically and ultrastructurally investigated by using light and electron microscopy. The embryo of mature seed has 4-6 subopposite primary leaves in the plumule. We found two types of idioblastic secretory cells (oil cells and mucilage cells) in the cotyledons, but observed only the oil cells in the embryonic axes. Cells in shoot and radicle meristem of the fresh mature embryo have a large nucleus and small vacuoles. The cytoplasm is dense with organelles, and the plastids contain some starch grains and few oil droplets. Under 75% relative humidity storage condition, the desiccation processes set off the subcellular damages (vacuolation, withdrawal of plasmalemma) of the mature seeds. Such processes intensified with time and ultimately resulted in the loss of viability.

The relationship between sugar content and loss of desiccation tolerance of hydrated crop seeds (tomato, okra, snow pea, mung bean, and cucumber) was evaluated by imbibing seeds with or without ABA, followed by dehydration and germination. During the process of hydration, but before the seeds lost desiccation tolerance, monosaccharide content increased only slightly, sucrose increased in snow pea, mung bean and cucumber, but maintained its original level in other species and the oligosaccharides declined dramatically. At the time of losing desiccation tolerance, the sucrose content of imbibed seeds was 2-3 times higher than the original level in most species. Positive significant correlation coefficients (r) were found in many, but not all crop seeds between desiccation tolerance and the oligosaccharide mass, or oligo/sucrose ratio. The ratio of oligo/sucrose in intact seeds at the time of losing desiccation tolerance, however, was not a fixed value and varied among species. Oligosaccharides declined significantly in different seed parts of imbibed cucumber seeds while sucrose increased to a higher level in the radicle than in the hypocotyl. Radicles were far more sensitive to desiccation than hypocotyls. The same observation was found for cucumber seeds imbibed in 100 μM ABA, yet desiccation tolerance was largely maintained in hypocotyls and cotyledons. It is concluded that sucrose and oligosaccharides are not the determinants of the loss of desiccation tolerance in hydrated seeds. Imbibed seeds did not show any differences between seed parts in their ability to resynthesize sugars during the process of slow dehydration. Differences in sensitivity to desiccation among seed parts were not due to differences in the initial water content or to the rate of water content increase among seed parts. Physiological regulation of the loss of desiccation tolerance in crop seeds during hydration is discussed.

Seeds of Taxus mairei are known for their deep dormancy which can only be broken by a procedure involving warm stratification followed by cold stratification. Treatments with alternating temperatures of 25}15 or 23}11 ∞C (12 h light) for 6 months followed by 5 ∞C for 3 months were successful in overcoming seed dormancy. After 6 months of warm stratification, cytological changes observed included: enlargement of the embryo; a decrease in the number of lipid bodies; appearance of ER; and increases in mitochondria, plastids, dictyosomes, vacuoles and microbodies in the shoot apical meristem. Cold stratification following the warm treatment induced cell division, and one or two distinct nucleoli in the shoot apical meristem cells were observed. Both warm and cold stratification reduced endogenous ABA concentrations from the original 8888 pg per freshly harvested seed to 392 and 536 pg, respectively. Treatment with exogenous gibberellins after seeds had been warm-stratified showed that GA % and GA ( were eective at promoting seed germination, but GA $ was not. These results suggest that the strong seed dormancy of T. mairei could be caused by a high ABA content and underdevelopment of the embryos in freshly shed seeds. We conclude that warm stratification with alternating temperatures increases the growth of embryos by cell expansion and enlargement and decreases ABA content, but seeds still remain ungerminated. Cold stratification may induce the response to GAs and initiate cell division resulting in release from physiological dormancy and subsequent germination of T. mairei seeds. # 1998 Annals of Botany Company

The once dominant endemic broadleaf tree species In Taiwan, CInnamomum kanehlrae Hay., has become a rare and endangered species due to overcutting. A done bank, consisting of at least 220 clones collected istandwide, was established at the Uukuel station, Taiwan Forestry Research Institute. Genetic diversity wtthln and genetic differentiation among four geographic areas of C. kanehlrae were Investigated using 164 clones collected from the clone bank. Seven out of the 11 loci examined were polymorphic. The average proportion of polymorphic loci per area was 51% at the 99% criterion for polymorphism. Mean expected heterozygosity ranged from 0.188-0.261 In the different areas, and 0.238 at the species level. On average the percent heterozygous loci per individual ranged from 13.9-21.6%, the number of alleies per locus ranged from 1.7-1.9, and the effective number of alleies per locus ranged from 1.34-1.54 at the area level. The much higher expected heterozygosity and higher number of aJtofes per locus compared to other local woody species investigated may support the hypothesis that Taiwan was a distributional center of CInnamomum. Partitioning the genetic variability Into withinand among-geographlc area components with F statistics and gene diversity analysis led to an estimate of wtthin-area variation amounting to 88% of the total variation. A slight barrier to gene flow among areas could be due to the large seed size and to Insect pollination. The limitation of seed dispersion, erratic flowering times, and several subpopulations wtthln the same geographic areas may contribute to the lower levels of observed heterozygosity than expected heterozygosity among the seven polymorphic loci, indicating some degree of Inbreeding and the Wahlund effect and thus a slight deficiency of heterozygotes (Fto = 0.157). Area 4, located in southeastern Taiwan has a much lower elevational distribution and showed a higher proportion of polymorphic loci, implying that genetic variation of area 4 may have developed under different climate conditions.

Low genetic variation in Amentotaxus formosana Li revealed by isozyme analysis and random amplified polymorphic DNA markers

Biochemical properties, i.e. endogenous abscisic acid, proline, sugars, respiration, adenosine phosphates and adenylate energy charge, and growth and moisture content were measured during the development of seeds of Machilus thunbergii. As dry matter accumulated in the embryo during development, moisture content, ABA, proline, respiration and sugars all declined. At maturity, the dry mass of the seeds failed to attain a plateau before the period of natural seed shedding; the axis and cotyledons reached moisture contents of 58 and 45%, respectively. Drying of immature seeds at 73% relative humidity and 25 °C for 30 d resulted in a complete loss of viability at all developmental stages tested with the exception of mature seeds that were able to tolerate a 5% decrease in moisture content before germination declined. ABA was detected in all embryos tested, with a maximum value 16.·16 μg g -1 d. wt about midway through development. Although the presence of ABA induced no tolerance to desiccation of mature seeds, it did coincide with decreased content of water in the developing seeds and decreased respiration. Desiccation damage of M. thunbergii seeds occurred when moisture content was still high (45%) and this damage was not related to the absence of oligosaccharides in the mature seeds. We conclude that developing embryos and mature seeds of M. thunbergii have properties common to many recalcitrant seeds, with seeds being sensitive to desiccation at all stages, having a prominent ABA peak, little proline, lacking oligosaccharides, and specifically, little dormancy and a moderate rate of respiration of mature seeds (0·9 μmol O 2 min -1 g -1 f. wt). Adenosine triphosphate content and energy charge decreased from stage four to stage eight of seed development, then increased again to 103 nmol g -1 d. wt and 0·73, respectively, in mature seeds. The moderate energy charge observed in mature seeds indicates that continuous metabolism is also a characteristic of recalcitrant seeds.