Search

Rhinogobius gigas is an amphidromous fish endemic to eastern Taiwan. Fishes with the diadromous behavior are expected to have a broader distribution range and higher genetic homogeneity despite that some amphidromous fishes with limited distribution are observed and R. gigas is an additional exception with a limited distribution range. Rhinogobius gigas has been documented to be retained inshore near the river plume with a short pelagic larval duration of 30–40 days, which may account for the endemism of this species. The short marine larval stage of R. gigas may imply a population genetic structure and the aim of the present study is to test whether the population genetic structure is present in R. gigas. To test the population genetic structure, fragments of mitochondrial displacement loop and cytochrome c oxidase subunit I were sequenced to provide molecular inference for genetic structure among populations. Sixty-nine haplotypes were identified among 191 R. gigas from 10 populations of eastern Taiwan and the mean haplotype and nucleotide diversities for all samples were 0.956 and 0.0024, respectively, implying a bottleneck followed by a recent population expansion further supported by Fu’s Fs (-26.6; p < 0.001) and Tajima’s D (-1.5; p = 0.037) values. The phylogenetic analysis revealed lack of genetic structure and the bush-like median joining network without commonly shared haplotypes supports the same scenario. The genetic homogeneity is probably due to the amphidromous life history providing the opportunity for passive larval transportation among the rivers through coastal currents in eastern Taiwan. The endemism to eastern Taiwan may be a consequence of complicated interactions among short pelagic larval duration, interspecific competition and coastal currents.

This study investigated the effects of HVEF as a potential postharvest technology in persimmon cultivation ( Diospyros kaki ). We used an electric field strength of 600 kV/m and treated samples for different lengths of time (0, 30, 60, 90 or 120 min) before storing the fruit for 15 d. The results showed that HVEF can reduce the rate of weight loss by 1.0–3.4-fold, demonstrating not only that HVEF has the ability to delay tissue deterioration but that the effect increases with treatment time. HVEF also delays the rate of decreasing hardness by 1.0–1.3-fold, indicating that it may have the ability to inhibit the activity of tissue enzymes. HVEF further demonstrated the ability to suppress the rate of malondialdehyde (MDA) production by 1.46–11.22-fold; increasing the treatment time improved the efficacy of the inhibition. HVEF can also delay the decreasing rate of carbon dioxides yield by 1.0–2.3-fold, indicating that it has the ability to inhibit metabolism. This inhibition rate of carbon dioxides yield also results in a delay of organizational deterioration. Finally, HVEF inhibited pectinesterase activity and had no impact on the amount of total phenols.

Most plant-produced monoterpenes can be degraded by soil microorganisms. Borneol is a plant terpene that is widely used in traditional Chinese medicine. Neither microbial borneol dehydrogenase (BDH) nor a microbial borneol degradation pathway has been reported previously. One borneol-degrading strain, Pseudomonas sp. strain TCU-HL1, was isolated by our group. Its genome was sequenced and annotated. The genome of TCU-HL1 consists of a 6.2-Mbp circular chromosome and one circular plasmid, pTHL1 (12.6 kbp). Our results suggest that borneol is first converted into camphor by BDH in TCU-HL1 and is further decomposed through a camphor degradation pathway. The recombinant BDH was produced in the form of inclusion bodies. The apparent K m values of refolded recombinant BDH for (+)-borneol and (−)-borneol were 0.20 ± 0.01 and 0.16 ± 0.01 mM, respectively, and the k cat values for (+)-borneol and (−)-borneol were 0.75 ± 0.01 and 0.53 ± 0.01 s −1 , respectively. Two plant BDH genes have been reported previously. The k cat and k cat / K m values of lavender BDH are about 1,800-fold and 500-fold lower, respectively, than those of TCU-HL1 BDH. IMPORTANCE The degradation of borneol in a soil microorganism through a camphor degradation pathway is reported in this study. We also report a microbial borneol dehydrogenase. The k cat and k cat / K m values of lavender BDH are about 1,800-fold and 500-fold lower, respectively, than those of TCU-HL1 BDH. The indigenous borneol- and camphor-degrading strain isolated, Pseudomonas sp. strain TCU-HL1, reminds us of the time 100 years ago when Taiwan was the major producer of natural camphor in the world.

The plant genus Cinnamomum contains economically important evergreen aromatic trees and shrubs belonging to the laurel family, Lauraceae. Our study tree species Cinnamomum osmophloeum Kaneh. (CO) has high economic value in Taiwan. The present study attempts to identify the gene resources of Cinnamomum osmophloeum Kaneh. by analyzing the nucleotide sequences of the partial noncoding internal transcribed spacer 2 (pITS2) of the ribosomal DNA and the trnL-trnF chloroplast genome. Seventy-three geographical strains of Cinnamomum osmophloeum, preserved in the Lien Hua-Chin Research Center of the Forestry Research Institute and the Hua-Lin Forestry Center of Chinese Culture University, were collected and analyzed by PCR amplification and DNA sequencing to study the genetic diversity and nucleotide sequence polymorphisms of the tested specimens. Our results allowed us to accurately identify the lineage of Cinnamomum osmophloeum and to conclude that the strains belonging to the Lien Hua-Chin Research Center had much higher genetic diversity than those preserved in the Hua-Lin Forestry Center. Multiple sequence alignments demonstrated that the variability of the nucleotide sequence polymorphisms for the pITS2 region was higher than those of the trnL intron and trnL-trnF intergenic spacer (IGS) regions among the 73 tested specimens of Cinnamomum osmophloeum. Cluster analyses, using the neighbor-joining and maximum parsimony methods, for the 73 tested geographical strains of Cinnamomum osmophloeum and species of Cinnamomum registered in the GenBank and EMBL databases were performed to demonstrate the genus and species distribution of the samples. Here, we describe the use of pITS2 polymorphisms as a genetic classifier and report the establishment of a DNA sequence database for CO gene resource identification. The sequence database described in this study can be used to identify CO specimens at the inter- or intraspecies level using pITS2 DNA sequences, which illustrates its value in gene resource identification. Our study results can be used further for correctly identifying the true Cinnamomum osmophloeum Kaneh.

Most plant-produced monoterpenes can be degraded by soil microorganisms. Borneol is a plant terpene that is widely used in traditional Chinese medicine. Neither microbial borneol dehydrogenase (BDH) nor a microbial borneol degradation pathway has been reported previously. One borneol-degrading strain, Pseudomonas sp. strain TCU-HL1, was isolated by our group. Its genome was sequenced and annotated. The genome of TCU-HL1 consists of a 6.2-Mbp circular chromosome and one circular plasmid, pTHL1 (12.6 kbp). Our results suggest that borneol is first converted into camphor by BDH in TCU-HL1 and is further decomposed through a camphor degradation pathway. The recombinant BDH was produced in the form of inclusion bodies. The apparent KThe degradation of borneol in a soil microorganism through a camphor degradation pathway is reported in this study. We also report a microbial borneol dehydrogenase. The k

Auricularia polytricha was cultivated on a sawdust basal substrate supplemented with different proportions (30%, 45%, and 60%, respectively) of stalks of three grass plants, i.e., Panicum repens (PRS), Pennisetum purpureum (PPS), and Zea mays (ZMS), to determine the most effective substrate. The mycelial growth rate, total colonization time, days to primordial formation, biological efficiency and chemical composition of fruiting bodies were evaluated. The results indicated that 30PPS was the best substrate for mycelial growth of A. polytricha, with a corresponding total colonization period of 32.0 days. With the exception of 30PPS, the total biological efficiency of all of the substrates containing P. repens stalk, P. purpureum stalk and Z. mays stalk was higher (P

The evolutionary origin of periodical mass‐flowering plants (shortly periodical plants), exhibiting periodical mass flowering and death immediately after flowering, has not been demonstrated. Within the genus Strobilanthes (Acanthaceae), which includes more than 50 periodical species, Strobilanthes flexicaulis on Okinawa Island, Japan, flowers gregariously every 6 years. We investigated the life history of S. flexicaulis in other regions and that of closely related species together with their molecular phylogeny to reveal the evolutionary origin of periodical mass flowering. S. flexicaulis on Taiwan Island was found to be a polycarpic perennial with no mass flowering and, in the Yaeyama Islands, Japan, a monocarpic perennial with no mass flowering. Molecular phylogenetic analyses indicated that a polycarpic perennial was the ancestral state in this whole group including S. flexicaulis and the closely related species. No distinctive genetic differentiation was found in S. flexicaulis among all three life histories (polycarpic perennial, monocarpic perennial, and periodical plant). These results suggest that among S. flexicaulis, the periodical mass flowering on Okinawa Island had evolved from the polycarpic perennial on Taiwan Island via the monocarpic perennial in the Yaeyama Islands. Thus, the evolution of life histories could have taken at the level of local populations within a species.

The global evolutionary pattern among the dracaenoid plant genera Dracaena, Pleomele, and Sansevieria has remained ambiguous. Their classification has been disputed due to different taxonomic interpretation and the difficulty in morphological characterization of the species and genera. This study explores the phylogenetic analysis of 95 species representing all three genera using four combined chloroplast intergenic spacer DNA regions (trnL-trnF, ndhF-rpl32, trnQ-rps16, and rpl32-trnL). The combined dataset was analyzed using parsimony, maximum likelihood, and Bayesian analysis. Results show that 1) dracaenoids are monophyletic; 2) the Hawaiian Pleomele species are the sister group to the remainder of the dracaenoid clade; 3) species of Dracaena and the remaining Pleomele are intermixed; 4) Sansevieria is monophyletic, but nested within Dracaena; 5) the Central American species D. americana and D. cubensis are the sister group to the remainder of the non-Hawaiian dracaenoid species. The Hawaiian Pleomele are morphologically and phylogenetically distinct from the remaining dracaenoids and are recognized as a distinct genus, Chrysodracon, and new species combinations are made. Dracaena is paraphyletic in regards to Sansevieria and those species should be recognized as species of Dracaena. The polyphyletic status of Pleomele species nested within Dracaena confirms previous morphology based studies that combined these genera.

The cause of fruit cracking can be diverse and the reasons vary among species. Wax apple (Syzygium samarangense) fruit is an economically valuable fruit in Southeast Asia and in Taiwan. The main problem in the production of wax apple is cracking which reduces its market value. The aim of this study is to identify the factors associated with fruit cracking in wax apple. Results showed that the contents of total soluble sugars and total titratable acid were both 20% higher in cracked fruits than in uncracked fruits, and the osmotic potential was 40% lower; water potential was similar; turgor pressure was 60% higher, and specific activity of polygalacturonase was 131% higher. Based on the above results, the physiological factors for fruit cracking in wax apple are hypothesized. The increase in total soluble sugars and total titratable acid during fruit maturation leads to decreased tissue osmotic potential. Water absorption in response to this decrease in osmotic potential can cause cells to swell, which increase the turgor pressure resulting in rupture of the cells and tissues. The increase in polygalacturonase activity weakens the cell walls. Those combined factors result in fruit cracking.doi: http://dx.doi.org/10.3126/botor.v8i0.5954 Botanica Orientalis – Journal of Plant Science (2011) 8: 70-76

Long-term ecological studies are critical for providing key insights in ecology, environmental change, natural resource management and biodiversity conservation. However, island fire ecology is poorly understood. No previous studies are available that analyze vegetative changes in burned and unburned dry forest remnants on Wa'ahila Ridge, Hawai'i. This study investigates vegetation succession from 2008 to 2015, following a fire in 2007 which caused significant differences in species richness, plant density, and the frequency of woody, herb, grass, and lichens between burned and unburned sites. These findings infer that introduced plants have better competitive ability to occupy open canopy lands than native plants after fire. This study also illustrates the essential management need to prevent alien plant invasion, and to restore the native vegetation in lowland areas of the Hawaiian Islands by removing invasive species out-planting native plants after fire. Language: en

The genus Chrysodracon has six endemic species in the Hawaii Islands. Chrysodracon hawaiiensis is endemic to Hawaii Island and was described as a distinct species in 1980. It was listed as an endangered species on the International Union for the Conservation of Nature and Natural Resources (IUCN) Red List in 1997. This woody plant species was, at one time, common in exposed dry forests, but it became very rare due to grazing pressure and human development. The tree species Chrysodracon auwahiensis (C. auwahiensis), endemic to Maui and Molokai, still has large adult populations in dry lands of the islands, but unfortunately no regeneration from seed has been reported in those areas for many years. The two endemic species were examined using the molecular technique of random amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) to determine the genetic structure of the populations and the amount of variation. Both species possess similar genetic structure. Larger and smaller populations of both species contain similar levels of genetic diversity as determined by the number of polymorphic loci, estimated heterozygosity, and Shannon’s index of genetic diversity. Although population diversity of Chrysodracon hawaiiensis (C. hawaiiensis) is thought to have remained near pre-disturbance levels, population size continues to decline as recruitment is either absent or does not keep pace with senescence of mature plants. Conservation recommendations for both species are suggested.

This research focuses on the biodiversity and the evolutionary history of the world-wide medicinal plant genus, Dracaena , and the plant genus Pleomele . The debate concerning the relationship between Dracaena and Pleomele has continued till date - some botanists continue to include Pleomele within Dracaena but others claimed to separate the two genera. Dracaena is a genus comprising of about 40-100 species world wide, mainly in tropics and subtropics, with the exception of America. Pleomele is a genus that has been circumscribed consisting of 10-50 species in Asia. Till date, its center of biodiversity is unknown. Pleomele is only classified well in Hawaii, but confused with Dracaena in the other parts of Asia. Phylogenetic relationship among the 33 taxa within the Dracaena and Pleomele were reconstructed. DNA sequences from the chloroplast DNA intergenic spacer, trnL-trnF and trnH-psbA were analyzed. A phylogeny was reconstructed using neighbor-joining, maximum parsimony in PAUP*, and likelihood criteria in RAxML, and Bayesian inference in MrBayes. The phylogeny with Agave missionum and Agave attenuata as outgroup taxa indicates that Pleomele is mixed with Dracaena . This study provides the first phylogenetic reconstruction with taxonomic sampling of the Dracaena and Pleomele to resolve their questionable placement. The relationships of the climate change adaptation, biogeography, and conservation with the two plant genera will be further discussed in this study. Some suggestions for the benefits of the biodiversity and natural resource conservation in Himalaya regions will be addressed. One significant contribution of this research will be in promoting molecular taxonomy to solve problems in systematics especially in cases when the classification is in debate. Key-words: Phylogeny; chloroplast DNA; Asparagaceae; Dracaena ; Pleomele . DOI: 10.3126/botor.v7i0.4385 Botanica Orientalis – Journal of Plant Science (2010) 7: 64-72