Elevations In Taiwan Research Articles

First Report of 'Candidatus Phytoplasma asteris'-related Strain (16SrI group) Associated with Small Leaves, Leaf Yellowing, and Shoot Proliferation of Morning Glory (Ipomoea biflora) in Taiwan.

Ipomoea biflora L., commonly known as morning glory, is an herbaceous vine plant in the Convolvulaceae family and is widespread at low elevations in Taiwan and other East Asian countries. In September 2023, six I. biflora plants exhibiting small leaves, leaf yellowing, and shoot proliferation were observed in a vacant lot in Taiwan Agricultural Research Institute (TARI), Wufeng District, Taichung, Taiwan, representing 100% disease incidence in the area. All the symptomatic morning glory climbed onto Murraya paniculata L. (common jasmine orange) which however showed no similar symptoms. The total DNA (two samples for each plant) from leaf tissues of three symptomatic morning glory plants, two asymptomatic morning glory plants, and one asymptomatic common jasmine orange was isolated by the CTAB method (Fulton et al. 1995) and used for PCR with the universal primers, P1 (Deng and Hiruki 1991)/P7 (Schneider et al. 1995), to amplify a fragment containing partial 16S rDNA. Expected 1.8-kb bands were amplified from DNA extracted from all symptomatic plants, whereas no PCR product was detected from that of the asymptomatic I.biflora and M. paniculata plants. Six PCR products were cloned and sequenced in the Biotechnology Center DNA-sequencing facility at National Chung Hsing University, and one representative sequence was selected and deposited in GenBank. BLAST analysis revealed that the obtained 16S rDNA sequence (PP230905) shared 99.92% identity with the following phytoplasma strains: rapeseed phyllody phytoplasma (CP055264), plumbago auriculata leaf yellowing phytoplasma (MN239503), and aster yellows phytoplasma (MK992774), which all belong to the 16SrI subgroup. The query 16S rDNA sequence shares 99.84% identity with that of the 'Candidatus Phytoplasma asteris' reference strain (M30790), suggesting that the phytoplasma is a 'Ca. Phytoplasma asteris'-related strain. A virtual restriction fragment length polymorphism (RFLP) analysis was conducted using iPhyClassifier tool (Zhao et al. 2009), and the pattern derived from the 16S rDNA fragment of the I. biflora phytoplasma was identical (similarity coefficient 1.00) to the reference pattern of 16SrI, subgroup B (onion yellows phytoplasma OY-M; AP006628). Six total DNA samples from symptomatic plants were used as templates to amplify 842 bp secA sequences with SecAfor1 and SecArev3 primers (Hodgetts et al. 2008), and one representative sequence was deposited in GenBank. The partial secA sequence (PP263636) showed 98.22% identity with that of Trema levigatum witches'-broom phytoplasma (MW032212) that also belongs to the 16SrI group (Wan et al. 2021). Phylogenetic analysis of both 16S rDNA and secA confirmed I. biflora phytoplasma as 16SrI, subgroup B. Taken together, we concluded that the morning glory phytoplasma in this study was a 'Ca. Phytoplasma asteris'-related strain belonging to the 16SrI group. To the best of our knowledge, this is the first report of a phytoplasma-infected I. biflora in Taiwan, suggesting morning glory as a new natural host of 16SrI phytoplasmas, alongside other plants like roselle and citrus (Tseng et al. 2014; Feng et al. 2015).

Phenotypic plasticity and genetic variation in leaf traits of Yushania niitakayamensis (Bambusoideae; Poaceae) in contrasting light environments.

Yushania niitakayamensis (Bambusoideae; Poaceae), a perennial grass distributed from mid to high elevations in Taiwan, is often found growing in exposed grassland or shaded forest understories. To answer the question how does Y. niitakayamensis cope with contrasting light availability of habitats, we compared (1) leaf ecophysiological traits between populations of Y. niitakayamensis growing in exposed and shaded habitats in four seasons, and (2) plasticity patterns of transplanted plants to two light treatments (full-sun and 70 % shading) in a phytotron. Significant differences in leaf morphological (leaf length, width, specific leaf area, stomatal density), anatomical (leaf thickness (LT), the frequency of cavity formed by collapsed fusoid cells), and biochemical (chlorophyll contents, nitrogen contents per unit area ([N]area) and stable carbon isotope ratio) features were found between populations across seasons. Common garden experiments suggested that most of the trait variations in field growing plants can be explained by the effect of growth light treatment but not by that of population. However, variations between the two populations in LT, [N]area, gas exchange parameters, and the degree of plasticity in LT and [N]area in responding to growth light regimes might have genetic basis. In comparison between transplants from different origins grown under same light regime, plants from the exposed population grown under full-sun expressed significantly higher LT, [N]area and light-saturated photosynthetic rates, whereas plants from the shaded population grown under shading had significantly higher water use efficiency. Accordingly, local specialization in populations of Y. niitakayamensis to particular environmental conditions might have arisen.

Comparison of subtropical surface water chemistry between the large Pearl River in China and small mountainous rivers in Taiwan

Small mountainous rivers in Oceania typically have higher sediment yields than larger rivers because of their steep gradients and frequent tropical storm-induced high rainfall. The high sediment yields of these small mountainous rivers enable them to transport a large amount of terrigenous material to the oceans. However, data are unfortunately sparse on this topic. In this study, we investigated the water quality and sediment geochemistry of 35 small rivers in Taiwan and compared these data with that of the large Pearl River.Although Taiwan and the Pearl River Basin are both traversed by the Tropic of Cancer, and thus have similar weather patterns, their water chemistry is quite different. The most notable difference is that despite higher rainfall in Taiwan, and hence, a larger dilution effect, the total dissolved solid concentration (TDS), Mg+2, Na++K+, Cl−, and SO4-2 are generally higher in the Taiwanese rivers compared to the Pearl River. On the other hand, the sediment load in Taiwanese rivers is higher compared with the Pearl River, as expected. These observations reflect the higher rate of chemical weathering and denudation in Taiwan due to its steeper terrain and the larger impact of typhoons, hence episodic heavyrainsin that region. The pattern of distribution vs. altitude is also different, with higher TDS, Ca+2, Mg+2, SO4-2,HCO3- and pH values at higher altitudes in the Pearl River Basin, whereas these values are lower at higher elevations in Taiwan. We see this difference because the upper reaches of the Pearl River are primarily covered with limestone, whereas the high mountains of Taiwan are mainly composed of slate and schist that are more resistant to chemical weathering and less affected by acid rain compared with limestone. Pollution-related parameters such as non-sea-salt SO4-2(nss-SO4-2), nss-SO4/(Na++K+) and Cl−/(Na++K+) also suggest that rivers in Taiwan are much more polluted than the Pearl River Basin, perhaps due to the widespread burning of coal and plastic-laden refuse in Taiwan.

Precipitation chemistry at a high elevation forest in central Taiwan

High elevation ecosystems are particularly sensitive to environmental change. Mountain agriculture is extending to areas at high elevations in Taiwan but the effects on nutrient cycling of the surrounding ecosystems are largely unknown. We examined precipitation chemistry at Piluchi Experimental Forest in central Taiwan to evaluate the contributions of local air pollution and long-range transport of air pollutants on nutrient cycling at this seemingly remote forest. Sea-salt aerosols and anthropogenic pollutants resulting from long-range transport of air pollutants and mountain agriculture activities are the key factors affecting precipitation chemistry at Piluchi Experimental Forest. Precipitation chemistry was dominated by ions of oceanic origin in the summer and by anthropogenic pollutants SO42−, NO3− and NH4+ in the winter and spring, the northeast monsoon season. The much higher concentrations of S and N in the northeast monsoon season than the summer suggest a substantial contribution from long-range transport as the prevailing air masses moved from inland China and passed over the industrialized east coast of China before arriving in Taiwan. The very high concentration of NH4+ (22 μeq L−1) in the spring, when the local application of N-containing fertilizers was high, signifies the influences of mountain agriculture. Despite very low concentrations relative to other sites in Taiwan, annual input of NH4+ (3.6 kg ha−1 year−1), NO3− (7.2 kg ha−1 year−1) and SO42− (10 kg ha−1 year−1) via precipitation was substantial suggesting that high elevation ecosystems of Taiwan are not free from the threat of atmospheric deposition of pollutants.

Isolation and characterization of 11 polymorphic microsatellite loci from Fatsia polycarpa (Araliaceae), an element of evergreen forests in Taiwan

Fatsia polycarpa Hayata (Araliaceae) is an element of evergreen forests at middle elevations in Taiwan, also representing the southern limitation in distribution of the genus. In this study, we described the development of 11 microsatellite loci from F. polycarpa in Taiwan for genetic studies. These new markers were tested in 20 individuals of 5 populations of the woody species. The number of alleles ranged from 9 to 18. The expected (HE) and observed (HO) heterozygosities were 0.80–0.95 and 0.10–0.75, respectively. Six of the 11 microsatellite loci are significantly deviated from Hardy–Weinberg expectations likely due to the population structure within samples. No linkage disequilibrium were observed from pairwise comparisons of loci.

Variation of Germination Response to Temperature in Formosan Lily (Lilium formosanum Wall.) Collected from Different Latitudes and Elevations in Taiwan

Germination characteristics at different temperatures were examined in Formosan lily (Lilium formosanum Wall.) seeds collected at different latitudes (22º 46’–24º 47’ N) and elevations (50-3000 m) in Taiwan. Germination was sensitive to temperature and varied among the populations, especially at 5ºC and 25ºC. All tested populations germinated fastest at 18ºC. At this temperature, it took 8-14 days for initiation of germination (Gin) and 10-19 days to reach 50% of final germination percentage (G50). Days to Gin and G50, were 10-21 and 14-41, respectively, at 10ºC, 42-82 and 51-136, respectively, at 5ºC and 10-39 and 15-100, respectively, at 25ºC. In the low elevation (50-880 m) populations, seeds from higher latitude populations germinated more rapidly at 5ºC but more slowly at 25ºC than those from a lower latitude. Furthermore, seeds from the lower latitude populations had significantly higher final germination percentages than those from the higher latitude populations at 25ºC. Some germination characteristics of seeds from higher elevation habitats at the middle latitude were very similar to those from lower elevation habitats at the lower latitude despite of the difference in air temperature between the habitats. The eco-physiological germination characteristics of Formosan lily in response to temperatures were discussed in relation to the climatic conditions of each habitat.

A Skeletochronological Study on a Subtropical, Riparian Ranid (Rana swinhoana) from Different Elevations in Taiwan

We estimated the age, longevity, and growth patterns of a subtropical ranid, Rana swinhoana from high (Lishing) and low (Wulai) elevations using skeletochronology. In addition, we also measured body mass and length of frogs from five other localities. Results showed that both snout-vent length and body mass of frogs were significantly correlated with altitudes for both sexes. Frogs of Lishing were significantly larger and older than that of Wulai. We used LAGs to estimate the age and growth of frogs and found that the growth of Wulai frog of both sexes slowed down at an earlier age than that of Lishing frogs. Male and female frogs from Wulai did not exceed 6 and 7 years, respectively, while the maximum age of males and females of Lishing was 7 and 11 years, respectively. Results suggest that the LAGs observed in R. swinhoana correspond to low temperature and/or decreased food availability instead of desiccation during the harsh annual period (November to February). Skeletochronological data suggest that the variations of body size of R. swinhoana among elevations are likely associated with the growth, age at sexual maturity, and longevity.

Reproductive Characteristics of Bufo bankorensis at Two Elevations in Taiwan

We compared the reproductive characteristics of two populations of Bufo bankorensis in central Taiwan, one inhabiting a temperate climate (Meifong, 2100 m), the other inhabiting a subtropical climate (Wushe, 1100 m). We determined ovary status, spermatogenetic activity, fat body and liver mass cycles, and plasma 17-betaestradiol and androgen levels over a 14 month period. B. bankorensis from both populations are prolonged breeders but the temperate population exhibits breeding activity throughout the year, while the subtropical population only breeds from September to March. Their spermatogenic cycles are continuous, and their spermatogenetic activities are invariably at stage 6, in which spermatozoa are predominant in the seminiferous tubule. Both populations show monthly variations in plasma androgen and 17-betaestradiol levels, but follow different patterns. Ovary mass is larger in the temperate than in the subtropical population. The reproduction differences of two elevation toads could be reflected by adaptations to the local environmental regimes of its habitat. The reproductive patterns of these populations of Bufo bankorensis are also compared to those of sympatric and allopatric populations of five anurans studied from sites throughout Taiwan.

Gas Exchange and Epidermal Characteristics of Miscanthus Populations in Taiwan Varying with Habitats and Nitrogen Application

Seventeen clones of C4 grass Miscanthus spp. collected from different climatic regions and elevations of Taiwan were transplanted in pots. 15-16 months after collection the plants received 0, 1, and 2 g of nitrogen fertiliser (N0, N1, and N2, respectively) per pot. All the measurements were done 10-12 d after N application. The relationships between net photosynthetic rate (PN) and photon flux density (PFD) showed a saturated curve, with PFD saturation at about 1 000 µmol m-2 s-1. The ranges of PFD saturated PN (Psat) for all the tested clones with N0, N1, and N2 were 8-16, 11-18, and 12-21 µmol m-2 s-1, respectively. The clones from southern Taiwan, a tropical region, showed the highest Psat, followed by the clones from northern Taiwan, a subtropical region, while those from mountainous area showed the lowest Psat. The clones collected from southern Taiwan showed the highest frequency of stomata on the adaxial surface, and those collected from the high mountainous area showed the lowest frequency. Also the adaxial surface of leaves from the higher mountainous area had more wax deposited than the leaves from the lowland. Thus the low Psat in mountain clones is limited by both stomatal and non-stomatal factors. Further, the lower leaf conductance and different epidermal characteristics of mountain clones might prevent excessive loss of heat through transpiration and provide production against ultraviolet-B radiation.

Response of photosynthetic gas exchange and chlorophyll a fluorescence of Miscanthus floridulus (Labill) Warb. to temperature and irradiance

Summary Miscanthus floridulus (Labill) Warb., a C 4 perennial grass, is widely distributed at low elevations in Taiwan. To determine whether chilling temperatures increase the susceptability of M. floridulus to photoinhibition, we investigated the effects of temperature and photon flux density (PFD) on the photosynthetic gas exchange and chlorophyll a fluorescence of this species. Photosaturated photosynthetic rates and the PFD required to saturate photosynthesis were reduced by low temperature exposure. Leaves exposed to 10 °C had decreases in the quantum efficiency (F v ′/F m ′) and coefficient of photochemical quenching (qP). A significandy positive linear relationship between the ratio of variable fluorescence to maximum fluorescence (F v /F m ) and quantum yield of photosynthesis was measured. Significant reductions in F v /F m values in leaves exposed to 10 °C indicate photoinhibition. The degree of reduction depends on the irradiance the higher the PFD, the more pronounced was the photoinhibition that had occurred. However, the F v /F m of 10 °C exposed leaves recovered 90 % of its initial value 6 h after plants were transferred to 30 °C and illuminated with a medium light.