Floral traits of mammal-pollinated Mucuna macrocarpa (Fabaceae): Implications for generalist-like pollination systems.

Floral traits are adapted by plants to attract pollinators. Some of those plants that have different pollinators in different regions adapt to each pollinator in each region to maximize their pollination success. Mucuna macrocarpa (Fabaceae) limits the pollinators using its floral structure and is pollinated by different mammals in different regions. Here, we examine the relationships between floral traits of M. macrocarpa and the external morphology of mammalian pollinators in different regions of its distribution. Field surveys were conducted on Kyushu and Okinawajima Island in Japan, and in Taiwan, where the main pollinators are the Japanese macaque Macaca fuscata, Ryukyu flying fox Pteropus dasymallus, and red-bellied squirrel Callosciurus erythraeus, respectively. We measured the floral shapes, nectar secretion patterns, sugar components, and external morphology of the pollinators. Results showed that floral shape was slightly different among regions and that flower sizes were not correlated with the external morphology of the pollinators. Volume and sugar rate of nectar were not significantly different among the three regions and did not change throughout the day in any of the regions. However, nectar concentration was higher in Kyushu than in the other two regions. These results suggest that the floral traits of M. macrocarpa are not adapted to each pollinator in each region. Although this plant limits the number of pollinators using its flower structure, it has not adapted to specific mammals and may attract several species of mammals. Such generalist-like pollination system might have evolved in the Old World.

Investigation of floristic similarities between Taiwan and terrestrial ecoregions in Asia using GBIF data.

BACKGROUND: Floristic compositions of non-endemic plants of continental islands were related to the neighboring continents because non-endemic plant species had historically migrated to continental islands from source areas. This study attempts to identify source areas of a continental island by means of floristic analysis and to assess possible migration routes on the basis of geographical distribution ranges of plants. Large quantities of angiosperm data records were downloaded from the Global Biodiversity Information Facility (GBIF). Similarity index and cluster analysis were used to identify the floristic similarities among 22 geographical localities of Taiwan (GLTs) and 34 terrestrial ecoregions in Asia. Geographical distribution ranges of non-endemic angiosperm species in Taiwan (NEASTs) were evaluated to mirror the possible migration routes from different source areas to Taiwan. RESULTS: There are 3275 angiosperm species in Taiwan derived from the dataset of GBIF. Among them, 847 are endemic and 2428 are NEASTs. Geographical distribution ranges of the 2428 NEASTs were categorized into 7 distribution groups. They were widely distribution from equator to Siberia (27 species), tropical ecoregions (345 species), tropical and subtropical ecoregions (663 species), tropical to temperate ecoregions (591 species), subtropical ecoregions (265 species), subtropical to temperate ecoregions (387 species), and temperate ecoregions (150 species). Results of similarity indices and cluster analysis demonstrated that high floristic similarities were observed among GLTs at lowland and southern Taiwan and tropical and subtropical ecoregions in Asia. GLTs at high mountains were assumed to have floristic similarity with temperate ecoregions in Asia, whereas the assumption was not supported by our analysis. It is partly because of that angiosperms with tropical and subtropical distributions extend their ranges from low to high elevations in Taiwan. CONCLUSIONS: Subtropical ecoregions at southern China and tropical ecoregions at Indochina were more important than temperate ecoregions on playing source areas of NEASTs. Geographical distribution ranges of NEASTs implied that most of the NEASTs were probably migrated from topical or subtropical ecoregions of Asian continent to Taiwan.

Experimental evaluation of the sustainability of dwarf bamboo (Pseudosasa usawai) sprout-harvesting practices in Yangminshan National Park, Taiwan.

Sustainable harvest of natural products that meets the needs of local people has been viewed by many as an important means for sustaining conservation projects. Although plants often respond to tissue damage through compensatory growth, it may not secure long-term sustainability of the populations because many plants enhance individual well-being at the expense of propagation. Sustainability may further be threatened by infrequent, large-scale events, especially ill-documented ones. We studied the impacts of sprout harvesting on sprout growth in a dwarf bamboo (Pseudosasa usawai) population that has seemingly recovered from an infrequent, large-scale masting event. Experimental results suggest that although a single sprout harvest did not significantly alter the subsequent abundance and structure of sprouts, culm damage that accompanied sprout harvesting resulted in shorter, thinner, and fewer sprouts. Weaker recovery was found in windward, continually harvested, and more severely damaged sites. These findings suggest that sprout growth of damaged dwarf bamboos is likely non-compensatory, but is instead supported through physiological integration whose strength is determined by the well-being of the supplying ramets. Healthy culms closer to the damage also provided more resources than those farther away. Sustainable harvesting of sprouts could benefit from organized community efforts to limit the magnitude of culm damage, provide adequate spacing between harvested sites, and ensure sufficient time interval between harvests. Vegetation boundaries relatively resilient to infrequent, large-scale events are likely maintained by climatic factors and may be sensitive to climate change. Continual monitoring is, therefore, integral to the sustainability of harvesting projects.

In vitro assessment of Macleaya cordata crude extract bioactivity and anticancer properties in normal and cancerous human lung cells.

The purpose of this study is to assess the bioactivity and anticancer properties of Macleaya cordata crude extract in vitro using normal fetal lung fibroblast MRC5 and adenocarcinomic epithelial cell A549 as model systems,. Treatment of extract induced cell detachment, rounding, and irregularity in shape, in both normal and adenocarcinomic human lung cells, in accompanied of significant reduction in cell proliferation. The data indicated that necrosis appeared to be involved in compromising cell growth in both types of lung cells since membrane permeability and cell granularity were elevated. Although apoptosis was evident, the responses were differential in normal and diseased lung cells. Viability of treated MRC5 cells was reduced in a dose-dependent manner, demonstrating that the normal lung cells are sensitive to the extract. Surprisingly, A549 viability was slightly elevated in response to extract exposure at low concentration, implying that cells survived were metabolically active; the viability was reduced accordingly to treatment at higher concentrations. The present findings demonstrate that the crude extract of M. cordata contains agents affecting the functioning of normal and diseased lung cells in vitro. The observed cytotoxic effects against adenocarcinomic lung cells validate the potential of using M. cordata as herbal intervention in combined with conventional chemotherapy for lung cancer treatment.