Size-dependent reproductive allocation ofGentianopsis paludosain different habits of the Qinghai-Tibetan Plateau

2016 ◽  
Vol 36 (9) ◽  
Author(s):  
侯勤正 HOU Qinzheng ◽  
叶广继 YE Guangji ◽  
马小兵 MA Xiaobing ◽  
苏雪 SU Xue ◽  
张世虎 ZHANG Shihu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Reproductive Allocation ◽  
Size Dependent

scholarly journals Size-dependent allocation of biomass to ancillary versus flowers of the inflorescences of the epiphyte Tillandsia stricta Soland (Bromeliaceae)

2009 ◽  
Vol 23 (1) ◽  
pp. 130-135 ◽  
Author(s):  
André Mantovani ◽  
Ricardo Rios Iglesias
Keyword(s):  
Leaf Area ◽  
Plant Species ◽  
Vegetative Growth ◽  
Reproductive Investment ◽  
Plant Size ◽  
Reproductive Allocation ◽  
Heterogeneous Environment ◽  
Plant Resources ◽  
Total Leaf Area ◽  
Size Dependent

The amount of resources invested in reproduction is closely correlated to plant size. However, the increase in reproductive investment is not always proportional to the increase in vegetative growth, as the proportion of plant resources allocated to reproduction can increase, decrease or be maintained along different plant sizes. Although comprising thousand of species, epiphytes are poorly studied in relation to reproductive allocation (RA). We describe the variation in the RA of the epiphytic bromeliad Tillandsia stricta Soland with increasing plant sizes. Our goal is not only to evaluate the RA of the whole inflorescence but also quantify the contribution of ancillary structures in the final RA of this plant species. With increasing sizes of T. stricta the reproductive allocation of biomass to the whole inflorescence decreased significantly along plant sizes from 37% to 12%. Reproductive allocation to ancillary and to flowers decreased respectively from 30% to 9% and 10% to 3%. As leaves are the main source of water and nutrients absorption in atmospheric Tillandsia, the total leaf area and area per leaf were used as indicators of foraging capacity, that also increased with plant size. We discuss these results with respect to the capacity of T. stricta to reproduce in the heterogeneous environment of the canopies.

An explanation for size-dependent reproductive allocation in Plantago major

1998 ◽  
Vol 76 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Edward G Reekie
Keyword(s):  
Life History Theory ◽  
Reproductive Output ◽  
Direct Consequence ◽  
Reproductive Allocation ◽  
Reproductive Cost ◽  
Trade Off ◽  
Size Dependent ◽  
Size Constraints ◽  
Controlled Environments ◽  
Size And Morphology

This study examined whether variation in reproductive allocation with size could be explained by differences in the trade-off between reproduction and growth. Seeds from 42 half-sibling families were collected from sites differing in mowing frequency and availability of light, nutrients, and water. Six seedlings from each family were grown in controlled environments and photoperiod manipulations were used to control reproduction. Mass of vegetative and reproductive plants of the same family were compared to assess the trade-off between reproduction and growth. Families collected from habitats with a tall canopy were larger and experienced a greater decrease in growth with reproduction than families from habitats where mowing maintained a short canopy. Reproductive output showed no relationship with size, while reproductive allocation (capsule mass to vegetative mass) decreased with size. This decrease may be a direct consequence of the increase in reproductive cost with size. The increase in cost can be partially explained by increased allocation to reproductive support structures; large individuals produce capsules on more elongate scapes and have a lower capsule to scape ratio. Differences in size and morphology among habitats are presumably the result of selection to avoid damage in mown sites and to avoid shade and ensure pollination in sites with a tall canopy and reduced wind movement.Key words: allometry, life-history theory, size constraints, reproductive effort, reproductive cost.

scholarly journals Biomass allocation to vegetative and reproductive organs of Chenopodium acuminatum Willd. under soil nutrient and water stress

2013 ◽  
Vol 42 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Yingxin Huang ◽  
Xueyong Zhao ◽  
Daowei Zhou ◽  
Tianhui Wang ◽  
Guandi Li ◽  
...  
Keyword(s):  
Water Stress ◽  
Population Density ◽  
Soil Water ◽  
Biomass Allocation ◽  
Soil Nutrient ◽  
Plant Size ◽  
Reproductive Organs ◽  
Reproductive Organ ◽  
Reproductive Allocation ◽  
Size Dependent

Biomass allocation was size-dependent. Under soil nutrient, the plasticity of the leaf and reproductive allocation was “true” plasticity, the plasticity of stem allocation was “apparent” plasticity, which is dependent on plant size, but there was no plasticity in root allocation. Under soil water stress, the plasticity of root, leaf and reproductive allocation was “true”. In response to population density, the plasticity of stem allocation is “true” plasticity, while the value of the stem allocation is consistent because of the trade off between the effects of plant size and population density. The biomass allocation strategy increases reproductive allocation but decrease leaf allocation with the decrease of soil nutrient, when compared at the same plant size. At lower soil water, the plant allocated more biomass to the root and leaf rather than to reproductive organ. DOI: http://dx.doi.org/10.3329/bjb.v42i1.15873 Bangladesh J. Bot. 42(1): 113-121, 2013 (June)

Production and STEM examination of controlled-size silver clusters

1983 ◽  
Vol 41 ◽  
pp. 338-339
Author(s):  
M. A. Listvan ◽  
R. P. Andres
Keyword(s):  
Cluster Size ◽  
Metal Clusters ◽  
Experimental Parameter ◽  
Carbon Films ◽  
Metal Species ◽  
Silver Clusters ◽  
Free Jet ◽  
Size Dependent ◽  
Cluster Properties ◽  
Controllable Size

Knowledge of the function and structure of small metal clusters is one goal of research in catalysis. One important experimental parameter is cluster size. Ideally, one would like to produce metal clusters of regulated size in order to characterize size-dependent cluster properties.A source has been developed which is capable of producing microscopic metal clusters of controllable size (in the range 5-500 atoms) This source, the Multiple Expansion Cluster Source, with a Free Jet Deceleration Filter (MECS/FJDF) operates as follows. The bulk metal is heated in an oven to give controlled concentrations of monomer and dimer which were expanded sonically. These metal species were quenched and condensed in He and filtered to produce areosol particles of a controlled size as verified by mass spectrometer measurements. The clusters were caught on pre-mounted, clean carbon films. The grids were then transferred in air for microscopic examination. MECS/FJDF was used to produce two different sizes of silver clusters for this study: nominally Ag6 and Ag50.

Transfer Technique for Electron Microscopy of Membrance Filter Samples

1974 ◽  
Vol 32 ◽  
pp. 554-555
Author(s):  
Lawrence W. Ortiz ◽  
Bonnie L. Isom
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pore Size ◽  
Membrane Filters ◽  
Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

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