Thermal Adaptation of Pennisetum: Leaf Photosynthesis and Photosynthate Translocation

1977 ◽  
Vol 4 (5) ◽  
pp. 763 ◽  
Author(s):  
CJ Pearson ◽  
GA Derrick
Keyword(s):  
Low Temperature ◽  
Growth Rates ◽  
Thermal Adaptation ◽  
Leaf Photosynthesis ◽  
Photosynthetic Rates ◽  
Photosynthate Translocation

Leaf photosynthetic rates, loss of photosynthate 14C, sucrose concentrations and invertase activities were measured in three genotypes of Pennisetum growing at daylnight temperatures that ranged from 18/13 to 33/28°C. Leaves at low temperature had low photosynthetic rates, exported 14C more slowly, retained a higher proportion of photosynthate 14C, had higher sucrose concentrations and aged (physiologically) more slowly than did leaves growing at higher temperatures. The genotype that retained most photosynthate in the source leaves was the most cold-intolerant whereas there was no correlation between photosynthetic rates and previously observed growth rates.

Morphological Instability of Polyhedral Ice Crystals Growing in Air at Low Temperature

1985 ◽  
Vol 6 ◽  
pp. 222-224 ◽  
Author(s):  
T. Gonda ◽  
H. Gomi
Keyword(s):  
Low Temperature ◽  
Growth Rates ◽  
Crystal Size ◽  
Air Pressure ◽  
Experimental Results ◽  
Ice Crystals ◽  
Polar Regions ◽  
Morphological Instability ◽  
Skeletal Structures ◽  
Snow Crystals

The morphology of snow crystals growing at a low temperature has been experimentally studied. The habit and the morphological instability of the crystals vary remarkably with air pressure. In addition, the morphological instability of the crystals depends not only on air pressure but also on supersaturation, crystal size, the ratio of growth rates and the ratio of axial lengths. It is supposed from the experimental results that long prisms with small skeletal structures forming at low supersaturation are precipitating in polar regions.

Low‐temperature cadmium telluride homoepitaxy at high growth rates

1989 ◽  
Vol 65 (5) ◽  
pp. 1932-1935
Author(s):  
N. W. Cody ◽  
U. Sudarsan ◽  
R. Solanki
Keyword(s):  
Low Temperature ◽  
Cadmium Telluride ◽  
Growth Rates ◽  
High Growth

Temperature response of dry matter accumulation, leaf photosynthesis, and chlorophyll fluorescence in an old and a new maize hybrid during early development

1991 ◽  
Vol 71 (2) ◽  
pp. 353-359 ◽  
Author(s):  
M. Tollenaar ◽  
M. Mihajlovic ◽  
A. Aguilera
Keyword(s):  
Chlorophyll Fluorescence ◽  
Low Temperature ◽  
Dry Matter ◽  
Temperature Tolerance ◽  
Dry Matter Accumulation ◽  
Leaf Photosynthesis ◽  
Short Term ◽  
Dry Matter Partitioning ◽  
Leaf Stage ◽  
Low Temperature Tolerance

Studies were conducted to investigate whether genetic improvement in dry matter accumulation of maize (Zea mays L.) hybrids recommended in Ontario from the late 1950s to the late 1980s is associated with cold-temperature tolerance during early phases of development. The maize hybrids Pride 5 (released in 1959) and Pioneer 3902 (released in 1988) were compared at 16/7, 23/14, and 33/24 °C under a 16-h photoperiod with a photosynthetic photon flux density of 650 μmol m−2 s−1 in long-term and short-term temperature experiments conducted in controlled-environment cabinets. In the long-term temperature experiment, plants were grown at the three temperature regimes from the 4- to the 12-leaf stage. Total and plant component dry matter was determined at the 8-, 10-, and 12-leaf stage, and leaf photosynthesis and chlorophyll fluorescence were measured at the 10-leaf stage. In the short-term temperature experiment, plants were exposed to the three temperature regimes during a 3-d period after the 9-leaf stage, followed by 2 d at 23/14 °C. Dry matter accumulation during the 5-d period was measured and leaf photosynthesis and chlorophyll fluorescence were measured during each of the last 3 d of the 5-d period. Results showed a highly significant temperature effect on all measured parameters. Dry matter of Pride 5 at the 10-leaf stage was higher than that of Pioneer 3902, but rates of dry matter accumulation and leaf photosynthesis did not differ among hybrids, and hybrid × temperature interactions were not significant for these parameters. Hybrid × temperature interactions were significant for dry matter partitioning and the fluorescence parameter Fv/Fm, suggesting better low-temperature tolerance for Pride 5. Results of the short-term temperature study showed a significant hybrid × temperature interaction for dry matter accumulation, with Pride 5 higher than Pioneer 3902 at the low temperature regime and Pride 5 lower than Pioneer 3902 at the high temperature regime. Results of these experiments suggest that improvement over the past 30 yr of Ontario maize hybrids is not associated with improved low-temperature tolerance during early development. Key words: Maize, low-temperature tolerance, dry matter accumulation, dry matter partitioning, photosynthesis, chlorophyll fluorescence

Thermal Adaptation of Pennisetum: Leaf Structure and Composition

1977 ◽  
Vol 4 (4) ◽  
pp. 541 ◽  
Author(s):  
CJ Pearson ◽  
DG Bishop ◽  
M Vesk
Keyword(s):  
Low Temperature ◽  
Temperature Sensitivity ◽  
Thermal Adaptation ◽  
Chloroplast Ultrastructure ◽  
Lipid Phase ◽  
Genotypic Differences ◽  
Lipid Phase Transitions ◽  
Chlorophyll Accumulation ◽  
Chlorophyll Distribution ◽  
Lower Temperature

Studies were made of the effects of growth temperatures and transition to colder temperature on chloroplast ultrastructure, chlorophyll accumulation, lipids and protein of two Pennisetum americanum cultivars and a P. americanum × P. purpureum biotype which differed in temperature sensitivity. All genotypes had structure and chlorophyll distribution consistent with NADP-malic enzyme C4 systems and lipid phase transitions at temperatures similar to those of other 'chilling-sensitive' plants. All accumulated less starch at low temperature and there was mobilization of starch, aggregation of thylakoids in mesophyll chloroplasts and swelling of loculi on transition from 24/19 to 18/13°C. Intolerance of Pennisetum to low temperature was clearly not due to accumulation of starch, nor were genotypic differences in temperature sensitivity related to starch. The cold susceptibility of cv. Ingrid Pearl, in contrast with the tolerance of the intraspecific and interspecific hybrids, was associated with inability to accumulate chlorophyll in the mesophyll of some leaves; fluctuations in chlorophyll a/b ratios within 5 days of transition to lower temperature; and inability to accumulate higher concentrations of soluble proteins in apparently normal leaves grown at 18/13°C. Genotypic differences in temperature sensitivity did not appear related to the physical properties of membranes, which did not change within 5 days of transition to 18/13°C.

Purification Effect of Lolium multiflorum Ecological Floating Beds System in Urban Malodorous River at Low Temperature

2012 ◽  
Vol 518-523 ◽  
pp. 2686-2689
Author(s):  
Yu Hong Chai ◽  
Wen Yao Yan ◽  
Ming Xin Wang
Keyword(s):  
Low Temperature ◽  
Chemical Oxygen Demand ◽  
Total Nitrogen ◽  
Growth Rates ◽  
Low Temperatures ◽  
Lolium Multiflorum ◽  
Oxygen Demand ◽  
Total Biomass ◽  
Water Plant ◽  
Natural Rivers

An ecological floating beds system was constructed to treat natural urban malodorous river in Changzhou at low temperature. Taking Lolium multiflorum as an example of water plant, the characteristics and contribution of its uptake to total nitrogen (TN), NH4+-N, total phosphorus (TP) and chemical oxygen demand (CODMn) in the system were studied in a period of 80 days. Significant growth of the plant Lolium multiflorum was observed with total biomass ranging from 53 g to 785 g, and the highest growth rates were 8.82 and 9.23 for biomass of above water and under water part, respectively. Different concentrations of TN, NH4+-N, TP and COD were found between in the floating beds and out the floating beds. The highest removal rates of TN, NH4+-N, TP and CODMn using Lolium multiflorum ecological floating beds system were 16.8%, 33.0%,10.8% and 17.8%, respectively. The purification effect of ecological floating beds shows it can be well applied to cleaning natural rivers at low temperatures.

Ge Epitaxy on (100) Ge: High Growth Rates at Low Temperature from GeH4 using N2 as a Carrier Gas

2019 ◽  
Vol 3 (7) ◽  
pp. 209-210 ◽  
Author(s):  
Frederik Leys ◽  
Renaud Bonzom ◽  
Roger Loo ◽  
Antoon Theuwis ◽  
Wilfried Vandervorst ◽  
...  
Keyword(s):  
Low Temperature ◽  
Growth Rates ◽  
High Growth ◽  
Carrier Gas

Interrelations in the growth and development of Lolium. I. Some effects of vernalization on growth and development

1965 ◽  
Vol 16 (6) ◽  
pp. 903 ◽  
Author(s):  
JH Silsbury
Keyword(s):  
Low Temperature ◽  
Growth Rates ◽  
Growth And Development ◽  
Growth Curves ◽  
High Growth ◽  
Reproductive Development ◽  
Controlled Environment ◽  
Lolium Rigidum ◽  
Vegetative Phase ◽  
Reproductive Phase

The responses of Lolium rigidum Gaud. and L. perenne L. to low temperature seed vernalization were determined by comparing the growth and development of vernalized and unvernalized plants raised in the field and in a controlled environment cabinet. Vernalization did not appear to influence growth in the vegetative phase, but usually induced earlier heading and a greater proportion of reproductive tillers. Comparisons of vernalized (reproductive) and unvernalized (vegetative) plants show increased reproductive development to be associated with higher growth rates, lower tillering, and greater weight per tiller. High growth rates during the reproductive phase are considered to be due to the ability of reproductive tillers to grow more rapidly than vegetative tillers through the growth of true stem functioning as a "sink" for assimilate. Generalized growth curves for vernalized and unvernalized ryegrass grown under long days are presented and discussed.

Novel Antimony Precursors for Low-Temperature CVD of Antimonide Thin Films

1997 ◽  
Vol 495 ◽  
Author(s):  
Michael A. Todd ◽  
Gautam Bhandari ◽  
T. H. Baum
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Growth Rates ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Lewis Base ◽  
Stable Carbon ◽  
Deuterium Substitution

ABSTRACTVolatile antimony precursors were synthesized for the low temperature chemical vapor deposition (CVD) of antimony thin films. The molecules synthesized include tris (trifluoromethyl)stibine, Sb(CF3)3, Lewis base adducts of Sb(CF3)3, and antimony trihydride (stibine), SbH3. Isotopie substitution of stibine with deuterium leads to a more thermally stable, carbon-free antimony source. Similarly, deuterium substitution of trimethylsilylmethyl antimony dihydride leads to a stabilized liquid antimony precursor. The molecules were characterized using FTIR, NMR and DSC / TGA. Pure antimony films were deposited at temperatures below 300 °C with growth rates approaching 170 Å / min using a low pressure hot-wall CVD reactor. The films were characterized using XRD, EDS, SEM and AFM.

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