Seed production, mass, germinability, and subsequent seedling growth responses to parental warming environment in Leymus chinensis

2012 ◽  
Vol 63 (1) ◽  
pp. 87 ◽  
Author(s):  
Song Gao ◽  
Junfeng Wang ◽  
Zhijing Zhang ◽  
Gang Dong ◽  
Jixun Guo
Keyword(s):  
Global Warming ◽  
Seed Production ◽  
Seedling Growth ◽  
Elevated Temperatures ◽  
Leymus Chinensis ◽  
Light Weight ◽  
Growth Responses ◽  
Heavy Weight ◽  
Increasing Temperature ◽  
Germinating Seeds

Understanding how the seed yield and seed quality respond to global warming is crucial for understanding how new grassland establishment responds to global change. This study evaluated Leymus chinensis, a dominant perennial grass widely distributed in the eastern regions of the Eurasian grassland zone, as a model to investigate the effect of increasing ambient temperature on seed production, seed mass, germinability, and subsequent seedling growth. As the temperature rose, there were significant reductions in the number of flowering plants and in seed number per square metre but significant increase in the number of florets and the number of seeds per plant. Increasing temperature decreased the proportion of light weight seeds, increased the proportion of heavy weight seeds and led to a significant increase in the mean dry weight. Germination success, germination rate and the root : shoot ratio of light weight seeds were reduced, while heavy weight seed did not appear to be affected by elevated temperatures. Finally, germinating seeds per unit area was reduced by increased temperature. The reduction in the number of germinating seeds with increasing temperature implies that continued global warming will further constrain new grassland establishment of L. chinensis in the eastern regions of Eurasia.

scholarly journals Strengthening epoxy adhesives at elevated temperatures based on dynamic disulfide bonds

2020 ◽  
Vol 1 (9) ◽  
pp. 3182-3188
Author(s):  
Hsing-Ying Tsai ◽  
Yasuyuki Nakamura ◽  
Takehiro Fujita ◽  
Masanobu Naito
Keyword(s):  
Glass Transition ◽  
Disulfide Bonds ◽  
Epoxy Resins ◽  
Elevated Temperatures ◽  
Adhesive Properties ◽  
Epoxy Adhesives ◽  
Transition Points ◽  
Increasing Temperature

Epoxy resins incorporating aromatic disulfide bonds demonstrated improved adhesive properties with increasing temperature below their glass transition points.

Tensile Properties of Low Nickel Austenitic Stainless Steel at Elevated Temperatures

2012 ◽  
Vol 159 ◽  
pp. 346-350
Author(s):  
Shu Min Liu ◽  
Jian Bin Zhang
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Elevated Temperatures ◽  
Peak Stress ◽  
Temperature Curve ◽  
Delta Ferrite ◽  
Cross Sectional ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Reduction Percentage

The elevated temperature short-time tensile test with the sample of casting low nickel stainless steel was conducted on SHIMADZU AG-10 at ten temperatures 300, 500, 600, 700, 800, 950, 1000, 1050, 1100, and 1250°C, respectively. The stress-strain curves with the thermal deformation at the different temperatures, the peak stress intensity-temperature curve, and the reduction percentage of cross sectional area-temperature curve were obtained. Metallographic test samples were prepared and the morphology of deforming zone was observed by optical microscopy. The experimental results show that the tensile strength of the test samples decreases with increasing temperature. From 300 to 800°C, the work harding occurred and the tensile strength increases with increasing strain. The work softening occurred and the tensile strength decreases with increasing strain at temperatures of 800 to 1250°C. The minimum value of reduction percentage was measured at 800 °C. The austenite and delta-ferrite are the main phase in the tested samples. When the tensile temperatures are increased to 1200°C, the delta-ferrite became thinner and broke down to be spheroidized.

Growth responses of Leymus chinensis (Trin.) Tzvelev to sheep saliva after defoliation

2010 ◽  
Vol 32 (4) ◽  
pp. 419 ◽  
Author(s):  
Xing Teng ◽  
Lei Ba ◽  
Deli Wang ◽  
Ling Wang ◽  
Jushan Liu
Keyword(s):  
Plant Growth ◽  
Aboveground Biomass ◽  
Field Experiments ◽  
Perennial Grass ◽  
Leaf Length ◽  
Leymus Chinensis ◽  
Growth Responses ◽  
Time Duration ◽  
Positive Effects ◽  
Leaf Weight

Many studies indicated that saliva from herbivores might be involved in plant growth responses when plants have been grazed. However, there is currently no general agreement on whether saliva can affect plant growth. Our aims were to determine the growth response of plants to sheep saliva after defoliation under diverse environmental conditions (different sward structures), and whether the effect of saliva is influenced by time (duration) after its application. We conducted field experiments with clipping treatments and the application of sheep saliva to the damaged parts of tillers to simulate sheep grazing on the perennial grass Leymus chinensis (Trin.) Tzvelev during the early growing seasons. Results demonstrated that clipping with saliva application significantly increased tiller numbers 8 weeks after treatments in comparison with clipping alone. A key finding is that the effect of sheep saliva on plant growth was short-lived. Clipping with saliva application increased leaf weight in the second week, while clipping alone had no effect. Moreover, clipping with saliva application promoted the elongation of new leaves (not the old ones) in the first week whereas clipping alone was ineffective. Results also showed that there were no differences between clipping with saliva application and clipping alone for relative height growth rate and aboveground biomass. Therefore, we concluded that saliva application to clipping treatment would produce an additional effect compared to clipping alone for the plant and the positive effects are time dependent. The additional effects primarily embodied in the individual level of plant, such as the changes of leaf weight and leaf length. Beyond the level, the effects of saliva only produced many more tiller numbers rather than the accumulation of aboveground biomass.

A Brief Overview on High Temperature Friction and Wear

2010 ◽  
Author(s):  
Mustafa Bulut Coskun ◽  
Mahmut Faruk Aksit
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Friction And Wear ◽  
Oxidation Behavior ◽  
Elevated Temperatures ◽  
Wear Performance ◽  
Large Pressure ◽  
Higher Power ◽  
Vibratory Motion ◽  
Increasing Temperature

With the race for higher power and efficiency new gas turbines operate at ever increasing pressures and temperatures. Increased compression ratios and firing temperatures require many engine parts to survive extended service hours under large pressure loads and thermal distortions while sustaining relative vibratory motion. On the other hand, wear at elevated temperatures limits part life. Combined with rapid oxidation for most materials wear resistance reduces rapidly with increasing temperature. In order to achieve improved wear performance at elevated temperatures better understanding of combined wear and oxidation behavior of high temperature super alloys and coatings needed. In an attempt to aid designers for high temperature applications, this work provides a quick reference for the high temperature friction and wear research available in open literature. High temperature friction and wear data have been collected, grouped and summarized in tables.

The High Temperature Deformation Behavior of A Cr2Nb Ordered Intermetallic System

1990 ◽  
Vol 213 ◽  
Author(s):  
G. E. Vignoul ◽  
J.M. Sanchez ◽  
J. K. Tien
Keyword(s):  
Deformation Behavior ◽  
Elevated Temperatures ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Deformation Law ◽  
Ordered Intermetallic ◽  
Intermetallic System ◽  
Increasing Temperature ◽  
Stress Term

ABSTRACTA basic characterization of the deformation behavior of Cr2Nb by microindention at ambient and elevated temperatures (up to 1400 °C) was undertaken. The microhardness of this system was seen to decrease with increasing temperature, from 1040 MPa at 25°C to 322 MPa at 1400 °C. Further, the microindention creep behavior of this system was studied by varying time on load at T = 1000 and 1200°C. Analysis of the data showed that m = 24 and Qapp = 477.61 kJ/mole. These unusually high values are indicative of the existence of an effective resisting stress against creep. When the data was fit against a microindention creep deformation law which was modified to incorporate an effective resisting stress term, it was determined that m = 4.5, Qcreep = 357 kJ/mole and the resisting stress term σr = 300 MPa.

scholarly journals Effects of storage period and egg weight of Japanese quail eggs on hatching results (short communication)

2005 ◽  
Vol 48 (5) ◽  
pp. 518-526
Author(s):  
I. Seker ◽  
S. Kul ◽  
M. Bayraktar
Keyword(s):  
Storage Period ◽  
Fertility Rate ◽  
Embryonic Mortality ◽  
Light Weight ◽  
Egg Weight ◽  
Heavy Weight ◽  
Japanese Quails ◽  
Early Embryonic Mortality ◽  
Hatching Eggs ◽  
Weight Groups

Abstract. This study was undertaken to determine the effects of storage period and egg weight of hatching eggs of Japanese quails on fertility, hatchability results. Eggs were obtained 150 females quails, all at 15 weeks of age. A total of 1942 hatching eggs were separated into 3 groups as light-weight (9.50-10.50 g), medium-weight (10.51-11.50 g), and heavy-weight (11.51-12.50 g). Based on storage period, eggs were divided into 5 groups as group 1 (0-3 days), group 2 (4-6 days), group 3 (7-9 days), group 4 (10-12 days), and group 5 (13-15 days). The influence of storage period on hatchability of fertile eggs and early, middle, and late period embryonic mortality rates was found significant (P<0.01). The effect of egg weight on fertility rate, hatchability of fertile eggs and early embryonic mortality was significant (P<0.05, P<0.01). The significant differences between storage period groups were observed in hatchability of fertile eggs. The differences between egg weight groups for fertility rate, hatchability of fertile eggs and early embryonic mortality was significantly higher in light weight group than the other egg weight groups. Results of this study concluded that a 12 day pre-incubation storage of hatching eggs of Japanese quails did not appreciably affect hatching parameters. Use of medium or heavy weight eggs for hatching may reduce early embryonic mortality rate.

Dose-Dependent Effects of the Action of Sulfur Nanoparticles on the Growth Response and Seed Production of Typical Steppe Phytocenoses

2017 ◽  
Vol 13 ◽  
pp. 156-161 ◽  
Author(s):  
Zinaida N. Ryabinina ◽  
Marija V. Ryabukhina ◽  
Maya V. Kolodina
Keyword(s):  
Seed Production ◽  
Biochemical Parameters ◽  
Growth Response ◽  
Growth Responses ◽  
Seed Productivity ◽  
Typical Steppe ◽  
Forms Of Life ◽  
Dose Dependent ◽  
Biological Group ◽  
Sulfur Nanoparticles

The article presents the results of a study of typical steppe phytocenoses presented one ecological and biological group - xeromesophyte but different systematic affiliation and forms of life, to the action of sulfur nanoparticles. Results of the study showed a relationship between the concentrations of sulfur nanoparticles and growth responses, biochemical parameters and seed productivity of investigated species

INTERACTION OF TEMPERATURE AND CO2 ENRICHMENT ON SOYBEAN: GROWTH AND DRY MATTER PARTITIONING

1987 ◽  
Vol 67 (1) ◽  
pp. 59-67 ◽  
Author(s):  
NASSER SIONIT ◽  
B. R. STRAIN ◽  
E. P. FLINT
Keyword(s):  
Low Temperature ◽  
Environmental Control ◽  
Weight Ratio ◽  
Controlled Environment ◽  
Plant Responses ◽  
Growth Responses ◽  
Dry Matter Partitioning ◽  
Leaf Weight ◽  
Temperature Regimes ◽  
Increasing Temperature

Projected increases in atmospheric CO2 concentration will affect growth and productivity of many plant species under various environmental conditions. Since these increases in CO2 may also increase mean annual temperatures, it is important to determine how the soybean (Glycine max (L.) Merr.) will respond to changes in temperature regimes associated with atmospheric CO2 enrichment. Morphology and growth responses of the Ransom cultivar, which is adapted to a southern U.S.A. climate, to day/night temperature regimes of 18/12, 22/16, and 26/20 °C and atmospheric CO2 concentrations of 350, 675 and 1000 μL L−1 were studied in controlled environment chambers. Plant responses were determined at 20, 40, 67 and 115 (late senescence to maturity) days after planting. Plant height and number of branches increased slightly with CO2 enrichment and more significantly with increasing temperature. Root to shoot ratio remained unchanged at different CO2 concentrations but decreased as temperature increased. Leaf weight ratio and specific leaf weight decreased with increasing temperature. Low temperature reduced dry weight of all plant parts, but the reduction was ameliorated by increasing atmospheric CO2 concentration. The results show that increasing the atmospheric CO2 level causes soybean to grow more vigorously at low temperatures. Although controlled environment experiments have their drawbacks in regard to natural field conditions, the present data indicate that soybean will have enhanced growth even at moderately cool temperatures in the future global CO2 concentrations.Key words: Soybean growth, low temperature, CO2 × temperature interaction, environmental control

Seedling Growth Responses of Buffelgrass (Pennisetum ciliare) to Tebuthiuron and Honey Mesquite (Prosopis glandulosa)

Weed Science ◽  
1986 ◽  
Vol 34 (1) ◽  
pp. 88-93 ◽  
Author(s):  
G. Allen Rasmussen ◽  
Roger P. Smith ◽  
Charles J. Scifres
Keyword(s):  
Seedling Growth ◽  
Woody Plants ◽  
Prosopis Glandulosa ◽  
Average Height ◽  
Growth Responses ◽  
Soil Columns ◽  
Pennisetum Ciliare ◽  
Shoot Weight ◽  
Soil Changes ◽  
Honey Mesquite

Tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} at 2 or 4 ppmw placed 0 to 3, 8 to 11, or 15 to 18 cm deep in soil columns reduced root and shoot weights of buffelgrass [Pennisetum ciliare(L.) Link # PESCI] 30 days after emergence. Plains bristlegrass (Setaria macrostachyaH.B.K.) seedling shoot weights were not reduced when 2 ppmw tebuthiuron was placed 8 to 11 cm deep or deeper. Effects of tebuthiuron at 0.13 to 0.50 ppmw on buffelgrass shoot and net tiller production were not moderated by the presence of honey mesquite (Prosopis glandulosa# PRCJG) in the pots. However, regardless of tebuthiuron dosage, average height and shoot weight of buffelgrass seedlings were greater when seedlings were grown in soil collected from beneath honey mesquite canopies compared to growth in soil from interspaces. Therefore, spatial variations in buffelgrass response to applications of tebuthiuron for control of invading shrubs may largely be attributed to soil changes induced by woody plants rather than to presence of shrubs.

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