Influence of Temperature Regimes and Water Stress on the Germination of Three Range Grasses and its Possible Ecological Significance to a Shortgrass Prairie

1975 ◽  
Vol 12 (1) ◽  
pp. 153 ◽  
Author(s):  
U. G. Bokhari ◽  
J. S. Singh ◽  
F. M. Smith
Keyword(s):  
Water Stress ◽  
Ecological Significance ◽  
Influence Of Temperature ◽  
Temperature Regimes ◽  
Shortgrass Prairie ◽  
Range Grasses

Sucrose accumulation in sugarcane is influenced by temperature and genotype through the carbon source - sink balance

2010 ◽  
Vol 61 (2) ◽  
pp. 111 ◽  
Author(s):  
N. G. Inman-Bamber ◽  
G. D. Bonnett ◽  
M. F. Spillman ◽  
M. H. Hewitt ◽  
D. Glassop
Keyword(s):  
Water Stress ◽  
Molecular Techniques ◽  
Clonal Variation ◽  
Sink Strength ◽  
Extension Rate ◽  
Cool Temperature ◽  
Sucrose Accumulation ◽  
Temperature Regimes ◽  
New Research ◽  
Source Sink

While substantial effort has been expended on molecular techniques in an attempt to break through the apparent ceiling for sucrose content (SC) in sugarcane stalks, molecular processes and genetics limiting sucrose accumulation remain unclear. Our own studies indicate that limiting expansive growth with water stress will enhance sucrose accumulation in both low- and high-sucrose clones. Sucrose accumulation was largely explained (72%) by an equation with terms for photosynthesis, plant extension rate (PER), and plant number. New research was conducted to determine if this simple model stands when using temperature rather than water stress to perturb the source–sink balance. We also applied a thinning treatment to test the proposal implicit in this equation that SC will increase if competition between plants for photo-assimilate is reduced. Four clones from a segregating population representing extremes in SC were planted in pots and subjected to warm and cool temperature regimes in a glasshouse facility. A thinning treatment was imposed on half the pots by removing all but 6 shoots per pot. Temperature as a means of reducing sink strength seemed initially to be more successful than water regime because PER was 43% lower in the cool than in the hot regime while photosynthesis was only 14% less. PER was a good indicator of dry matter allocation to expansive growth, limited by water stress but not by temperature, because stalks tended to thicken in low temperature. Thinning had little effect on any of the attributes measured. Nevertheless the clonal variation in plant numbers and the response of PER to temperature helped to explain at least 69% of the variation in sucrose accumulation observed in this experiment. Thus the earlier model for sucrose accumulation appeared to be valid for the effect on sucrose accumulation of both temperature and water stress on the source–sink balance. The next step is to include internodes in models of assimilate partitioning to help understand the limiting steps in sucrose accumulation from the basics of source–sink dynamics.

The effect of high temperature regimes or short periods of water stress on development of small fruiting saltana vines

1965 ◽  
Vol 16 (5) ◽  
pp. 817 ◽  
Author(s):  
D McEAlexander
Keyword(s):  
High Temperature ◽  
Water Stress ◽  
Shoot Growth ◽  
Fruit Set ◽  
Shoot Elongation ◽  
Night Temperature ◽  
Applied Water ◽  
Temperature Regimes ◽  
Controlled Environments ◽  
Maximum Temperatures

Poor fruit set of sultanas in the Murray Valley is sometimes attributed to excessively high temperatures around flowering time. Experiments with small fruiting sultana vines in pots suggest that water stress is the more important factor. Fruit set was significantly less when a 3-day period of water stress was imposed at flowering or 1, 2, or 4 weeks after flowering, but not when it was imposed 6 weeks after flowering. Three days with maximum temperatures above 45°C at or 1 week after flowering did not reduce fruit set when ample water was supplied. When controlled environments combining day temperatures between 21 and 30°C with night temperatures between 19 and 25° were used, no significant differences in fruit set were found, although shoot growth increased with increasing night temperature. Shoot elongation slowed down during periods of applied water stress but recovered, when the stress was ended, to a rate greater than that of plants which had not been stressed.

Influence of Temperature on Population Development of Two Color Morphs of the Tobacco Aphid (Homoptera: Aphididae) on Flue-Cured Tobacco

1991 ◽  
Vol 26 (1) ◽  
pp. 33-38 ◽  
Author(s):  
T. David Reed ◽  
Paul J. Semtner
Keyword(s):  
Growth Parameters ◽  
Reproductive Age ◽  
Population Development ◽  
Influence Of Temperature ◽  
Temperature Regimes ◽  
Color Morphs ◽  
Myzus Nicotianae ◽  
Influence Of Temperature On ◽  
Population Growth Parameters ◽  
Tobacco Aphid

Tests were conducted at seven constant temperature regimes in controlled environmental chambers to compare population growth parameters of red and green morphs of the tobacco aphid, Myzus nicotianae Blackman. The optimal temperature for population development of both color morphs was 25°C. At 25°C and above, the red morph had three advantages over the green; most striking was the ability to survive to reproductive age. The red morph also developed faster and was more fecund than the green. Although neither morph reproduced at 32°C, longevity of the red morph was 120% greater. Results of this study may help to explain the disproportionate development of populations of the red morph in the field.

Water stress, temperature regimes and light control induction, and loss of secondary dormancy in Brassica napus L. seeds

2017 ◽  
Vol 27 (3) ◽  
pp. 217-230 ◽  
Author(s):  
Elias Soltani ◽  
Sabine Gruber ◽  
Mostafa Oveisi ◽  
Nader Salehi ◽  
Iraj Alahdadi ◽  
...  
Keyword(s):  
Water Stress ◽  
Brassica Napus ◽  
High Potential ◽  
Brassica Napus L ◽  
Genetic Potential ◽  
Secondary Dormancy ◽  
Temperature Regimes ◽  
Depth Of Burial ◽  
Dormancy Induction ◽  
Medium Potential

AbstractThis study investigated the induction and loss of dormancy in oilseed rape (Brassica napus). Twenty genotypes were preliminary screened; from these, two genotypes, RGS003 and Hayola 308, which possess high potential for dormancy induction (HSD) and medium potential to induce secondary dormancy (MSD), were selected. The stratification of seeds at alternating temperatures of 5–30°C (in dark) significantly relieved secondary dormancy, but dormancy was not fully released. The ψb(50) values were −1.05 and −1.06 MPa for the MSD and the HSD before dormancy induction. After inducing dormancy, the ψb(50) values for the MSD and the HSD were increased to −0.59 and −0.01 on day 0 stratification at 20°C. The hydrothermal time (θHT) value was low for one-day stratification for HSD in comparison with other stratification treatments. Water stress can induce dormancy (if the seeds have the genetic potential for secondary dormancy) and warm stratification (in dark) can only reduce the intensity of dormancy. The seeds with a high potential of dormancy induction can overcome dormancy at alternating temperatures and in the presence of light. It can, therefore, be concluded that a portion of seeds can enter the cycle of dormancy ↔ non-dormancy. The secondary dormant seeds of B. napus cannot become non-dormant in darkness, but the level of dormancy may change from maximum (after water stress) to minimum (after warm stratification). It seems that the dormancy imposed by the conditions of deep burial (darkness in combination with water stress and more constant temperatures) might be more important to seed persistence than secondary dormancy induction and release. The dormancy cycle is an important pre-requisite in order to sense the depth of burial and the best time for seed germination.

scholarly journals Transmission of Cyclocoelum mutabile (Digenea) to snails: the influence of temperature on the egg and miracidium

1994 ◽  
Vol 72 (10) ◽  
pp. 1745-1751 ◽  
Author(s):  
Christopher W. McKindsey ◽  
J. Daniel McLaughlin
Keyword(s):  
Hatching Success ◽  
Incubation Temperature ◽  
Transmission Efficiency ◽  
Influence Of Temperature ◽  
Seasonal Transmission ◽  
Temperature Regimes ◽  
Influence Of Temperature On ◽  
Two Peaks

This study examined the survival and hatching dynamics of eggs of the digenean Cyclocoelum mutabile and the survivorship and infectivity of the miracidia under different temperature regimes. Hatching did not occur at or below 12 °C. Hatching success was similar at 14, 16, and 20 °C (69–73%). Two peaks in hatching were seen. Most eggs hatched within 12 h following immersion in water; a smaller hatching peak occurred about 24 h later. Storing eggs at 12 °C for up to 4 weeks prior to raising the incubation temperature to 14 °C had no effect on hatching success. However, hatching success was dependent on the source of the eggs. Between 62 and 71% of the eggs from faeces and 90–98% of the eggs dissected from flukes hatched under the same protocol. Miracidia hatching from eggs stored for 0–7 weeks at 7 °C prior to hatching at 14 °C did not differ in their infectivity to snails (75–86%). The survivorship of miracidia was higher at lower temperatures and when they were obtained from eggs dissected from the fluke. The longer survival and prolonged infectivity of miracidia at lower temperatures produced the highest transmission efficiency at 14 °C. These results are discussed in relation to the seasonal transmission and ecology of the fluke.

INFLUENCE OF TEMPERATURE ON GROWTH OF FROKER OATS FOR FORAGE.: 1. DRY MATTER YIELDS AND GROWTH RATES

1974 ◽  
Vol 54 (4) ◽  
pp. 725-730 ◽  
Author(s):  
DALE SMITH
Keyword(s):  
Growth Rates ◽  
Avena Sativa ◽  
Dry Matter ◽  
The Other ◽  
Night Temperature ◽  
Influence Of Temperature ◽  
Temperature Regimes ◽  
Influence Of Temperature On

Oats (Avena sativa L. cv. Froker) were grown to initial panicle emergence in three day/night temperature regimes; H (32/26 C), W (27/21 C), and C (21/15 C). At initial panicle emergence, some plants were transferred to the other regimes until complete panicle emergence. Plants grown continuously in the W regime reached initial panicle emergence in 34 days and complete panicle emergence in 42 days. These stages were reached about a week later in C regime and about 2 wk later in H regime. As compared with plants retained at one temperature to complete panicle emergence, moving plants at initial panicle emergence from H to W or C, or from C to H or W, decreased time to complete panicle emergence by 4 to 6 days. However, complete panicle emergence was delayed 4 to 5 days when plants were moved from W to C or H. Dry matter yields and growth rates (mg/pot/day) of plants grown continuously in the same regime to initial and to complete panicle emergence were highest, and similar, in the W and C regimes, but were significantly lower in the H. As compared with plants retained at one temperature to complete panicle emergence, changing at initial panicle emergence from H to W or C increased dry matter yields and growth rates at complete panicle emergence, whereas changing from W or C to H decreased these parameters. Yields and growth were changed very little by change from W to C or from C to W.

scholarly journals Impact of water stress under ambient and elevated carbon dioxide across three temperature regimes on soybean canopy gas exchange and productivity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shardendu K. Singh ◽  
Vangimalla R. Reddy ◽  
Mura Jyostna Devi ◽  
Dennis J. Timlin
Keyword(s):  
Water Stress ◽  
Seed Yield ◽  
Plant Traits ◽  
Negative Impact ◽  
Dry Weight ◽  
Dry Mass ◽  
Stress Factors ◽  
Interactive Effects ◽  
Growth And Yield ◽  
Temperature Regimes

AbstractThe present study investigated the interactive effects of three environmental stress factors elevated CO2, temperature, and drought stress on soybean growth and yield. Experiments were conducted in the sunlit, controlled environment Soil–Plant–Atmosphere–Research chambers under two-level of irrigation (WW-well water and WS-water stress-35%WW) and CO2 (aCO2-ambient 400 µmol mol−1 and eCO2-elevated 800 µmol mol−1) and each at the three day/night temperature regimes of 24/18 °C (MLT-moderately low), 28/22 °C (OT-optimum), and 32/26 °C (MHT-moderately high). Results showed the greatest negative impact of WS on plant traits such as canopy photosynthesis (PCnet), total dry weight (TDwt), and seed yield. The decreases in these traits under WS ranged between 40 and 70% averaged across temperature regimes with a greater detrimental impact in plants grown under aCO2 than eCO2. The MHT had an increased PCnet, TDwt, and seed yield primarily under eCO2, with a greater increase under WW than WS conditions. The eCO2 stimulated PCnet, TDwt, and seed yield more under WS than WW. For instance, on average across T regimes, eCO2 stimulated around 25% and 90% dry mass under WW and WS, respectively, relative to aCO2. Overall, eCO2 appears to benefit soybean productivity, at least partially, under WS and the moderately warmer temperature of this study.

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