Influence of time of sowing, photoperiod, and temperature on supernumerary spikelet expression in wheat (Triticum)

1984 ◽  
Vol 62 (8) ◽  
pp. 1687-1692 ◽  
Author(s):  
Annabel L. Pennell ◽  
G. M. Halloran
Keyword(s):  
Low Temperature ◽  
Triticum Turgidum ◽  
Triticum Aestivum L ◽  
Vernalization Response ◽  
Spikelet Number ◽  
Grain Number ◽  
Temperature Regimes ◽  
Temperature Environment ◽  
Long Photoperiod ◽  
Supernumerary Spikelets

Three tetraploid (Triticum turgidum L. emend, gr. turgidum and gr. durum) and six hexaploid wheats (Triticum × aestivum L. emend aestivum) with reported tendencies for "branched" heads (supernumerary spikelets) exhibited variation for this character when grown under different photoperiod and temperature regimes. Wheats with a weak vernalization response under short photoperiod in an outdoor (low temperature) environment and those with a strong vernalization response under a long-photoperiod outdoor (low temperature) environment developed more supernumerary spikelets than under other photoperiods and temperatures. There was a variation among the nine wheats in the level and stability of supernumerary spikelet expression and in their fertility and grain number per head over the different times of sowing. This indicates the feasibility for selecting high and stable expression of supernumerary spikelets in breeding to increase spikelet number per head in wheat.

scholarly journals Relationship between low-temperature tolerance and vernalization response in wheat and rye

1996 ◽  
Vol 76 (1) ◽  
pp. 37-42 ◽  
Author(s):  
D. B. Fowler ◽  
A. E. Limin ◽  
Shi-Ying Wang ◽  
R. W. Ward
Keyword(s):  
Low Temperature ◽  
Cold Hardiness ◽  
Triticum Aestivum L ◽  
Temperature Tolerance ◽  
Temperature Acclimation ◽  
Rate Of Change ◽  
Curvilinear Relationship ◽  
Vernalization Response ◽  
Low Temperature Tolerance ◽  
Winter Cereals

Vernalization response and low-temperature acclimation are survival mechanisms that cereals have evolved to cope with low-temperature stress. Both responses have similar optimum temperature ranges for induction, and they are controlled by genetic systems that are interrelated. It has also been suggested that the completion of vernalization is responsible for the gradual loss in low-temperature tolerance observed in winter cereals maintained for long periods of time at temperatures in the optimum range for low-temperature acclimation. In the present study, two experiments were conducted with the objective of clarifying the relationship between vernalization response and low-temperature tolerance in wheat (Triticum aestivum L.) and rye (Secale cereale L.). The plants of all cultivars began to low-temperature acclimate at a rapid rate when exposed to a constant 4 °C. The rate of change in low-temperature tolerance then gradually slowed and eventually started to decline, producing a curvilinear relationship between low-temperature tolerance and stage of acclimation. A close relationship was observed between the time to vernalization saturation and the start of the decline in low-temperature tolerance of cultivars held at 4 °C. However, cereal plants retained at least a partial ability to low-temperature acclimate following exposure to warm temperatures after vernalization saturation, indicating that vernalization saturation does not result in a "switching off" of the low-temperature tolerance genes. The possibility that vernalization genes have a more subtle regulatory role in the expression of low-temperature tolerance genes could not be ruled out, and future avenues for investigation are discussed. Key words: Cold hardiness, winter hardiness, cold resistance, low-temperature acclimation, deacclimation, vernalization, wheat, rye

Developmental responses in tetraploid wheat (Triticum turgidum)

1983 ◽  
Vol 61 (10) ◽  
pp. 2539-2545 ◽  
Author(s):  
R. G. Flood ◽  
G. M. Halloran
Keyword(s):  
Triticum Aestivum ◽  
Genetic Control ◽  
Hexaploid Wheat ◽  
Triticum Turgidum ◽  
Tetraploid Wheat ◽  
Photoperiod Sensitivity ◽  
Vernalization Response ◽  
Spikelet Number ◽  
Photoperiod Insensitivity ◽  
Developmental Responses

Nineteen lines of tetraploid wheat (Triticum turgidum) were examined for the presence and strength of developmental responses in the field during 1980 and 1981 and compared with lines of known vernalization and photoperiod responses in the hexaploid wheat (Triticum aestivum). Five of them had stronger vernalization responses than the winter habit hexaploid line cv. Triple Dirk C. Strong vernalization response of the tetraploids was usually associated with photoperiod insensitivity and vice versa although several lines had a combination of high photoperiod sensitivity and moderate levels of vernalization response. Compared with hexaploids the tetraploids exhibited much more variation in spikelet number per head following vernalization treatment which was less marked in some of the domesticated lines. Speculations are made on the genetic control of vernalization response in tetraploid wheat and the possible significance of greater stability in the expression of spikelet number in the evolution of wheat.

scholarly journals Research on Performance Test System of Space Harmonic Reducer in High Vacuum and Low Temperature Environment

Machines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Jing Wang ◽  
Zhihua Wan ◽  
Zhurong Dong ◽  
Zhengguo Li
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Performance Test ◽  
High Reliability ◽  
High Vacuum ◽  
Test System ◽  
Low Noise ◽  
Speed Ratio ◽  
Space Harmonic ◽  
Temperature Environment

The harmonic reducer, with its advantages of high precision, low noise, light weight, and high speed ratio, has been widely used in aerospace solar wing deployment mechanisms, antenna pointing mechanisms, robot joints, and other precision transmission fields. Accurately predicting the performance of the harmonic reducer under various application conditions is of great significance to the high reliability and long life of the harmonic reducer. In this paper, a set of automatic harmonic reducer performance test systems is designed. By using the CANOpen bus interface to control the servo motor as the drive motor, through accurately controlling the motor speed and rotation angle, collecting the angle, torque, and current in real time, the life cycle test of space harmonic reducer was carried out in high vacuum and low temperature environment on the ground. Then, the collected data were automatically analyzed and calculated. The test data of the transmission accuracy, backlash, and transmission efficiency of the space harmonic reducer were obtained. It is proven by experiments that the performance data of the harmonic reducer in space work can be more accurately obtained by using the test system mentioned in this paper, which is convenient for further research on related lubricating materials.

scholarly journals Biosolids Benefit Yield and Nitrogen Uptake in Winter Cereals without Excess Risk of N Leaching

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1482
Author(s):  
Silvia Pampana ◽  
Alessandro Rossi ◽  
Iduna Arduini
Keyword(s):  
Triticum Turgidum ◽  
N Uptake ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
N Leaching ◽  
Specific Rate ◽  
Mineral Fertilization ◽  
Hordeum Vulgare L ◽  
Mineral N ◽  
Winter Cereals

Winter cereals are excellent candidates for biosolid application because their nitrogen (N) requirement is high, they are broadly cultivated, and their deep root system efficiently takes up mineral N. However, potential N leaching from BS application can occur in Mediterranean soils. A two-year study was conducted to determine how biosolids affect biomass and grain yield as well as N uptake and N leaching in barley (Hordeum vulgare L.), common wheat (Triticum aestivum L.), durum wheat (Triticum turgidum L. var. durum), and oat (Avena byzantina C. Koch). Cereals were fertilized at rates of 5, 10, and 15 Mg ha−1 dry weight (called B5, B10, and B15, respectively) of biosolids (BS). Mineral-fertilized (MF) and unfertilized (C) controls were included. Overall, results highlight that BS are valuable fertilizers for winter cereals as these showed higher yields with BS as compared to control. Nevertheless, whether 5 Mg ha−1 of biosolids could replace mineral fertilization still depended on the particular cereal due to the different yield physiology of the crops. Moreover, nitrate leaching from B5 was comparable to MF, and B15 increased the risk by less than 30 N-NO3 kg ha−1. We therefore concluded that with specific rate settings, biosolid application can sustain yields of winter cereals without significant additional N leaching as compared to MF.

scholarly journals Analysis of Mechanical Properties and Mechanism of Natural Rubber Waterstop after Aging in Low-Temperature Environment

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2119
Author(s):  
Lin Yu ◽  
Shiman Liu ◽  
Weiwei Yang ◽  
Mengying Liu
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Energy Dispersive Spectrometry ◽  
Permanent Deformation ◽  
Test Chamber ◽  
Accelerate Aging ◽  
Aging Mechanism ◽  
Temperature Environment ◽  
Freezing Test ◽  
Temperature Water

In order to elucidate the aging performance and aging mechanism of a rubber waterstop in low-temperature environments, the rubber waterstops were placed in the freezing test chamber to accelerate aging, and then we tested its tensile strength, elongation, tear strength, compression permanent deformation and hardness at different times. Additionally, the damaged specimens were tested by scanning electron microscope, Fourier transform infrared spectroscopy and energy dispersive spectrometry. The results showed that with the growth of aging time, the mechanical properties of the rubber waterstop are reduced. At the same time, many protrusions appeared on the surface of the rubber waterstop, the C element gradually decreased, and the O element gradually increased. During the period of 72–90 days, the content of the C element in the low-temperature air environment significantly decreased compared with that in low-temperature water, while the content of O element increased significantly.

scholarly journals Experimental Study of Low Temperature Performance of Porous Asphalt Mixture

2021 ◽  
Vol 11 (9) ◽  
pp. 4029
Author(s):  
Jian Wang ◽  
Pui-Lam Ng ◽  
Yuhua Gong ◽  
Han Su ◽  
Jinsheng Du
Keyword(s):  
Low Temperature ◽  
Test Temperature ◽  
Asphalt Mixture ◽  
Aging Condition ◽  
Porous Asphalt ◽  
Bending Strain ◽  
Temperature Performance ◽  
Temperature Environment ◽  
Modifier Content ◽  
Low Temperature Performance

Porous asphalt mixture can be used as a road surface paving material with the remarkable advantage to prevent water accumulation and ponding. However, the performance of porous asphalt mixture in low temperature environment has not been thoroughly investigated, and this forms the subject of research in the present study. The mineral aggregate gradation of porous asphalt mixture was designed based on Bailey method, and the low temperature performance of porous asphalt mixture was studied by means of the low temperature bending test. The factors affecting the low temperature performance of porous asphalt mixture were analyzed through the orthogonal experimental design method, and the effects of porosity, modifier content, aging condition, and test temperature on the low temperature performance of porous asphalt mixture were evaluated. The results showed that the modifier content was the most important factor affecting the low temperature performance of porous asphalt mixture, followed by the test temperature, while the porosity and the aging condition were the least. Among the three performance evaluation indicators, namely the flexural tensile strength, maximum bending strain, and bending stiffness modulus, the maximum bending strain had the highest sensitivity to the porosity. It can be seen from the single factor influence test of porosity that there existed an approximately linear relationship between the maximum bending strain and the porosity of porous asphalt mixture, and the maximum bending strain decreased with increasing porosity. Furthermore, in order to ensure the good working performance of porous asphalt mixture in low temperature environment, the porosity should also satisfy the required limits of the maximum bending strain.

A low-temperature, environment-friendly approach to the synthesis of magnesium borates using magnesium waste scraps

2015 ◽  
Vol 0 (0) ◽  
Author(s):  
Aycin Kaplan ◽  
Azmi Seyhun Kipcak ◽  
Fatma Tugce Senberber ◽  
Emek Moroydor Derun ◽  
Sabriye Piskin
Keyword(s):  
Low Temperature ◽  
Boric Acid ◽  
Boron Oxide ◽  
X Ray Diffraction ◽  
Magnesium Borate ◽  
Environment Friendly ◽  
X Ray ◽  
Temperature Environment ◽  
Mixing Method ◽  
Boron Source

AbstractIn the present study, magnesium borate synthesis was performed by a hydrothermal mixing method, with the use of magnesium waste scraps (W) as the magnesium source, along with boric acid (H) or boron oxide (B) as the boron source. For an environment-friendly approach, a solid waste of magnesium was used at low reaction temperatures. Results of X-ray diffraction analyses showed that admontite [MgO(B

A Study on Behavior of Dust Cover Under Low Temperature Environment

2012 ◽  
Author(s):  
Tatsuro Hosen ◽  
Tadahisa Yamabe ◽  
Shin Ito ◽  
Naoki Matsumoto ◽  
Kenichi Uchida ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Environment

Deposition of pyrocarbon in a low temperature environment

1986 ◽  
Vol 4 (3) ◽  
pp. 375-378 ◽  
Author(s):  
A. Inspektor ◽  
U. Carmi ◽  
A. Raveh ◽  
Y. Khait ◽  
R. Avni
Keyword(s):  
Low Temperature ◽  
Temperature Environment
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