Factors affecting vegetative growth and the production of perithecia in culture by Ophiobolus graminis. II. Variations in light and temperature

1970 ◽  
Vol 18 (1) ◽  
pp. 11 ◽  
Author(s):  
G Weste
Keyword(s):  
Vegetative Growth ◽  
Unit Area ◽  
Red Light ◽  
Light Period ◽  
Factors Affecting ◽  
Temperature Range ◽  
Temperature Controlled

Sixty-one isolates of O. graminis were shown to be obligate photosporulators. Fertile perithecia developed only when the cultures were exposed to light of between 65 and 360 f.c., with a maximum at 200 f.c. The temperature range for the production of fertile perithecia was between 13 and 24°c, with the optimum at 20°. Studies on the interaction of light and temperature showed that when cultures received sufficient light, temperature controlled perithecial numbers. Light most effective in photosporulation was of wavelengths between 390 and 450 mμ. Red light neither inhibited nor stimulated reproduction. At least 12 hr of illumination was required, and perithecial numbers per unit area increased with increasing light period until the cultures dried out.

Tagesperiodische antagonistische Schwankungen der Blauviolett- und Gelbrot-Empfindlichkeit als Grundlage der photoperiodischen Diapause-Induktion bei Pieris brassicae

1960 ◽  
Vol 15 (4) ◽  
pp. 205-213 ◽  
Author(s):  
Erwin Bünning ◽  
Gabriele Joerrens
Keyword(s):  
Dark Period ◽  
Red Light ◽  
Pieris Brassicae ◽  
Light Period ◽  
Measuring Process ◽  
The Third ◽  
Long Day ◽  
Critical Daylength ◽  
Qualitative Responses ◽  
Short Days

In Pieris brassicae, diapause is inhibited if long-day conditions are imposed during and immediately after the third molting. The critical daylength is approximately 14 hours. Under short-day conditions with a main light period of 6 or 12 hours’ duration, supplementary light given in the period from 14 to 16 hours after the beginning of the main light period will inhibit diapause. In contrast to this effect of late exposures to light, light given from 1 to 12 hours after the beginning of the main light period promotes diapause. Experiments with extremely long light periods (10—35 hours), but always with a dark period of 10 hours, show that these diurnal fluctuations in quantitative and qualitative responses to light can continue endogenously for several days. Thus, this time-measuring process operates through the mechanism of endogenous diurnal oscillations in just the same way as do photoperiodic reactions in plants.The inhibition of diapause by light in the second half of the diurnal oscillation (under long days or by light interruptions in the dark period) and the promotion by light in the first half (under short days) occur only with light of short wavelengths: ultraviolet, violet, and blue up to about 550 mμ. Yellow and red light act in the opposite fashion, giving diapause inhibition in the first half of the cycle and promotion in the second half. In white light the violet reaction predominates, so that diapause is promoted by short days and inhibited by long days.

Flowering.

2021 ◽  
pp. 186-202
Author(s):  
Shu-Yen Lin ◽  
Po-An Chen
Keyword(s):  
Vegetative Growth ◽  
Crop Production ◽  
Agricultural Practices ◽  
Factors Affecting ◽  
Reproductive Phase

Abstract This chapter covers the various factors affecting the transformation of vegetative growth to reproductive phase of guava trees, and the phenology, anthesis and pollination in guava. The agricultural practices for regulating crop production are also discussed.

CHEMICAL WEED KILLERS: II. FACTORS AFFECTING ESTIMATION OF TOXICITY OF LEAF SPRAYS

1937 ◽  
Vol 15c (8) ◽  
pp. 380-390 ◽  
Author(s):  
W. H. Cook
Keyword(s):  
No Value ◽  
Unit Area ◽  
Effective Dosage ◽  
Minimum Volume ◽  
Factors Affecting ◽  
Spray Solution ◽  
Number Of Leaves ◽  
Annual Weeds ◽  
Sigmoid Shape

Chemicals applied to annual weeds frequently gave dosage-mortality curves that were not of the usual sigmoid shape. These departures appear to be attributable to the method of application, as the spray is only partly retained by the leaves and stems. The proportion of the applied quantity of poisonous constituent retained by the plant decreases as the volume of spray is increased, and increases as the concentration of the spray solution is increased. Leaf sprays will therefore be most effective if the minimum volume of solution required for coverage is used, and the effective dosage of the chemical obtained by adjusting the concentration.A few indices sometimes used for estimating the efficacy of herbicides were compared with the mortality criterion. The number of leaves left, and the height of the living plants after treatment are of little or no value for estimating the effect of the chemical. The weight per unit area of the living plants remaining after treatment may be of some value.

Temperature-Controlled Growth of ZnO Nanowires and Nanoplates in the Temperature Range 250−300 °C

2006 ◽  
Vol 110 (43) ◽  
pp. 21741-21746 ◽  
Author(s):  
Congkang Xu ◽  
Dongeon Kim ◽  
Junghwan Chun ◽  
Keehan Rho ◽  
Bonghwan Chon ◽  
...  
Keyword(s):  
Zno Nanowires ◽  
Controlled Growth ◽  
Temperature Range ◽  
Temperature Controlled

Quantitative trait loci associated with lettuce seed germination under different temperature and light environments

Genome ◽  
2008 ◽  
Vol 51 (11) ◽  
pp. 928-947 ◽  
Author(s):  
Eiji Hayashi ◽  
Natsuyo Aoyama ◽  
David W. Still
Keyword(s):  
Quantitative Trait Loci ◽  
Seed Germination ◽  
Path Analysis ◽  
Quantitative Trait ◽  
Germination Rate ◽  
Red Light ◽  
Seed Maturation ◽  
Lettuce Seed ◽  
Factors Affecting ◽  
Trait Loci

Temperature and light are primary environmental cues affecting seed germination. To elucidate the genetic architecture underlying lettuce ( Lactuca sativa L.) seed germination under different environmental conditions, an F8 recombinant inbred line population consisting of 131 families was phenotyped for final germination and germination rate. Seeds were imbibed in water at 20 °C under continuous red light (20-Rc), 20 °C continuous dark (20-Dc), 31.5 °C continuous red light (31.5-Rc), 31.5 °C continuous dark (31.5-Dc), or 20 °C far-red light for 24 h followed by continuous dark (20-FRc-Dc). Thirty-eight quantitative trait loci (QTL) were identified from two seed maturation environments: 10 for final germination and 28 for germination rate. The amount of variation attributed to an individual QTL ranged from 9.3% to 17.2% and from 5.6% to 26.2% for final germination and germination rate, respectively. Path analysis indicated that factors affecting germination under 31.5-Rc or 31.5-Dc are largely the same, and these appear to differ from those employed under 20-FRc-Dc. QTL and path analysis support the notion of common and unique factors for germination under diverse temperature and light regimes. A highly significant effect of the seed maturation environment on subsequent germination capacity under environmental stress was observed.

Environmental factors affecting germination of Cronartium comandrae aeciospores

1974 ◽  
Vol 52 (3) ◽  
pp. 659-667 ◽  
Author(s):  
J. M. Powell
Keyword(s):  
Environmental Factors ◽  
Germ Tube ◽  
Free Water ◽  
Direct Sunlight ◽  
Factors Affecting ◽  
Temperature Range ◽  
Ph Range ◽  
Germ Tubes ◽  
Germ Tube Elongation

Cronartium comandrae Pk. aeciospores germinated over the temperature range 1 to 30 °C, but germination outside the range 5 to 22 °C was poor. Optimum for germination was about 15 °C, although initial germination was better at 20 °C. Some aeciospores germinated after 1 h of incubation and most within 4 to 5 h. The rate of germ tube elongation was reduced after 8 h, and generally had ceased after 24 h. Each spore produced an average of two germ tubes, but only one developed. Appressoria usually formed only at 15 and 20 °C. Free water was apparently necessary for germination. Hydration of spores initially improved germination but extended periods of hydration decreased it. Viable spores swelled more than non-viable spores. Aeciospores germinated well in the dark and in light but not in direct sunlight. Fresh aeciospores germinated on media with a pH range of 4.5 to 8.0, but did best between pH 6.0 and 6.5. Germination results are compared with those reported for other Cronartium rusts.

scholarly journals INFLUENCE OF SPECTRAL FILTERS ON LEAF PIGMENTS AND ANATOMY OF `SPEARS' CHRYSANTHEMUM

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 648g-648
Author(s):  
Margaret J. McMahon ◽  
John W. Kelly
Keyword(s):  
Chlorophyll A ◽  
Unit Area ◽  
Red Light ◽  
Leaf Size ◽  
Blue Dye ◽  
Textile Dye ◽  
Chlorophyll B ◽  
Spectral Filtering ◽  
Spectral Filters ◽  
Β Carotene

`Spears' chrysanthemums were grown in chambers fitted with double-walled exolite filled with spectral filtering solutions: a blue textile dye that absorbed red light, CuSO4·5H2O that absorbed far-red light, and H2O that was spectrally non-selective (control). Leaves of `Spears' grown under CuSO4-filters had increased chlorophyll a (23%), chlorophyll b (26%), xanthophyll (22%), and β-carotene (24%) compared to plants grown under H2O or blue-dye filters. Ratios of total carotenoid: chlorophyll and chlorophyll a: chlorophyll b were not affected by filter. Individual leaf area was reduced 25% under CuSO4 filters compared to other filters. Stomates per unit area were not affected by filters, however stomates per leaf were reduced 25% under CuSO4 filters because of leaf size reduction. Stomate length and width were not affected by filter. Leaves from plants grown under CuSO4-filters had an internal structure resembling that of sun-type leaves. Other filters induced a shade-type leaf.

scholarly journals Factors Affecting the Microstructure, Tensile Properties and Corrosion Resistance of AA7075 Forgings

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5776
Author(s):  
Teng-Shih Shih ◽  
Ho-Tieh Hsu ◽  
Lih-Ren Hwang
Keyword(s):  
Corrosion Resistance ◽  
Grain Boundary ◽  
Tensile Properties ◽  
Room Temperature ◽  
Unit Area ◽  
Phase Particle ◽  
High Strength ◽  
Accelerated Corrosion ◽  
Factors Affecting ◽  
Particle Counts

AA7075 alloys are high strength alloys and are used as an important material for making engineering parts. Forged AA7075 alloys showed significantly decreased toughness when the material was hot deformed at a high temperature. This study investigated the effects of forging parameters on the tensile properties and the microstructure of AA7075 forgings. The tensile properties and corrosion resistance of different forgings were determined to be correlated with their microstructures. The experiment annealed and hot-deformed sample bars at 633 K, cold-deformed them at room temperature (RF), and at sub-zero temperatures (CF). After T73 heat treatment, the microstructures depended on the deformation temperature. This varied significantly, from elongated grains for hot-forged samples to equiaxial grains for cold-deformed samples. The hot-deformed samples had a tensile strength of 592 MPa for UTS, 538 MPa for YS, and 13.4% for elongation. These were stronger but less elongated than the cold-deformed samples. All hot-deformed (HF), RF, and CF samples exhibited mechanical properties that exceeded UTS > 505 MPa, YS > 435 MPa, and an elongation > 13%, and showed moderate corrosion resistance if samples were in contact with a 3.5 wt.% NaCl solution. The toughness of the forgings could be significantly improved by decreasing the forging temperatures. The corrosion resistance of AA7075-T73 forgings was affected by the total grain boundary (GB) lengths per unit area and the 2nd phase particle counts per unit area. Increasing the high-angle grain boundary lengths (HAGBs) per unit area accelerated corrosion and increased the Icorr value.

scholarly journals Factors affecting strength of clays in the temperature range 110 to 800%

2017 ◽  
Vol 7 (079) ◽  
pp. 26
Author(s):  
W. H. Sutton ◽  
F. R. Matson
Keyword(s):  
Factors Affecting ◽  
Temperature Range

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