Studies on sunflower rust. VII. Effect of light and temperature during spore formation on the germinability of fresh and stored urediospores of Puccinia helianthi

1971 ◽  
Vol 49 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Praim N. Sood ◽  
W. E. Sackston
Keyword(s):  
Adverse Effect ◽  
Light Intensity ◽  
Spore Formation ◽  
Effect Of Temperature ◽  
Consistent Effect ◽  
Puccinia Helianthi ◽  
Light Intensities ◽  
Race 1 ◽  
And Storage ◽  
Effect Of Light

Light intensity from 2200 to 43 000 lux during production of urediospores of Puccinia helianthi had little influence on germinability of fresh spores. The higher light intensities had an adverse effect on germinability of spores stored at −16 °C for 2 months. Daylength had little consistent effect on germinability of fresh or stored spores. Spores produced at day temperatures of 16, 21, and 27 °C showed no effect of temperature on germinability when fresh. After 2 months storage at −16 °C germination was highest for spores produced at 21°. Spores of races 1 and 3 germinated well after 1218 days of storage at −16°, and a small percentage germinated after storage at 4 °C. Races 2 and 4 germinated well after 1136 days storage at −16 and 4 °C. Races 2 and 4 survived longer than races 1 and 3 at 30° and at 23 °C, but not at 13 °C. Race 3 appeared more susceptible than race 1 to effects of light, temperature, and storage.

Does light intensity affect embryonic development of squid (Heterololigo bleekeri)?

2004 ◽  
Vol 84 (6) ◽  
pp. 1215-1219 ◽  
Author(s):  
Yuzuru Ikeda ◽  
Kingo Ito ◽  
Gen Matsumoto
Keyword(s):  
Body Size ◽  
Light Intensity ◽  
Embryonic Development ◽  
Early Stage ◽  
Constant Darkness ◽  
Light Intensities ◽  
Development Duration ◽  
Experimental Group ◽  
Effect Of Light

The effect of light intensity on the course of embryonic development of squid (Heterololigo bleekeri) was examined. Heterololigo bleekeri embryos at an early stage were incubated in the egg cases under six to seven gradients of light intensities which varied from constant darkness to intensive light >1000 lx (12L:12D for all experimental groups except for the constant darkness group). Duration of hatching in every experimental group ranged from seven to 15 days with a peak for ≈30–50% of total number of hatchlings. However, there were no particular relationships between light intensities and duration of embryonic development, duration of hatching, number of hatchlings at hatching peak, and body size of hatchlings. In all groups, body size of hatchlings increased up to seven days post-hatching and thereafter did not change remarkably. Just after hatching, strongly positive photo taxis was observed for H. bleekeri

Investigations into the increased rust (Puccinia helianthi) intensity on some hybrid sunflower cultivars grown in Queensland

1984 ◽  
Vol 35 (1) ◽  
pp. 99
Author(s):  
KC Goulter ◽  
JK Kochman ◽  
JF Brown
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Liquid Nitrogen ◽  
Low Light ◽  
Puccinia Helianthi ◽  
Low Light Intensity ◽  
Generation Times ◽  
Race 1 ◽  
Hybrid Sunflower

Sunflower rust intensity in crops of several hybrid cultivars in Queensland during the 1980, 1981 and 1982 seasons ranged from 30 to 60% of leaf area. In previous years, these cultivars had rust ratings of 2-5%. Rust was also found on some crops of usually immune hybrids grown during winter in central Queensland. A number of rust differential lines were inoculated with several isolates collected from throughout Queensland during 1981 and 1982, as well as with isolates stored in liquid nitrogen from the years 1976, 1978 and 1980. Because all isolates failed to infect the differentials possessing either the R1 or R2 genes for resistance, all collections were allocated to race 1. Comparisons of the temporal isolates revealed that no differences could be detected among the generation times, pustule number and pustule size produced by isolates on a range of sunflower rust differentials and hybrid cultivars. These data indicated that the composition of the pathogenic population had not altered. The application of higher inoculum densities shortened generation times and produced more pustules; both relationships were linear. The development of race 1 rust on seedlings of the immune hybrid Hysun 30 was induced by maintaining the plants under low light intensity or short photoperiods.

Laboratory study of the effect of light on the emergence behaviour of eight species of commercially important adult penaeid prawns

1994 ◽  
Vol 45 (1) ◽  
pp. 43 ◽  
Author(s):  
TJ Wassenberg ◽  
BJ Hill
Keyword(s):  
Light Intensity ◽  
Laboratory Study ◽  
Carapace Length ◽  
Rate Of Change ◽  
Metapenaeus Ensis ◽  
The Third ◽  
Light Intensities ◽  
Commercially Important ◽  
Penaeus Merguiensis ◽  
Effect Of Light

The emergence behaviour of eight species of commercial prawns (between 25.0 and 30.0 mm carapace length) was studied in the laboratory. All except Penaeus merguiensis were nocturnal: they emerged from the substratum in the evening when the light was dimmed and buried themselves in the morning, usually before dawn. P. merguiensis generally remained on the substratum during the day. The species can be grouped on the basis of their behaviour: the first group (P. plebejus and P. latisulcatus) was most sensitive to light, the second group (P. semisulcatus, Metapenaeus ensis, P. esculentus, M. endeavouri and M. bennettae) was less sensitive to light, and the third (P. merguiensis) was least sensitive to light. To find out what triggered emergence, two species (P. esculentus and P. plebejus) were exposed to different rates of light dimming at dusk. Both species responded to absolute light intensity, but the response of P. plebejus was affected by the rate of change of light intensity. The different responses of the species to different light intensities explains some of the differences in catchability in a multi-species prawn fishery.

LIGHT-STIMULATED LEAF GROWTH ON INTACT AND EXCISED BEAN PLANTS (PHASEOLUS VULGARIS L.) III. EFFECT OF LIGHT INTENSITY

1999 ◽  
Vol 47 (4) ◽  
pp. 231-236
Author(s):  
Shimon Lavee ◽  
Elizabeth Van Volkenburgh ◽  
Robert Cleland E.
Keyword(s):  
Light Intensity ◽  
Leaf Growth ◽  
Energy Requirement ◽  
Red Light ◽  
Continuous Light ◽  
Leaf Expansion ◽  
Minimal Amount ◽  
Light Intensities ◽  
Bean Plants ◽  
Effect Of Light

The effect of light intensity on primary bean leaf unfolding and elongation was studied with intact and excised 10-day-old plants grown under red light. Continuous light of 40 μmol; m−2S−1 was enough to induce maximal leaf expansion both on intact and excised bean plants. Lower light intensities had a partial effect. The growth rate during the first 24 h in light was linearly related to light intensity up to 130 μmol; m−2S−1, although this light intensity was already supra-optimal for final leaf size. The minimal amount of light energy needed for full leaf expansion was about 15 mol photons m−2. The mode of light application, level of intensity, and irradiance duration were not critical when the total energy requirement was fulfilled. Under insufficient light applications for full leaf expansion, interrupted irradiance and longer low light intensity application induced leaf elongation more efficiently. Generally, the effect of different white light intensities on primary bean leaf expansion was the same on both intact and excised red-light-grown plants.

scholarly journals Larval growth and survival in Indian Butter Catfish, Ompok bimaculatus (Bloch): effect of light intensity and photoperiod

2019 ◽  
Author(s):  
Kalpana Arambam ◽  
Pradyut Biswas ◽  
Soibam Khogen Singh ◽  
A. B. Patel ◽  
Alok Kumar Jena ◽  
...  
Keyword(s):  
Light Intensity ◽  
Larval Growth ◽  
Maximum Growth ◽  
Continuous Darkness ◽  
Growth And Survival ◽  
Light Intensities ◽  
Randomized Design ◽  
Significant Difference ◽  
Ompok Bimaculatus ◽  
Effect Of Light

AbstractTwo sequential indoor rearing trials each of 21 days duration were conducted to investigate the effect of light intensity and photoperiod respectively on the growth and survival of Ompok bimaculatus larvae. In first trial, five different light intensities viz. 0, 300, 500, 900, 1200 lx were applied randomly to 800 larvae (0.003 g; 0.51 cm) stocked in triplicate following a completely randomized design into aquarium (30.0 x 15.0 x 15.0 cm) tanks. Sequentially, in second trial, five photoperiod cycles (light: dark, L: D) namely, 24L: 0D, 16L: 8D, 12L: 12D, 8L: 16D and 0L: 24D in combination with the best performing light intensity (300 lx) as observed from the first trial were employed in triplicates in similar set up. From the first trial, significantly higher survival was observed in 0 and 300 lx, whereas growth was highest in 900 lx (P < 0.05). In the second trial, survival was higher in continuous darkness (0L: 24D), whereas, maximum growth was recorded in 24L: 0D and 16L: 8D groups (P < 0.05). Performance index (PI) showed no significant difference (P > 0.05) among 0 and 300 lx light intensities, but were reduced at higher light intensities. The lowest PI was found in 12L: 12D and 8L: 16D condition but did not have any effect in other photoperiod cycles. Overall, from the present study it can be concluded that growth of the larvae is found to be higher in higher light intensity (900lx) and longer photoperiodic cycles (24L: 0D and 16L: 8D), however, better survival was recorded in total dark conditions suggesting that continuous dark condition is recommended for better hatchery performance of the larvae.

Differential Regulation of Flavone Glycosylation during Ontogeny of Silene pratensis

1983 ◽  
Vol 38 (7-8) ◽  
pp. 544-548 ◽  
Author(s):  
J. M. Steyns ◽  
G. van Nigtevecht ◽  
G. J. Niemann ◽  
J. v. Brederode
Keyword(s):  
Light Intensity ◽  
Differential Regulation ◽  
Low Light ◽  
Leaf Pair ◽  
Low Light Intensity ◽  
Light Intensities ◽  
Flower Stem ◽  
Pair Number ◽  
Silene Pratensis ◽  
Effect Of Light

Two isovitexin glycosides have been found in the cotyledons and foliage leaves of Sitene pratensis plants that are unable to glycosylate isovitexin in their petals (genotype gg glgl fgfg). The glycosides (isovitexin 7-O-galactoside and isovitexin 7-O-galactose 2″-O-arabinoside) were present only in the lower leaves: leaves produced later in the development of the flower stem accumulated only the aglycon isovitexin. The transition in the flavone composition during the ontogeny of the plants could be influenced by light intensity. In plants grown at low light intensity, glycoside production continued until a higher leaf pair number than in plants grown at higher light intensities. However, the effect of light intensity is indirect: the transition in the flavone composition is correlated with the transition from rosette leaves to stem leaves. The presence of the 7-O-galactosides in cotyledons and rosette leaves suggests that in addition to the g, gl and fg loci, there are further glycosylating loci which are not expressed in stem leaves and petals.

Factors affecting growith and distribution of kauri (Agathis australis Salisb.) I. Effect of light on the establishment of Kaura and of Phyllocladus trichomanoides D.Don

1959 ◽  
Vol 7 (3) ◽  
pp. 252 ◽  
Author(s):  
RL Bieleski
Keyword(s):  
Light Intensity ◽  
Frequency Distribution ◽  
High Light Intensity ◽  
High Light ◽  
Low Light ◽  
Factors Affecting ◽  
Light Intensities ◽  
Seedling Distribution ◽  
Conifer Seedling ◽  
Effect Of Light

A method for determining the effect of light on seedling distribution in the field is described. It can be applied when seedling frequencies are as low as 1/m2. The frequency distribution of light intensities occupied by seedlings in a quadrat is compared with the frequency distribution of light intensities measured on a grid in the quadrat. This method was used to study the effect of light intensity on the establishment of two New Zealand gymnosperms, kauri (Agathis australis) and Phyllocladus trichomanoides, in the nursery community, a semimature Leptospermum scoparium – L. ericoides associes. Kauri and Phyllocladus did not occur at light intensities below 0.015 and 0.018 full daylight respectively. This limitation appeared to be due to the low light intensity presumably limiting photosynthesis. Kauri, but not Phyllocladus, also showed a high light intensity limit, at 0.30 full daylight, above which seedlings did not establish. Reasons are given for considering this as an indirect effect, probably through related solar heating affecting soil temperature or moisture. The optimal light intensity for kauri and Phyllocladus seedling establishment was close to the modal light intensity under the Leptospermum community: Leptospermum spp. were incapable of regenerating under their own cover. These two reasons appear to explain the suitability of the Leptospermum community as a nurse crop for the two conifer seedling species.

Effect of Light Intensity on Schottky Barrier Widths and I-V Characteristics of Polymer Heterojunction Photodiodes

2011 ◽  
Vol 1359 ◽  
Author(s):  
Ali Bilge Guvenc ◽  
Cengiz Ozkan ◽  
Mihrimah Ozkan
Keyword(s):  
Experimental Data ◽  
Light Intensity ◽  
Mathematical Models ◽  
Schottky Barrier ◽  
Butyric Acid ◽  
Organic Semiconductor ◽  
Schottky Barriers ◽  
Light Intensities ◽  
Effect Of Light

ABSTRACTThe Schottky barriers that forms on the interface between aluminum and organic semiconductor of polymer heterojunction photodiodes based on poly(3-hexylthiophene): [6,6]-phenyl-C61-butyric acid methylester blend, has been investigated according to Mott-Schottky curves. We focused on the effect of light intensity on the Schottky barrier widths and I-V characteristics of the devices. Comparison of the mathematical models and experimental data measured under different light intensities indicate a dependency of Schottky barrier to the light intensity.

Studies on sunflower rust. XI. Effect of temperature and light on germination and infection of sunflowers by Puccinia helianthi

1972 ◽  
Vol 50 (9) ◽  
pp. 1879-1886 ◽  
Author(s):  
P. N. Sood ◽  
W. E. Sackston
Keyword(s):  
Light Intensity ◽  
Incubation Period ◽  
Dark Period ◽  
Effect Of Temperature ◽  
Appressorium Formation ◽  
Leaf Discs ◽  
Puccinia Helianthi ◽  
Race 2 ◽  
Race 4

Urediospores of four races of Puccinia helianthi incubated on water agar for 6 h or on sunflower leaf discs for 16 h germinated equally well from 10 to 25 °C, but significantly less at 30° and least at 5 °C. Appressorium formation was highest at 10 to 25 °C, lower at 30 °C, and lowest at 5 °C for races 1 and 3; none occurred at 30 and 5° in races 2 and 4. The optimum for penetration by races 1 and 3 was 20 °C, for race 2, 15° to 20 °C, and for race 4, 20° to 25 °C. Results were the same on susceptible and resistant hosts.Germination percentage on water agar was reduced with increasing light intensity from 2200 to 17 600 lx during incubation for 6 h. Germination on sunflower leaf discs was reduced with increasing light intensity during incubation for 16 h. Appressorium formation and penetration were adversely affected by increasing light intensity.Inhibition by light was overcome during a subsequent dark period when inoculated leaf discs were exposed to various cycles of light and dark during a 16-h incubation period.

Effect of light intensity on feeding of striped trumpeter Latris lineata larvae

1998 ◽  
Vol 49 (5) ◽  
pp. 363 ◽  
Author(s):  
Patricia M. Pankhurst ◽  
Pollyanna E. Hilder
Keyword(s):  
Light Intensity ◽  
Feeding Response ◽  
Ontogenetic Changes ◽  
Fish Feeding ◽  
First Feeding ◽  
Light Intensities ◽  
Latris Lineata ◽  
Striped Trumpeter ◽  
Dependent Behaviour ◽  
Effect Of Light

This study investigates the influence of light intensity on feeding of striped trumpeter larvae, correlating feeding responses with changes in morphology of the retina during growth. A pigmented single-cone retina had differentiated one day before first feeding, and rod precursor cells and double cones were visible in the retina on the 23rd, and 25th day after hatching, respectively. Feeding performance at four light intensities (0, 1, 30, 150 and 700 lux), revealed that striped trumpeter larvae are primarily dependent on vision, a light-dependent behaviour, to feed. The youngest larvae tested (15, 18 and 19 days of age) showed a poor feeding response at 1 lux (range 2–10%), but a 98–100% feeding response at 30, 50 and 700 lux. By 28 days of age, feeding behaviour had changed significantly, with 52% of fish now feeding at 1 lux, 100% of fish feeding at the intermediate light intensities of 30 and 150 lux, and only 62% of fish feeding at 700 lux. The apparent increased photopic sensitivity in 28-day-old fish may reflect increased areas for photon capture provided by double cones, or may reflect ontogenetic changes in cone spectral sensitivity.

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