scholarly journals Effects of Light, Temperature, and Leaf Wetness Duration on Daylily Rust

Plant Disease ◽  
2003 ◽  
Vol 87 (4) ◽  
pp. 442-445 ◽  
Author(s):  
D. S. Mueller ◽  
J. W. Buck
Keyword(s):  
Light Intensity ◽  
Effect Of Temperature ◽  
Leaf Wetness ◽  
Disease Development ◽  
Lesion Development ◽  
Leaf Wetness Duration ◽  
Different Temperatures ◽  
Controlled Environments ◽  
Incubation Temperatures

Experiments in controlled environments were completed to determine the influence of light intensity, temperature, and leaf wetness duration on daylily rust caused by Puccinia hemerocallidis. As light intensity increased, there was a significant decrease in urediniospore germination (R2 = 0.88 and Y = 96 - 0.6x). Urediniospores germinated in vitro between 7 and 34°C with an optimal temperature of 22 to 24°C. To test the effect of temperature on infection efficiency, plants were inoculated with urediniospores, incubated under high relative humidity at 4, 10, 22, 30, or 36°C, and then transferred to a greenhouse at 23°C for 15 days. Plants incubated at 22°C had an average of 13 lesions cm leaf-1. Incubation temperatures of 4, 10, 30, or 36°C resulted in less than 1.5 lesions cm leaf-1. Plants were inoculated, incubated at 22°C for 24 h, and then incubated at different temperatures for 15 days to test the effect of temperature on disease development. There were no significant differences in disease development at 22 and 30°C; however, there were significantly fewer lesions at 10°C and no lesions developed at 36°C within 15 days. Five to six h of leaf wetness were required for lesion development and as the duration of leaf wetness increased, there was a significant increase in the number of lesions that developed. These studies indicate that for disease development of P. hemerocallidis on daylily, temperatures around 22°C and 5 h of leaf wetness are required during infection. However, once a daylily is infected, disease development is not as sensitive to environmental conditions.

Effect of Temperature and Safeners on Glutathione Levels and Glutathione S-Transferase Activity in Maize

1991 ◽  
Vol 46 (9-10) ◽  
pp. 856-860 ◽  
Author(s):  
Daniel L. Kunkel ◽  
John C. Steffens ◽  
Robin R. Bellinder
Keyword(s):  
Low Temperatures ◽  
Herbicide Tolerance ◽  
Effect Of Temperature ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Different Temperatures ◽  
Maize Plants ◽  
Incubation Temperatures ◽  
Gst Activity

Abstract Studies were conducted to determine the biochemical aspects of chloroacetamide injury to maize and the mechanism by which safeners maintain herbicide tolerance, even at reduced temperatures. The objectives of these studies were threefold: one, determine whether gluta­thione (GSH) content varies in maize plants grown at three different temperatures in safener-treated and non-treated plants; two, determine whether glutathione S-transferase (GST) activ­ity varies in plants grown at different temperatures; and three, determine if GSH activity is sensitive to low temperatures in vitro. The herbicide safeners CGA -154281 [4-(dichloroacetyl)-3,4-dihydro-3-methyl-2 H-1 ,4-benzoxazine] and dichlormid [2,2-dichloro-N,N-di-2-propenylacetamide] were used with metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-n-(2-methoxy-1-methyl)acetamide] or acetochlor [2-chloro-N-(ethoxymethyl)-N-2-ethyl-6-methylphenyl)-acetamide], respectively, to determine the mechanisms of maize tolerance. CGA -154281 signifi­cantly increased GSH levels in maize seedlings grown at 27 °C compared to non-safened seed­lings, however significant differences were not seen at 17 or 37 °C. Dichlormid increased GSH levels by 1.6-fold at all growth temperatures. Both CGA -154281 and dichlormid increased GST activity significantly at all growth temperatures. The safener-induced GST activity was main­tained at in vitro incubation temperatures of 5 and 15 °C for acetochlor and metolachlor, re­spectively. In contrast, GST activity from non-safened tissue was essentially absent at these temperatures. Therefore, greater GST activity following safener treatment may result in higher levels of herbicide metabolism, even at low temperatures.

scholarly journals Effect of temperature, CO2 and O2 on motility and mobility of Anisakidae larvae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aiyan Guan ◽  
Inge Van Damme ◽  
Frank Devlieghere ◽  
Sarah Gabriël
Keyword(s):  
Enzymatic Digestion ◽  
Infected Fish ◽  
Effect Of Temperature ◽  
Video Recordings ◽  
Different Temperatures ◽  
Semi Solid ◽  
Zoonotic Parasites ◽  
The Impact ◽  
Phosphate Buffered Saline

AbstractAnisakidae, marine nematodes, are underrecognized fish-borne zoonotic parasites. Studies on factors that could trigger parasites to actively migrate out of the fish are very limited. The objective of this study was to assess the impact of different environmental conditions (temperature, CO2 and O2) on larval motility (in situ movement) and mobility (migration) in vitro. Larvae were collected by candling or enzymatic digestion from infected fish, identified morphologically and confirmed molecularly. Individual larvae were transferred to a semi-solid Phosphate Buffered Saline agar, and subjected to different temperatures (6 ℃, 12 ℃, 22 ℃, 37 ℃) at air conditions. Moreover, different combinations of CO2 and O2 with N2 as filler were tested, at both 6 °C and 12 °C. Video recordings of larvae were translated into scores for larval motility and mobility. Results showed that temperature had significant influence on larval movements, with the highest motility and mobility observed at 22 ℃ for Anisakis spp. larvae and 37 ℃ for Pseudoterranova spp. larvae. During the first 10 min, the median migration of Anisakis spp. larvae was 10 cm at 22 ℃, and the median migration of Pseudoterranova spp. larvae was 3 cm at 37 ℃. Larval mobility was not significantly different under the different CO2 or O2 conditions at 6 °C and 12 ℃. It was concluded that temperature significantly facilitated larval movement with the optimum temperature being different for Anisakis spp. and Pseudoterranova spp., while CO2 and O2 did not on the short term. This should be further validated in parasite-infected/spiked fish fillets.

scholarly journals Temperature, Leaf Wetness, and Isolate Effects on Infection of Minneola Tangelo Leaves by Alternaria sp.

Plant Disease ◽  
1999 ◽  
Vol 83 (5) ◽  
pp. 429-433 ◽  
Author(s):  
Y. Canihos ◽  
T. L. Peever ◽  
L. W. Timmer
Keyword(s):  
Polynomial Equation ◽  
Brown Spot ◽  
Effect Of Temperature ◽  
Leaf Wetness ◽  
Significant Difference ◽  
Alternaria Brown Spot ◽  
Detached Leaves ◽  
Alternaria Sp ◽  
Response To Temperature

Alternaria brown spot causes necrotic lesions on immature leaves, twigs, and fruit of tangerines and their hybrids, reducing yield and fruit quality. The effect of temperature, leaf wetness, and isolate was evaluated in an in vitro system using immature detached leaves of Minneola tangelo Infection was greatest at 27°C, decreased gradually as the temperature declined to 24, 20, and 17°C, and dropped sharply at 32°C. Levels of infection were low at 4 and 8 h of leaf wetness and continued to increase with longer wetting periods up to 36 h. A polynomial equation was developed that provided a good fit for the data (adjusted R2 = 0.93). Isolates differed in aggressiveness, but there was no significant difference among isolates in their response to temperature and leaf wetness duration.

scholarly journals Effect of temperature on immunocompetence of the blue mussel (Mytilus edulis)

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Alexandre Beaudry ◽  
Marlène Fortier ◽  
Stéphane Masson ◽  
Michel Auffret ◽  
Pauline Brousseau ◽  
...  
Keyword(s):  
Blue Mussel ◽  
Lysozyme Activity ◽  
Effect Of Temperature ◽  
Gonad Maturation ◽  
Gland Weight ◽  
Immune Parameters ◽  
Serum Lysozyme ◽  
Different Temperatures ◽  
Maturation Stages

The blue mussel is a filter-feeding bivalve commonly used in ecotoxicological monitoring as a sentinel species. Due to climate change and the increase of temperature expected in marine environment, it is important to anticipate potential impacts on this species. The aim of this study was to investigate the immunocompetence of blue mussels acclimated to different temperatures and on the effects of increasing temperatures (5, 10 and 20°C). Different indices and gonad maturation stages were also determined throughout the experiments. Cell viability, phagocytosis, serum lysozyme activity and cyclooxygenase (COX) activity were evaluated as immune parameters. The cellular immunity was also evaluated after hemocytes exposure to various cadmium concentrations <em>in vitro</em>. The results obtained demonstrate modulation of hemocyte viability and the ability of these cells to phagocytize in absence of contaminants. After the exposure to cadmium, hemocytes showed greater viability at 5°C while maintaining a higher phagocytic competence. In addition, the lysozyme activity stayed stable at all tested temperatures, contrary to that of COX, which increased when the mussels were maintained at 20°C. The evaluation of indices demonstrated no reduction of general conditions during all the experiment despite the increase of temperature and the reduction of the digestive gland weight. Moreover, the lack of food does not affect gonad maturation and the spawning process.

scholarly journals Effect of Temperature on Urediniospore Production and Germinability in Puccinia arachidis1

1994 ◽  
Vol 21 (2) ◽  
pp. 79-81
Author(s):  
P. V. Subba Rao ◽  
P. Subrahmanyam ◽  
D. McDonald
Keyword(s):  
Arachis Hypogaea ◽  
Effect Of Temperature ◽  
Optimal Temperature ◽  
Puccinia Arachidis ◽  
Arachis Hypogaea L ◽  
Different Temperatures ◽  
Percent Germination ◽  
Detached Leaves

Abstract Effect of temperature on urediniospore production in Puccinia arachidis was investigated under monocyclic infection using detached leaves of the susceptible peanut (Arachis hypogaea L.) cultivar TMV 2. Urediniospores produced at different temperatures were also examined for their germinability in vitro. The optimal temperature for urediniospore production was at about 20 and 25 C. Temperatures below 20 C or above 30 C were highly detrimental to urediniospore production. There were also marked differences in the percent germination of urediniospores produced at different temperatures. Urediniospores produced at 20 and 25 C showed the highest germination percentages. The interaction of temperature with urediniospore production and germinability is important in understanding the development of peanut rust epidemics.

scholarly journals Effect of temperature and leaf wetness duration on infection of sweet oranges by Asiatic citrus canker

2006 ◽  
Vol 55 (5) ◽  
pp. 657-663 ◽  
Author(s):  
M. Dalla Pria ◽  
R. C. S. Christiano ◽  
E. L. Furtado ◽  
L. Amorim ◽  
A. Bergamin Filho
Keyword(s):  
Citrus Canker ◽  
Effect Of Temperature ◽  
Leaf Wetness ◽  
Leaf Wetness Duration

scholarly journals Temperature and light intensity interaction on Cercospora coffeicola sporulation and conidia germination

2016 ◽  
Vol 40 (2) ◽  
pp. 198-204 ◽  
Author(s):  
Marília Goulart da Silva ◽  
Edson Ampélio Pozza ◽  
Caio Vitor Rodrigues Vaz de Lima ◽  
Tales Jesus Fernandes
Keyword(s):  
Light Intensity ◽  
Significant Interaction ◽  
Limiting Factor ◽  
Dark Treatment ◽  
Different Temperatures ◽  
Cercospora Coffeicola ◽  
Environmental Requirements ◽  
Favorable Conditions ◽  
Sporulation Rate

ABSTRACT Difficulty in obtaining abundant sporulation in culture of many species of Cercospora may be the limiting factor for studies of biology, systematics, and inoculation of the genus. Therefore, it is necessary to understand the nutritional and environmental requirements that influence mycelial growth, sporulation and germination. As it is difficult to obtain conidia of Cercospora coffeicola in vitro, different temperatures (17, 22, 27, and 32 °C) and light intensities (80, 160, 240, and 320 μmol m-2 s-1) were evaluated to optimize pathogen sporulation and assess favorable conditions for spore germination, aiming for a strategy of disease control. The dark treatment (0 μmol m-2 s-1) was added for sporulation. A significant interaction was found between temperature and light intensity for both variables. The highest sporulation rate of C. coffeicola occurred at a light intensity of 240 μmol m-2 s-1 and air temperature of 22 °C, reaching 5.9x106 con mL-1. Germination was higher at temperature 17 °C and light intensity of 320 μmol m-2 s-1, reaching 52%. Interaction between light intensity and temperature proved to influence the processes of sporulation and germination of C. coffeicola.

scholarly journals Light Intensity Alters the Behavior of Monilinia spp. in vitro and the Disease Development on Stone Fruit-Pathogen Interaction

2021 ◽  
Vol 12 ◽  
Author(s):  
Marta Balsells-Llauradó ◽  
Rosario Torres ◽  
Núria Vall-llaura ◽  
Carla Casals ◽  
Neus Teixidó ◽  
...  
Keyword(s):  
Ethylene Production ◽  
Growth Parameters ◽  
Abiotic Factors ◽  
Brown Rot ◽  
Stone Fruit ◽  
Effect Of Temperature ◽  
Disease Development ◽  
Fruit Bagging

The development of brown rot caused by the necrotrophic fungi Monilinia spp. in stone fruit under field and postharvest conditions depends, among others, on environmental factors. The effect of temperature and humidity are well studied but there is little information on the role of light in disease development. Herein, we studied the effect of two lighting treatments and a control condition (darkness) on: (i) several growth parameters of two Monilinia spp. (M. laxa and M. fructicola) grown in vitro and (ii) the light effect in their capacity to rot the fruit (nectarines) when exposed to the different lighting treatments. We also assessed the effect of such abiotic factors in the development of the disease on inoculated nectarines during postharvest storage. Evaluations also included testing the effect of fruit bagging on disease development as well as on ethylene production. Under in vitro conditions, lighting treatments altered colony morphology and conidiation of M. laxa but this effect was less acute in M. fructicola. Such light-induced changes under in vitro development also altered the capacity of M. laxa and M. fructicola to infect nectarines, with M. laxa becoming less virulent. The performance of Monilinia spp. exposed to treatments was also determined in vivo by inoculating four bagged or unbagged nectarine cultivars, indicating an impaired disease progression. Incidence and lesion diameter of fruit exposed to the different lighting treatments during postharvest showed that the effect of the light was intrinsic to the nectarine cultivar but also Monilinia spp. dependent. While lighting treatments reduced M. laxa incidence, they enhanced M. fructicola development. Preharvest conditions such as fruit bagging also impaired the ethylene production of inoculated fruit, which was mainly altered by M. laxa and M. fructicola, while the bag and light effects were meaningless. Thus, we provide several indications of how lighting treatments significantly alter Monilinia spp. behavior both in vitro and during the interaction with stone fruit. This study highlights the importance of modulating the lighting environment as a potential strategy to minimize brown rot development on stone fruit and to extent the shelf-life period of fruit in postharvest, market, and consumer’s house.

scholarly journals Toward Breeding for Resistance to Fusarium Tuber Rot in Caladium: Inoculation Technique and Sources of Resistance

HortScience ◽  
2007 ◽  
Vol 42 (5) ◽  
pp. 1135-1139 ◽  
Author(s):  
Fahrettin Goktepe ◽  
Teresa Seijo ◽  
Zhanao Deng ◽  
Brent K. Harbaugh ◽  
Natalia A. Peres ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Optimal Growth ◽  
Effect Of Temperature ◽  
Tuber Quality ◽  
Disease Development ◽  
Sources Of Resistance ◽  
Cultivar Susceptibility ◽  
Tuber Rot

Fusarium tuber rot, incited by Fusarium solani, is the major cause of losses of tuber quality and quantity in caladium (Caladium ×hortulanum) during storage and production. To develop a reliable inoculation method for evaluating cultivar susceptibility to Fusarium tuber rot and identifying sources of resistance, the effect of temperature on the mycelial growth of F. solani in vitro and on tuber rot in vivo was examined. The optimal temperature was then used to study the aggressiveness of F. solani isolates. The effect of temperature (13, 18, 23, 28, and 33 °C) on radial mycelial growth of nine F. solani isolates in vitro was determined, and all responded similarly to temperature variables, with optimal growth predicted to be at 30.5 °C. The relationship of these temperatures to disease development was then determined for the most aggressive F. solani isolate 05-20 and it was found that disease development in inoculated tubers was greatest at low temperatures (13 and 18 °C). Cold damage to tubers was observed at 13 °C; therefore, 18 °C was chosen for all future disease screening. The aggressiveness of nine isolates was tested on two caladium cultivars. Significant differences among isolates were observed for the diameter of rotted tissue in both cultivars, indicating that choice of isolate was important for screening. Isolates 05-20 and 05-257 were highly aggressive on both cultivars. Tubers of 17 commercial caladium cultivars were inoculated with three isolates (04-03, 05-20, and 05-527) and incubated at 18 °C. The interaction between isolates and cultivars was highly significant (P < 0.0001), indicating that cultivars were not equally susceptible to different pathogenic isolates of F. solani. Lesion diameters differed significantly (P < 0.0001) among cultivars/isolates and ranged from 9.5 mm (‘Rosebud’ and ‘White Christmas’ for isolate 04-03) to 23.9 mm (‘Carolyn Whorton’ for isolate 05-20). The cultivars were ranked for susceptibility to tuber rot within each isolate and the normalized total rank for the three isolates was used to place cultivars into four categories: resistant (‘Candidum’, ‘Rosebud’, ‘White Christmas’, ‘Florida Sweetheart’, and ‘Aaron’), moderately resistant (‘White Wing’ and ‘Red Flash’), susceptible (‘Candidum Jr.’, ‘White Queen’, ‘Red Frill’, ‘Florida Cardinal’, ‘Miss Muffet’, and ‘Postman Joyner’), and highly susceptible (‘Fannie Munson’, ‘Gingerland’, ‘Frieda Hemple’, and ‘Carolyn Whorton’). The availability of these sources of host plant resistance, aggressive isolates, and resistance assessment techniques will facilitate the development of new Fusarium-resistant caladium cultivars.

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