scholarly journals Oospore Production of Phytophthora infestans in Potato and Tomato Leaves

1997 ◽  
Vol 87 (2) ◽  
pp. 191-196 ◽  
Author(s):  
Y. Cohen ◽  
S. Farkash ◽  
Z. Reshit ◽  
A. Baider
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Phytophthora Infestans ◽  
Optimal Conditions ◽  
In Planta ◽  
Fungal Host ◽  
Factors Affecting ◽  
Detached Leaves ◽  
Oospore Formation ◽  
Initial Lesions

Fungal, host, and environmental factors affecting sexual reproduction of Phytophthora infestans in planta were studied. Intact and detached leaves were coinoculated with sporangia of various combinations of A1 and A2 mating-type isolates; leaves were incubated under various conditions, and oospore production was estimated microscopically within whole, clarified leaflets. Some A1 + A2 isolate combinations were more reproductive than others, whereas some potato genotypes better supported oospore formation than others. Tomato usually supported more oospore formation than potato. To induce oospore formation, A1 and A2 sporangia were usually mixed at a 1:1 ratio. Ratios of 1:19 to 19:1, however, also allowed abundant production of oospores. Optimal temperatures for sexual sporulation ranged from 8 to 15°C, but oospores also were produced at 23°C. Oogonia developed 5 to 6 days after sporangial coinoculation, and oospores developed after 8 to 10 days. Light had little effect on oospore formation in both tomato and potato leaves provided that initial lesions were established under photoperiodic conditions. Although A1 and A2 sporangia usually were mixed before inoculation on leaves to obtain oospores, we found that discrete A1 and A2 lesions produced on opposite sides of the midvein of tomato leaves also induced oospore formation in the midvein and adjacent tissues. Oospores also formed when the two halves of the leaves were cut and separated at 3 days after sporangial coinoculation, which corresponded with the appearance of late blight lesions. The continuous supply of moisture to infected leaves was essential to oospore production. No oospores or oogonia formed in severely diseased plants kept at 50 to 80% relative humidity. Such plants did allow some oospore formation when kept continuously wet for 2 weeks in plastic boxes or tents. Detached leaves floated on water supported the highest sexual sporulation. Under optimal conditions of wetness and temperature, as many as 100 oospores per mm2 of tissue were observed.

EFFECTS OF ENVIRONMENT ON GROWING HYDROPONICS MAIZE FODDER USING LOW-COST GREENHOUSE CULTIVATING UNIT FOR LIVESTOCK PRODUCTION.

2021 ◽  
pp. 71-72
Author(s):  
Adamu, B. ◽  
Abdullahi, S. ◽  
Saidu, S. G ◽  
Yustus Sunday Francis
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Production System ◽  
Low Cost ◽  
Factors Affecting ◽  
Production Water ◽  
Fodder Production ◽  
Food Requirement ◽  
Greenhouse Cultivation ◽  
Near Future

The term 'Hydroponics' was derived from Greek words 'hydro' means water and 'ponics' means labor. Hydroponic is a modern agricultural technique that uses nutrient solution rather than soil solution for fodder production. As population increases the food demand also increased, the existing system of agriculture will not be able to meet the food requirement in the near future due to environmental challenges in the industry. The major environmental factors affecting the hydroponics production system are; Temperature, relative humidity, and light. The objectives of this studies are to examine the hydroponics greenhouse technologies, impact of environmental factors on hydroponics greenhouse cultivation and challenges of growing on hydroponics greenhouse system. This study revealed that hydroponics greenhouse cultivation is a better option for improved fodder production, water utilization, palatability and digestibility.

scholarly journals Environmental Factors Affecting the Diversity and Photosynthetic Pigments of Trentepohlia Species in Northern Thailand’s Chiang Dao Wildlife Sanctuary

2020 ◽  
Vol 89 (1) ◽  
Author(s):  
Santi Saraphol ◽  
Srunya Vajrodaya ◽  
Ekaphan Kraichak ◽  
Anchalee Sirikhachornkit ◽  
Nuttha Sanevas
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Photosynthetic Pigments ◽  
Dominant Species ◽  
Winter Season ◽  
Morphological Identification ◽  
Wildlife Sanctuary ◽  
Total Carotenoids ◽  
Carotene Content ◽  
Factors Affecting

This study addressed the environmental factors that affect <em>Trentepohlia</em> spp. in the Chiang Dao Wildlife Sanctuary at altitudes of 399 to 1,503 meters above sea level (m a.s.l.) during the rainy, winter, and summer seasons. Species were identified using characteristic morphological identification. The influence of environmental factors on the algae was analyzed using a statistical program, and seasonal changes in the quantity of photosynthetic pigments in the dominant species were evaluated. The average relative humidity was 69.34 ± 12.90%, the average temperature was 26.23 ± 3.79 °C, and the average light intensity was 139.78 ± 42.21 µmol photon m<sup data-id="superscript-1">−2</sup> s<sup data-id="superscript-2">−1</sup>. Thirteen species were found: <em>Trentepohlia chapmanii</em>, <em>Trentepohlia</em> sp. 1, <em>Trentepohlia</em> sp. 2, <em>Trentepohlia sundarbanensis</em>, <em>Trentepohlia</em> sp. 3, <em>Trentepohlia rigidula</em>, <em>Trentepohlia</em> sp. 4, <em>Trentepohlia effusa</em>, <em>Trentepohlia monilia</em>, <em>Trentepohlia abietina</em>, <em>Trentepohlia</em> sp. 5, <em>Trentepohlia aurea</em>, and <em>Trentepohlia umbrina</em>. The largest number of species (seven to nine) were found at lower altitudes, from 473 to 517 m a.s.l. Species diversity was greatest in the winter season (13 species). Species found at low attitude were grouped together (Group 1) and had the greatest diversity, and the remaining species were divided into Groups 2, 3, and 4. Environmental factors had both positive and negative influences on the species, especially <em>T. chapmanii</em>, which was found below 1,003 m a.s.l., and <em>T. monilia</em>, which was found in areas with a high relative humidity of 74.50% to 83.93%. The ratio of the total carotenoids to chlorophyll of <em>T. rigidula</em>, the dominant species, was relatively high at 4.96:1, and the β-carotene content (46.89 %w/w) was highest during winter.

scholarly journals Sprinkling Irrigation Enhances Production of Oospores of Phytophthora Infestans in Field-Grown Crops of Potato

2000 ◽  
Vol 90 (10) ◽  
pp. 1105-1111 ◽  
Author(s):  
Yigal Cohen ◽  
Sonja Farkash ◽  
Alexander Baider ◽  
David S. Shaw
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Field Experiments ◽  
Soil Surface ◽  
Field Trials ◽  
Detached Leaves ◽  
Oospore Formation ◽  
Potato Crops ◽  
Host Tissues

Two field experiments were conducted to study the effect of overhead sprinkling irrigation on oospore formation by the late blight fungus Phytophthora infestans in potato. Total rain (natural + sprinkling) accumulated in treatments of experiment 1 (winter 1997 to 1998) were 765, 287, and 219 mm and treatments of experiment 2 (winter 1999 to 2000) were 641, 193, and 129 mm. Sporangia from 11 isolates of P. infestans were combined in eight pairs, seven of A1 and A2 and one of A2 and A2 mating type, and were sprayed on field-grown potato crops (42 plants per plot at 7 m2 each) and examined for their ability to form oospores in the host tissues. In experiment 1, oospores were recorded in a total of 132 of 1,680 leaflets (7.9%), 24 of 105 stems, and 2 of 90 tubers. In experiment 2, oospores were recorded in 40 of 519 leaflets (7.7%), but not in any of the 90 stems or the 45 tubers examined. Both the proportion of leaflets containing oospores and the number of oospores per leaflet increased with time after inoculation and were dependent on the rain regime, the position of leaves on the plant, and the isolate pair combination. In both field trials, increasing the rainfall significantly enhanced oospore production in leaves. Leaf samples collected from the soil surface had significantly more oospores than those collected from the midcanopy. Two pairs in experiment 1 were more fertile than the others, whereas the pair used in experiment 2 was the least fertile. The total number of oospores per leaflet usually ranged from 10 to 100 in experiment 1, but only from 2 to 10 in experiment 2. Maximal oospore counts in the field were 200 and 50 in experiments 1 and 2, respectively, but ranged from ≈2,000 to 12,000 oospores per leaflet in detached leaves in the laboratory. We concluded that P. infestans can produce oospores in the foliage of field-grown potato crops, especially when kept wet by regular overhead sprinkling irrigation, but production was far below that in the laboratory.

scholarly journals Environmental factors affecting sporulation of Fuligo septica (Myxomycetes) on sugar cane bagasse

2003 ◽  
Vol 46 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Alda de Andrade Chiappeta ◽  
Kêsia Xisto Fonseca R. de Sena ◽  
Laise de Holanda Cavalcanti
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Sugar Cane ◽  
Abundant Species ◽  
Saccharum Officinarum ◽  
Sugar Cane Bagasse ◽  
Northeastern Brazil ◽  
Factors Affecting

The influence of environmental factors on sporulation of Fuligo septica (L.) Wigg. and the abundance of this species on sugar cane bagasse (Saccharum officinarum L.), stored outdoors was studied.In Northeastern Brazil, between January/1997 and January/1998, a total of 29 specimens were collected through monthly collections of aethalia. The relationships between the abundance of aethalia and rainfall, temperature, relative humidity of the air and insolation were studied. Results indicated that on the substrate analyzed, F. septica was an abundant species. Sporulation occurred in all seasons of the year, with a well-defined peak at the end of winter and beginning of spring (August/September),which was strongly influenced by rainfall.

Environmental factors affecting the capture of southern hairy-nosed wombats (Lasiorhinus latifrons) by stunning

2003 ◽  
Vol 30 (5) ◽  
pp. 539 ◽  
Author(s):  
David A. Taggart ◽  
Graeme R. Finlayson ◽  
Nadine Richings ◽  
Glenn Shimmin ◽  
Ron Dibben ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Success Rate ◽  
Controlling Factors ◽  
Dew Point ◽  
Optimal Conditions ◽  
Factors Affecting ◽  
Air Density ◽  
Temperature And Humidity ◽  
Point Light ◽  
Capture Technique

A 'stunning' technique, combining a rifle shot with spotlighting and hand netting was used for the live-capture of southern hairy-nosed wombats. A successful stun was defined as a rifle shot that resulted in the temporary deafening and disorientation of a wombat. When combined with spotlighting, this technique enabled catchers with nets to approach the wombat undetected to secure an easy capture. Environmental factors (temperature, humidity, dew point, light and wind) were examined in order to determine the optimal conditions for the use of this capture procedure. In all, 558 shots were fired, resulting in ~25% of successful stuns. Stunning was primarily affected by temperature and humidity in a normally distributed manner. Stunning was greatest between 12°C and 18°C with a success rate of 40–51%. At temperatures either side of this significantly fewer stuns were achieved, and below 6°C or above 24°C no successful stuns were recorded. Likewise, stunning worked best at humiditys of 70–90%, declined when humidity was >90% and did not work at all at a humidity of 40% or less. Together, temperature and humidity data suggest that air density, for which these parameters are correlates, may be the key component in the success of this capture technique. Variation in stunning success resulting from changes in temperature and humidity may affect either the frequency spectrum of the sound created by the shot or perhaps the manner in which the eardrum receives the sound. Other factors, including dew point and light, also varied significantly with stunning, but were considered of less importance. Whatever the controlling factors, it was clear that stunning, in combination with spotlighting and netting is a rapid, highly effective, and potentially much less stressful method of capturing southern hairy-nosed wombats than the methods that have been used previously.

THE FEATURES OF BIODESTRUCTION PROCESSES OF THE SURFACES OF HYDRAULIC ENGINEERING CONSTRUCTIONS

2017 ◽  
Author(s):  
Marina Vasilenko ◽  
Marina Vasilenko ◽  
Elena Goncharova ◽  
Elena Goncharova ◽  
Yury Rubanov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Environmental Factors ◽  
Food Chain ◽  
Building Materials ◽  
Microbial Growth ◽  
Mineralogical Composition ◽  
Mechanical Action ◽  
Chemical Processes ◽  
Hydraulic Engineering ◽  
Optimal Conditions

The surfaces of building materials of hydrotechnical constructions undergo the process of algae biofouling. The degree of damage depends on the environmental factors that are affect-ed by the level of anthropogenic load areas. Modeling the biofouling process of concrete with algae under laboratory conditions has allowed determining their impact on the building ma-terial, accompanied by changes in chemical and mineralogical composition of the surface of products. The microscopic examination of sample’s surfaces and evaluation of the effective-ness of various ions leaching from building materials shows the results of "algal attack" relat-ed to the acceleration of biodegradation of materials under the influence of aggressive meta-bolic products, mechanical action neoplasms, creating optimal conditions for the development of subsequent aerobic microbial decomposers. To clarify the nature of chemical processes in the system “algocenosis – concrete” the changes of chemical and phase (mineralogical) com-position of the surface layer of concrete sample were studied. The effect that algae produce on hydraulic engineering constructions is due to the fact that these organisms, belonging to phototrophs and standing at the beginning of the food chain, initiate new microbial growth.

THE FEATURES OF BIODESTRUCTION PROCESSES OF THE SURFACES OF HYDRAULIC ENGINEERING CONSTRUCTIONS

2017 ◽  
Author(s):  
Marina Vasilenko ◽  
Marina Vasilenko ◽  
Elena Goncharova ◽  
Elena Goncharova ◽  
Yury Rubanov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Environmental Factors ◽  
Food Chain ◽  
Building Materials ◽  
Microbial Growth ◽  
Mineralogical Composition ◽  
Mechanical Action ◽  
Chemical Processes ◽  
Hydraulic Engineering ◽  
Optimal Conditions

The surfaces of building materials of hydrotechnical constructions undergo the process of algae biofouling. The degree of damage depends on the environmental factors that are affect-ed by the level of anthropogenic load areas. Modeling the biofouling process of concrete with algae under laboratory conditions has allowed determining their impact on the building ma-terial, accompanied by changes in chemical and mineralogical composition of the surface of products. The microscopic examination of sample’s surfaces and evaluation of the effective-ness of various ions leaching from building materials shows the results of "algal attack" relat-ed to the acceleration of biodegradation of materials under the influence of aggressive meta-bolic products, mechanical action neoplasms, creating optimal conditions for the development of subsequent aerobic microbial decomposers. To clarify the nature of chemical processes in the system “algocenosis – concrete” the changes of chemical and phase (mineralogical) com-position of the surface layer of concrete sample were studied. The effect that algae produce on hydraulic engineering constructions is due to the fact that these organisms, belonging to phototrophs and standing at the beginning of the food chain, initiate new microbial growth.

Environmental factors affecting reproducibility of bioremediation field assays in Antarctica

2020 ◽  
Vol 169 ◽  
pp. 102915 ◽  
Author(s):  
L.M. Martínez Álvarez ◽  
L.A.M. Ruberto ◽  
J.M. Gurevich ◽  
W.P. Mac Cormack
Keyword(s):  
Environmental Factors ◽  
Factors Affecting

scholarly journals Impact of Environmental Factors on Stilbene Biosynthesis

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 90
Author(s):  
Alessio Valletta ◽  
Lorenzo Maria Iozia ◽  
Francesca Leonelli
Keyword(s):  
Environmental Factors ◽  
Biosynthetic Pathway ◽  
In Planta ◽  
Organ Cultures ◽  
Related Plant ◽  
Valuable Compounds ◽  
Stilbene Compounds ◽  
Stilbene Biosynthesis ◽  
Abiotic Environmental Factors

Stilbenes are a small family of polyphenolic secondary metabolites that can be found in several distantly related plant species. These compounds act as phytoalexins, playing a crucial role in plant defense against phytopathogens, as well as being involved in the adaptation of plants to abiotic environmental factors. Among stilbenes, trans-resveratrol is certainly the most popular and extensively studied for its health properties. In recent years, an increasing number of stilbene compounds were subjected to investigations concerning their bioactivity. This review presents the most updated knowledge of the stilbene biosynthetic pathway, also focusing on the role of several environmental factors in eliciting stilbenes biosynthesis. The effects of ultraviolet radiation, visible light, ultrasonication, mechanical stress, salt stress, drought, temperature, ozone, and biotic stress are reviewed in the context of enhancing stilbene biosynthesis, both in planta and in plant cell and organ cultures. This knowledge may shed some light on stilbene biological roles and represents a useful tool to increase the accumulation of these valuable compounds.

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