Effects of temperature, moisture, substrates and soil coverage on sclerotium germination and hyphal growth of Southern blight of apple in China

2021 ◽  
Author(s):  
Xiang-li Dong ◽  
Chang-yan Gao ◽  
Ping-liang Li ◽  
Sen Lian ◽  
Shan-yue Zhou ◽  
...  
Keyword(s):  
Hyphal Growth ◽  
Southern Blight ◽  
Effects Of Temperature

scholarly journals Effects of Temperature, Humidity, and Wound Age on Valsa mali Infection of Apple Shoot Pruning Wounds

Plant Disease ◽  
2016 ◽  
Vol 100 (12) ◽  
pp. 2394-2401 ◽  
Author(s):  
Chong Chen ◽  
Bao-Hua Li ◽  
Xiang-Li Dong ◽  
Cai-Xia Wang ◽  
Sen Lian ◽  
...  
Keyword(s):  
Hyphal Growth ◽  
Wound Age ◽  
Protective Film ◽  
Critical Periods ◽  
Effective Measure ◽  
Valsa Canker ◽  
Effects Of Temperature ◽  
Valsa Mali

Valsa canker, caused by Valsa mali, is a destructive disease of apple in China. The pathogen infects apple branches, mainly through pruning wounds, and causes branch and tree death. To determine the conditions required for V. mali infection through pruning wounds and growth within the xylem, pruning wounds on 1- to 4-year-old apple branches were inoculated with conidia in vitro under artificially controlled conditions and in vivo in the orchard. The effects of temperature, wetness duration, and wound age on conidial infection through pruning wounds as well as hyphal growth in the xylem were examined. The results showed that, after invading through pruning wounds, V. mali hyphae grew along xylem vessels, tracheids, and rays, expanding longitudinally and laterally. The hyphae could enter adjacent xylem vessels and tracheids through micropores to form a dense hyphal network. Wetness duration did not exhibit an essential effect on conidial infection from pruning wounds. Conidia spread to pruning wounds with rainwater could infect the xylem without any other extra moisture. Temperature for V. mali conidia infection through pruning wounds and hyphal extension in the xylem ranged from 5 to 35°C, with the optimum at 20°C. Pruning wounds made in late March were susceptible to V. mali infection in March, April, and May; the susceptibility was markedly deceased by June, and the pathogen could barely infect through the pruning wounds in November. The infected pruning wounds began to show symptoms from the spring of the following year. More than half of the observed Valsa canker lesions emerged in the spring of the second year, and new canker twigs were also developed from the inoculations in the spring of the third year. March, April, and May are the critical periods for protecting pruning wounds against infection by V. mali in China, and coating pruning wounds with protective film immediately after pruning is an easy and effective measure to protect the pruning wounds.

Temperature-responded biological fitness of carbendazim-resistance Fusarium graminearum mutants conferring the F167Y, E198K and E198L substitutions

Plant Disease ◽  
2021 ◽  
Author(s):  
Yingfan Wang ◽  
Yi-ping Hou ◽  
XueWei Mao ◽  
fuyu Liu ◽  
Mingguo Zhou
Keyword(s):  
Low Temperature ◽  
Fusarium Graminearum ◽  
Hyphal Growth ◽  
Atmospheric Temperature ◽  
Cross Resistance ◽  
Wild Type ◽  
Head Blight ◽  
Flower Stage ◽  
Effects Of Temperature ◽  
Resistance Mutants

Understanding the effects of temperature on Fusarium graminearum infection can provide the theoretical guidance for chemical control of Fusarium head blight (FHB)．Here, we evaluated the effects of various temperatures on biological fitness development of wild-type sensitive strain 2021 and carbendazim-resistance mutants conferring β2-tubulin substitutions F167Y, E198K and E198L. The results showed that mycelial growth and conidiation of four strains increased with the increase of the temperature between 10°C and 25°C. Conidia of F167Y displayed strong adaptability to low temperature. The virulence of the four strains was largely similar at the same temperature, showing an upward trend between 10°C and 25°C. At 10°C, the hyphal growth of all strains was significantly inhibited, and metabolism slowed down and the accumulation of secondary metabolites decreased. Subsequently, the production of deoxynivalenol (DON) and its intermediate, pyruvate and aurofusarin decreased at low temperature, and the expression of DON biosynthesis-related genes Tri5, FgPK and AUR decreased accordingly. At the same temperature, the aurofusarin production of the strains F167Y and E198K was higher than that of strains 2021 and E198L. The contents of DON and pyruvic acid in carbendazim-resistance mutants were higher than that of the wild-type strain 2021. The sensitivity of four strains to different fungicides changed at various temperatures. The sensitivity to most fungicides increased with the temperature decreasing. The carbendazim-resistance mutants appeared positive cross-resistance with other benzimidazoles. But there was no cross-resistance to pyraclostrobin and azoles. These results would direct us to use fungicide preventing the infection of F. graminearum with changeable atmospheric temperature at wheat flower stage.

Microscopy studies of powdery mildew on summer squash

1991 ◽  
Vol 49 ◽  
pp. 520-521
Author(s):  
John S. Gardner ◽  
W. M. Hess
Keyword(s):  
Powdery Mildew ◽  
Tip Growth ◽  
Hyphal Growth ◽  
Plant Tissues ◽  
Vegetative Hypha ◽  
Powdery Mildews ◽  
Summer Squash ◽  
Conidial Formation ◽  
Polar Tip Growth ◽  
Short Conidiophore

Powdery mildews are characterized by the appearance of spots or patches of a white to grayish, powdery, mildewy growth on plant tissues, entire leaves or other organs. Ervsiphe cichoracearum, the powdery mildew of cucurbits is among the most serious parasites, and the most common. The conidia are formed similar to the process described for Ervsiphe graminis by Cole and Samson. Theconidial chains mature basipetally from a short, conidiophore mother-cell at the base of the fertile hypha which arises holoblastically from the conidiophore. During early development it probably elongates by polar-tip growth like a vegetative hypha. A septum forms just above the conidiophore apex. Additional septa develop in acropetal succession. However, the conidia of E. cichoracearum are more doliform than condia from E. graminis. The purpose of these investigations was to use scanning electron microscopy (SEM) to demonstrate the nature of hyphal growth and conidial formation of E. cichoracearum on field-grown squash leaves.

Effects of temperature on life history set the sensitivity to fishing in Atlantic cod Gadus morhua

2014 ◽  
Vol 514 ◽  
pp. 217-229 ◽  
Author(s):  
HY Wang ◽  
LW Botsford ◽  
JW White ◽  
MJ Fogarty ◽  
F Juanes ◽  
...  
Keyword(s):  
Life History ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Effects Of Temperature

Relationships between temperature and Pacific hake distribution vary across latitude and life-history stage

2020 ◽  
Vol 639 ◽  
pp. 185-197 ◽  
Author(s):  
MJ Malick ◽  
ME Hunsicker ◽  
MA Haltuch ◽  
SL Parker-Stetter ◽  
AM Berger ◽  
...  
Keyword(s):  
Life History ◽  
Environmental Effects ◽  
Environmental Conditions ◽  
Vancouver Island ◽  
Additive Models ◽  
Life History Stage ◽  
Fish Stocks ◽  
Merluccius Productus ◽  
Multiple Dimensions ◽  
Effects Of Temperature

Environmental conditions can have spatially complex effects on the dynamics of marine fish stocks that change across life-history stages. Yet the potential for non-stationary environmental effects across multiple dimensions, e.g. space and ontogeny, are rarely considered. In this study, we examined the evidence for spatial and ontogenetic non-stationary temperature effects on Pacific hake Merluccius productus biomass along the west coast of North America. Specifically, we used Bayesian additive models to estimate the effects of temperature on Pacific hake biomass distribution and whether the effects change across space or life-history stage. We found latitudinal differences in the effects of temperature on mature Pacific hake distribution (i.e. age 3 and older); warmer than average subsurface temperatures were associated with higher biomass north of Vancouver Island, but lower biomass offshore of Washington and southern Vancouver Island. In contrast, immature Pacific hake distribution (i.e. age 2) was better explained by a nonlinear temperature effect; cooler than average temperatures were associated with higher biomass coastwide. Together, our results suggest that Pacific hake distribution is driven by interactions between age composition and environmental conditions and highlight the importance of accounting for varying environmental effects across multiple dimensions.

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