scholarly journals Interactive effects of biotic stressors and provenance on chemical defence induction by holm oak (Quercus ilex)

Trees ◽  
2021 ◽  
Author(s):  
Manuela Rodríguez-Romero ◽  
Alejandro Gallardo ◽  
Andrea Pérez ◽  
Fernando Pulido
Keyword(s):  
Quercus Ilex ◽  
Phytophthora Cinnamomi ◽  
Material Selection ◽  
Interactive Effect ◽  
Genetic Material ◽  
Chemical Defence ◽  
Holm Oak ◽  
Interactive Effects ◽  
Induced Response ◽  
Chemical Defences

Abstract Key Message The patterns of induced chemical defences in Quercus ilex leaves are specific to the biotic stress factor that causes them. Interactive effects between stressors depend on provenance. Abstract Quercus forests are suffering serious decline worldwide, closely linked to the consequences of climate change. The increase of biotic stressors threatens the survival of the holm oak (Quercus ilex), a dominant tree species in the Mediterranean Basin. A better understanding of its resistance mechanisms is urgently required to enable a better control of its decline. In this work, the ability of holm oaks from six Iberian provenances to respond to multiple biotic damage is studied through an analysis of their induced chemical defence patterns. Using 2016 seedlings established in a common garden trial (6 regions × 12 families/region × 7 seedlings/family × 4 treatments), biotic damage was induced at the root level (by infection with the widespread pathogen Phytophthora cinnamomi) and at the above-ground level (by mechanical defoliation). The levels of constitutive and induced total phenols, total tannins and condensed tannins were measured. Results showed that (1) the defensive chemical patterns present significant local and geographical variation, (2) survival to stress is more related to constitutive defences than induced ones, (3) the induced response is stressor-specific, and (4) there is an interactive effect amongst stressors whose sign (induction/inhibition) depends on the provenance. These findings on biotic stressor effects on the chemical defences and survival of holm oak can contribute to the development of genetic material selection programs in the integrated control of the widespread decline of Quercus.

scholarly journals Factores ambientales en la distribución de la seca en la encina (Quercus ilex subsp. ballota) = Environmental Variables in the Distribution of La Seca Disease in the Holm Oak (Quercus Ilex Subsp. Ballota)

2018 ◽  
pp. 107
Author(s):  
Mario Corral Ribera ◽  
Concepción Fidalgo Hijano ◽  
Begoña Peco Vázquez
Keyword(s):  
Environmental Variables ◽  
Quercus Ilex ◽  
Phytophthora Cinnamomi ◽  
Abiotic Factors ◽  
Information Criteria ◽  
Holm Oak ◽  
Oak Decline ◽  
Topographic Wetness Index ◽  
Daphne Gnidium ◽  
Field Samples

La combinación de factores bióticos y abióticos (clima, orografía, litología, competencia interespecífica, etc.) y la patogenicidad de agentes como el hongo Phytophthora cinnamomi Rands han generado la enfermedad fitosanitaria denominada en España como la seca de encinas y alcornoques de la Península Ibérica. El objetivo del presente estudio es el análisis que desempeñan las variables ambientales en el desarrollo de dicha enfermedad y determinar cuáles tienen una mayor influencia en su propagación. Se toma como área de estudio el Monte de Valdelatas, Alcobendas, Madrid (hoja 534 del Mapa Topográfico Nacional a escala 1:50.000. Coordenadas UTM X: X: 442592.51, Y: 4487266.63 zona 30T). Se obtivieron muestras en campo de 100 árboles de Quercus ilex subsp. ballota (50 con apariencia saludable y 50 con síntomas aparentes de enfermedad) azarosamente ubicados en 7 transectos. En relación al modelo estadístico se empleó un modelo binomial cuya variable respuesta se definió como sano/enfermo, según la apariencia del árbol. Así mismo, se manejó el Criterio de Información de Akaike (AIC) con el fin de establecer el mejor modelo. En su caso, presentando un 44% de la varianza (D2 = 0.437) y un valor de 89.68 en AIC. Las principales variables ambientales que interfieren en la enfermedad fueron: proximidad a cursos fluviales, índice de humedad topográfico, cobertura de Daphne gnidium y Quercus ilex subsp. ballota y la edad de los individuos muestreados. Dada la pérdida en la masa forestal de Quercus debido a la enfermedad de la seca, es necesario comprender el comportamiento de dicha enfermedad, así como conocer los factores ambientales que contribuyen a su expansión, pudiendo llegar de tal modo a identificar algún factor inhibidor. The combination of biotic and abiotic factors (climate, orography, lithology, interspecific competition, etc.) and the pathogenicity of agents such as the fungus Phytophthora cinnamomi Rands has generated the phytosanitary disease known as the oak decline (la seca) in holm oak and cork oak stand of the Iberian Peninsula. The aim of this study is to analyse the role played by environmental variables in the development of this disease, and to determine which have a stronger influence in the spread of the disease. Data has been obtained from Monte de Valdelatas, Alcobendas, Madrid (sheet 534 national topographic map, scale 1:50.000, UTM coordinates X: 442592.51, Y: 4487266.63 zone 30T). Field samples were taken from 100 randomly selected Quercus ilex subsp. ballota individuals (50 with a healthy appearance and 50 that showed disease symptoms), located within 7 transects. In relation to the statistical model, in this work a binomial model was used. On it, the response variable was defined as healthy/unhealthy, depending on the appearance of each tree. Akaike Information Criteria (AIC) was used to define the quality of the model. We selected model obtained a score of 89.68 and accounts for approximately 44% of data variability (D2 = 0,437). The main environmental variables that impact disease were: proximity to river course, topographic wetness index, cover of Daphne gnidium and Quercus ilex subsp. ballota, and the age of the individuals. Given the loss of Quercus forest mass caused by the spread of the oak decline disease, detected in several countries, including Spain, it becomes necessary to adequately understand the different factors that contribute and, in some cases, is the cause of the expansion of the disease, as well as to identify any inhibiting factors.

scholarly journals Differences in the Response to Acute Drought and Phytophthora cinnamomi Rands Infection in Quercus ilex L. Seedlings

Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 634 ◽  
Author(s):  
Francisco Ruiz Gómez ◽  
Alejandro Pérez-de-Luque ◽  
Rafael Sánchez-Cuesta ◽  
José Quero ◽  
Rafael Navarro Cerrillo
Keyword(s):  
Water Stress ◽  
Biomass Allocation ◽  
Root Rot ◽  
Tree Mortality ◽  
Quercus Ilex ◽  
Phytophthora Cinnamomi ◽  
Growth Patterns ◽  
Holm Oak ◽  
Stress Factors ◽  
Oak Decline

The sustainability of “dehesas” is threatened by the Holm oak decline. It is thought that the effects of root rot on plant physiology vary depending on external stress factors. Plant growth and biomass allocation are useful tools to characterize differences in the response to drought and infection. The study of physiological responses together with growth patterns will clarify how and to what extent root rot is able to damage the plant. A fully factorial experiment, including drought and Phytophtora cinnamomi Rands infection as factors, was carried out with Quercus ilex L. seedlings. Photosynthesis, biomass allocation and root traits were assessed. Photosynthetic variables responded differently to drought and infection over time. The root mass fraction showed a significant reduction due to infection. P. cinnamomi root rot altered the growth patterns. Plants could not recover from the physiological effects of infection only when the root rot coincided with water stress. Without additional stressors, the strategy of our seedlings in the face of root rot was to reduce the biomass increment and reallocate resources. Underlying mechanisms involved in plant-pathogen interactions should be considered in the study of holm oak decline, beyond the consideration of water stress as the primary cause of tree mortality.

scholarly journals Small-Scale Abiotic Factors Influencing the Spatial Distribution of Phytophthora cinnamomi under Declining Quercus ilex Trees

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 375
Author(s):  
Rafael Sánchez-Cuesta ◽  
Rafael M. Navarro-Cerrillo ◽  
José L. Quero ◽  
Francisco J. Ruiz-Gómez
Keyword(s):  
Spatial Analysis ◽  
Spatial Patterns ◽  
Quercus Ilex ◽  
Phytophthora Cinnamomi ◽  
Abiotic Factors ◽  
Canopy Cover ◽  
Holm Oak ◽  
Small Scale ◽  
Aggregation Index ◽  
Phytophthora Root Rot

Phytophthora root rot is considered one of the main factors associated with holm oak (Quercus ilex L.) mortality. The effectiveness and accuracy of soilborne pathogen and management could be influenced by soil spatial heterogeneity. This factor is of special relevance in many afforestation of southwestern Spain, which were carried out without phytosanitary control of the nursery seedlings. We selected a study area located in a 15 year-old afforestation of Q. ilex, known to be infested by Phytophthora cinnamomi Rands. Soil samples (ntotal = 132) were taken systematically from a grid under 4 trees, and analysed to quantify 12 variables, the colony forming units (cfu) of P. cinnamomi plus 11 physical and chemical soil properties. The combined analysis of all variables was performed with linear mixed models (GLMM), and the spatial patterns of cfu were characterised using an aggregation index (Ia) and a clustering index (ν) by SADIE. Cfu values ranged from 0 to 211 cfu g−1, and the GLMM built with the variables silt, P, K and soil moisture explained the cfu distribution to the greatest extent. The spatial analysis showed that 9 of the 12 variables presented spatial aggregation (Ia > 1), and the clustering of local patches (νi ≥ 1.5) for organic matter, silt, and Ca. The spatial patterns of the P. cinnamomi cfu under planted holm oak trees are related to edaphic variables and canopy cover. Small-scale spatial analysis of microsite variability can predict which areas surrounding trees can influence lower oomycetes cfu availability.

scholarly journals Phytophthora cinnamomi Involved in the Decline of Holm Oak (Quercus ilex) Stands in Southern Italy

2018 ◽  
Vol 64 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Salvatore Frisullo ◽  
Giuseppe Lima ◽  
Gaetano Magnano di San Lio ◽  
Ippolito Camele ◽  
Luigi Melissano ◽  
...  
Keyword(s):  
Quercus Ilex ◽  
Southern Italy ◽  
Phytophthora Cinnamomi ◽  
Holm Oak

Physiological and proteomics analyses of Holm oak (Quercus ilex subsp. ballota [Desf.] Samp.) responses to Phytophthora cinnamomi

2013 ◽  
Vol 71 ◽  
pp. 191-202 ◽  
Author(s):  
Besma Sghaier-Hammami ◽  
José Valero-Galvàn ◽  
Mª Cristina Romero-Rodríguez ◽  
Rafael Mª Navarro-Cerrillo ◽  
Chedly Abdelly ◽  
...  
Keyword(s):  
Quercus Ilex ◽  
Phytophthora Cinnamomi ◽  
Holm Oak

scholarly journals A method to quantify infection and colonization of holm oak (Quercus ilex) roots by Phytophthora cinnamomi

Plant Methods ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 39 ◽  
Author(s):  
Francisco J Ruiz-Gómez ◽  
Rafael Sánchez-Cuesta ◽  
Rafael M Navarro-Cerrillo ◽  
Alejandro Pérez-de-Luque
Keyword(s):  
Quercus Ilex ◽  
Phytophthora Cinnamomi ◽  
Holm Oak

Interactive toxic effects of agrochemicals on aquatic organisms

1999 ◽  
Vol 40 (1) ◽  
pp. 357-364 ◽  
Author(s):  
A. Kungolos ◽  
P. Samaras ◽  
A. M. Kipopoulou ◽  
A. Zoumboulis ◽  
G. P. Sakellaropoulos
Keyword(s):  
Daphnia Magna ◽  
Marine Bacterium ◽  
Methyl Parathion ◽  
Vibrio Fischeri ◽  
Interactive Effect ◽  
Algal Growth ◽  
Aquatic Organisms ◽  
Interactive Effects ◽  
Selenastrum Capricornutum ◽  
Toxic Compound

The effects of three common agrochemicals, lindane, methyl parathion and atrazine, on crustacean Daphnia magna, alga Selenastrum capricornutum and marine bacterium Vibrio fischeri were investigated in this study. Methyl parathion was the most toxic compound towards all three organisms, while lindane was more toxic to Daphnia magna and Vibrio fischeri than atrazine, and atrazine was more toxic to Selenastrum capricornutum than lindane. Among the three aquatic organisms, Selenastrum capricornutum was most sensitive in detecting lindane and atrazine toxicity, while Daphnia magna was most sensitive in detecting methyl parathion toxicity. The interactive effects of the pesticides were also investigated. The interactive effect between lindane and methyl parathion on survival of Daphnia magna was synergistic, while the ones between lindane and atrazine and between methyl parathion and atrazine were generally additive. The interactive effect of the three pesticides applied together on Daphnia magna was synergistic. The interactive effect of the three pesticides on the growth of Selenastrum capricornutum was antagonistic with few cases of addition, while the effect of all the three pairs of pesticides on algal growth was also antagonistic. The interactive effect of lindane and methyl parathion on Vibrio fischeri was additive.

Categorization flexibility and unconventional choices: is life an adventure?

2020 ◽  
Vol 54 (8) ◽  
pp. 1963-1986
Author(s):  
Tilottama G. Chowdhury ◽  
Feisal Murshed
Keyword(s):  
Interactive Effect ◽  
Interactive Effects ◽  
Cognitive Capacity ◽  
Purchase Behavior ◽  
Consumer Decision Making ◽  
Cross Sectional ◽  
Content Type ◽  
Cross Domain ◽  
Multiple Domains

Purpose This paper proposes that categorization flexibility, operationalized as the cognitive capacity that cross-categorizes products in multiple situational categories across multiple domains, might favorably influence a consumer’s evaluation of unconventional options. Design/methodology/approach Experimental research design is used to test the theory. An exploratory study first establishes the effect of categorization flexibility in a non-food domain. Study 1 documents the moderating role of decision domain, showing that the effect works only under low- (vs high-) consequence domain. Studies 2A and 2B further refine the notion by showing that individuals can be primed in a relatively higher categorization flexibility frame of mind. Study 3 demonstrates the interactive effect of categorization flexibility and adventure priming in a high-consequence domain. Study 4 integrates the interactive effects of decisions with low- vs high-consequence, adventure priming and categorization flexibility within a single decision domain of high consequence. Findings Consumers with higher- (vs lower-) categorization flexibility tend to opt for unconventional choices when the decision domain entails low consequences, whereas such a result does not hold under decision domain of high consequences. The categorization flexibility effects in case of low-consequence decision domain holds true even when consumers are primed to be categorization flexible. Furthermore, with additional adventure priming, consumers show an increased preference for unconventional options even under a decision domain with high consequence. Research limitations/implications This study could not examine real purchase behavior as results are based on cross-sectional, behavioral intention data. In addition, it did not examine the underlying reason for presence of cross-domain categorization flexibility index. Practical implications The results suggest that stimuli may be tailored to consumers in ways that increase the salience and the perceived attractiveness of unconventional choices. Further, data reinforce the notion of cross-categorical interrelations among different domains, which could be leveraged by marketers. Originality/value This study represents the first documentation of the potential ways by which unconventional product choice might be a function of individuals’ categorization flexibility level across different types of decision domains. The findings yield implications that are novel to both categorization and consumer decision-making literature.

Wind tunnel tests and dynamic analysis of wind-induced response of a transmission tower on a hill

2021 ◽  
pp. 136943322110339
Author(s):  
Jian Guo ◽  
Changliang Xiao ◽  
Jiantao Li
Keyword(s):  
Wind Tunnel ◽  
Wind Field ◽  
Dynamic Responses ◽  
Interactive Effects ◽  
Induced Response ◽  
Transmission Tower ◽  
Structural Dynamic ◽  
Wind Tunnel Tests ◽  
Hill Slope ◽  
The Hill

A hill with a lattice transmission tower presents complex wind field characteristics. The commonly used computational fluid dynamics (CFD) simulations are difficult to analyze the wind resistance and dynamic responses of the transmission tower due to structural complexity. In this study, wind tunnel tests and numerical simulations are conducted to analyze the wind field of the hill and the dynamic responses of the transmission tower built on it. The hill models with different slopes are investigated by wind tunnel tests to measure the wind field characteristics, such as mean speed and turbulence intensity. The study shows that the existence of a transmission tower reduces the wind speed on the leeward slope significantly but has little effect on the windward slope. To study the dynamic behavior of the transmission tower, a hybrid analysis procedure is used by introducing the measured experimental wind information to the finite element tower model established using ANSYS. The effects of hill slope on the maximum displacement response of the tower are studied. The results show that the maximum value of the response is the largest when the hill slope is 25° compared to those when hill slope is 15° and 35°. The results extend the knowledge concerning wind tunnel tests on hills of different terrain and provide a comprehensive understanding of the interactive effects between the hill and existing transmission tower regarding to the wind field characteristics and structural dynamic responses.

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