Effect of temperature, relative humidity and light on conidial germination of oak powdery mildew (Microsphaera alphitoides Griff. et Maubl.) under controlled conditions

Abstract

The influence of temperature, humidity and light on the conidial germination and germ tube elongation of oak powdery mildew (Microsphaera alphitoides Griff. et Maubl.) was studied in controlled conditions. The maximal germ tube length was attained at 25°C, whereas at lower and higher than optimal temperatures, germ tube growth was significantly lower. Germ tubes begin to develop at all values of relative humidity (10-100%), reaching the maximum length at 90%. The development of germ tubes was the most intense in full light and the lowest in total darkness. The artificial infection of floating leaves showed that an increasing age had an inhibitory effect on the mycelium development and spore formation. Since conidia play a crucial role in powdery mildew epidemiology, it is of particular importance to elucidate the influence of environmental factors in the complex relations that exist between the plant and its pathogen. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Studying climate change and its influence on the environment: Impacts, adaptation and mitigation

Plant age and ambient temperature: significant drivers for powdery mildew (Erysiphe cruciferarum) epidemics on oilseed rape (Brassica napus)

“…Mild temperatures favoured the development of E. cruciferarum . The finding in the current study that the maximum growth of E. cruciferarum germ tubes was reached at 15–20 °C and survival of conidia was reduced by temperatures greater than 30 °C is similar to results published for other genera and/or species of powdery mildew such as E. necator (Moyer et al ., ; Peduto et al ., ), P. macularis (Peetz et al ., ), Microsphaera alphitoide s (Pap et al ., ) and Podosphaera clandestina (Grove, ). Ambient temperature is one of the factors that dramatically affects the success of powdery mildew infections, and mild temperatures generally favour the disease.…”

Defense Compounds Rather Than Nutrient Availability Shape Aggressiveness Trait Variation Along a Leaf Maturity Gradient in a Biotrophic Plant Pathogen

“…Variation in latent period and spore volume might have been affected by an unidentified environmental factor. Even though inoculated leaf disks were incubated under controlled conditions of temperature and light, micro-scale variation may have occurred for these crucial parameters influencing fungal development and infection dynamics ( Cochrane, 1959 ; Rotem et al, 1978 ; Trapero-Casas and Kaiser, 1992 ; Turechek and Stevenson, 1998 ; Turechek et al, 2001 ; Pap et al, 2013 ). Moreover, the initial position of the disk in the leaf might have influenced infection outcome ( Katsuya and Green, 1967 ; Johnston et al, 2016 ).…”

Microclimate in agrosilvopastoral system enhances powdery mildew severity compared to agropastoral and non-integrated crop

“…In addition to providing shorter leaf wetness, temperature changes provided by the trees in ASP may have contributed directly to greater PM severity. It was demonstrated that low variation in temperature favors M. diffusa (Phillips 1984;Alves et al 2009;Pap et al 2013), while greater variation reduces infection. In the present work, a smaller temperature difference was observed in the ASP, with similar nighttime and daytime temperatures.…”