Effects of Acute Low-Temperature Events on Development ofErysiphe necatorand Susceptibility ofVitis vinifera

Abstract

Growth and development of Erysiphe necator (syn. Uncinula necator) has been extensively studied under controlled conditions, primarily with a focus on development of grapevine powdery mildew within the optimal temperature range and the lethal effects of high temperatures. However, little is known of the effect of cold temperatures (above freezing but <8 degrees C) on pathogen development or host resistance. Pretreatment of susceptible Vitis vinifera leaf tissue by exposure to cold temperatures (2 to 8 degrees C for 2 to 8 h) reduced infection efficiency and colony expansion when tissues were subsequently inoculated. Furthermore, nascent colonies exposed to similar cold events exhibited hyphal mortality, reduced expansion, and increased latent periods. Historical weather data and an analysis of the radiational cooling of leaf tissues in the field indicated that early-season cold events capable of inducing the foregoing responses occur commonly and frequently across many if not most viticultural regions worldwide. These phenomena may partially explain (i) the unexpectedly slow development of powdery mildew during the first month after budbreak in some regions and (ii) the sudden increase in epidemic development once seasonal temperatures increase above the threshold for acute cold events.

The susceptibility of bananas to crown rot disease is influenced by geographical and seasonal effects

“…Low temperatures favour assimilate availability, and affects growth (plant size) more than carbon assimilation (Pollack, 1990;Equiza et al, 1997). Such effects of low temperatures on host resistance have also been reported for other pathosystems such as Bipolaris sorokiniana/barley, Puccinia poae-nemoralis/bluegrass and Erysiphe necator/Vitis vinifera through the possible triggering of biochemical pathways associated with disease resistance (Moyer et al, 2010). As for banana wound anthracnose (Chillet et al, 2007), it was hypothesized that in such low-temperature conditions, assimilates are produced in excess as indicated by the bigger grade observed in Ekona at harvest.…”

Pengaruh Kemasaman, Suhu, dan Cahaya terhadap Golovinomyces sordidus Penyebab Penyakit Embun Tepung pada Plantago major

“…Inkubasi pada suhu 36 °C atau lebih tinggi selama 12 jam akan menyebabkan koloni E. necator tidak mampu bersporulasi meskipun lingkungan kembali normal (Peduto et al 2013). Cendawan E. necator apabila diinkubasi pada suhu 8 °C akan menghasilkan apresorium yang lebih sedikit tetapi percabangan hifa yang lebih banyak dibandingkan dengan yang diinkubasi pada 2 °C (Moyer et al 2010). Suhu merupakan faktor lingkungan yang penting untuk ketahanan tanaman, E trifolii mampu menginfeksi kacang kapri (P. sativum) yang mengandung gen tahan Er3, ditandai adanya koloni embun tepung pada hari ke-9 apabila tanaman diinkubasi pada suhu 25 °C, tetapi tidak apabila diinkubasi pada 20 °C (Fondevilla et al 2013).…”

Cold Stress-Induced Disease Resistance (SIDR): indirect effects of low temperatures on host-pathogen interactions and disease progress in the grapevine powdery mildew pathosystem

“…Temperature has been well documented in terms of its influence on the grapevine host (Bogoni et al 1993;Buttrose and Hale 1973;Ferrini et al 1995;Flexas et al 1999;Greer and Weedon 2013;Hendrickson et al 2004;Keller and Tarara 2010;Parker et al 2011) and powdery mildew pathogen (Austin and Wilcox 2011;Chellemi and Marois 1991c;Choudhury et al 2014;Delp 1954;Diehl and Heintz 1987;Gadoury and Pearson 1990;Hall and Mahaffee 2001;Jailloux et al 1999;Moyer et al 2010;Peduto et al 2013;Rumbolz et al 2000). The effect of temperature on the host and pathogen is key to many forecast and disease epidemic simulation models (Bendek et al 2007;Caffi et al 2011;Calonnec et al 2008;Chellemi and Marois 1991a;Kast and Bleyer 2010;Legler et al 2012a;Moyer et al 2014;Peduto et al 2013;Sall 1980).…”

“…They may also include high temperature limitations that most commonly occur in the mid-to late parts of the growing season. However, in nearly all viticultural regions, sub-optimal low temperature often occur with great frequency during the early stages of the epidemic development (Moyer et al 2010). Acute low temperature events (e.g., 4°C for 1 h) result in a transiently reduced susceptibility in leaves of V. vinifera (Moyer et al 2010).…”

“…However, in nearly all viticultural regions, sub-optimal low temperature often occur with great frequency during the early stages of the epidemic development (Moyer et al 2010). Acute low temperature events (e.g., 4°C for 1 h) result in a transiently reduced susceptibility in leaves of V. vinifera (Moyer et al 2010). This response has been observed in young, susceptible leaves (those that have not developed ontogenic, or age-related resistance), and the phenotype mimics the response observed as infected leaves acquire ontogenic resistance.…”