Effects of water on germination of powdery mildew conidia

Las cenicillas en cultivos agrícolas de Sinaloa: Situación actual sobre su identificación y líneas futuras de investigación

“…Although mildew is common and causes considerable damage in cool areas; they are even more common and severe in areas with warm, dry climates, because in these conditions the wind easily detaches and spreads the conidia (RomeroCova, 1988); also, it has been established that mildew presents itself in the succulent tissue of the host in cool, shady areas (Yarwood, 1973). The lives of conidia are brief and they are favored by high relative humidity, but not by rain and inmersion in water (Sivapalan, 1993a;Sivapalan, 1993b). In general, the mycelium is epiphitic, except in genuses Leveillula, Phyllactinia, Pleochaeta where the mycelium is hemi-endophytic, and occasionally in species of Cystotheca; in this case, hyphae penetrate the leaves through the stomata and form mycelia inside, although the mycelia of the species of Leveillula are more abundant inside the leaf of the host (Braun et al, 2002).…”

“…In con clima cálido y seco, porque en estas condiciones el viento fácilmente desprende y disemina los conidios (Romero-Cova, 1988); además se ha establecido que, las cenicillas se presentan en tejido suculento del hospedante en ambientes sombreados y frescos (Yarwood, 1973). La vida de los conidios es corta y les favorecen altos niveles de humedad relativa, pero no son favorecidos por lluvia e inmersión en agua (Sivapalan, 1993a;Sivapalan, 1993b). En general, el micelio es epifítico excepto en los géne-ros Leveillula, Phyllactinia, Pleochaeta el micelio es hemiendofítico y ocasionalmente en especies de Cystotheca; en este caso, las hifas penetran las hojas a través de los estomas y forman micelio en el interior, sin embargo, el micelio de las especies de Leveillula es más abundante en el interior de la hoja del hospedante (Braun et al, 2002).…”

Assessment of Partial Resistance to Powdery Mildew (Podosphaera pannosa) in a Tetraploid Rose Population Using a Spore-suspension Inoculation Method

“…Water appears to have a negative effect on the germination and viability of mildew conidia (Yarwood, 1939;Wheeler, 1973). An extensive study of the effects of water on the germination of conidia from a variety of mildew species conducted by Sivapalan (1993), however, indicated that short-time storage of conidia in water will not dramatically affect their ability to infect leaves. Our findings are in agreement with his observations.…”

“…The use of spore suspensions in water has been extensively employed for the inoculation of powdery mildew in cucumber (Zijlstra et al, 1995), tomato (Bai et al, 2003) and pepper (Lefebvre et al, 2003), but has never been used in rose since research has shown that water adversely affects the viability and infectivity of the conidia (Yarwood, 1939;Wheeler, 1973). However, Sivapalan (1993) observed that mildew conidia differ in their ability to germinate in water, depending on mildew species and duration of conidial exposure to water.…”

Programmeringsstudie Meeldauw : Invloed van bestaande en nieuwe interventies op geïnduceerde weerbaarheid tegen biotrofe schimmel

“…Van meeldauwsporen op roos is bekend dat deze gevoelig zijn voor vrij water (Sivapalan, 1993) en dat infecties makkelijker uit te voeren zijn met droge sporen dan vanuit sporensuspensies. Dat deze eigenschappen ook van toepassing zijn op gerberasporen was tot nu toe nog niet zo bekend.…”