Release, germination, and pathogenicity of ascospores of Uncinula necator under controlled conditions

1998 ◽  
Vol 76 (5) ◽  
pp. 777-781 ◽  
Author(s):  
F Jailloux ◽  
T Thind ◽  
M Clerjeau
Keyword(s):  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Storage Conditions ◽  
Vitis Vinifera L ◽  
Uncinula Necator ◽  
Grapevine Powdery Mildew ◽  
Germination Ability ◽  
Ascospore Release ◽  
Probable Role ◽  
Leaf Disks

A laboratory technique was standardized for studying the release, maturation, germination, and pathogenicity of ascospores of Uncinula necator (Schw.) Burr. Surface disinfestation and wetting of grape (Vitis vinifera L.) leaf disks bearing cleistothecia collected in the vineyard before incubation in a humid chamber for 48 h at 20°C were found essential for obtaining the release of ascospores (8 ascospores/cm2). Storage conditions involving periodic wetting treatments of cleistothecia at 5°C during 110 days were necessary to induce both ascospore release (80 ascospores/cm2) and germination ability (62%). The matured ascospores were pathogenic on healthy leaf disks at 20°C indicating their probable role as a primary inoculum source. This technique can be helpful in studying the inheritance of characteristics such as pathogenicity and fungicidal resistance.Key words: cleistothecia, ascospores, maturation, germination, pathogenicity, Uncinula necator, grapevine, powdery mildew.

Development of SCAR markers linked to powdery mildew (Uncinula necator) resistance in grapevine (Vitis vinifera L. and Vitis sp.)

2006 ◽  
Vol 19 (2) ◽  
pp. 103-111 ◽  
Author(s):  
Murat Akkurt ◽  
Leocir Welter ◽  
Erika Maul ◽  
Reinhard Töpfer ◽  
Eva Zyprian
Keyword(s):  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Vitis Vinifera L ◽  
Uncinula Necator ◽  
Scar Markers ◽  
Vitis Sp

Effect of weather factors on the release of ascospores of Uncinula necator, the cause of grape powdery mildew, in the Bordeaux region

1999 ◽  
Vol 77 (7) ◽  
pp. 1044-1051 ◽  
Author(s):  
F Jailloux ◽  
L Willocquet ◽  
L Chapuis ◽  
G Froidefond
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Weather Conditions ◽  
Vitis Vinifera L ◽  
Uncinula Necator ◽  
Good Growth ◽  
Bud Burst ◽  
Weather Factors ◽  
Average Temperature ◽  
Ascospore Release

During a 5-year period (1993-1997), the release of Uncinula necator (Schweiniz) Burrill ascospores was monitored under natural conditions in the Bordeaux region. Ascospore release always began after bud burst and generally ended before blossoming. The release periods of ascospores were always associated with a rainfall higher than 2 mm, a wetting duration greater than 2.5 h, an average temperature generally above 11°C and a daily mean temperature sum from November 1 to the first ascospore release above 1100°C. There was no relation between earliness, number of ascospores released, and disease severity on grapes (Vitis vinifera L. cv. Merlot). The primary infection did not appear to be important for the increase of the powdery mildew population; on the other hand, the weather conditions of April (rainfall and temperature) seemed to strongly influence disease severity on berries by enabling good growth of the pathogen on leaves. These findings could be used to determine the optimal dates of the first fungicide treatments for powdery mildew according to the weather conditions.Key words: cleistothecia, ascospores, release, weather conditions, powdery mildew, Uncinula necator, grapevine.

scholarly journals Suppression of Grapevine Powdery Mildew by a Mycophagous Mite

Plant Disease ◽  
2005 ◽  
Vol 89 (12) ◽  
pp. 1331-1338 ◽  
Author(s):  
Heather S. Melidossian ◽  
Robert C. Seem ◽  
Greg English-Loeb ◽  
Wayne F. Wilcox ◽  
David M. Gadoury
Keyword(s):  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Uncinula Necator ◽  
Laboratory Studies ◽  
Rapid Loss ◽  
Infection Efficiency ◽  
Grapevine Powdery Mildew ◽  
Grape Powdery Mildew

Orthotydeus lambi reduced the severity of grape powdery mildew (Uncinula necator) on fruit and foliage of Vitis vinifera ‘Chardonnay’ and ‘Riesling’ in repeated field and laboratory trials. Vines were infested with O. lambi at two densities (5 or 30 mites per leaf) at each of two times (2 to 3 weeks prebloom and 1 week postbloom). Overall, powdery mildew on the berries and foliage was suppressed by early (prebloom) mite releases at both densities, but only by the higher density in late (postbloom) releases. In a separate trial, when foliage was infested at 30 mites per leaf but mites were excluded from certain fruit clusters, severity of powdery mildew was significantly reduced on the mite-free clusters of mite-infested shoots. Thus, O. lambi may suppress powdery mildew on the fruit by reducing inoculum from foliar infections. In laboratory studies, both immature and mature mites reduced infection efficiency, colony expansion, and sporulation of the mildew colonies; but immature mites were more voracious feeders, consuming more pathogen biomass per unit of mite biomass. Mites tore at the mycelium and conidia with their palps during feeding, leading to leakage, rapid loss of hyphal turgor, and collapse of hyphae.

The Effect of Downy and Powdery Mildew on Grapevine (Vitis vinifera L.) Leaf Gas Exchange

2005 ◽  
Vol 153 (6) ◽  
pp. 350-357 ◽  
Author(s):  
M. Moriondo ◽  
S. Orlandini ◽  
A. Giuntoli ◽  
M. Bindi
Keyword(s):  
Gas Exchange ◽  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Leaf Gas Exchange ◽  
Vitis Vinifera L

scholarly journals Powdery mildew infection dependent on weather factors in vineyards near Keszthely in 2008

2010 ◽  
Vol 16 (2) ◽  
Author(s):  
P. Taksony ◽  
E. Tarczal ◽  
K. Maráczi ◽  
I. J. Holb ◽  
L. Kocsis
Keyword(s):  
High Temperature ◽  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Vitis Vinifera L ◽  
Weather Factors ◽  
Vegetative Period ◽  
Favorable Conditions ◽  
Powdery Mildew Infection

Weather conditions are extremely influential on grapevine productivity and quality. High temperature and humidity makes favorable conditions for powdery mildew infection respectively. The meteorological data around Keszthely, Hungary show the vegetative period is dryer and warmer than it was closely hundred years ago. We examined the development of powdery mildew infection  on  two variet ies Vitis vinifera L. cv Italian Riesling and cv Merlot in relation with meteorological data. No primer infections were appeared in the vineyard. The year of 2008 was quite ideal for the accumulation of Erysiphe necator in the experimental vineyard. Although the dry summer can lower the infection, but if the high temperature is coupling with rainfall, the possibilities of powdery mildew infection is going to grow higher during the upcoming years.

Vitis Species from the Southwestern United States Vary in Their Susceptibility to Powdery Mildew

Plant Disease ◽  
2021 ◽  
pp. PDIS-10-20-2103
Author(s):  
Laila Fayyaz ◽  
Alan Tenscher ◽  
Andy Viet Nguyen ◽  
Huma Qazi ◽  
M. Andrew Walker
Keyword(s):  
United States ◽  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Resistance Breeding ◽  
Vitis Vinifera L ◽  
Southwestern United States ◽  
Breeding Programs ◽  
Vitis Species ◽  
Northern Mexico ◽  
Eastern Species

The European grapevine (Vitis vinifera L.) has been cultivated in North America for about 500 years. One of the major limitations to its culture is the powdery mildew (PM) fungus, Erysiphe necator Schw. This study reports on the most extensive screening of Vitis species from the southwestern United States and northern Mexico for resistance to PM, testing 147 accessions of 13 Vitis species. In addition, Vitis vinifera cv. Carignane, a highly susceptible wine grape cultivar, was used as a reference to evaluate the effect of the inoculum 14 days postinoculation. Inoculation was done with a vacuum-operated settling tower using a broadly virulent isolate of E. necator, the C-strain. Resistant accessions (nine), moderately susceptible accessions (39), and highly susceptible accessions (99) were detected. The resistant accessions were then inoculated with an additional fungal isolate, e1-101, and they retained their resistance. Vitis species susceptibility was not associated with a North-South gradation, but Western species were more susceptible than Midwestern and Eastern species. All five of the V. monticola accessions were susceptible, as were the accessions of V. treleasei. The species V. acerifolia, V. candicans, V. cinerea, and V. × doaniana had significantly more resistant to moderately susceptible accessions compared with V. arizonica, V. berlandieri, V. californica, V. × champinii, V. girdiana, V. riparia, and V. rupestris, which had relatively more susceptible accessions than the other species. This research identified new sources of PM resistance in Vitis from the southwestern United States that could be incorporated into PM resistance breeding programs throughout the world.

Uncinula necator. [Descriptions of Fungi and Bacteria].

1967 ◽  
Author(s):  
J. N. Kapoor
Keyword(s):  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Geographical Distribution ◽  
World Wide ◽  
Uncinula Necator

Abstract A description is provided for Uncinula necator. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Vitis spp., chiefly Vitis vinifera; also on Parthenocissus spp., Ampelopsis spp. DISEASE: Powdery mildew of vine. GEOGRAPHICAL DISTRIBUTION: World-wide. TRANSMISSION: Conidia and mycelium overwinter in diseased buds, fallen berries or on overwintered stems. Cleistothecia, when formed, are capable of overwintering (Blumer, 1967).

In silico development of microsatellites associated with resistance genes to powdery mildew in Vitis vinifera L.

2020 ◽  
pp. 493-498
Author(s):  
S. Mojemmi ◽  
M. Mdarhri Alaoui ◽  
F. Rchok ◽  
Z.E.A. Triqui ◽  
O. Chlyah ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Resistance Genes ◽  
In Silico ◽  
Vitis Vinifera L
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