Histological and ultrastructural studies on teh curative effects of mandipropamid on Plasmopara viticola
Articolo
Data di Pubblicazione:
2011
Citazione:
Histological and ultrastructural studies on teh curative effects of mandipropamid on Plasmopara viticola / S.L. Toffolatti, D. Maffi, L. Serrati, A. Vercesi. - In: JOURNAL OF PHYTOPATHOLOGY. - ISSN 0931-1785. - 159:4(2011), pp. 201-207.
Abstract:
The mandelic acid amide, mandipropamid, which
belongs to the carboxylic acid amide (CAA) fungicides,
is active against Plasmopara viticola, the causal
agent of grapevine downy mildew. The fungicide primarily
inhibits the germination of encysted zoospores,
thus preventing the pathogen s penetration into the
host tissues, but it also shows curative effects. In this
study, the infection structures of P. viticola in both
leaves and berries were investigated to detect the histological
and ultrastructural alterations induced by mandipropamid
when applied after inoculation. Compared
to the untreated samples characterized by a diffuse colonization
of the tissues and by a normal ultrastructure
of the pathogen, the application of mandipropamid
24 h after inoculation with P. viticola reduced pathogen
colonization in leaves and berries. In addition,
detachment of the plasmalemma from the hyphal and
haustorial walls was observed 72 h after inoculation.
In the berries, an abnormal proliferation of the pathogen
plasma membrane was observed. Collapsed
hyphae and haustoria in treated leaves were surrounded
by callose or encapsulated in an amorphous
material inside the host cell 72 h after inoculation,
while a similar effect was observed in later stages
(7 days) in berries. The results confirm that mandipropamid,
which acts at the interface between the
pathogen plasmalemma and cell wall, has curative
activity against P. viticola, appearing more rapidly in
leaves than in berries.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
oomycete ; obligate biotroph ; carboxylic acid amide fungicides
Elenco autori:
S.L. Toffolatti, D. Maffi, L. Serrati, A. Vercesi
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