Urbión
ActiveLactuca sativa L. · Lettuce
RAMIRO ARNEDO, S.A.
ES
2 records
Diseases
Downy mildew of lettuce
Lactuca sativa L.
A fungal disease of lettuce caused by the obligate oomycete Bremia lactucae, characterized by high pathogen variability and the appearance of chlorotic angular spots with sporulation on the underside of leaves.
In the reference 2 007 varieties crop Lettuce, where this is mentioned in the description.
The disease is caused by the oomycete Bremia lactucae Regel, which exhibits high genetic variability. Pathogen populations include numerous physiological races, designated by the code Bl followed by a sequence number, the composition of which is constantly changing, making it difficult to maintain cultivar resistance.
Symptoms appear as chlorotic angular spots on the upper side of the leaf, restricted by veins. On the underside, a characteristic loose whitish, gray, or violet sporulation layer forms. Affected tissues become necrotic, leading to leaf desiccation and stunted seedling growth.
Breeding for resistance is based on the use of Dm-genes (Downy mildew) and quantitative trait loci (QTL). Cultivar resistance is determined by the ability to withstand specific races of the pathogen; however, the effectiveness of protection is limited due to the ability of local Bremia lactucae populations to overcome genetic resistance.
General information about the subject — on the page Downy mildew.
Varieties of Lettuce mentioned in the description
Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.
Anikaï
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
3 records
Hamita
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Annare
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Antipasti
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
2 records
Lakan
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Incanto
ActiveLactuca sativa L. · Lettuce
BLUMEN GROUP S.P.A
IT
2 records
Happi
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
SV7314LA
TerminatedLactuca sativa L. · Lettuce
Seminis Vegetable Seeds
NL
3 records
Lauleta
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Pleiade
TerminatedLactuca sativa L. · Lettuce
Seminis Vegetable Seeds
NL
3 records
Camarde
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Nymeria
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Atella
TerminatedLactuca sativa L. · Lettuce
Seminis Vegetable Seeds
NL
3 records
Ravenna
Application submittedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
3 records
Funride
TerminatedLactuca sativa L. · Lettuce
Syngenta Seeds BV (NL)
FR
3 records
Ainoha
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Styria
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
6 records
Magellan
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
6 records
Giannole
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
3 records
Amplus
TerminatedLactuca sativa L. · Lettuce
VAN DEN BERG (NL)
FR
2 records
Verigo
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Red rocket
ActiveLactuca sativa L. · Lettuce
MARALDI SEMENTI S.r.l.
FR
3 records
Danteria
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records