Laurenzio
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 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.
ICE 40005
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
3 records
Belanice
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
3 records
Tyros
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
4 records
Whisper
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Lagave
TerminatedLactuca sativa L. · Lettuce
Nunhems B.V.
NL
4 records
Mandaro
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Lirina
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
7 records
Ranger
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Qualif
TerminatedLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
3 records
Senorita
ActiveLactuca sativa L. · Lettuce
Nunhems Germany GmbH
DE
4 records
Brillita
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Diamanti
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
2 records
Sorgenti
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
2 records
Alquijote
Application submittedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
3 records
Argelès
TerminatedLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
3 records
Aquarita
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
3 records
Chandler
TerminatedLactuca sativa L. · Lettuce
Nunhems B.V.
NL
4 records
Curos
TerminatedLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Grinie
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Design
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Averya
TerminatedLactuca sativa L. · Lettuce
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR
FR
3 records
Carthagian
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Salazara
Application submittedLactuca sativa L. · Lettuce
Nunhems Netherlands B.V.
NL
3 records