Tuttifree
TerminatedLactuca sativa L. · Lettuce
Seminis Vegetable Seeds
FR
3 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.
Agribel
ActiveLactuca sativa L. · Lettuce
Bejo Zaden B.V.
NL
2 records
Crispenza
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Sylvita
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Picnic
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Nolaf
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Ivernia
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Ivernice
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
3 records
Multired 197
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
4 records
Florigo
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Bradley
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Mareika
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
6 records
Calaflor
Application submittedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Chandor
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Cuartel
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
3 records
Smartie
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
3 records
Formigal
ActiveLactuca sativa L. · Lettuce
RAMIRO ARNEDO, S.A.
ES
2 records
Joconda
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
3 records
Augoral
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
3 records
Santino
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Triskel
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Nuvola
Application submittedLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
3 records
Maïko
ActiveLactuca sativa L. · Lettuce
Clause (FR)
FR
3 records
Starix
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records