Seurat
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
8 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.
Diskoa
ActiveLactuca sativa L. · Lettuce
VILMORIN, VILMORIN
FR
7 records
Clarke
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
9 records
Lungavilla
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
9 records
Fanela
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
8 records
Meteore
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds, NL
NL
7 records
Flambine
ActiveLactuca sativa L. · Lettuce
VILMORIN, VILMORIN
FR
6 records
Affic
ActiveLactuca sativa L. · Lettuce
Seminis Vegetable Seeds
NL
8 records
Renoir
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
8 records
Calorina
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
7 records
Exquise
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
HR
6 records
Salmarinas
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Multired 166
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
8 records
Redfun
TerminatedLactuca sativa L. · Lettuce
Syngenta Seeds BV (NL)
ES
FR
NL
6 records
Expedition
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
8 records
Multired 3
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
9 records
Concorde
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
HU
6 records
Maradone
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
7 records
Maugli
ActiveLactuca sativa L. · Lettuce
MoravoSeed, CZ
CZ
SK
5 records
Cousteau
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
8 records
Danstar
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
10 records
Wolflash
ActiveLactuca sativa L. · Lettuce
Nunhems B.V., 6083 AB Nunhem
NL
7 records
Multired 98
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
8 records
Webber
ActiveLactuca sativa L. · Lettuce
RIJK ZWAAN ZAADTEELT EN ZAADHANDEL B.V.
NL
9 records