Tralex
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan, NL
NL
9 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.
Tonale
ActiveLactuca sativa L. · Lettuce
Vilmorin, F
FR
HR
7 records
Suntred
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
9 records
Starfighter
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Saula
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
8 records
Sangria
ActiveLactuca sativa L. · Lettuce
VILMORIN, S.A.
ES
FR
IT
7 records
Salvina
Protection expiredLactuca sativa L. · Lettuce
L CLAUSE S.A.
ES
FR
IT
NL
7 records
Rubette
ActiveLactuca sativa L. · Lettuce
RIJK ZWAAN ZAADTEELT EN ZAADHANDEL BV
CZ
NL
7 records
Radian
ActiveLactuca sativa L. · Lettuce
Syngenta, NL
NL
8 records
Poplar
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
10 records
Olgada
ActiveLactuca sativa L. · Lettuce
Seminis Vegetable Seeds
ES
NL
10 records
Navarone
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
8 records
Multy
ActiveLactuca sativa L. · Lettuce
NUNZA B.V.
NL
9 records
Multired 5
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
9 records
Multired 187
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
9 records
Multigreen 60
ActiveLactuca sativa L. · Lettuce
P.DEGREEF
NL
9 records
Multigreen 2
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
8 records
Multigreen 114
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
9 records
Multigreen 1
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
10 records
Multiblond 2
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
9 records
Mestiza
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
8 records
Matador
ActiveLactuca sativa L. · Lettuce
ISI SEMENTI SPA
FR
NL
6 records
Libusa
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
CZ
HR
HU
NL
SK
8 records
Lea
ActiveLactuca sativa L. · Lettuce
ENZA ZADEN BEHEER B.V., NL
NL
9 records