Oakwen
WithdrawnLactuca sativa L. · Lettuce
Nunhems B.V.
NL
4 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.
Cristel
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
SK
4 records
Geraldine
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
ES
NL
7 records
Malua
Application submittedLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
3 records
Ruatan
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Redial
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Marinski
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
6 records
Sylvesta
ActiveLactuca sativa L. · Lettuce
NUNHEMS ZADEN B.V.
NL
5 records
Inferno
ActiveLactuca sativa L. · Lettuce
Yaojin Peng
NL
3 records
Vista
ActiveLactuca sativa L. · Lettuce
Vilmorin SA (FR)
FR
4 records
Spirole
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
5 records
Aruanas
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Bertolt
ActiveLactuca sativa L. · Lettuce
MORAVOSEED
CZ
3 records
Fortress
ActiveLactuca sativa L. · Lettuce
VILMORIN-MIKADO USA
NL
4 records
Gagarin
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Lentenas
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Forlina
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Kitare
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Graffiti
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
6 records
Ribaï
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Basilisk
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
5 records
Abago
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Dracos
TerminatedLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
5 records
Mignone
ActiveLactuca sativa L. · Lettuce
Vilmorin, F
FR
4 records