Karmian
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
6 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.
Killur
ActiveLactuca sativa L. · Lettuce
MERIDIEM SEEDS S.L.
ES
2 records
Saroga
Application submittedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
3 records
Divisor
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Lenir
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Venegia
ActiveLactuca sativa L. · Lettuce
Petoseed Co INC (US)
FR
2 records
Rodanice
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Xanbera
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Alburnus
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Tence
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Curtis
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Kinshasa
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
3 records
Animix
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Guapi
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Araro
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Kuzco
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Tanakan
Application submittedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
3 records
Fabiana
ActiveLactuca sativa L. · Lettuce
Panora s.p.a.
NL
2 records
Glorinice
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Kurko
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Primice
TerminatedLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
5 records
Vancrisp
Protection expiredLactuca sativa L. · Lettuce
ROYAL SLUIS
ES
2 records
Griselda
TerminatedLactuca sativa L. · Lettuce
SVS Holland B.V.
NL
3 records
Ladynice
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records