Morfos
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds 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.
Multiblond 181
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
4 records
Batlusa
TerminatedLactuca sativa L. · Lettuce
Nunhems B.V.
NL
4 records
Brisamar
ActiveLactuca sativa L. · Lettuce
HAZERA GENETICS
ES
2 records
Antonela
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Valdelinares
ActiveLactuca sativa L. · Lettuce
RAMIRO ARNEDO, S.A.
ES
2 records
Siplia
TerminatedLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
3 records
Saralyn
WithdrawnLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
3 records
Napelo
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Joliac
ActiveLactuca sativa L. · Lettuce
Seminis Vegetable Seeds
NL
3 records
Elixir
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Basidra
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Invernalia
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Vicary
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Palatina
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
3 records
Capitole
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Annaba
Application submittedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
3 records
Clotilde
ActiveLactuca sativa L. · Lettuce
Panora s.p.a.
NL
3 records
Ibery
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Hiligo
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Monopolis
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Ice Nina
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Oakita
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Kobuka
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records