Periti
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
3 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.
Malyeva
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Encierro
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Sirtaki
ActiveLactuca sativa L. · Lettuce
Panora s.p.a.
NL
2 records
Ozzy
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Mercury
TerminatedLactuca sativa L. · Lettuce
Graines Gautier SA (FR)
FR
3 records
Boussole
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
2 records
Madiran
Application submittedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
3 records
Escale
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Incitatos
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Anselo
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Easala
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Kravitz
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Exbury
TerminatedLactuca sativa L. · Lettuce
A L TOZER LTD
NL
3 records
Dulcemia
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Imperatris
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Littlespy
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Pavarotti
Application submittedLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
2 records
Supradai
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Licato
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Pandrera
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Amoretta
TerminatedLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
3 records
Roxxita
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
5 records
SV1065LA
ActiveLactuca sativa L. · Lettuce
Seminis Vegetable Seeds
NL
3 records